1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/assembler.inline.hpp"
  26 #include "cds/cdsConfig.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/dependencies.hpp"
  30 #include "code/nativeInst.hpp"
  31 #include "code/nmethod.inline.hpp"
  32 #include "code/scopeDesc.hpp"
  33 #include "compiler/abstractCompiler.hpp"
  34 #include "compiler/compilationLog.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/compileLog.hpp"
  37 #include "compiler/compilerDirectives.hpp"
  38 #include "compiler/compilerOracle.hpp"
  39 #include "compiler/compileTask.hpp"
  40 #include "compiler/directivesParser.hpp"
  41 #include "compiler/disassembler.hpp"
  42 #include "compiler/oopMap.inline.hpp"
  43 #include "gc/shared/barrierSet.hpp"
  44 #include "gc/shared/barrierSetNMethod.hpp"
  45 #include "gc/shared/classUnloadingContext.hpp"
  46 #include "gc/shared/collectedHeap.hpp"
  47 #include "interpreter/bytecode.inline.hpp"
  48 #include "jvm.h"
  49 #include "logging/log.hpp"
  50 #include "logging/logStream.hpp"
  51 #include "memory/allocation.inline.hpp"
  52 #include "memory/resourceArea.hpp"
  53 #include "memory/universe.hpp"
  54 #include "oops/access.inline.hpp"
  55 #include "oops/klass.inline.hpp"
  56 #include "oops/method.inline.hpp"
  57 #include "oops/methodData.hpp"
  58 #include "oops/oop.inline.hpp"
  59 #include "oops/weakHandle.inline.hpp"
  60 #include "prims/jvmtiImpl.hpp"
  61 #include "prims/jvmtiThreadState.hpp"
  62 #include "prims/methodHandles.hpp"
  63 #include "runtime/atomicAccess.hpp"
  64 #include "runtime/continuation.hpp"
  65 #include "runtime/deoptimization.hpp"
  66 #include "runtime/flags/flagSetting.hpp"
  67 #include "runtime/frame.inline.hpp"
  68 #include "runtime/handles.inline.hpp"
  69 #ifdef COMPILER2
  70 #include "runtime/hotCodeCollector.hpp"
  71 #endif // COMPILER2
  72 #include "runtime/icache.hpp"
  73 #include "runtime/jniHandles.inline.hpp"
  74 #include "runtime/orderAccess.hpp"
  75 #include "runtime/os.hpp"
  76 #include "runtime/safepointVerifiers.hpp"
  77 #include "runtime/serviceThread.hpp"
  78 #include "runtime/sharedRuntime.hpp"
  79 #include "runtime/signature.hpp"
  80 #include "runtime/threadWXSetters.inline.hpp"
  81 #include "runtime/vmThread.hpp"
  82 #include "utilities/align.hpp"
  83 #include "utilities/copy.hpp"
  84 #include "utilities/dtrace.hpp"
  85 #include "utilities/events.hpp"
  86 #include "utilities/globalDefinitions.hpp"
  87 #include "utilities/hashTable.hpp"
  88 #include "utilities/xmlstream.hpp"
  89 #if INCLUDE_JVMCI
  90 #include "jvmci/jvmciRuntime.hpp"
  91 #endif
  92 
  93 #ifdef DTRACE_ENABLED
  94 
  95 // Only bother with this argument setup if dtrace is available
  96 
  97 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  98   {                                                                       \
  99     Method* m = (method);                                                 \
 100     if (m != nullptr) {                                                   \
 101       Symbol* klass_name = m->klass_name();                               \
 102       Symbol* name = m->name();                                           \
 103       Symbol* signature = m->signature();                                 \
 104       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
 105         (char *) klass_name->bytes(), klass_name->utf8_length(),          \
 106         (char *) name->bytes(), name->utf8_length(),                      \
 107         (char *) signature->bytes(), signature->utf8_length());           \
 108     }                                                                     \
 109   }
 110 
 111 #else //  ndef DTRACE_ENABLED
 112 
 113 #define DTRACE_METHOD_UNLOAD_PROBE(method)
 114 
 115 #endif
 116 
 117 // Cast from int value to narrow type
 118 #define CHECKED_CAST(result, T, thing)      \
 119   result = static_cast<T>(thing); \
 120   guarantee(static_cast<int>(result) == thing, "failed: %d != %d", static_cast<int>(result), thing);
 121 
 122 //---------------------------------------------------------------------------------
 123 // NMethod statistics
 124 // They are printed under various flags, including:
 125 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
 126 // (In the latter two cases, they like other stats are printed to the log only.)
 127 
 128 #ifndef PRODUCT
 129 // These variables are put into one block to reduce relocations
 130 // and make it simpler to print from the debugger.
 131 struct java_nmethod_stats_struct {
 132   uint nmethod_count;
 133   uint total_nm_size;
 134   uint total_immut_size;
 135   uint total_mut_size;
 136   uint relocation_size;
 137   uint consts_size;
 138   uint insts_size;
 139   uint stub_size;
 140   uint oops_size;
 141   uint metadata_size;
 142   uint dependencies_size;
 143   uint nul_chk_table_size;
 144   uint handler_table_size;
 145   uint scopes_pcs_size;
 146   uint scopes_data_size;
 147 #if INCLUDE_JVMCI
 148   uint speculations_size;
 149   uint jvmci_data_size;
 150 #endif
 151 
 152   void note_nmethod(nmethod* nm) {
 153     nmethod_count += 1;
 154     total_nm_size       += nm->size();
 155     total_immut_size    += nm->immutable_data_size();
 156     total_mut_size      += nm->mutable_data_size();
 157     relocation_size     += nm->relocation_size();
 158     consts_size         += nm->consts_size();
 159     insts_size          += nm->insts_size();
 160     stub_size           += nm->stub_size();
 161     oops_size           += nm->oops_size();
 162     metadata_size       += nm->metadata_size();
 163     scopes_data_size    += nm->scopes_data_size();
 164     scopes_pcs_size     += nm->scopes_pcs_size();
 165     dependencies_size   += nm->dependencies_size();
 166     handler_table_size  += nm->handler_table_size();
 167     nul_chk_table_size  += nm->nul_chk_table_size();
 168 #if INCLUDE_JVMCI
 169     speculations_size   += nm->speculations_size();
 170     jvmci_data_size     += nm->jvmci_data_size();
 171 #endif
 172   }
 173   void print_nmethod_stats(const char* name) {
 174     if (nmethod_count == 0)  return;
 175     tty->print_cr("Statistics for %u bytecoded nmethods for %s:", nmethod_count, name);
 176     uint total_size = total_nm_size + total_immut_size + total_mut_size;
 177     if (total_nm_size != 0) {
 178       tty->print_cr(" total size      = %u (100%%)", total_size);
 179       tty->print_cr(" in CodeCache    = %u (%f%%)", total_nm_size, (total_nm_size * 100.0f)/total_size);
 180     }
 181     uint header_size = (uint)(nmethod_count * sizeof(nmethod));
 182     if (nmethod_count != 0) {
 183       tty->print_cr("   header        = %u (%f%%)", header_size, (header_size * 100.0f)/total_nm_size);
 184     }
 185     if (consts_size != 0) {
 186       tty->print_cr("   constants     = %u (%f%%)", consts_size, (consts_size * 100.0f)/total_nm_size);
 187     }
 188     if (insts_size != 0) {
 189       tty->print_cr("   main code     = %u (%f%%)", insts_size, (insts_size * 100.0f)/total_nm_size);
 190     }
 191     if (stub_size != 0) {
 192       tty->print_cr("   stub code     = %u (%f%%)", stub_size, (stub_size * 100.0f)/total_nm_size);
 193     }
 194     if (oops_size != 0) {
 195       tty->print_cr("   oops          = %u (%f%%)", oops_size, (oops_size * 100.0f)/total_nm_size);
 196     }
 197     if (total_mut_size != 0) {
 198       tty->print_cr(" mutable data    = %u (%f%%)", total_mut_size, (total_mut_size * 100.0f)/total_size);
 199     }
 200     if (relocation_size != 0) {
 201       tty->print_cr("   relocation    = %u (%f%%)", relocation_size, (relocation_size * 100.0f)/total_mut_size);
 202     }
 203     if (metadata_size != 0) {
 204       tty->print_cr("   metadata      = %u (%f%%)", metadata_size, (metadata_size * 100.0f)/total_mut_size);
 205     }
 206 #if INCLUDE_JVMCI
 207     if (jvmci_data_size != 0) {
 208       tty->print_cr("   JVMCI data    = %u (%f%%)", jvmci_data_size, (jvmci_data_size * 100.0f)/total_mut_size);
 209     }
 210 #endif
 211     if (total_immut_size != 0) {
 212       tty->print_cr(" immutable data  = %u (%f%%)", total_immut_size, (total_immut_size * 100.0f)/total_size);
 213     }
 214     if (dependencies_size != 0) {
 215       tty->print_cr("   dependencies  = %u (%f%%)", dependencies_size, (dependencies_size * 100.0f)/total_immut_size);
 216     }
 217     if (nul_chk_table_size != 0) {
 218       tty->print_cr("   nul chk table = %u (%f%%)", nul_chk_table_size, (nul_chk_table_size * 100.0f)/total_immut_size);
 219     }
 220     if (handler_table_size != 0) {
 221       tty->print_cr("   handler table = %u (%f%%)", handler_table_size, (handler_table_size * 100.0f)/total_immut_size);
 222     }
 223     if (scopes_pcs_size != 0) {
 224       tty->print_cr("   scopes pcs    = %u (%f%%)", scopes_pcs_size, (scopes_pcs_size * 100.0f)/total_immut_size);
 225     }
 226     if (scopes_data_size != 0) {
 227       tty->print_cr("   scopes data   = %u (%f%%)", scopes_data_size, (scopes_data_size * 100.0f)/total_immut_size);
 228     }
 229 #if INCLUDE_JVMCI
 230     if (speculations_size != 0) {
 231       tty->print_cr("   speculations  = %u (%f%%)", speculations_size, (speculations_size * 100.0f)/total_immut_size);
 232     }
 233 #endif
 234   }
 235 };
 236 
 237 struct native_nmethod_stats_struct {
 238   uint native_nmethod_count;
 239   uint native_total_size;
 240   uint native_relocation_size;
 241   uint native_insts_size;
 242   uint native_oops_size;
 243   uint native_metadata_size;
 244   void note_native_nmethod(nmethod* nm) {
 245     native_nmethod_count += 1;
 246     native_total_size       += nm->size();
 247     native_relocation_size  += nm->relocation_size();
 248     native_insts_size       += nm->insts_size();
 249     native_oops_size        += nm->oops_size();
 250     native_metadata_size    += nm->metadata_size();
 251   }
 252   void print_native_nmethod_stats() {
 253     if (native_nmethod_count == 0)  return;
 254     tty->print_cr("Statistics for %u native nmethods:", native_nmethod_count);
 255     if (native_total_size != 0)       tty->print_cr(" N. total size  = %u", native_total_size);
 256     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %u", native_relocation_size);
 257     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %u", native_insts_size);
 258     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %u", native_oops_size);
 259     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %u", native_metadata_size);
 260   }
 261 };
 262 
 263 struct pc_nmethod_stats_struct {
 264   uint pc_desc_init;     // number of initialization of cache (= number of caches)
 265   uint pc_desc_queries;  // queries to nmethod::find_pc_desc
 266   uint pc_desc_approx;   // number of those which have approximate true
 267   uint pc_desc_repeats;  // number of _pc_descs[0] hits
 268   uint pc_desc_hits;     // number of LRU cache hits
 269   uint pc_desc_tests;    // total number of PcDesc examinations
 270   uint pc_desc_searches; // total number of quasi-binary search steps
 271   uint pc_desc_adds;     // number of LUR cache insertions
 272 
 273   void print_pc_stats() {
 274     tty->print_cr("PcDesc Statistics:  %u queries, %.2f comparisons per query",
 275                   pc_desc_queries,
 276                   (double)(pc_desc_tests + pc_desc_searches)
 277                   / pc_desc_queries);
 278     tty->print_cr("  caches=%d queries=%u/%u, hits=%u+%u, tests=%u+%u, adds=%u",
 279                   pc_desc_init,
 280                   pc_desc_queries, pc_desc_approx,
 281                   pc_desc_repeats, pc_desc_hits,
 282                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 283   }
 284 };
 285 
 286 #ifdef COMPILER1
 287 static java_nmethod_stats_struct c1_java_nmethod_stats;
 288 #endif
 289 #ifdef COMPILER2
 290 static java_nmethod_stats_struct c2_java_nmethod_stats;
 291 #endif
 292 #if INCLUDE_JVMCI
 293 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 294 #endif
 295 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 296 
 297 static native_nmethod_stats_struct native_nmethod_stats;
 298 static pc_nmethod_stats_struct pc_nmethod_stats;
 299 
 300 static void note_java_nmethod(nmethod* nm) {
 301 #ifdef COMPILER1
 302   if (nm->is_compiled_by_c1()) {
 303     c1_java_nmethod_stats.note_nmethod(nm);
 304   } else
 305 #endif
 306 #ifdef COMPILER2
 307   if (nm->is_compiled_by_c2()) {
 308     c2_java_nmethod_stats.note_nmethod(nm);
 309   } else
 310 #endif
 311 #if INCLUDE_JVMCI
 312   if (nm->is_compiled_by_jvmci()) {
 313     jvmci_java_nmethod_stats.note_nmethod(nm);
 314   } else
 315 #endif
 316   {
 317     unknown_java_nmethod_stats.note_nmethod(nm);
 318   }
 319 }
 320 #endif // !PRODUCT
 321 
 322 //---------------------------------------------------------------------------------
 323 
 324 
 325 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 326   assert(pc != nullptr, "Must be non null");
 327   assert(exception.not_null(), "Must be non null");
 328   assert(handler != nullptr, "Must be non null");
 329 
 330   _count = 0;
 331   _exception_type = exception->klass();
 332   _next = nullptr;
 333   _purge_list_next = nullptr;
 334 
 335   add_address_and_handler(pc,handler);
 336 }
 337 
 338 
 339 address ExceptionCache::match(Handle exception, address pc) {
 340   assert(pc != nullptr,"Must be non null");
 341   assert(exception.not_null(),"Must be non null");
 342   if (exception->klass() == exception_type()) {
 343     return (test_address(pc));
 344   }
 345 
 346   return nullptr;
 347 }
 348 
 349 
 350 bool ExceptionCache::match_exception_with_space(Handle exception) {
 351   assert(exception.not_null(),"Must be non null");
 352   if (exception->klass() == exception_type() && count() < cache_size) {
 353     return true;
 354   }
 355   return false;
 356 }
 357 
 358 
 359 address ExceptionCache::test_address(address addr) {
 360   int limit = count();
 361   for (int i = 0; i < limit; i++) {
 362     if (pc_at(i) == addr) {
 363       return handler_at(i);
 364     }
 365   }
 366   return nullptr;
 367 }
 368 
 369 
 370 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 371   if (test_address(addr) == handler) return true;
 372 
 373   int index = count();
 374   if (index < cache_size) {
 375     set_pc_at(index, addr);
 376     set_handler_at(index, handler);
 377     increment_count();
 378     return true;
 379   }
 380   return false;
 381 }
 382 
 383 ExceptionCache* ExceptionCache::next() {
 384   return AtomicAccess::load(&_next);
 385 }
 386 
 387 void ExceptionCache::set_next(ExceptionCache *ec) {
 388   AtomicAccess::store(&_next, ec);
 389 }
 390 
 391 //-----------------------------------------------------------------------------
 392 
 393 
 394 // Helper used by both find_pc_desc methods.
 395 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 396   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 397   if (!approximate) {
 398     return pc->pc_offset() == pc_offset;
 399   } else {
 400     // Do not look before the sentinel
 401     assert(pc_offset > PcDesc::lower_offset_limit, "illegal pc_offset");
 402     return pc_offset <= pc->pc_offset() && (pc-1)->pc_offset() < pc_offset;
 403   }
 404 }
 405 
 406 void PcDescCache::init_to(PcDesc* initial_pc_desc) {
 407   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_init);
 408   // initialize the cache by filling it with benign (non-null) values
 409   assert(initial_pc_desc != nullptr && initial_pc_desc->pc_offset() == PcDesc::lower_offset_limit,
 410          "must start with a sentinel");
 411   for (int i = 0; i < cache_size; i++) {
 412     _pc_descs[i] = initial_pc_desc;
 413   }
 414 }
 415 
 416 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 417   // Note: one might think that caching the most recently
 418   // read value separately would be a win, but one would be
 419   // wrong.  When many threads are updating it, the cache
 420   // line it's in would bounce between caches, negating
 421   // any benefit.
 422 
 423   // In order to prevent race conditions do not load cache elements
 424   // repeatedly, but use a local copy:
 425   PcDesc* res;
 426 
 427   // Step one:  Check the most recently added value.
 428   res = _pc_descs[0];
 429   assert(res != nullptr, "PcDesc cache should be initialized already");
 430 
 431   // Approximate only here since PcDescContainer::find_pc_desc() checked for exact case.
 432   if (approximate && match_desc(res, pc_offset, approximate)) {
 433     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 434     return res;
 435   }
 436 
 437   // Step two:  Check the rest of the LRU cache.
 438   for (int i = 1; i < cache_size; ++i) {
 439     res = _pc_descs[i];
 440     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 441     if (match_desc(res, pc_offset, approximate)) {
 442       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 443       return res;
 444     }
 445   }
 446 
 447   // Report failure.
 448   return nullptr;
 449 }
 450 
 451 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 452   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 453   // Update the LRU cache by shifting pc_desc forward.
 454   for (int i = 0; i < cache_size; i++)  {
 455     PcDesc* next = _pc_descs[i];
 456     _pc_descs[i] = pc_desc;
 457     pc_desc = next;
 458   }
 459 }
 460 
 461 // adjust pcs_size so that it is a multiple of both oopSize and
 462 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 463 // of oopSize, then 2*sizeof(PcDesc) is)
 464 static int adjust_pcs_size(int pcs_size) {
 465   int nsize = align_up(pcs_size,   oopSize);
 466   if ((nsize % sizeof(PcDesc)) != 0) {
 467     nsize = pcs_size + sizeof(PcDesc);
 468   }
 469   assert((nsize % oopSize) == 0, "correct alignment");
 470   return nsize;
 471 }
 472 
 473 // Returns a string version of the method state.
 474 const char* nmethod::state() const {
 475   int state = get_state();
 476   switch (state) {
 477   case not_installed:
 478     return "not installed";
 479   case in_use:
 480     return "in use";
 481   case not_entrant:
 482     return "not_entrant";
 483   default:
 484     fatal("unexpected method state: %d", state);
 485     return nullptr;
 486   }
 487 }
 488 
 489 void nmethod::set_deoptimized_done() {
 490   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 491   if (_deoptimization_status != deoptimize_done) { // can't go backwards
 492     AtomicAccess::store(&_deoptimization_status, deoptimize_done);
 493   }
 494 }
 495 
 496 ExceptionCache* nmethod::exception_cache_acquire() const {
 497   return AtomicAccess::load_acquire(&_exception_cache);
 498 }
 499 
 500 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 501   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 502   assert(new_entry != nullptr,"Must be non null");
 503   assert(new_entry->next() == nullptr, "Must be null");
 504 
 505   for (;;) {
 506     ExceptionCache *ec = exception_cache();
 507     if (ec != nullptr) {
 508       Klass* ex_klass = ec->exception_type();
 509       if (!ex_klass->is_loader_alive()) {
 510         // We must guarantee that entries are not inserted with new next pointer
 511         // edges to ExceptionCache entries with dead klasses, due to bad interactions
 512         // with concurrent ExceptionCache cleanup. Therefore, the inserts roll
 513         // the head pointer forward to the first live ExceptionCache, so that the new
 514         // next pointers always point at live ExceptionCaches, that are not removed due
 515         // to concurrent ExceptionCache cleanup.
 516         ExceptionCache* next = ec->next();
 517         if (AtomicAccess::cmpxchg(&_exception_cache, ec, next) == ec) {
 518           CodeCache::release_exception_cache(ec);
 519         }
 520         continue;
 521       }
 522       ec = exception_cache();
 523       if (ec != nullptr) {
 524         new_entry->set_next(ec);
 525       }
 526     }
 527     if (AtomicAccess::cmpxchg(&_exception_cache, ec, new_entry) == ec) {
 528       return;
 529     }
 530   }
 531 }
 532 
 533 void nmethod::clean_exception_cache() {
 534   // For each nmethod, only a single thread may call this cleanup function
 535   // at the same time, whether called in STW cleanup or concurrent cleanup.
 536   // Note that if the GC is processing exception cache cleaning in a concurrent phase,
 537   // then a single writer may contend with cleaning up the head pointer to the
 538   // first ExceptionCache node that has a Klass* that is alive. That is fine,
 539   // as long as there is no concurrent cleanup of next pointers from concurrent writers.
 540   // And the concurrent writers do not clean up next pointers, only the head.
 541   // Also note that concurrent readers will walk through Klass* pointers that are not
 542   // alive. That does not cause ABA problems, because Klass* is deleted after
 543   // a handshake with all threads, after all stale ExceptionCaches have been
 544   // unlinked. That is also when the CodeCache::exception_cache_purge_list()
 545   // is deleted, with all ExceptionCache entries that were cleaned concurrently.
 546   // That similarly implies that CAS operations on ExceptionCache entries do not
 547   // suffer from ABA problems as unlinking and deletion is separated by a global
 548   // handshake operation.
 549   ExceptionCache* prev = nullptr;
 550   ExceptionCache* curr = exception_cache_acquire();
 551 
 552   while (curr != nullptr) {
 553     ExceptionCache* next = curr->next();
 554 
 555     if (!curr->exception_type()->is_loader_alive()) {
 556       if (prev == nullptr) {
 557         // Try to clean head; this is contended by concurrent inserts, that
 558         // both lazily clean the head, and insert entries at the head. If
 559         // the CAS fails, the operation is restarted.
 560         if (AtomicAccess::cmpxchg(&_exception_cache, curr, next) != curr) {
 561           prev = nullptr;
 562           curr = exception_cache_acquire();
 563           continue;
 564         }
 565       } else {
 566         // It is impossible to during cleanup connect the next pointer to
 567         // an ExceptionCache that has not been published before a safepoint
 568         // prior to the cleanup. Therefore, release is not required.
 569         prev->set_next(next);
 570       }
 571       // prev stays the same.
 572 
 573       CodeCache::release_exception_cache(curr);
 574     } else {
 575       prev = curr;
 576     }
 577 
 578     curr = next;
 579   }
 580 }
 581 
 582 // public method for accessing the exception cache
 583 // These are the public access methods.
 584 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 585   // We never grab a lock to read the exception cache, so we may
 586   // have false negatives. This is okay, as it can only happen during
 587   // the first few exception lookups for a given nmethod.
 588   ExceptionCache* ec = exception_cache_acquire();
 589   while (ec != nullptr) {
 590     address ret_val;
 591     if ((ret_val = ec->match(exception,pc)) != nullptr) {
 592       return ret_val;
 593     }
 594     ec = ec->next();
 595   }
 596   return nullptr;
 597 }
 598 
 599 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 600   // There are potential race conditions during exception cache updates, so we
 601   // must own the ExceptionCache_lock before doing ANY modifications. Because
 602   // we don't lock during reads, it is possible to have several threads attempt
 603   // to update the cache with the same data. We need to check for already inserted
 604   // copies of the current data before adding it.
 605 
 606   MutexLocker ml(ExceptionCache_lock);
 607   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 608 
 609   if (target_entry == nullptr || !target_entry->add_address_and_handler(pc,handler)) {
 610     target_entry = new ExceptionCache(exception,pc,handler);
 611     add_exception_cache_entry(target_entry);
 612   }
 613 }
 614 
 615 // private method for handling exception cache
 616 // These methods are private, and used to manipulate the exception cache
 617 // directly.
 618 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 619   ExceptionCache* ec = exception_cache_acquire();
 620   while (ec != nullptr) {
 621     if (ec->match_exception_with_space(exception)) {
 622       return ec;
 623     }
 624     ec = ec->next();
 625   }
 626   return nullptr;
 627 }
 628 
 629 bool nmethod::is_at_poll_return(address pc) {
 630   RelocIterator iter(this, pc, pc+1);
 631   while (iter.next()) {
 632     if (iter.type() == relocInfo::poll_return_type)
 633       return true;
 634   }
 635   return false;
 636 }
 637 
 638 
 639 bool nmethod::is_at_poll_or_poll_return(address pc) {
 640   RelocIterator iter(this, pc, pc+1);
 641   while (iter.next()) {
 642     relocInfo::relocType t = iter.type();
 643     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
 644       return true;
 645   }
 646   return false;
 647 }
 648 
 649 void nmethod::verify_oop_relocations() {
 650   // Ensure sure that the code matches the current oop values
 651   RelocIterator iter(this, nullptr, nullptr);
 652   while (iter.next()) {
 653     if (iter.type() == relocInfo::oop_type) {
 654       oop_Relocation* reloc = iter.oop_reloc();
 655       if (!reloc->oop_is_immediate()) {
 656         reloc->verify_oop_relocation();
 657       }
 658     }
 659   }
 660 }
 661 
 662 
 663 ScopeDesc* nmethod::scope_desc_at(address pc) {
 664   PcDesc* pd = pc_desc_at(pc);
 665   guarantee(pd != nullptr, "scope must be present");
 666   return new ScopeDesc(this, pd);
 667 }
 668 
 669 ScopeDesc* nmethod::scope_desc_near(address pc) {
 670   PcDesc* pd = pc_desc_near(pc);
 671   guarantee(pd != nullptr, "scope must be present");
 672   return new ScopeDesc(this, pd);
 673 }
 674 
 675 address nmethod::oops_reloc_begin() const {
 676   // If the method is not entrant then a JMP is plastered over the
 677   // first few bytes.  If an oop in the old code was there, that oop
 678   // should not get GC'd.  Skip the first few bytes of oops on
 679   // not-entrant methods.
 680   if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
 681       code_begin() + frame_complete_offset() >
 682       verified_entry_point() + NativeJump::instruction_size)
 683   {
 684     // If we have a frame_complete_offset after the native jump, then there
 685     // is no point trying to look for oops before that. This is a requirement
 686     // for being allowed to scan oops concurrently.
 687     return code_begin() + frame_complete_offset();
 688   }
 689 
 690   address low_boundary = verified_entry_point();
 691   return low_boundary;
 692 }
 693 
 694 // Method that knows how to preserve outgoing arguments at call. This method must be
 695 // called with a frame corresponding to a Java invoke
 696 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
 697   if (method() == nullptr) {
 698     return;
 699   }
 700 
 701   // handle the case of an anchor explicitly set in continuation code that doesn't have a callee
 702   JavaThread* thread = reg_map->thread();
 703   if ((thread->has_last_Java_frame() && fr.sp() == thread->last_Java_sp())
 704       JVMTI_ONLY(|| (method()->is_continuation_enter_intrinsic() && thread->on_monitor_waited_event()))) {
 705     return;
 706   }
 707 
 708   if (!method()->is_native()) {
 709     address pc = fr.pc();
 710     bool has_receiver, has_appendix;
 711     Symbol* signature;
 712 
 713     // The method attached by JIT-compilers should be used, if present.
 714     // Bytecode can be inaccurate in such case.
 715     Method* callee = attached_method_before_pc(pc);
 716     if (callee != nullptr) {
 717       has_receiver = !(callee->access_flags().is_static());
 718       has_appendix = false;
 719       signature    = callee->signature();
 720 
 721       // If inline types are passed as fields, use the extended signature
 722       // which contains the types of all (oop) fields of the inline type.
 723       if (is_compiled_by_c2() && callee->has_scalarized_args()) {
 724         const GrowableArray<SigEntry>* sig = callee->adapter()->get_sig_cc();
 725         assert(sig != nullptr, "sig should never be null");
 726         TempNewSymbol tmp_sig = SigEntry::create_symbol(sig);
 727         has_receiver = false; // The extended signature contains the receiver type
 728         fr.oops_compiled_arguments_do(tmp_sig, has_receiver, has_appendix, reg_map, f);
 729         return;
 730       }
 731     } else {
 732       SimpleScopeDesc ssd(this, pc);
 733 
 734       Bytecode_invoke call(methodHandle(Thread::current(), ssd.method()), ssd.bci());
 735       has_receiver = call.has_receiver();
 736       has_appendix = call.has_appendix();
 737       signature    = call.signature();
 738     }
 739 
 740     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
 741   } else if (method()->is_continuation_enter_intrinsic()) {
 742     // This method only calls Continuation.enter()
 743     Symbol* signature = vmSymbols::continuationEnter_signature();
 744     fr.oops_compiled_arguments_do(signature, false, false, reg_map, f);
 745   }
 746 }
 747 
 748 Method* nmethod::attached_method(address call_instr) {
 749   assert(code_contains(call_instr), "not part of the nmethod");
 750   RelocIterator iter(this, call_instr, call_instr + 1);
 751   while (iter.next()) {
 752     if (iter.addr() == call_instr) {
 753       switch(iter.type()) {
 754         case relocInfo::static_call_type:      return iter.static_call_reloc()->method_value();
 755         case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
 756         case relocInfo::virtual_call_type:     return iter.virtual_call_reloc()->method_value();
 757         default:                               break;
 758       }
 759     }
 760   }
 761   return nullptr; // not found
 762 }
 763 
 764 Method* nmethod::attached_method_before_pc(address pc) {
 765   if (NativeCall::is_call_before(pc)) {
 766     NativeCall* ncall = nativeCall_before(pc);
 767     return attached_method(ncall->instruction_address());
 768   }
 769   return nullptr; // not a call
 770 }
 771 
 772 void nmethod::clear_inline_caches() {
 773   assert(SafepointSynchronize::is_at_safepoint() || (NMethodState_lock->owned_by_self() && is_not_installed()), "clearing of IC's only allowed at safepoint or when not installed");
 774   RelocIterator iter(this);
 775   while (iter.next()) {
 776     iter.reloc()->clear_inline_cache();
 777   }
 778 }
 779 
 780 #ifdef ASSERT
 781 // Check class_loader is alive for this bit of metadata.
 782 class CheckClass : public MetadataClosure {
 783   void do_metadata(Metadata* md) {
 784     Klass* klass = nullptr;
 785     if (md->is_klass()) {
 786       klass = ((Klass*)md);
 787     } else if (md->is_method()) {
 788       klass = ((Method*)md)->method_holder();
 789     } else if (md->is_methodData()) {
 790       klass = ((MethodData*)md)->method()->method_holder();
 791     } else if (md->is_methodCounters()) {
 792       klass = ((MethodCounters*)md)->method()->method_holder();
 793     } else {
 794       md->print();
 795       ShouldNotReachHere();
 796     }
 797     assert(klass->is_loader_alive(), "must be alive");
 798   }
 799 };
 800 #endif // ASSERT
 801 
 802 // Clean references to unloaded nmethods at addr from this one, which is not unloaded.
 803 template <typename CallsiteT>
 804 static void clean_if_nmethod_is_unloaded(CallsiteT* callsite, bool clean_all) {
 805   CodeBlob* cb = CodeCache::find_blob(callsite->destination());
 806   if (!cb->is_nmethod()) {
 807     return;
 808   }
 809   nmethod* nm = cb->as_nmethod();
 810   if (clean_all || !nm->is_in_use() || nm->is_unloading() || nm->method()->code() != nm) {
 811     callsite->set_to_clean();
 812   }
 813 }
 814 
 815 // Cleans caches in nmethods that point to either classes that are unloaded
 816 // or nmethods that are unloaded.
 817 //
 818 // Can be called either in parallel by G1 currently or after all
 819 // nmethods are unloaded.  Return postponed=true in the parallel case for
 820 // inline caches found that point to nmethods that are not yet visited during
 821 // the do_unloading walk.
 822 void nmethod::unload_nmethod_caches(bool unloading_occurred) {
 823   ResourceMark rm;
 824 
 825   // Exception cache only needs to be called if unloading occurred
 826   if (unloading_occurred) {
 827     clean_exception_cache();
 828   }
 829 
 830   cleanup_inline_caches_impl(unloading_occurred, false);
 831 
 832 #ifdef ASSERT
 833   // Check that the metadata embedded in the nmethod is alive
 834   CheckClass check_class;
 835   metadata_do(&check_class);
 836 #endif
 837 }
 838 
 839 void nmethod::run_nmethod_entry_barrier() {
 840   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
 841   if (bs_nm != nullptr) {
 842     // We want to keep an invariant that nmethods found through iterations of a Thread's
 843     // nmethods found in safepoints have gone through an entry barrier and are not armed.
 844     // By calling this nmethod entry barrier, it plays along and acts
 845     // like any other nmethod found on the stack of a thread (fewer surprises).
 846     nmethod* nm = this;
 847     bool alive = bs_nm->nmethod_entry_barrier(nm);
 848     assert(alive, "should be alive");
 849   }
 850 }
 851 
 852 // Only called by whitebox test
 853 void nmethod::cleanup_inline_caches_whitebox() {
 854   assert_locked_or_safepoint(CodeCache_lock);
 855   CompiledICLocker ic_locker(this);
 856   cleanup_inline_caches_impl(false /* unloading_occurred */, true /* clean_all */);
 857 }
 858 
 859 address* nmethod::orig_pc_addr(const frame* fr) {
 860   return (address*) ((address)fr->unextended_sp() + orig_pc_offset());
 861 }
 862 
 863 // Called to clean up after class unloading for live nmethods
 864 void nmethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) {
 865   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
 866   ResourceMark rm;
 867 
 868   // Find all calls in an nmethod and clear the ones that point to bad nmethods.
 869   RelocIterator iter(this, oops_reloc_begin());
 870   bool is_in_static_stub = false;
 871   while(iter.next()) {
 872 
 873     switch (iter.type()) {
 874 
 875     case relocInfo::virtual_call_type:
 876       if (unloading_occurred) {
 877         // If class unloading occurred we first clear ICs where the cached metadata
 878         // is referring to an unloaded klass or method.
 879         CompiledIC_at(&iter)->clean_metadata();
 880       }
 881 
 882       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), clean_all);
 883       break;
 884 
 885     case relocInfo::opt_virtual_call_type:
 886     case relocInfo::static_call_type:
 887       clean_if_nmethod_is_unloaded(CompiledDirectCall::at(iter.reloc()), clean_all);
 888       break;
 889 
 890     case relocInfo::static_stub_type: {
 891       is_in_static_stub = true;
 892       break;
 893     }
 894 
 895     case relocInfo::metadata_type: {
 896       // Only the metadata relocations contained in static/opt virtual call stubs
 897       // contains the Method* passed to c2i adapters. It is the only metadata
 898       // relocation that needs to be walked, as it is the one metadata relocation
 899       // that violates the invariant that all metadata relocations have an oop
 900       // in the compiled method (due to deferred resolution and code patching).
 901 
 902       // This causes dead metadata to remain in compiled methods that are not
 903       // unloading. Unless these slippery metadata relocations of the static
 904       // stubs are at least cleared, subsequent class redefinition operations
 905       // will access potentially free memory, and JavaThread execution
 906       // concurrent to class unloading may call c2i adapters with dead methods.
 907       if (!is_in_static_stub) {
 908         // The first metadata relocation after a static stub relocation is the
 909         // metadata relocation of the static stub used to pass the Method* to
 910         // c2i adapters.
 911         continue;
 912       }
 913       is_in_static_stub = false;
 914       if (is_unloading()) {
 915         // If the nmethod itself is dying, then it may point at dead metadata.
 916         // Nobody should follow that metadata; it is strictly unsafe.
 917         continue;
 918       }
 919       metadata_Relocation* r = iter.metadata_reloc();
 920       Metadata* md = r->metadata_value();
 921       if (md != nullptr && md->is_method()) {
 922         Method* method = static_cast<Method*>(md);
 923         if (!method->method_holder()->is_loader_alive()) {
 924           AtomicAccess::store(r->metadata_addr(), (Method*)nullptr);
 925 
 926           if (!r->metadata_is_immediate()) {
 927             r->fix_metadata_relocation();
 928           }
 929         }
 930       }
 931       break;
 932     }
 933 
 934     default:
 935       break;
 936     }
 937   }
 938 }
 939 
 940 address nmethod::continuation_for_implicit_exception(address pc, bool for_div0_check) {
 941   // Exception happened outside inline-cache check code => we are inside
 942   // an active nmethod => use cpc to determine a return address
 943   int exception_offset = int(pc - code_begin());
 944   int cont_offset = ImplicitExceptionTable(this).continuation_offset( exception_offset );
 945 #ifdef ASSERT
 946   if (cont_offset == 0) {
 947     Thread* thread = Thread::current();
 948     ResourceMark rm(thread);
 949     CodeBlob* cb = CodeCache::find_blob(pc);
 950     assert(cb != nullptr && cb == this, "");
 951 
 952     // Keep tty output consistent. To avoid ttyLocker, we buffer in stream, and print all at once.
 953     stringStream ss;
 954     ss.print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
 955     print_on(&ss);
 956     // Buffering to a stringStream, disable internal buffering so it's not done twice.
 957     method()->print_codes_on(&ss, 0, false);
 958     print_code_on(&ss);
 959     print_pcs_on(&ss);
 960     tty->print("%s", ss.as_string()); // print all at once
 961   }
 962 #endif
 963   if (cont_offset == 0) {
 964     // Let the normal error handling report the exception
 965     return nullptr;
 966   }
 967   if (cont_offset == exception_offset) {
 968 #if INCLUDE_JVMCI
 969     Deoptimization::DeoptReason deopt_reason = for_div0_check ? Deoptimization::Reason_div0_check : Deoptimization::Reason_null_check;
 970     JavaThread *thread = JavaThread::current();
 971     thread->set_jvmci_implicit_exception_pc(pc);
 972     thread->set_pending_deoptimization(Deoptimization::make_trap_request(deopt_reason,
 973                                                                          Deoptimization::Action_reinterpret));
 974     return (SharedRuntime::deopt_blob()->implicit_exception_uncommon_trap());
 975 #else
 976     ShouldNotReachHere();
 977 #endif
 978   }
 979   return code_begin() + cont_offset;
 980 }
 981 
 982 class HasEvolDependency : public MetadataClosure {
 983   bool _has_evol_dependency;
 984  public:
 985   HasEvolDependency() : _has_evol_dependency(false) {}
 986   void do_metadata(Metadata* md) {
 987     if (md->is_method()) {
 988       Method* method = (Method*)md;
 989       if (method->is_old()) {
 990         _has_evol_dependency = true;
 991       }
 992     }
 993   }
 994   bool has_evol_dependency() const { return _has_evol_dependency; }
 995 };
 996 
 997 bool nmethod::has_evol_metadata() {
 998   // Check the metadata in relocIter and CompiledIC and also deoptimize
 999   // any nmethod that has reference to old methods.
1000   HasEvolDependency check_evol;
1001   metadata_do(&check_evol);
1002   if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)) {
1003     ResourceMark rm;
1004     log_debug(redefine, class, nmethod)
1005             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata",
1006              _method->method_holder()->external_name(),
1007              _method->name()->as_C_string(),
1008              _method->signature()->as_C_string(),
1009              compile_id());
1010   }
1011   return check_evol.has_evol_dependency();
1012 }
1013 
1014 int nmethod::total_size() const {
1015   return
1016     consts_size()        +
1017     insts_size()         +
1018     stub_size()          +
1019     scopes_data_size()   +
1020     scopes_pcs_size()    +
1021     handler_table_size() +
1022     nul_chk_table_size();
1023 }
1024 
1025 const char* nmethod::compile_kind() const {
1026   if (is_osr_method())     return "osr";
1027   if (method() != nullptr && is_native_method()) {
1028     if (method()->is_continuation_native_intrinsic()) {
1029       return "cnt";
1030     }
1031     return "c2n";
1032   }
1033   return nullptr;
1034 }
1035 
1036 const char* nmethod::compiler_name() const {
1037   return compilertype2name(_compiler_type);
1038 }
1039 
1040 #ifdef ASSERT
1041 class CheckForOopsClosure : public OopClosure {
1042   bool _found_oop = false;
1043  public:
1044   virtual void do_oop(oop* o) { _found_oop = true; }
1045   virtual void do_oop(narrowOop* o) { _found_oop = true; }
1046   bool found_oop() { return _found_oop; }
1047 };
1048 class CheckForMetadataClosure : public MetadataClosure {
1049   bool _found_metadata = false;
1050   Metadata* _ignore = nullptr;
1051  public:
1052   CheckForMetadataClosure(Metadata* ignore) : _ignore(ignore) {}
1053   virtual void do_metadata(Metadata* md) { if (md != _ignore) _found_metadata = true; }
1054   bool found_metadata() { return _found_metadata; }
1055 };
1056 
1057 static void assert_no_oops_or_metadata(nmethod* nm) {
1058   if (nm == nullptr) return;
1059   assert(nm->oop_maps() == nullptr, "expectation");
1060 
1061   CheckForOopsClosure cfo;
1062   nm->oops_do(&cfo);
1063   assert(!cfo.found_oop(), "no oops allowed");
1064 
1065   // We allow an exception for the own Method, but require its class to be permanent.
1066   Method* own_method = nm->method();
1067   CheckForMetadataClosure cfm(/* ignore reference to own Method */ own_method);
1068   nm->metadata_do(&cfm);
1069   assert(!cfm.found_metadata(), "no metadata allowed");
1070 
1071   assert(own_method->method_holder()->class_loader_data()->is_permanent_class_loader_data(),
1072          "Method's class needs to be permanent");
1073 }
1074 #endif
1075 
1076 static int required_mutable_data_size(CodeBuffer* code_buffer,
1077                                       int jvmci_data_size = 0) {
1078   return align_up(code_buffer->total_relocation_size(), oopSize) +
1079          align_up(code_buffer->total_metadata_size(), oopSize) +
1080          align_up(jvmci_data_size, oopSize);
1081 }
1082 
1083 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
1084   int compile_id,
1085   CodeBuffer *code_buffer,
1086   int vep_offset,
1087   int frame_complete,
1088   int frame_size,
1089   ByteSize basic_lock_owner_sp_offset,
1090   ByteSize basic_lock_sp_offset,
1091   OopMapSet* oop_maps,
1092   int exception_handler) {
1093   code_buffer->finalize_oop_references(method);
1094   // create nmethod
1095   nmethod* nm = nullptr;
1096   int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
1097   {
1098     MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1099 
1100     CodeOffsets offsets;
1101     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
1102     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
1103     if (exception_handler != -1) {
1104       offsets.set_value(CodeOffsets::Exceptions, exception_handler);
1105     }
1106 
1107     int mutable_data_size = required_mutable_data_size(code_buffer);
1108 
1109     // MH intrinsics are dispatch stubs which are compatible with NonNMethod space.
1110     // IsUnloadingBehaviour::is_unloading needs to handle them separately.
1111     bool allow_NonNMethod_space = method->can_be_allocated_in_NonNMethod_space();
1112     nm = new (native_nmethod_size, allow_NonNMethod_space)
1113     nmethod(method(), compiler_none, native_nmethod_size,
1114             compile_id, &offsets,
1115             code_buffer, frame_size,
1116             basic_lock_owner_sp_offset,
1117             basic_lock_sp_offset,
1118             oop_maps, mutable_data_size);
1119     DEBUG_ONLY( if (allow_NonNMethod_space) assert_no_oops_or_metadata(nm); )
1120     NOT_PRODUCT(if (nm != nullptr) native_nmethod_stats.note_native_nmethod(nm));
1121   }
1122 
1123   if (nm != nullptr) {
1124     // verify nmethod
1125     DEBUG_ONLY(nm->verify();) // might block
1126 
1127     nm->log_new_nmethod();
1128   }
1129   return nm;
1130 }
1131 
1132 nmethod* nmethod::new_nmethod(const methodHandle& method,
1133   int compile_id,
1134   int entry_bci,
1135   CodeOffsets* offsets,
1136   int orig_pc_offset,
1137   DebugInformationRecorder* debug_info,
1138   Dependencies* dependencies,
1139   CodeBuffer* code_buffer, int frame_size,
1140   OopMapSet* oop_maps,
1141   ExceptionHandlerTable* handler_table,
1142   ImplicitExceptionTable* nul_chk_table,
1143   AbstractCompiler* compiler,
1144   CompLevel comp_level
1145 #if INCLUDE_JVMCI
1146   , char* speculations,
1147   int speculations_len,
1148   JVMCINMethodData* jvmci_data
1149 #endif
1150 )
1151 {
1152   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
1153   code_buffer->finalize_oop_references(method);
1154   // create nmethod
1155   nmethod* nm = nullptr;
1156   int nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
1157 
1158   int immutable_data_size =
1159       adjust_pcs_size(debug_info->pcs_size())
1160     + align_up((int)dependencies->size_in_bytes(), oopSize)
1161     + align_up(handler_table->size_in_bytes()    , oopSize)
1162     + align_up(nul_chk_table->size_in_bytes()    , oopSize)
1163 #if INCLUDE_JVMCI
1164     + align_up(speculations_len                  , oopSize)
1165 #endif
1166     + align_up(debug_info->data_size()           , oopSize);
1167 
1168   // First, allocate space for immutable data in C heap.
1169   address immutable_data = nullptr;
1170   if (immutable_data_size > 0) {
1171     immutable_data_size += ImmutableDataRefCountSize;
1172     immutable_data = (address)os::malloc(immutable_data_size, mtCode);
1173     if (immutable_data == nullptr) {
1174       vm_exit_out_of_memory(immutable_data_size, OOM_MALLOC_ERROR, "nmethod: no space for immutable data");
1175       return nullptr;
1176     }
1177   }
1178 
1179   int mutable_data_size = required_mutable_data_size(code_buffer
1180     JVMCI_ONLY(COMMA (compiler->is_jvmci() ? jvmci_data->size() : 0)));
1181 
1182   {
1183     MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1184 
1185     nm = new (nmethod_size, comp_level)
1186     nmethod(method(), compiler->type(), nmethod_size, immutable_data_size, mutable_data_size,
1187             compile_id, entry_bci, immutable_data, offsets, orig_pc_offset,
1188             debug_info, dependencies, code_buffer, frame_size, oop_maps,
1189             handler_table, nul_chk_table, compiler, comp_level
1190 #if INCLUDE_JVMCI
1191             , speculations,
1192             speculations_len,
1193             jvmci_data
1194 #endif
1195             );
1196 
1197     if (nm != nullptr) {
1198       // To make dependency checking during class loading fast, record
1199       // the nmethod dependencies in the classes it is dependent on.
1200       // This allows the dependency checking code to simply walk the
1201       // class hierarchy above the loaded class, checking only nmethods
1202       // which are dependent on those classes.  The slow way is to
1203       // check every nmethod for dependencies which makes it linear in
1204       // the number of methods compiled.  For applications with a lot
1205       // classes the slow way is too slow.
1206       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1207         if (deps.type() == Dependencies::call_site_target_value) {
1208           // CallSite dependencies are managed on per-CallSite instance basis.
1209           oop call_site = deps.argument_oop(0);
1210           MethodHandles::add_dependent_nmethod(call_site, nm);
1211         } else {
1212           InstanceKlass* ik = deps.context_type();
1213           if (ik == nullptr) {
1214             continue;  // ignore things like evol_method
1215           }
1216           // record this nmethod as dependent on this klass
1217           ik->add_dependent_nmethod(nm);
1218         }
1219       }
1220       NOT_PRODUCT(if (nm != nullptr)  note_java_nmethod(nm));
1221     }
1222   }
1223   // Do verification and logging outside CodeCache_lock.
1224   if (nm != nullptr) {
1225     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
1226     DEBUG_ONLY(nm->verify();)
1227     nm->log_new_nmethod();
1228   }
1229   return nm;
1230 }
1231 
1232 // Fill in default values for various fields
1233 void nmethod::init_defaults(CodeBuffer *code_buffer, CodeOffsets* offsets) {
1234   // avoid uninitialized fields, even for short time periods
1235   _exception_cache            = nullptr;
1236   _gc_data                    = nullptr;
1237   _oops_do_mark_link          = nullptr;
1238   _compiled_ic_data           = nullptr;
1239 
1240   _is_unloading_state         = 0;
1241   _state                      = not_installed;
1242 
1243   _has_unsafe_access          = 0;
1244   _has_wide_vectors           = 0;
1245   _has_monitors               = 0;
1246   _has_scoped_access          = 0;
1247   _has_flushed_dependencies   = 0;
1248   _is_unlinked                = 0;
1249   _load_reported              = 0; // jvmti state
1250 
1251   _deoptimization_status      = not_marked;
1252 
1253   // SECT_CONSTS is first in code buffer so the offset should be 0.
1254   int consts_offset = code_buffer->total_offset_of(code_buffer->consts());
1255   assert(consts_offset == 0, "const_offset: %d", consts_offset);
1256 
1257   _stub_offset = content_offset() + code_buffer->total_offset_of(code_buffer->stubs());
1258 
1259   CHECKED_CAST(_entry_offset,              uint16_t, (offsets->value(CodeOffsets::Entry)));
1260   CHECKED_CAST(_verified_entry_offset,     uint16_t, (offsets->value(CodeOffsets::Verified_Entry)));
1261 
1262   _inline_entry_offset             = _entry_offset;
1263   _verified_inline_entry_offset    = _verified_entry_offset;
1264   _verified_inline_ro_entry_offset = _verified_entry_offset;
1265 
1266   _skipped_instructions_size = code_buffer->total_skipped_instructions_size();
1267 }
1268 
1269 // Post initialization
1270 void nmethod::post_init() {
1271   clear_unloading_state();
1272 
1273   finalize_relocations();
1274 
1275   // Flush generated code
1276   ICache::invalidate_range(code_begin(), code_size());
1277 
1278   Universe::heap()->register_nmethod(this);
1279 
1280 #ifdef COMPILER2
1281   HotCodeCollector::register_nmethod(this);
1282 #endif // COMPILER2
1283 
1284   DEBUG_ONLY(Universe::heap()->verify_nmethod(this));
1285 
1286   CodeCache::commit(this);
1287 }
1288 
1289 // For native wrappers
1290 nmethod::nmethod(
1291   Method* method,
1292   CompilerType type,
1293   int nmethod_size,
1294   int compile_id,
1295   CodeOffsets* offsets,
1296   CodeBuffer* code_buffer,
1297   int frame_size,
1298   ByteSize basic_lock_owner_sp_offset,
1299   ByteSize basic_lock_sp_offset,
1300   OopMapSet* oop_maps,
1301   int mutable_data_size)
1302   : CodeBlob("native nmethod", CodeBlobKind::Nmethod, code_buffer, nmethod_size, sizeof(nmethod),
1303              offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false, mutable_data_size),
1304   _deoptimization_generation(0),
1305   _gc_epoch(CodeCache::gc_epoch()),
1306   _method(method),
1307   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
1308   _native_basic_lock_sp_offset(basic_lock_sp_offset)
1309 {
1310   {
1311     DEBUG_ONLY(NoSafepointVerifier nsv;)
1312     assert_locked_or_safepoint(CodeCache_lock);
1313     assert(!method->has_scalarized_args(), "scalarized native wrappers not supported yet");
1314     init_defaults(code_buffer, offsets);
1315 
1316     _osr_entry_point         = nullptr;
1317     _pc_desc_container       = nullptr;
1318     _entry_bci               = InvocationEntryBci;
1319     _compile_id              = compile_id;
1320     _comp_level              = CompLevel_none;
1321     _compiler_type           = type;
1322     _orig_pc_offset          = 0;
1323     _num_stack_arg_slots     = 0;
1324 
1325     if (offsets->value(CodeOffsets::Exceptions) != -1) {
1326       // Continuation enter intrinsic
1327       _exception_offset      = code_offset() + offsets->value(CodeOffsets::Exceptions);
1328     } else {
1329       _exception_offset      = 0;
1330     }
1331     // Native wrappers do not have deopt handlers. Make the values
1332     // something that will never match a pc like the nmethod vtable entry
1333     _deopt_handler_entry_offset    = 0;
1334     _unwind_handler_offset   = 0;
1335 
1336     int metadata_size = align_up(code_buffer->total_metadata_size(), wordSize);
1337     JVMCI_ONLY( _metadata_size = metadata_size; )
1338     assert(_mutable_data_size == _relocation_size + metadata_size,
1339            "wrong mutable data size: %d != %d + %d",
1340            _mutable_data_size, _relocation_size, metadata_size);
1341 
1342     // native wrapper does not have read-only data but we need unique not null address
1343     _immutable_data          = blob_end();
1344     _immutable_data_size     = 0;
1345     _nul_chk_table_offset    = 0;
1346     _handler_table_offset    = 0;
1347     _scopes_pcs_offset       = 0;
1348     _scopes_data_offset      = 0;
1349 #if INCLUDE_JVMCI
1350     _speculations_offset     = 0;
1351 #endif
1352     _immutable_data_ref_count_offset = 0;
1353 
1354     code_buffer->copy_code_and_locs_to(this);
1355     code_buffer->copy_values_to(this);
1356 
1357     post_init();
1358   }
1359 
1360   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
1361     ttyLocker ttyl;  // keep the following output all in one block
1362     // This output goes directly to the tty, not the compiler log.
1363     // To enable tools to match it up with the compilation activity,
1364     // be sure to tag this tty output with the compile ID.
1365     if (xtty != nullptr) {
1366       xtty->begin_head("print_native_nmethod");
1367       xtty->method(_method);
1368       xtty->stamp();
1369       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
1370     }
1371     // Print the header part, then print the requested information.
1372     // This is both handled in decode2(), called via print_code() -> decode()
1373     if (PrintNativeNMethods) {
1374       tty->print_cr("-------------------------- Assembly (native nmethod) ---------------------------");
1375       print_code();
1376       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1377 #if defined(SUPPORT_DATA_STRUCTS)
1378       if (AbstractDisassembler::show_structs()) {
1379         if (oop_maps != nullptr) {
1380           tty->print("oop maps:"); // oop_maps->print_on(tty) outputs a cr() at the beginning
1381           oop_maps->print_on(tty);
1382           tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1383         }
1384       }
1385 #endif
1386     } else {
1387       print(); // print the header part only.
1388     }
1389 #if defined(SUPPORT_DATA_STRUCTS)
1390     if (AbstractDisassembler::show_structs()) {
1391       if (PrintRelocations) {
1392         print_relocations();
1393         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1394       }
1395     }
1396 #endif
1397     if (xtty != nullptr) {
1398       xtty->tail("print_native_nmethod");
1399     }
1400   }
1401 }
1402 
1403 
1404 nmethod::nmethod(const nmethod &nm) : CodeBlob(nm._name, nm._kind, nm._size, nm._header_size)
1405 {
1406 
1407   if (nm._oop_maps != nullptr) {
1408     _oop_maps                   = nm._oop_maps->clone();
1409   } else {
1410     _oop_maps                   = nullptr;
1411   }
1412 
1413   _size                         = nm._size;
1414   _relocation_size              = nm._relocation_size;
1415   _content_offset               = nm._content_offset;
1416   _code_offset                  = nm._code_offset;
1417   _data_offset                  = nm._data_offset;
1418   _frame_size                   = nm._frame_size;
1419 
1420   S390_ONLY( _ctable_offset     = nm._ctable_offset; )
1421 
1422   _header_size                  = nm._header_size;
1423   _frame_complete_offset        = nm._frame_complete_offset;
1424 
1425   _kind                         = nm._kind;
1426 
1427   _caller_must_gc_arguments     = nm._caller_must_gc_arguments;
1428 
1429 #ifndef PRODUCT
1430   _asm_remarks.share(nm._asm_remarks);
1431   _dbg_strings.share(nm._dbg_strings);
1432 #endif
1433 
1434   // Allocate memory and copy mutable data to C heap
1435   _mutable_data_size            = nm._mutable_data_size;
1436   if (_mutable_data_size > 0) {
1437     _mutable_data = (address)os::malloc(_mutable_data_size, mtCode);
1438     if (_mutable_data == nullptr) {
1439       vm_exit_out_of_memory(_mutable_data_size, OOM_MALLOC_ERROR, "nmethod: no space for mutable data");
1440     }
1441     memcpy(mutable_data_begin(), nm.mutable_data_begin(), nm.mutable_data_size());
1442   } else {
1443     _mutable_data               = nullptr;
1444   }
1445 
1446   _deoptimization_generation    = 0;
1447   _gc_epoch                     = CodeCache::gc_epoch();
1448   _method                       = nm._method;
1449   _osr_link                     = nullptr;
1450 
1451   _exception_cache              = nullptr;
1452   _gc_data                      = nullptr;
1453   _oops_do_mark_nmethods        = nullptr;
1454   _oops_do_mark_link            = nullptr;
1455   _compiled_ic_data             = nullptr;
1456 
1457   // Relocate the OSR entry point from nm to the new nmethod.
1458   if (nm._osr_entry_point == nullptr) {
1459     _osr_entry_point = nullptr;
1460   } else {
1461     address new_addr = nm._osr_entry_point - (address) &nm + (address) this;
1462     assert(new_addr >= code_begin() && new_addr < code_end(),
1463            "relocated address must be within code bounds");
1464     _osr_entry_point = new_addr;
1465   }
1466   _entry_offset                 = nm._entry_offset;
1467   _verified_entry_offset        = nm._verified_entry_offset;
1468   _inline_entry_offset             = nm._inline_entry_offset;
1469   _verified_inline_entry_offset    = nm._verified_inline_entry_offset;
1470   _verified_inline_ro_entry_offset = nm._verified_inline_ro_entry_offset;
1471 
1472   _entry_bci                    = nm._entry_bci;
1473   _immutable_data_size          = nm._immutable_data_size;
1474 
1475   _skipped_instructions_size    = nm._skipped_instructions_size;
1476   _stub_offset                  = nm._stub_offset;
1477   _exception_offset             = nm._exception_offset;
1478   _deopt_handler_entry_offset   = nm._deopt_handler_entry_offset;
1479   _unwind_handler_offset        = nm._unwind_handler_offset;
1480   _num_stack_arg_slots          = nm._num_stack_arg_slots;
1481 #if INCLUDE_JVMCI
1482   _metadata_size                = nm._metadata_size;
1483 #endif
1484   _nul_chk_table_offset         = nm._nul_chk_table_offset;
1485   _handler_table_offset         = nm._handler_table_offset;
1486   _scopes_pcs_offset            = nm._scopes_pcs_offset;
1487   _scopes_data_offset           = nm._scopes_data_offset;
1488 #if INCLUDE_JVMCI
1489   _speculations_offset          = nm._speculations_offset;
1490 #endif
1491   _immutable_data_ref_count_offset = nm._immutable_data_ref_count_offset;
1492 
1493   // Increment number of references to immutable data to share it between nmethods
1494   if (_immutable_data_size > 0) {
1495     _immutable_data             = nm._immutable_data;
1496     inc_immutable_data_ref_count();
1497   } else {
1498     _immutable_data             = blob_end();
1499   }
1500 
1501   _orig_pc_offset               = nm._orig_pc_offset;
1502   _compile_id                   = nm._compile_id;
1503   _comp_level                   = nm._comp_level;
1504   _compiler_type                = nm._compiler_type;
1505   _is_unloading_state           = nm._is_unloading_state;
1506   _state                        = not_installed;
1507 
1508   _has_unsafe_access            = nm._has_unsafe_access;
1509   _has_wide_vectors             = nm._has_wide_vectors;
1510   _has_monitors                 = nm._has_monitors;
1511   _has_scoped_access            = nm._has_scoped_access;
1512   _has_flushed_dependencies     = nm._has_flushed_dependencies;
1513   _is_unlinked                  = nm._is_unlinked;
1514   _load_reported                = nm._load_reported;
1515 
1516   _deoptimization_status        = nm._deoptimization_status;
1517 
1518   if (nm._pc_desc_container != nullptr) {
1519     _pc_desc_container          = new PcDescContainer(scopes_pcs_begin());
1520   } else {
1521     _pc_desc_container          = nullptr;
1522   }
1523 
1524   // Copy nmethod contents excluding header
1525   // - Constant part          (doubles, longs and floats used in nmethod)
1526   // - Code part:
1527   //   - Code body
1528   //   - Exception handler
1529   //   - Stub code
1530   //   - OOP table
1531   memcpy(consts_begin(), nm.consts_begin(), nm.data_end() - nm.consts_begin());
1532 
1533   // Fix relocation
1534   RelocIterator iter(this);
1535   CodeBuffer src(&nm);
1536   CodeBuffer dst(this);
1537   while (iter.next()) {
1538 #ifdef USE_TRAMPOLINE_STUB_FIX_OWNER
1539     // After an nmethod is moved, some direct call sites may end up out of range.
1540     // CallRelocation::fix_relocation_after_move() assumes the target is always
1541     // reachable and does not check branch range. Calling it without range checks
1542     // could cause us to write an offset too large for the instruction.
1543     //
1544     // If a call site has a trampoline, we skip the normal call relocation. The
1545     // associated trampoline_stub_Relocation will handle the call and the
1546     // trampoline, including range checks and updating the branch as needed.
1547     //
1548     // If no trampoline exists, we can assume the call target is always
1549     // reachable and therefore within direct branch range, so calling
1550     // CallRelocation::fix_relocation_after_move() is safe.
1551     if (iter.reloc()->is_call()) {
1552       address trampoline = trampoline_stub_Relocation::get_trampoline_for(iter.reloc()->addr(), this);
1553       if (trampoline != nullptr) {
1554         continue;
1555       }
1556     }
1557 #endif
1558 
1559     iter.reloc()->fix_relocation_after_move(&src, &dst);
1560   }
1561 
1562   {
1563     MutexLocker ml(NMethodState_lock, Mutex::_no_safepoint_check_flag);
1564     clear_inline_caches();
1565   }
1566 
1567   post_init();
1568 }
1569 
1570 nmethod* nmethod::relocate(CodeBlobType code_blob_type) {
1571   assert(NMethodRelocation, "must enable use of function");
1572 
1573   // Locks required to be held by caller to ensure the nmethod
1574   // is not modified or purged from code cache during relocation
1575   assert_lock_strong(CodeCache_lock);
1576   assert_lock_strong(Compile_lock);
1577   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
1578 
1579   if (!is_relocatable()) {
1580     return nullptr;
1581   }
1582 
1583   run_nmethod_entry_barrier();
1584   nmethod* nm_copy = new (size(), code_blob_type) nmethod(*this);
1585 
1586   if (nm_copy == nullptr) {
1587     return nullptr;
1588   }
1589 
1590   // To make dependency checking during class loading fast, record
1591   // the nmethod dependencies in the classes it is dependent on.
1592   // This allows the dependency checking code to simply walk the
1593   // class hierarchy above the loaded class, checking only nmethods
1594   // which are dependent on those classes.  The slow way is to
1595   // check every nmethod for dependencies which makes it linear in
1596   // the number of methods compiled.  For applications with a lot
1597   // classes the slow way is too slow.
1598   for (Dependencies::DepStream deps(nm_copy); deps.next(); ) {
1599     if (deps.type() == Dependencies::call_site_target_value) {
1600       // CallSite dependencies are managed on per-CallSite instance basis.
1601       oop call_site = deps.argument_oop(0);
1602       MethodHandles::add_dependent_nmethod(call_site, nm_copy);
1603     } else {
1604       InstanceKlass* ik = deps.context_type();
1605       if (ik == nullptr) {
1606         continue;  // ignore things like evol_method
1607       }
1608       // record this nmethod as dependent on this klass
1609       ik->add_dependent_nmethod(nm_copy);
1610     }
1611   }
1612 
1613   MutexLocker ml_NMethodState_lock(NMethodState_lock, Mutex::_no_safepoint_check_flag);
1614 
1615   // Verify the nm we copied from is still valid
1616   if (!is_marked_for_deoptimization() && is_in_use()) {
1617     assert(method() != nullptr && method()->code() == this, "should be if is in use");
1618 
1619     // Attempt to start using the copy
1620     if (nm_copy->make_in_use()) {
1621       methodHandle mh(Thread::current(), nm_copy->method());
1622       nm_copy->method()->set_code(mh, nm_copy);
1623 
1624       make_not_entrant(InvalidationReason::RELOCATED);
1625 
1626       nm_copy->post_compiled_method_load_event();
1627 
1628       nm_copy->log_relocated_nmethod(this);
1629 
1630       return nm_copy;
1631     }
1632   }
1633 
1634   nm_copy->make_not_used();
1635 
1636   return nullptr;
1637 }
1638 
1639 bool nmethod::is_relocatable() {
1640   if (!is_java_method()) {
1641     return false;
1642   }
1643 
1644   if (!is_in_use()) {
1645     return false;
1646   }
1647 
1648   if (is_osr_method()) {
1649     return false;
1650   }
1651 
1652   if (is_marked_for_deoptimization()) {
1653     return false;
1654   }
1655 
1656 #if INCLUDE_JVMCI
1657   if (jvmci_nmethod_data() != nullptr && jvmci_nmethod_data()->has_mirror()) {
1658     return false;
1659   }
1660 #endif
1661 
1662   if (is_unloading()) {
1663     return false;
1664   }
1665 
1666   if (has_evol_metadata()) {
1667     return false;
1668   }
1669 
1670   return true;
1671 }
1672 
1673 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
1674   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
1675 }
1676 
1677 void* nmethod::operator new(size_t size, int nmethod_size, CodeBlobType code_blob_type) throw () {
1678   return CodeCache::allocate(nmethod_size, code_blob_type);
1679 }
1680 
1681 void* nmethod::operator new(size_t size, int nmethod_size, bool allow_NonNMethod_space) throw () {
1682   // Try MethodNonProfiled and MethodProfiled.
1683   void* return_value = CodeCache::allocate(nmethod_size, CodeBlobType::MethodNonProfiled);
1684   if (return_value != nullptr || !allow_NonNMethod_space) return return_value;
1685   // Try NonNMethod or give up.
1686   return CodeCache::allocate(nmethod_size, CodeBlobType::NonNMethod);
1687 }
1688 
1689 // For normal JIT compiled code
1690 nmethod::nmethod(
1691   Method* method,
1692   CompilerType type,
1693   int nmethod_size,
1694   int immutable_data_size,
1695   int mutable_data_size,
1696   int compile_id,
1697   int entry_bci,
1698   address immutable_data,
1699   CodeOffsets* offsets,
1700   int orig_pc_offset,
1701   DebugInformationRecorder* debug_info,
1702   Dependencies* dependencies,
1703   CodeBuffer *code_buffer,
1704   int frame_size,
1705   OopMapSet* oop_maps,
1706   ExceptionHandlerTable* handler_table,
1707   ImplicitExceptionTable* nul_chk_table,
1708   AbstractCompiler* compiler,
1709   CompLevel comp_level
1710 #if INCLUDE_JVMCI
1711   , char* speculations,
1712   int speculations_len,
1713   JVMCINMethodData* jvmci_data
1714 #endif
1715   )
1716   : CodeBlob("nmethod", CodeBlobKind::Nmethod, code_buffer, nmethod_size, sizeof(nmethod),
1717              offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false, mutable_data_size),
1718   _deoptimization_generation(0),
1719   _gc_epoch(CodeCache::gc_epoch()),
1720   _method(method),
1721   _osr_link(nullptr)
1722 {
1723   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
1724   {
1725     DEBUG_ONLY(NoSafepointVerifier nsv;)
1726     assert_locked_or_safepoint(CodeCache_lock);
1727 
1728     init_defaults(code_buffer, offsets);
1729 
1730     _osr_entry_point = code_begin() + offsets->value(CodeOffsets::OSR_Entry);
1731     _entry_bci       = entry_bci;
1732     _compile_id      = compile_id;
1733     _comp_level      = comp_level;
1734     _compiler_type   = type;
1735     _orig_pc_offset  = orig_pc_offset;
1736 
1737     _num_stack_arg_slots = entry_bci != InvocationEntryBci ? 0 : _method->constMethod()->num_stack_arg_slots();
1738 
1739     set_ctable_begin(header_begin() + content_offset());
1740 
1741 #if INCLUDE_JVMCI
1742     if (compiler->is_jvmci()) {
1743       // JVMCI might not produce any stub sections
1744       if (offsets->value(CodeOffsets::Exceptions) != -1) {
1745         _exception_offset        = code_offset() + offsets->value(CodeOffsets::Exceptions);
1746       } else {
1747         _exception_offset        = -1;
1748       }
1749       if (offsets->value(CodeOffsets::Deopt) != -1) {
1750         _deopt_handler_entry_offset    = code_offset() + offsets->value(CodeOffsets::Deopt);
1751       } else {
1752         _deopt_handler_entry_offset    = -1;
1753       }
1754     } else
1755 #endif
1756     {
1757       // Exception handler and deopt handler are in the stub section
1758       assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
1759 
1760       bool has_exception_handler = (offsets->value(CodeOffsets::Exceptions) != -1);
1761       assert(has_exception_handler == (compiler->type() != compiler_c2),
1762              "C2 compiler doesn't provide exception handler stub code.");
1763       if (has_exception_handler) {
1764         _exception_offset = _stub_offset + offsets->value(CodeOffsets::Exceptions);
1765       } else {
1766         _exception_offset = -1;
1767       }
1768 
1769       _deopt_handler_entry_offset = _stub_offset + offsets->value(CodeOffsets::Deopt);
1770     }
1771     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
1772       // C1 generates UnwindHandler at the end of instructions section.
1773       // Calculate positive offset as distance between the start of stubs section
1774       // (which is also the end of instructions section) and the start of the handler.
1775       int unwind_handler_offset = code_offset() + offsets->value(CodeOffsets::UnwindHandler);
1776       CHECKED_CAST(_unwind_handler_offset, int16_t, (_stub_offset - unwind_handler_offset));
1777     } else {
1778       _unwind_handler_offset = -1;
1779     }
1780 
1781     int metadata_size = align_up(code_buffer->total_metadata_size(), wordSize);
1782     JVMCI_ONLY( _metadata_size = metadata_size; )
1783     int jvmci_data_size = 0 JVMCI_ONLY( + align_up(compiler->is_jvmci() ? jvmci_data->size() : 0, oopSize));
1784     if (offsets->value(CodeOffsets::Inline_Entry) != CodeOffsets::no_such_entry_point) {
1785       CHECKED_CAST(_inline_entry_offset            , uint16_t, offsets->value(CodeOffsets::Inline_Entry));
1786     }
1787     if (offsets->value(CodeOffsets::Verified_Inline_Entry) != CodeOffsets::no_such_entry_point) {
1788       CHECKED_CAST(_verified_inline_entry_offset   , uint16_t, offsets->value(CodeOffsets::Verified_Inline_Entry));
1789     }
1790     if (offsets->value(CodeOffsets::Verified_Inline_Entry_RO) != CodeOffsets::no_such_entry_point) {
1791       CHECKED_CAST(_verified_inline_ro_entry_offset, uint16_t, offsets->value(CodeOffsets::Verified_Inline_Entry_RO));
1792     }
1793 
1794     assert(_mutable_data_size == _relocation_size + metadata_size + jvmci_data_size,
1795            "wrong mutable data size: %d != %d + %d + %d",
1796            _mutable_data_size, _relocation_size, metadata_size, jvmci_data_size);
1797     assert(nmethod_size == data_end() - header_begin(), "wrong nmethod size: %d != %d",
1798            nmethod_size, (int)(code_end() - header_begin()));
1799 
1800     _immutable_data_size  = immutable_data_size;
1801     if (immutable_data_size > 0) {
1802       assert(immutable_data != nullptr, "required");
1803       _immutable_data     = immutable_data;
1804     } else {
1805       // We need unique not null address
1806       _immutable_data     = blob_end();
1807     }
1808     CHECKED_CAST(_nul_chk_table_offset, uint16_t, (align_up((int)dependencies->size_in_bytes(), oopSize)));
1809     CHECKED_CAST(_handler_table_offset, uint16_t, (_nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize)));
1810     _scopes_pcs_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
1811     _scopes_data_offset   = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
1812 
1813 #if INCLUDE_JVMCI
1814     _speculations_offset  = _scopes_data_offset   + align_up(debug_info->data_size(), oopSize);
1815     _immutable_data_ref_count_offset = _speculations_offset + align_up(speculations_len, oopSize);
1816 #else
1817     _immutable_data_ref_count_offset = _scopes_data_offset + align_up(debug_info->data_size(), oopSize);
1818 #endif
1819     DEBUG_ONLY( int immutable_data_end_offset = _immutable_data_ref_count_offset + ImmutableDataRefCountSize; )
1820     assert(immutable_data_end_offset <= immutable_data_size, "wrong read-only data size: %d > %d",
1821            immutable_data_end_offset, immutable_data_size);
1822 
1823     // Copy code and relocation info
1824     code_buffer->copy_code_and_locs_to(this);
1825     // Copy oops and metadata
1826     code_buffer->copy_values_to(this);
1827     dependencies->copy_to(this);
1828     // Copy PcDesc and ScopeDesc data
1829     debug_info->copy_to(this);
1830 
1831     // Create cache after PcDesc data is copied - it will be used to initialize cache
1832     _pc_desc_container = new PcDescContainer(scopes_pcs_begin());
1833 
1834 #if INCLUDE_JVMCI
1835     if (compiler->is_jvmci()) {
1836       // Initialize the JVMCINMethodData object inlined into nm
1837       jvmci_nmethod_data()->copy(jvmci_data);
1838     }
1839 #endif
1840 
1841     // Copy contents of ExceptionHandlerTable to nmethod
1842     handler_table->copy_to(this);
1843     nul_chk_table->copy_to(this);
1844 
1845 #if INCLUDE_JVMCI
1846     // Copy speculations to nmethod
1847     if (speculations_size() != 0) {
1848       memcpy(speculations_begin(), speculations, speculations_len);
1849     }
1850 #endif
1851     init_immutable_data_ref_count();
1852 
1853     post_init();
1854 
1855     // we use the information of entry points to find out if a method is
1856     // static or non static
1857     assert(compiler->is_c2() || compiler->is_jvmci() ||
1858            _method->is_static() == (entry_point() == verified_entry_point()),
1859            " entry points must be same for static methods and vice versa");
1860   }
1861 }
1862 
1863 // Print a short set of xml attributes to identify this nmethod.  The
1864 // output should be embedded in some other element.
1865 void nmethod::log_identity(xmlStream* log) const {
1866   log->print(" compile_id='%d'", compile_id());
1867   const char* nm_kind = compile_kind();
1868   if (nm_kind != nullptr)  log->print(" compile_kind='%s'", nm_kind);
1869   log->print(" compiler='%s'", compiler_name());
1870   if (TieredCompilation) {
1871     log->print(" level='%d'", comp_level());
1872   }
1873 #if INCLUDE_JVMCI
1874   if (jvmci_nmethod_data() != nullptr) {
1875     const char* jvmci_name = jvmci_nmethod_data()->name();
1876     if (jvmci_name != nullptr) {
1877       log->print(" jvmci_mirror_name='");
1878       log->text("%s", jvmci_name);
1879       log->print("'");
1880     }
1881   }
1882 #endif
1883 }
1884 
1885 
1886 #define LOG_OFFSET(log, name)                    \
1887   if (p2i(name##_end()) - p2i(name##_begin())) \
1888     log->print(" " XSTR(name) "_offset='%zd'"    , \
1889                p2i(name##_begin()) - p2i(this))
1890 
1891 
1892 void nmethod::log_new_nmethod() const {
1893   if (LogCompilation && xtty != nullptr) {
1894     ttyLocker ttyl;
1895     xtty->begin_elem("nmethod");
1896     log_identity(xtty);
1897     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
1898     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
1899 
1900     LOG_OFFSET(xtty, relocation);
1901     LOG_OFFSET(xtty, consts);
1902     LOG_OFFSET(xtty, insts);
1903     LOG_OFFSET(xtty, stub);
1904     LOG_OFFSET(xtty, scopes_data);
1905     LOG_OFFSET(xtty, scopes_pcs);
1906     LOG_OFFSET(xtty, dependencies);
1907     LOG_OFFSET(xtty, handler_table);
1908     LOG_OFFSET(xtty, nul_chk_table);
1909     LOG_OFFSET(xtty, oops);
1910     LOG_OFFSET(xtty, metadata);
1911 
1912     xtty->method(method());
1913     xtty->stamp();
1914     xtty->end_elem();
1915   }
1916 }
1917 
1918 
1919 void nmethod::log_relocated_nmethod(nmethod* original) const {
1920   if (LogCompilation && xtty != nullptr) {
1921     ttyLocker ttyl;
1922     xtty->begin_elem("relocated nmethod");
1923     log_identity(xtty);
1924     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
1925 
1926     const char* original_code_heap_name = CodeCache::get_code_heap_name(CodeCache::get_code_blob_type(original));
1927     xtty->print(" original_address='" INTPTR_FORMAT "'", p2i(original));
1928     xtty->print(" original_code_heap='%s'", original_code_heap_name);
1929 
1930     const char* new_code_heap_name = CodeCache::get_code_heap_name(CodeCache::get_code_blob_type(this));
1931     xtty->print(" new_address='" INTPTR_FORMAT "'", p2i(this));
1932     xtty->print(" new_code_heap='%s'", new_code_heap_name);
1933 
1934     LOG_OFFSET(xtty, relocation);
1935     LOG_OFFSET(xtty, consts);
1936     LOG_OFFSET(xtty, insts);
1937     LOG_OFFSET(xtty, stub);
1938     LOG_OFFSET(xtty, scopes_data);
1939     LOG_OFFSET(xtty, scopes_pcs);
1940     LOG_OFFSET(xtty, dependencies);
1941     LOG_OFFSET(xtty, handler_table);
1942     LOG_OFFSET(xtty, nul_chk_table);
1943     LOG_OFFSET(xtty, oops);
1944     LOG_OFFSET(xtty, metadata);
1945 
1946     xtty->method(method());
1947     xtty->stamp();
1948     xtty->end_elem();
1949   }
1950 }
1951 
1952 #undef LOG_OFFSET
1953 
1954 
1955 // Print out more verbose output usually for a newly created nmethod.
1956 void nmethod::print_on_with_msg(outputStream* st, const char* msg) const {
1957   if (st != nullptr) {
1958     ttyLocker ttyl;
1959     if (WizardMode) {
1960       CompileTask::print(st, this, msg, /*short_form:*/ true);
1961       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
1962     } else {
1963       CompileTask::print(st, this, msg, /*short_form:*/ false);
1964     }
1965   }
1966 }
1967 
1968 void nmethod::maybe_print_nmethod(const DirectiveSet* directive) {
1969   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
1970   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
1971     print_nmethod(printnmethods);
1972   }
1973 }
1974 
1975 void nmethod::print_nmethod(bool printmethod) {
1976   ttyLocker ttyl;  // keep the following output all in one block
1977   if (xtty != nullptr) {
1978     xtty->begin_head("print_nmethod");
1979     log_identity(xtty);
1980     xtty->stamp();
1981     xtty->end_head();
1982   }
1983   // Print the header part, then print the requested information.
1984   // This is both handled in decode2().
1985   if (printmethod) {
1986     ResourceMark m;
1987     if (is_compiled_by_c1()) {
1988       tty->cr();
1989       tty->print_cr("============================= C1-compiled nmethod ==============================");
1990     }
1991     if (is_compiled_by_jvmci()) {
1992       tty->cr();
1993       tty->print_cr("=========================== JVMCI-compiled nmethod =============================");
1994     }
1995     tty->print_cr("----------------------------------- Assembly -----------------------------------");
1996     decode2(tty);
1997 #if defined(SUPPORT_DATA_STRUCTS)
1998     if (AbstractDisassembler::show_structs()) {
1999       // Print the oops from the underlying CodeBlob as well.
2000       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2001       print_oops(tty);
2002       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2003       print_metadata(tty);
2004       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2005       print_pcs_on(tty);
2006       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2007       if (oop_maps() != nullptr) {
2008         tty->print("oop maps:"); // oop_maps()->print_on(tty) outputs a cr() at the beginning
2009         oop_maps()->print_on(tty);
2010         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2011       }
2012     }
2013 #endif
2014   } else {
2015     print(); // print the header part only.
2016   }
2017 
2018 #if defined(SUPPORT_DATA_STRUCTS)
2019   if (AbstractDisassembler::show_structs()) {
2020     methodHandle mh(Thread::current(), _method);
2021     if (printmethod || PrintDebugInfo || CompilerOracle::has_option(mh, CompileCommandEnum::PrintDebugInfo)) {
2022       print_scopes();
2023       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2024     }
2025     if (printmethod || PrintRelocations || CompilerOracle::has_option(mh, CompileCommandEnum::PrintRelocations)) {
2026       print_relocations();
2027       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2028     }
2029     if (printmethod || PrintDependencies || CompilerOracle::has_option(mh, CompileCommandEnum::PrintDependencies)) {
2030       print_dependencies_on(tty);
2031       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2032     }
2033     if (printmethod || PrintExceptionHandlers) {
2034       print_handler_table();
2035       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2036       print_nul_chk_table();
2037       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2038     }
2039 
2040     if (printmethod) {
2041       print_recorded_oops();
2042       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2043       print_recorded_metadata();
2044       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
2045     }
2046   }
2047 #endif
2048 
2049   if (xtty != nullptr) {
2050     xtty->tail("print_nmethod");
2051   }
2052 }
2053 
2054 
2055 // Promote one word from an assembly-time handle to a live embedded oop.
2056 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
2057   if (handle == nullptr ||
2058       // As a special case, IC oops are initialized to 1 or -1.
2059       handle == (jobject) Universe::non_oop_word()) {
2060     *(void**)dest = handle;
2061   } else {
2062     *dest = JNIHandles::resolve_non_null(handle);
2063   }
2064 }
2065 
2066 
2067 // Have to have the same name because it's called by a template
2068 void nmethod::copy_values(GrowableArray<jobject>* array) {
2069   int length = array->length();
2070   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
2071   oop* dest = oops_begin();
2072   for (int index = 0 ; index < length; index++) {
2073     initialize_immediate_oop(&dest[index], array->at(index));
2074   }
2075 
2076   // Now we can fix up all the oops in the code.  We need to do this
2077   // in the code because the assembler uses jobjects as placeholders.
2078   // The code and relocations have already been initialized by the
2079   // CodeBlob constructor, so it is valid even at this early point to
2080   // iterate over relocations and patch the code.
2081   fix_oop_relocations(/*initialize_immediates=*/ true);
2082 }
2083 
2084 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
2085   int length = array->length();
2086   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
2087   Metadata** dest = metadata_begin();
2088   for (int index = 0 ; index < length; index++) {
2089     dest[index] = array->at(index);
2090   }
2091 }
2092 
2093 bool nmethod::fix_oop_relocations(bool initialize_immediates) {
2094   // re-patch all oop-bearing instructions, just in case some oops moved
2095   RelocIterator iter(this);
2096   bool modified_code = false;
2097   while (iter.next()) {
2098     if (iter.type() == relocInfo::oop_type) {
2099       oop_Relocation* reloc = iter.oop_reloc();
2100       if (!reloc->oop_is_immediate()) {
2101         // Refresh the oop-related bits of this instruction.
2102         reloc->set_value(reloc->value());
2103         modified_code = true;
2104       } else if (initialize_immediates) {
2105         oop* dest = reloc->oop_addr();
2106         jobject obj = *reinterpret_cast<jobject*>(dest);
2107         initialize_immediate_oop(dest, obj);
2108       }
2109     } else if (iter.type() == relocInfo::metadata_type) {
2110       metadata_Relocation* reloc = iter.metadata_reloc();
2111       reloc->fix_metadata_relocation();
2112       modified_code |= !reloc->metadata_is_immediate();
2113     }
2114   }
2115   return modified_code;
2116 }
2117 
2118 void nmethod::fix_oop_relocations() {
2119   ICacheInvalidationContext icic;
2120   fix_oop_relocations(&icic);
2121 }
2122 
2123 void nmethod::fix_oop_relocations(ICacheInvalidationContext* icic) {
2124   assert(icic != nullptr, "must provide context to track if code was modified");
2125   bool modified_code = fix_oop_relocations(/*initialize_immediates=*/ false);
2126   if (modified_code) {
2127     icic->set_has_modified_code();
2128   }
2129 }
2130 
2131 static void install_post_call_nop_displacement(nmethod* nm, address pc) {
2132   NativePostCallNop* nop = nativePostCallNop_at((address) pc);
2133   intptr_t cbaddr = (intptr_t) nm;
2134   intptr_t offset = ((intptr_t) pc) - cbaddr;
2135 
2136   int oopmap_slot = nm->oop_maps()->find_slot_for_offset(int((intptr_t) pc - (intptr_t) nm->code_begin()));
2137   if (oopmap_slot < 0) { // this can happen at asynchronous (non-safepoint) stackwalks
2138     log_debug(codecache)("failed to find oopmap for cb: " INTPTR_FORMAT " offset: %d", cbaddr, (int) offset);
2139   } else if (!nop->patch(oopmap_slot, offset)) {
2140     log_debug(codecache)("failed to encode %d %d", oopmap_slot, (int) offset);
2141   }
2142 }
2143 
2144 void nmethod::finalize_relocations() {
2145   NoSafepointVerifier nsv;
2146 
2147   GrowableArray<NativeMovConstReg*> virtual_call_data;
2148 
2149   // Make sure that post call nops fill in nmethod offsets eagerly so
2150   // we don't have to race with deoptimization
2151   RelocIterator iter(this);
2152   while (iter.next()) {
2153     if (iter.type() == relocInfo::virtual_call_type) {
2154       virtual_call_Relocation* r = iter.virtual_call_reloc();
2155       NativeMovConstReg* value = nativeMovConstReg_at(r->cached_value());
2156       virtual_call_data.append(value);
2157     } else if (iter.type() == relocInfo::post_call_nop_type) {
2158       post_call_nop_Relocation* const reloc = iter.post_call_nop_reloc();
2159       address pc = reloc->addr();
2160       install_post_call_nop_displacement(this, pc);
2161     }
2162   }
2163 
2164   if (virtual_call_data.length() > 0) {
2165     // We allocate a block of CompiledICData per nmethod so the GC can purge this faster.
2166     _compiled_ic_data = new CompiledICData[virtual_call_data.length()];
2167     CompiledICData* next_data = _compiled_ic_data;
2168 
2169     for (NativeMovConstReg* value : virtual_call_data) {
2170       value->set_data((intptr_t)next_data);
2171       next_data++;
2172     }
2173   }
2174 }
2175 
2176 void nmethod::make_deoptimized() {
2177   if (!Continuations::enabled()) {
2178     // Don't deopt this again.
2179     set_deoptimized_done();
2180     return;
2181   }
2182 
2183   assert(method() == nullptr || can_be_deoptimized(), "");
2184 
2185   CompiledICLocker ml(this);
2186   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
2187 
2188   // If post call nops have been already patched, we can just bail-out.
2189   if (has_been_deoptimized()) {
2190     return;
2191   }
2192 
2193   ResourceMark rm;
2194   RelocIterator iter(this, oops_reloc_begin());
2195 
2196   // Assume there will be some calls to make deoptimized.
2197   MACOS_AARCH64_ONLY(os::thread_wx_enable_write());
2198 
2199   while (iter.next()) {
2200 
2201     switch (iter.type()) {
2202       case relocInfo::virtual_call_type: {
2203         CompiledIC *ic = CompiledIC_at(&iter);
2204         address pc = ic->end_of_call();
2205         NativePostCallNop* nop = nativePostCallNop_at(pc);
2206         if (nop != nullptr) {
2207           nop->make_deopt();
2208         }
2209         assert(NativeDeoptInstruction::is_deopt_at(pc), "check");
2210         break;
2211       }
2212       case relocInfo::static_call_type:
2213       case relocInfo::opt_virtual_call_type: {
2214         CompiledDirectCall *csc = CompiledDirectCall::at(iter.reloc());
2215         address pc = csc->end_of_call();
2216         NativePostCallNop* nop = nativePostCallNop_at(pc);
2217         //tty->print_cr(" - static pc %p", pc);
2218         if (nop != nullptr) {
2219           nop->make_deopt();
2220         }
2221         // We can't assert here, there are some calls to stubs / runtime
2222         // that have reloc data and doesn't have a post call NOP.
2223         //assert(NativeDeoptInstruction::is_deopt_at(pc), "check");
2224         break;
2225       }
2226       default:
2227         break;
2228     }
2229   }
2230   // Don't deopt this again.
2231   set_deoptimized_done();
2232 }
2233 
2234 void nmethod::verify_clean_inline_caches() {
2235   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
2236 
2237   ResourceMark rm;
2238   RelocIterator iter(this, oops_reloc_begin());
2239   while(iter.next()) {
2240     switch(iter.type()) {
2241       case relocInfo::virtual_call_type: {
2242         CompiledIC *ic = CompiledIC_at(&iter);
2243         CodeBlob *cb = CodeCache::find_blob(ic->destination());
2244         assert(cb != nullptr, "destination not in CodeBlob?");
2245         nmethod* nm = cb->as_nmethod_or_null();
2246         if (nm != nullptr) {
2247           // Verify that inline caches pointing to bad nmethods are clean
2248           if (!nm->is_in_use() || nm->is_unloading()) {
2249             assert(ic->is_clean(), "IC should be clean");
2250           }
2251         }
2252         break;
2253       }
2254       case relocInfo::static_call_type:
2255       case relocInfo::opt_virtual_call_type: {
2256         CompiledDirectCall *cdc = CompiledDirectCall::at(iter.reloc());
2257         CodeBlob *cb = CodeCache::find_blob(cdc->destination());
2258         assert(cb != nullptr, "destination not in CodeBlob?");
2259         nmethod* nm = cb->as_nmethod_or_null();
2260         if (nm != nullptr) {
2261           // Verify that inline caches pointing to bad nmethods are clean
2262           if (!nm->is_in_use() || nm->is_unloading() || nm->method()->code() != nm) {
2263             assert(cdc->is_clean(), "IC should be clean");
2264           }
2265         }
2266         break;
2267       }
2268       default:
2269         break;
2270     }
2271   }
2272 }
2273 
2274 void nmethod::mark_as_maybe_on_stack() {
2275   MACOS_AARCH64_ONLY(os::thread_wx_enable_write());
2276   AtomicAccess::store(&_gc_epoch, CodeCache::gc_epoch());
2277 }
2278 
2279 bool nmethod::is_maybe_on_stack() {
2280   // If the condition below is true, it means that the nmethod was found to
2281   // be alive the previous completed marking cycle.
2282   return AtomicAccess::load(&_gc_epoch) >= CodeCache::previous_completed_gc_marking_cycle();
2283 }
2284 
2285 void nmethod::inc_decompile_count() {
2286   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
2287   // Could be gated by ProfileTraps, but do not bother...
2288 #if INCLUDE_JVMCI
2289   if (jvmci_skip_profile_deopt()) {
2290     return;
2291   }
2292 #endif
2293   Method* m = method();
2294   if (m == nullptr)  return;
2295   MethodData* mdo = m->method_data();
2296   if (mdo == nullptr)  return;
2297   // There is a benign race here.  See comments in methodData.hpp.
2298   mdo->inc_decompile_count();
2299 }
2300 
2301 bool nmethod::try_transition(signed char new_state_int) {
2302   signed char new_state = new_state_int;
2303   assert_lock_strong(NMethodState_lock);
2304   signed char old_state = _state;
2305   if (old_state >= new_state) {
2306     // Ensure monotonicity of transitions.
2307     return false;
2308   }
2309   AtomicAccess::store(&_state, new_state);
2310   return true;
2311 }
2312 
2313 void nmethod::invalidate_osr_method() {
2314   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
2315   // Remove from list of active nmethods
2316   if (method() != nullptr) {
2317     method()->method_holder()->remove_osr_nmethod(this);
2318   }
2319 }
2320 
2321 void nmethod::log_state_change(InvalidationReason invalidation_reason) const {
2322   if (LogCompilation) {
2323     if (xtty != nullptr) {
2324       ttyLocker ttyl;  // keep the following output all in one block
2325       xtty->begin_elem("make_not_entrant thread='%zu' reason='%s'",
2326                        os::current_thread_id(), invalidation_reason_to_string(invalidation_reason));
2327       log_identity(xtty);
2328       xtty->stamp();
2329       xtty->end_elem();
2330     }
2331   }
2332 
2333   ResourceMark rm;
2334   stringStream ss(NEW_RESOURCE_ARRAY(char, 256), 256);
2335   ss.print("made not entrant: %s", invalidation_reason_to_string(invalidation_reason));
2336 
2337   CompileTask::print_ul(this, ss.freeze());
2338   if (PrintCompilation) {
2339     print_on_with_msg(tty, ss.freeze());
2340   }
2341 }
2342 
2343 void nmethod::unlink_from_method() {
2344   if (method() != nullptr) {
2345     method()->unlink_code(this);
2346   }
2347 }
2348 
2349 // Invalidate code
2350 bool nmethod::make_not_entrant(InvalidationReason invalidation_reason) {
2351   // This can be called while the system is already at a safepoint which is ok
2352   NoSafepointVerifier nsv;
2353 
2354   if (is_unloading()) {
2355     // If the nmethod is unloading, then it is already not entrant through
2356     // the nmethod entry barriers. No need to do anything; GC will unload it.
2357     return false;
2358   }
2359 
2360   if (AtomicAccess::load(&_state) == not_entrant) {
2361     // Avoid taking the lock if already in required state.
2362     // This is safe from races because the state is an end-state,
2363     // which the nmethod cannot back out of once entered.
2364     // No need for fencing either.
2365     return false;
2366   }
2367 
2368   MACOS_AARCH64_ONLY(os::thread_wx_enable_write());
2369 
2370   {
2371     // Enter critical section.  Does not block for safepoint.
2372     ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
2373 
2374     if (AtomicAccess::load(&_state) == not_entrant) {
2375       // another thread already performed this transition so nothing
2376       // to do, but return false to indicate this.
2377       return false;
2378     }
2379 
2380     if (is_osr_method()) {
2381       // This logic is equivalent to the logic below for patching the
2382       // verified entry point of regular methods.
2383       // this effectively makes the osr nmethod not entrant
2384       invalidate_osr_method();
2385     } else {
2386       // The caller can be calling the method statically or through an inline
2387       // cache call.
2388       BarrierSet::barrier_set()->barrier_set_nmethod()->make_not_entrant(this);
2389     }
2390 
2391     if (update_recompile_counts()) {
2392       // Mark the method as decompiled.
2393       inc_decompile_count();
2394     }
2395 
2396     BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2397     if (bs_nm == nullptr || !bs_nm->supports_entry_barrier(this)) {
2398       // If nmethod entry barriers are not supported, we won't mark
2399       // nmethods as on-stack when they become on-stack. So we
2400       // degrade to a less accurate flushing strategy, for now.
2401       mark_as_maybe_on_stack();
2402     }
2403 
2404     // Change state
2405     bool success = try_transition(not_entrant);
2406     assert(success, "Transition can't fail");
2407 
2408     // Log the transition once
2409     log_state_change(invalidation_reason);
2410 
2411     // Remove nmethod from method.
2412     unlink_from_method();
2413 
2414   } // leave critical region under NMethodState_lock
2415 
2416 #if INCLUDE_JVMCI
2417   // Invalidate can't occur while holding the NMethodState_lock
2418   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
2419   if (nmethod_data != nullptr) {
2420     nmethod_data->invalidate_nmethod_mirror(this, invalidation_reason);
2421   }
2422 #endif
2423 
2424 #ifdef ASSERT
2425   if (is_osr_method() && method() != nullptr) {
2426     // Make sure osr nmethod is invalidated, i.e. not on the list
2427     bool found = method()->method_holder()->remove_osr_nmethod(this);
2428     assert(!found, "osr nmethod should have been invalidated");
2429   }
2430 #endif
2431 
2432   return true;
2433 }
2434 
2435 // For concurrent GCs, there must be a handshake between unlink and flush
2436 void nmethod::unlink() {
2437   if (is_unlinked()) {
2438     // Already unlinked.
2439     return;
2440   }
2441 
2442   flush_dependencies();
2443 
2444   // unlink_from_method will take the NMethodState_lock.
2445   // In this case we don't strictly need it when unlinking nmethods from
2446   // the Method, because it is only concurrently unlinked by
2447   // the entry barrier, which acquires the per nmethod lock.
2448   unlink_from_method();
2449 
2450   if (is_osr_method()) {
2451     invalidate_osr_method();
2452   }
2453 
2454 #if INCLUDE_JVMCI
2455   // Clear the link between this nmethod and a HotSpotNmethod mirror
2456   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
2457   if (nmethod_data != nullptr) {
2458     nmethod_data->invalidate_nmethod_mirror(this, is_cold() ?
2459             nmethod::InvalidationReason::UNLOADING_COLD :
2460             nmethod::InvalidationReason::UNLOADING);
2461   }
2462 #endif
2463 
2464   // Post before flushing as jmethodID is being used
2465   post_compiled_method_unload();
2466 
2467   // Register for flushing when it is safe. For concurrent class unloading,
2468   // that would be after the unloading handshake, and for STW class unloading
2469   // that would be when getting back to the VM thread.
2470   ClassUnloadingContext::context()->register_unlinked_nmethod(this);
2471 }
2472 
2473 void nmethod::purge(bool unregister_nmethod) {
2474 
2475   MutexLocker ml(CodeCache_lock, Mutex::_no_safepoint_check_flag);
2476 
2477   // completely deallocate this method
2478   Events::log_nmethod_flush(Thread::current(), "flushing %s nmethod " INTPTR_FORMAT, is_osr_method() ? "osr" : "", p2i(this));
2479 
2480   LogTarget(Debug, codecache) lt;
2481   if (lt.is_enabled()) {
2482     ResourceMark rm;
2483     LogStream ls(lt);
2484     const char* method_name = method()->name()->as_C_string();
2485     const size_t codecache_capacity = CodeCache::capacity()/1024;
2486     const size_t codecache_free_space = CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024;
2487     ls.print("Flushing nmethod %6d/" INTPTR_FORMAT ", level=%d, osr=%d, cold=%d, epoch=" UINT64_FORMAT ", cold_count=" UINT64_FORMAT ". "
2488               "Cache capacity: %zuKb, free space: %zuKb. method %s (%s)",
2489               _compile_id, p2i(this), _comp_level, is_osr_method(), is_cold(), _gc_epoch, CodeCache::cold_gc_count(),
2490               codecache_capacity, codecache_free_space, method_name, compiler_name());
2491   }
2492 
2493   // We need to deallocate any ExceptionCache data.
2494   // Note that we do not need to grab the nmethod lock for this, it
2495   // better be thread safe if we're disposing of it!
2496   ExceptionCache* ec = exception_cache();
2497   while(ec != nullptr) {
2498     ExceptionCache* next = ec->next();
2499     delete ec;
2500     ec = next;
2501   }
2502   if (_pc_desc_container != nullptr) {
2503     delete _pc_desc_container;
2504   }
2505   delete[] _compiled_ic_data;
2506 
2507   if (_immutable_data != blob_end()) {
2508     // Free memory if this was the last nmethod referencing immutable data
2509     if (dec_immutable_data_ref_count() == 0) {
2510       os::free(_immutable_data);
2511     }
2512 
2513     _immutable_data = blob_end(); // Valid not null address
2514   }
2515 
2516   if (unregister_nmethod) {
2517     Universe::heap()->unregister_nmethod(this);
2518   }
2519 
2520 #ifdef COMPILER2
2521   HotCodeCollector::unregister_nmethod(this);
2522 #endif // COMPILER2
2523 
2524   CodeCache::unregister_old_nmethod(this);
2525 
2526   JVMCI_ONLY( _metadata_size = 0; )
2527   CodeBlob::purge();
2528 }
2529 
2530 oop nmethod::oop_at(int index) const {
2531   if (index == 0) {
2532     return nullptr;
2533   }
2534 
2535   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2536   return bs_nm->oop_load_no_keepalive(this, index);
2537 }
2538 
2539 oop nmethod::oop_at_phantom(int index) const {
2540   if (index == 0) {
2541     return nullptr;
2542   }
2543 
2544   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2545   return bs_nm->oop_load_phantom(this, index);
2546 }
2547 
2548 //
2549 // Notify all classes this nmethod is dependent on that it is no
2550 // longer dependent.
2551 
2552 void nmethod::flush_dependencies() {
2553   if (!has_flushed_dependencies()) {
2554     set_has_flushed_dependencies(true);
2555     for (Dependencies::DepStream deps(this); deps.next(); ) {
2556       if (deps.type() == Dependencies::call_site_target_value) {
2557         // CallSite dependencies are managed on per-CallSite instance basis.
2558         oop call_site = deps.argument_oop(0);
2559         MethodHandles::clean_dependency_context(call_site);
2560       } else {
2561         InstanceKlass* ik = deps.context_type();
2562         if (ik == nullptr) {
2563           continue;  // ignore things like evol_method
2564         }
2565         // During GC liveness of dependee determines class that needs to be updated.
2566         // The GC may clean dependency contexts concurrently and in parallel.
2567         ik->clean_dependency_context();
2568       }
2569     }
2570   }
2571 }
2572 
2573 void nmethod::post_compiled_method(CompileTask* task) {
2574   task->mark_success();
2575   task->set_nm_content_size(content_size());
2576   task->set_nm_insts_size(insts_size());
2577   task->set_nm_total_size(total_size());
2578 
2579   // JVMTI -- compiled method notification (must be done outside lock)
2580   post_compiled_method_load_event();
2581 
2582   if (CompilationLog::log() != nullptr) {
2583     CompilationLog::log()->log_nmethod(JavaThread::current(), this);
2584   }
2585 
2586   const DirectiveSet* directive = task->directive();
2587   maybe_print_nmethod(directive);
2588 }
2589 
2590 #if INCLUDE_CDS
2591 static GrowableArrayCHeap<nmethod*, mtClassShared>* _delayed_compiled_method_load_events = nullptr;
2592 
2593 void nmethod::add_delayed_compiled_method_load_event(nmethod* nm) {
2594   precond(CDSConfig::is_using_aot_linked_classes());
2595   precond(!ServiceThread::has_started());
2596 
2597   // We are still in single threaded stage of VM bootstrap. No need to lock.
2598   if (_delayed_compiled_method_load_events == nullptr) {
2599     _delayed_compiled_method_load_events = new GrowableArrayCHeap<nmethod*, mtClassShared>();
2600   }
2601   _delayed_compiled_method_load_events->append(nm);
2602 }
2603 
2604 void nmethod::post_delayed_compiled_method_load_events() {
2605   precond(ServiceThread::has_started());
2606   if (_delayed_compiled_method_load_events != nullptr) {
2607     for (int i = 0; i < _delayed_compiled_method_load_events->length(); i++) {
2608       nmethod* nm = _delayed_compiled_method_load_events->at(i);
2609       nm->post_compiled_method_load_event();
2610     }
2611     delete _delayed_compiled_method_load_events;
2612     _delayed_compiled_method_load_events = nullptr;
2613   }
2614 }
2615 #endif
2616 
2617 // ------------------------------------------------------------------
2618 // post_compiled_method_load_event
2619 // new method for install_code() path
2620 // Transfer information from compilation to jvmti
2621 void nmethod::post_compiled_method_load_event(JvmtiThreadState* state) {
2622 #if INCLUDE_CDS
2623   if (!ServiceThread::has_started()) {
2624     // With AOT-linked classes, we could compile wrappers for native methods before the
2625     // ServiceThread has been started, so we must delay the events to be posted later.
2626     assert(state == nullptr, "must be");
2627     add_delayed_compiled_method_load_event(this);
2628     return;
2629   }
2630 #endif
2631 
2632   // This is a bad time for a safepoint.  We don't want
2633   // this nmethod to get unloaded while we're queueing the event.
2634   NoSafepointVerifier nsv;
2635 
2636   Method* m = method();
2637   HOTSPOT_COMPILED_METHOD_LOAD(
2638       (char *) m->klass_name()->bytes(),
2639       m->klass_name()->utf8_length(),
2640       (char *) m->name()->bytes(),
2641       m->name()->utf8_length(),
2642       (char *) m->signature()->bytes(),
2643       m->signature()->utf8_length(),
2644       insts_begin(), insts_size());
2645 
2646 
2647   if (JvmtiExport::should_post_compiled_method_load()) {
2648     // Only post unload events if load events are found.
2649     set_load_reported();
2650     // If a JavaThread hasn't been passed in, let the Service thread
2651     // (which is a real Java thread) post the event
2652     JvmtiDeferredEvent event = JvmtiDeferredEvent::compiled_method_load_event(this);
2653     if (state == nullptr) {
2654       // Execute any barrier code for this nmethod as if it's called, since
2655       // keeping it alive looks like stack walking.
2656       run_nmethod_entry_barrier();
2657       ServiceThread::enqueue_deferred_event(&event);
2658     } else {
2659       // This enters the nmethod barrier outside in the caller.
2660       state->enqueue_event(&event);
2661     }
2662   }
2663 }
2664 
2665 void nmethod::post_compiled_method_unload() {
2666   assert(_method != nullptr, "just checking");
2667   DTRACE_METHOD_UNLOAD_PROBE(method());
2668 
2669   // If a JVMTI agent has enabled the CompiledMethodUnload event then
2670   // post the event. The Method* will not be valid when this is freed.
2671 
2672   // Don't bother posting the unload if the load event wasn't posted.
2673   if (load_reported() && JvmtiExport::should_post_compiled_method_unload()) {
2674     JvmtiDeferredEvent event =
2675       JvmtiDeferredEvent::compiled_method_unload_event(
2676           method()->jmethod_id(), insts_begin());
2677     ServiceThread::enqueue_deferred_event(&event);
2678   }
2679 }
2680 
2681 // Iterate over metadata calling this function.   Used by RedefineClasses
2682 void nmethod::metadata_do(MetadataClosure* f) {
2683   {
2684     // Visit all immediate references that are embedded in the instruction stream.
2685     RelocIterator iter(this, oops_reloc_begin());
2686     while (iter.next()) {
2687       if (iter.type() == relocInfo::metadata_type) {
2688         metadata_Relocation* r = iter.metadata_reloc();
2689         // In this metadata, we must only follow those metadatas directly embedded in
2690         // the code.  Other metadatas (oop_index>0) are seen as part of
2691         // the metadata section below.
2692         assert(1 == (r->metadata_is_immediate()) +
2693                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
2694                "metadata must be found in exactly one place");
2695         if (r->metadata_is_immediate() && r->metadata_value() != nullptr) {
2696           Metadata* md = r->metadata_value();
2697           if (md != _method) f->do_metadata(md);
2698         }
2699       } else if (iter.type() == relocInfo::virtual_call_type) {
2700         // Check compiledIC holders associated with this nmethod
2701         ResourceMark rm;
2702         CompiledIC *ic = CompiledIC_at(&iter);
2703         ic->metadata_do(f);
2704       }
2705     }
2706   }
2707 
2708   // Visit the metadata section
2709   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
2710     if (*p == Universe::non_oop_word() || *p == nullptr)  continue;  // skip non-oops
2711     Metadata* md = *p;
2712     f->do_metadata(md);
2713   }
2714 
2715   // Visit metadata not embedded in the other places.
2716   if (_method != nullptr) f->do_metadata(_method);
2717 }
2718 
2719 // Heuristic for nuking nmethods even though their oops are live.
2720 // Main purpose is to reduce code cache pressure and get rid of
2721 // nmethods that don't seem to be all that relevant any longer.
2722 bool nmethod::is_cold() {
2723   if (!MethodFlushing || is_not_installed()) {
2724     // No heuristic unloading at all
2725     return false;
2726   }
2727 
2728   if (!is_maybe_on_stack() && is_not_entrant()) {
2729     // Not entrant nmethods that are not on any stack can just
2730     // be removed
2731     return true;
2732   }
2733 
2734   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2735   if (bs_nm == nullptr || !bs_nm->supports_entry_barrier(this)) {
2736     // On platforms that don't support nmethod entry barriers, we can't
2737     // trust the temporal aspect of the gc epochs. So we can't detect
2738     // cold nmethods on such platforms.
2739     return false;
2740   }
2741 
2742   if (!UseCodeCacheFlushing) {
2743     // Bail out if we don't heuristically remove nmethods
2744     return false;
2745   }
2746 
2747   // Other code can be phased out more gradually after N GCs
2748   return CodeCache::previous_completed_gc_marking_cycle() > _gc_epoch + 2 * CodeCache::cold_gc_count();
2749 }
2750 
2751 // The _is_unloading_state encodes a tuple comprising the unloading cycle
2752 // and the result of IsUnloadingBehaviour::is_unloading() for that cycle.
2753 // This is the bit layout of the _is_unloading_state byte: 00000CCU
2754 // CC refers to the cycle, which has 2 bits, and U refers to the result of
2755 // IsUnloadingBehaviour::is_unloading() for that unloading cycle.
2756 
2757 class IsUnloadingState: public AllStatic {
2758   static const uint8_t _is_unloading_mask = 1;
2759   static const uint8_t _is_unloading_shift = 0;
2760   static const uint8_t _unloading_cycle_mask = 6;
2761   static const uint8_t _unloading_cycle_shift = 1;
2762 
2763   static uint8_t set_is_unloading(uint8_t state, bool value) {
2764     state &= (uint8_t)~_is_unloading_mask;
2765     if (value) {
2766       state |= 1 << _is_unloading_shift;
2767     }
2768     assert(is_unloading(state) == value, "unexpected unloading cycle overflow");
2769     return state;
2770   }
2771 
2772   static uint8_t set_unloading_cycle(uint8_t state, uint8_t value) {
2773     state &= (uint8_t)~_unloading_cycle_mask;
2774     state |= (uint8_t)(value << _unloading_cycle_shift);
2775     assert(unloading_cycle(state) == value, "unexpected unloading cycle overflow");
2776     return state;
2777   }
2778 
2779 public:
2780   static bool is_unloading(uint8_t state) { return (state & _is_unloading_mask) >> _is_unloading_shift == 1; }
2781   static uint8_t unloading_cycle(uint8_t state) { return (state & _unloading_cycle_mask) >> _unloading_cycle_shift; }
2782 
2783   static uint8_t create(bool is_unloading, uint8_t unloading_cycle) {
2784     uint8_t state = 0;
2785     state = set_is_unloading(state, is_unloading);
2786     state = set_unloading_cycle(state, unloading_cycle);
2787     return state;
2788   }
2789 };
2790 
2791 bool nmethod::is_unloading() {
2792   uint8_t state = AtomicAccess::load(&_is_unloading_state);
2793   bool state_is_unloading = IsUnloadingState::is_unloading(state);
2794   if (state_is_unloading) {
2795     return true;
2796   }
2797   uint8_t state_unloading_cycle = IsUnloadingState::unloading_cycle(state);
2798   uint8_t current_cycle = CodeCache::unloading_cycle();
2799   if (state_unloading_cycle == current_cycle) {
2800     return false;
2801   }
2802 
2803   // The IsUnloadingBehaviour is responsible for calculating if the nmethod
2804   // should be unloaded. This can be either because there is a dead oop,
2805   // or because is_cold() heuristically determines it is time to unload.
2806   state_unloading_cycle = current_cycle;
2807   state_is_unloading = IsUnloadingBehaviour::is_unloading(this);
2808   uint8_t new_state = IsUnloadingState::create(state_is_unloading, state_unloading_cycle);
2809 
2810   MACOS_AARCH64_ONLY(os::thread_wx_enable_write());
2811 
2812   // Note that if an nmethod has dead oops, everyone will agree that the
2813   // nmethod is_unloading. However, the is_cold heuristics can yield
2814   // different outcomes, so we guard the computed result with a CAS
2815   // to ensure all threads have a shared view of whether an nmethod
2816   // is_unloading or not.
2817   uint8_t found_state = AtomicAccess::cmpxchg(&_is_unloading_state, state, new_state, memory_order_relaxed);
2818 
2819   if (found_state == state) {
2820     // First to change state, we win
2821     return state_is_unloading;
2822   } else {
2823     // State already set, so use it
2824     return IsUnloadingState::is_unloading(found_state);
2825   }
2826 }
2827 
2828 void nmethod::clear_unloading_state() {
2829   uint8_t state = IsUnloadingState::create(false, CodeCache::unloading_cycle());
2830   AtomicAccess::store(&_is_unloading_state, state);
2831 }
2832 
2833 
2834 // This is called at the end of the strong tracing/marking phase of a
2835 // GC to unload an nmethod if it contains otherwise unreachable
2836 // oops or is heuristically found to be not important.
2837 void nmethod::do_unloading(bool unloading_occurred) {
2838   // Make sure the oop's ready to receive visitors
2839   if (is_unloading()) {
2840     unlink();
2841   } else {
2842     unload_nmethod_caches(unloading_occurred);
2843     BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2844     if (bs_nm != nullptr) {
2845       bs_nm->disarm(this);
2846     }
2847   }
2848 }
2849 
2850 void nmethod::oops_do(OopClosure* f) {
2851   // Prevent extra code cache walk for platforms that don't have immediate oops.
2852   if (relocInfo::mustIterateImmediateOopsInCode()) {
2853     RelocIterator iter(this, oops_reloc_begin());
2854 
2855     while (iter.next()) {
2856       if (iter.type() == relocInfo::oop_type ) {
2857         oop_Relocation* r = iter.oop_reloc();
2858         // In this loop, we must only follow those oops directly embedded in
2859         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
2860         assert(1 == (r->oop_is_immediate()) +
2861                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
2862                "oop must be found in exactly one place");
2863         if (r->oop_is_immediate() && r->oop_value() != nullptr) {
2864           f->do_oop(r->oop_addr());
2865         }
2866       }
2867     }
2868   }
2869 
2870   // Scopes
2871   // This includes oop constants not inlined in the code stream.
2872   for (oop* p = oops_begin(); p < oops_end(); p++) {
2873     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
2874     f->do_oop(p);
2875   }
2876 }
2877 
2878 void nmethod::follow_nmethod(OopIterateClosure* cl) {
2879   // Process oops in the nmethod
2880   oops_do(cl);
2881 
2882   // CodeCache unloading support
2883   mark_as_maybe_on_stack();
2884 
2885   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2886   bs_nm->disarm(this);
2887 
2888   // There's an assumption made that this function is not used by GCs that
2889   // relocate objects, and therefore we don't call fix_oop_relocations.
2890 }
2891 
2892 nmethod* volatile nmethod::_oops_do_mark_nmethods;
2893 
2894 void nmethod::oops_do_log_change(const char* state) {
2895   LogTarget(Trace, gc, nmethod) lt;
2896   if (lt.is_enabled()) {
2897     LogStream ls(lt);
2898     CompileTask::print(&ls, this, state, true /* short_form */);
2899   }
2900 }
2901 
2902 bool nmethod::oops_do_try_claim() {
2903   if (oops_do_try_claim_weak_request()) {
2904     nmethod* result = oops_do_try_add_to_list_as_weak_done();
2905     assert(result == nullptr, "adding to global list as weak done must always succeed.");
2906     return true;
2907   }
2908   return false;
2909 }
2910 
2911 bool nmethod::oops_do_try_claim_weak_request() {
2912   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2913 
2914   if ((_oops_do_mark_link == nullptr) &&
2915       (AtomicAccess::replace_if_null(&_oops_do_mark_link, mark_link(this, claim_weak_request_tag)))) {
2916     oops_do_log_change("oops_do, mark weak request");
2917     return true;
2918   }
2919   return false;
2920 }
2921 
2922 void nmethod::oops_do_set_strong_done(nmethod* old_head) {
2923   _oops_do_mark_link = mark_link(old_head, claim_strong_done_tag);
2924 }
2925 
2926 nmethod::oops_do_mark_link* nmethod::oops_do_try_claim_strong_done() {
2927   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2928 
2929   oops_do_mark_link* old_next = AtomicAccess::cmpxchg(&_oops_do_mark_link, mark_link(nullptr, claim_weak_request_tag), mark_link(this, claim_strong_done_tag));
2930   if (old_next == nullptr) {
2931     oops_do_log_change("oops_do, mark strong done");
2932   }
2933   return old_next;
2934 }
2935 
2936 nmethod::oops_do_mark_link* nmethod::oops_do_try_add_strong_request(nmethod::oops_do_mark_link* next) {
2937   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2938   assert(next == mark_link(this, claim_weak_request_tag), "Should be claimed as weak");
2939 
2940   oops_do_mark_link* old_next = AtomicAccess::cmpxchg(&_oops_do_mark_link, next, mark_link(this, claim_strong_request_tag));
2941   if (old_next == next) {
2942     oops_do_log_change("oops_do, mark strong request");
2943   }
2944   return old_next;
2945 }
2946 
2947 bool nmethod::oops_do_try_claim_weak_done_as_strong_done(nmethod::oops_do_mark_link* next) {
2948   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2949   assert(extract_state(next) == claim_weak_done_tag, "Should be claimed as weak done");
2950 
2951   oops_do_mark_link* old_next = AtomicAccess::cmpxchg(&_oops_do_mark_link, next, mark_link(extract_nmethod(next), claim_strong_done_tag));
2952   if (old_next == next) {
2953     oops_do_log_change("oops_do, mark weak done -> mark strong done");
2954     return true;
2955   }
2956   return false;
2957 }
2958 
2959 nmethod* nmethod::oops_do_try_add_to_list_as_weak_done() {
2960   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2961 
2962   assert(extract_state(_oops_do_mark_link) == claim_weak_request_tag ||
2963          extract_state(_oops_do_mark_link) == claim_strong_request_tag,
2964          "must be but is nmethod " PTR_FORMAT " %u", p2i(extract_nmethod(_oops_do_mark_link)), extract_state(_oops_do_mark_link));
2965 
2966   nmethod* old_head = AtomicAccess::xchg(&_oops_do_mark_nmethods, this);
2967   // Self-loop if needed.
2968   if (old_head == nullptr) {
2969     old_head = this;
2970   }
2971   // Try to install end of list and weak done tag.
2972   if (AtomicAccess::cmpxchg(&_oops_do_mark_link, mark_link(this, claim_weak_request_tag), mark_link(old_head, claim_weak_done_tag)) == mark_link(this, claim_weak_request_tag)) {
2973     oops_do_log_change("oops_do, mark weak done");
2974     return nullptr;
2975   } else {
2976     return old_head;
2977   }
2978 }
2979 
2980 void nmethod::oops_do_add_to_list_as_strong_done() {
2981   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2982 
2983   nmethod* old_head = AtomicAccess::xchg(&_oops_do_mark_nmethods, this);
2984   // Self-loop if needed.
2985   if (old_head == nullptr) {
2986     old_head = this;
2987   }
2988   assert(_oops_do_mark_link == mark_link(this, claim_strong_done_tag), "must be but is nmethod " PTR_FORMAT " state %u",
2989          p2i(extract_nmethod(_oops_do_mark_link)), extract_state(_oops_do_mark_link));
2990 
2991   oops_do_set_strong_done(old_head);
2992 }
2993 
2994 void nmethod::oops_do_process_weak(OopsDoProcessor* p) {
2995   if (!oops_do_try_claim_weak_request()) {
2996     // Failed to claim for weak processing.
2997     oops_do_log_change("oops_do, mark weak request fail");
2998     return;
2999   }
3000 
3001   p->do_regular_processing(this);
3002 
3003   nmethod* old_head = oops_do_try_add_to_list_as_weak_done();
3004   if (old_head == nullptr) {
3005     return;
3006   }
3007   oops_do_log_change("oops_do, mark weak done fail");
3008   // Adding to global list failed, another thread added a strong request.
3009   assert(extract_state(_oops_do_mark_link) == claim_strong_request_tag,
3010          "must be but is %u", extract_state(_oops_do_mark_link));
3011 
3012   oops_do_log_change("oops_do, mark weak request -> mark strong done");
3013 
3014   oops_do_set_strong_done(old_head);
3015   // Do missing strong processing.
3016   p->do_remaining_strong_processing(this);
3017 }
3018 
3019 void nmethod::oops_do_process_strong(OopsDoProcessor* p) {
3020   oops_do_mark_link* next_raw = oops_do_try_claim_strong_done();
3021   if (next_raw == nullptr) {
3022     p->do_regular_processing(this);
3023     oops_do_add_to_list_as_strong_done();
3024     return;
3025   }
3026   // Claim failed. Figure out why and handle it.
3027   if (oops_do_has_weak_request(next_raw)) {
3028     oops_do_mark_link* old = next_raw;
3029     // Claim failed because being weak processed (state == "weak request").
3030     // Try to request deferred strong processing.
3031     next_raw = oops_do_try_add_strong_request(old);
3032     if (next_raw == old) {
3033       // Successfully requested deferred strong processing.
3034       return;
3035     }
3036     // Failed because of a concurrent transition. No longer in "weak request" state.
3037   }
3038   if (oops_do_has_any_strong_state(next_raw)) {
3039     // Already claimed for strong processing or requested for such.
3040     return;
3041   }
3042   if (oops_do_try_claim_weak_done_as_strong_done(next_raw)) {
3043     // Successfully claimed "weak done" as "strong done". Do the missing marking.
3044     p->do_remaining_strong_processing(this);
3045     return;
3046   }
3047   // Claim failed, some other thread got it.
3048 }
3049 
3050 void nmethod::oops_do_marking_prologue() {
3051   assert_at_safepoint();
3052 
3053   log_trace(gc, nmethod)("oops_do_marking_prologue");
3054   assert(_oops_do_mark_nmethods == nullptr, "must be empty");
3055 }
3056 
3057 void nmethod::oops_do_marking_epilogue() {
3058   assert_at_safepoint();
3059 
3060   nmethod* next = _oops_do_mark_nmethods;
3061   _oops_do_mark_nmethods = nullptr;
3062   if (next != nullptr) {
3063     nmethod* cur;
3064     do {
3065       cur = next;
3066       next = extract_nmethod(cur->_oops_do_mark_link);
3067       cur->_oops_do_mark_link = nullptr;
3068       DEBUG_ONLY(cur->verify_oop_relocations());
3069 
3070       LogTarget(Trace, gc, nmethod) lt;
3071       if (lt.is_enabled()) {
3072         LogStream ls(lt);
3073         CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
3074       }
3075       // End if self-loop has been detected.
3076     } while (cur != next);
3077   }
3078   log_trace(gc, nmethod)("oops_do_marking_epilogue");
3079 }
3080 
3081 inline bool includes(void* p, void* from, void* to) {
3082   return from <= p && p < to;
3083 }
3084 
3085 
3086 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
3087   assert(count >= 2, "must be sentinel values, at least");
3088 
3089 #ifdef ASSERT
3090   // must be sorted and unique; we do a binary search in find_pc_desc()
3091   int prev_offset = pcs[0].pc_offset();
3092   assert(prev_offset == PcDesc::lower_offset_limit,
3093          "must start with a sentinel");
3094   for (int i = 1; i < count; i++) {
3095     int this_offset = pcs[i].pc_offset();
3096     assert(this_offset > prev_offset, "offsets must be sorted");
3097     prev_offset = this_offset;
3098   }
3099   assert(prev_offset == PcDesc::upper_offset_limit,
3100          "must end with a sentinel");
3101 #endif //ASSERT
3102 
3103   int size = count * sizeof(PcDesc);
3104   assert(scopes_pcs_size() >= size, "oob");
3105   memcpy(scopes_pcs_begin(), pcs, size);
3106 
3107   // Adjust the final sentinel downward.
3108   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
3109   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
3110   last_pc->set_pc_offset(content_size() + 1);
3111   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
3112     // Fill any rounding gaps with copies of the last record.
3113     last_pc[1] = last_pc[0];
3114   }
3115   // The following assert could fail if sizeof(PcDesc) is not
3116   // an integral multiple of oopSize (the rounding term).
3117   // If it fails, change the logic to always allocate a multiple
3118   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
3119   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
3120 }
3121 
3122 void nmethod::copy_scopes_data(u_char* buffer, int size) {
3123   assert(scopes_data_size() >= size, "oob");
3124   memcpy(scopes_data_begin(), buffer, size);
3125 }
3126 
3127 #ifdef ASSERT
3128 static PcDesc* linear_search(int pc_offset, bool approximate, PcDesc* lower, PcDesc* upper) {
3129   PcDesc* res = nullptr;
3130   assert(lower != nullptr && lower->pc_offset() == PcDesc::lower_offset_limit,
3131          "must start with a sentinel");
3132   // lower + 1 to exclude initial sentinel
3133   for (PcDesc* p = lower + 1; p < upper; p++) {
3134     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
3135     if (match_desc(p, pc_offset, approximate)) {
3136       if (res == nullptr) {
3137         res = p;
3138       } else {
3139         res = (PcDesc*) badAddress;
3140       }
3141     }
3142   }
3143   return res;
3144 }
3145 #endif
3146 
3147 
3148 #ifndef PRODUCT
3149 // Version of method to collect statistic
3150 PcDesc* PcDescContainer::find_pc_desc(address pc, bool approximate, address code_begin,
3151                                       PcDesc* lower, PcDesc* upper) {
3152   ++pc_nmethod_stats.pc_desc_queries;
3153   if (approximate) ++pc_nmethod_stats.pc_desc_approx;
3154 
3155   PcDesc* desc = _pc_desc_cache.last_pc_desc();
3156   assert(desc != nullptr, "PcDesc cache should be initialized already");
3157   if (desc->pc_offset() == (pc - code_begin)) {
3158     // Cached value matched
3159     ++pc_nmethod_stats.pc_desc_tests;
3160     ++pc_nmethod_stats.pc_desc_repeats;
3161     return desc;
3162   }
3163   return find_pc_desc_internal(pc, approximate, code_begin, lower, upper);
3164 }
3165 #endif
3166 
3167 // Finds a PcDesc with real-pc equal to "pc"
3168 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, address code_begin,
3169                                                PcDesc* lower_incl, PcDesc* upper_incl) {
3170   if ((pc < code_begin) ||
3171       (pc - code_begin) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
3172     return nullptr;  // PC is wildly out of range
3173   }
3174   int pc_offset = (int) (pc - code_begin);
3175 
3176   // Check the PcDesc cache if it contains the desired PcDesc
3177   // (This as an almost 100% hit rate.)
3178   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
3179   if (res != nullptr) {
3180     assert(res == linear_search(pc_offset, approximate, lower_incl, upper_incl), "cache ok");
3181     return res;
3182   }
3183 
3184   // Fallback algorithm: quasi-linear search for the PcDesc
3185   // Find the last pc_offset less than the given offset.
3186   // The successor must be the required match, if there is a match at all.
3187   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
3188   PcDesc* lower = lower_incl;     // this is initial sentinel
3189   PcDesc* upper = upper_incl - 1; // exclude final sentinel
3190   if (lower >= upper)  return nullptr;  // no PcDescs at all
3191 
3192 #define assert_LU_OK \
3193   /* invariant on lower..upper during the following search: */ \
3194   assert(lower->pc_offset() <  pc_offset, "sanity"); \
3195   assert(upper->pc_offset() >= pc_offset, "sanity")
3196   assert_LU_OK;
3197 
3198   // Use the last successful return as a split point.
3199   PcDesc* mid = _pc_desc_cache.last_pc_desc();
3200   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
3201   if (mid->pc_offset() < pc_offset) {
3202     lower = mid;
3203   } else {
3204     upper = mid;
3205   }
3206 
3207   // Take giant steps at first (4096, then 256, then 16, then 1)
3208   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ DEBUG_ONLY(-1);
3209   const int RADIX = (1 << LOG2_RADIX);
3210   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
3211     while ((mid = lower + step) < upper) {
3212       assert_LU_OK;
3213       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
3214       if (mid->pc_offset() < pc_offset) {
3215         lower = mid;
3216       } else {
3217         upper = mid;
3218         break;
3219       }
3220     }
3221     assert_LU_OK;
3222   }
3223 
3224   // Sneak up on the value with a linear search of length ~16.
3225   while (true) {
3226     assert_LU_OK;
3227     mid = lower + 1;
3228     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
3229     if (mid->pc_offset() < pc_offset) {
3230       lower = mid;
3231     } else {
3232       upper = mid;
3233       break;
3234     }
3235   }
3236 #undef assert_LU_OK
3237 
3238   if (match_desc(upper, pc_offset, approximate)) {
3239     assert(upper == linear_search(pc_offset, approximate, lower_incl, upper_incl), "search mismatch");
3240     if (!Thread::current_in_asgct()) {
3241       // we don't want to modify the cache if we're in ASGCT
3242       // which is typically called in a signal handler
3243       _pc_desc_cache.add_pc_desc(upper);
3244     }
3245     return upper;
3246   } else {
3247     assert(nullptr == linear_search(pc_offset, approximate, lower_incl, upper_incl), "search mismatch");
3248     return nullptr;
3249   }
3250 }
3251 
3252 bool nmethod::check_dependency_on(DepChange& changes) {
3253   // What has happened:
3254   // 1) a new class dependee has been added
3255   // 2) dependee and all its super classes have been marked
3256   bool found_check = false;  // set true if we are upset
3257   for (Dependencies::DepStream deps(this); deps.next(); ) {
3258     // Evaluate only relevant dependencies.
3259     if (deps.spot_check_dependency_at(changes) != nullptr) {
3260       found_check = true;
3261       NOT_DEBUG(break);
3262     }
3263   }
3264   return found_check;
3265 }
3266 
3267 // Called from mark_for_deoptimization, when dependee is invalidated.
3268 bool nmethod::is_dependent_on_method(Method* dependee) {
3269   for (Dependencies::DepStream deps(this); deps.next(); ) {
3270     if (Dependencies::has_method_dep(deps.type())) {
3271       Method* method = deps.method_argument(0);
3272       if (method == dependee) return true;
3273     }
3274   }
3275   return false;
3276 }
3277 
3278 void nmethod_init() {
3279   // make sure you didn't forget to adjust the filler fields
3280   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
3281 }
3282 
3283 // -----------------------------------------------------------------------------
3284 // Verification
3285 
3286 class VerifyOopsClosure: public OopClosure {
3287   nmethod* _nm;
3288   bool     _ok;
3289 public:
3290   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
3291   bool ok() { return _ok; }
3292   virtual void do_oop(oop* p) {
3293     if (oopDesc::is_oop_or_null(*p)) return;
3294     // Print diagnostic information before calling print_nmethod().
3295     // Assertions therein might prevent call from returning.
3296     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
3297                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
3298     if (_ok) {
3299       _nm->print_nmethod(true);
3300       _ok = false;
3301     }
3302   }
3303   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
3304 };
3305 
3306 class VerifyMetadataClosure: public MetadataClosure {
3307  public:
3308   void do_metadata(Metadata* md) {
3309     if (md->is_method()) {
3310       Method* method = (Method*)md;
3311       assert(!method->is_old(), "Should not be installing old methods");
3312     }
3313   }
3314 };
3315 
3316 
3317 void nmethod::verify() {
3318   if (is_not_entrant())
3319     return;
3320 
3321   // assert(oopDesc::is_oop(method()), "must be valid");
3322 
3323   ResourceMark rm;
3324 
3325   if (!CodeCache::contains(this)) {
3326     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
3327   }
3328 
3329   if(is_native_method() )
3330     return;
3331 
3332   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
3333   if (nm != this) {
3334     fatal("find_nmethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
3335   }
3336 
3337   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3338     if (! p->verify(this)) {
3339       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
3340     }
3341   }
3342 
3343 #ifdef ASSERT
3344 #if INCLUDE_JVMCI
3345   {
3346     // Verify that implicit exceptions that deoptimize have a PcDesc and OopMap
3347     ImmutableOopMapSet* oms = oop_maps();
3348     ImplicitExceptionTable implicit_table(this);
3349     for (uint i = 0; i < implicit_table.len(); i++) {
3350       int exec_offset = (int) implicit_table.get_exec_offset(i);
3351       if (implicit_table.get_exec_offset(i) == implicit_table.get_cont_offset(i)) {
3352         assert(pc_desc_at(code_begin() + exec_offset) != nullptr, "missing PcDesc");
3353         bool found = false;
3354         for (int i = 0, imax = oms->count(); i < imax; i++) {
3355           if (oms->pair_at(i)->pc_offset() == exec_offset) {
3356             found = true;
3357             break;
3358           }
3359         }
3360         assert(found, "missing oopmap");
3361       }
3362     }
3363   }
3364 #endif
3365 #endif
3366 
3367   VerifyOopsClosure voc(this);
3368   oops_do(&voc);
3369   assert(voc.ok(), "embedded oops must be OK");
3370   Universe::heap()->verify_nmethod(this);
3371 
3372   assert(_oops_do_mark_link == nullptr, "_oops_do_mark_link for %s should be nullptr but is " PTR_FORMAT,
3373          nm->method()->external_name(), p2i(_oops_do_mark_link));
3374   verify_scopes();
3375 
3376   CompiledICLocker nm_verify(this);
3377   VerifyMetadataClosure vmc;
3378   metadata_do(&vmc);
3379 }
3380 
3381 
3382 void nmethod::verify_interrupt_point(address call_site, bool is_inline_cache) {
3383 
3384   // Verify IC only when nmethod installation is finished.
3385   if (!is_not_installed()) {
3386     if (CompiledICLocker::is_safe(this)) {
3387       if (is_inline_cache) {
3388         CompiledIC_at(this, call_site);
3389       } else {
3390         CompiledDirectCall::at(call_site);
3391       }
3392     } else {
3393       CompiledICLocker ml_verify(this);
3394       if (is_inline_cache) {
3395         CompiledIC_at(this, call_site);
3396       } else {
3397         CompiledDirectCall::at(call_site);
3398       }
3399     }
3400   }
3401 
3402   HandleMark hm(Thread::current());
3403 
3404   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
3405   assert(pd != nullptr, "PcDesc must exist");
3406   for (ScopeDesc* sd = new ScopeDesc(this, pd);
3407        !sd->is_top(); sd = sd->sender()) {
3408     sd->verify();
3409   }
3410 }
3411 
3412 void nmethod::verify_scopes() {
3413   if( !method() ) return;       // Runtime stubs have no scope
3414   if (method()->is_native()) return; // Ignore stub methods.
3415   // iterate through all interrupt point
3416   // and verify the debug information is valid.
3417   RelocIterator iter(this);
3418   while (iter.next()) {
3419     address stub = nullptr;
3420     switch (iter.type()) {
3421       case relocInfo::virtual_call_type:
3422         verify_interrupt_point(iter.addr(), true /* is_inline_cache */);
3423         break;
3424       case relocInfo::opt_virtual_call_type:
3425         stub = iter.opt_virtual_call_reloc()->static_stub();
3426         verify_interrupt_point(iter.addr(), false /* is_inline_cache */);
3427         break;
3428       case relocInfo::static_call_type:
3429         stub = iter.static_call_reloc()->static_stub();
3430         verify_interrupt_point(iter.addr(), false /* is_inline_cache */);
3431         break;
3432       case relocInfo::runtime_call_type:
3433       case relocInfo::runtime_call_w_cp_type: {
3434         address destination = iter.reloc()->value();
3435         // Right now there is no way to find out which entries support
3436         // an interrupt point.  It would be nice if we had this
3437         // information in a table.
3438         break;
3439       }
3440       default:
3441         break;
3442     }
3443     assert(stub == nullptr || stub_contains(stub), "static call stub outside stub section");
3444   }
3445 }
3446 
3447 
3448 // -----------------------------------------------------------------------------
3449 // Printing operations
3450 
3451 void nmethod::print_on_impl(outputStream* st) const {
3452   ResourceMark rm;
3453 
3454   st->print("Compiled method ");
3455 
3456   if (is_compiled_by_c1()) {
3457     st->print("(c1) ");
3458   } else if (is_compiled_by_c2()) {
3459     st->print("(c2) ");
3460   } else if (is_compiled_by_jvmci()) {
3461     st->print("(JVMCI) ");
3462   } else {
3463     st->print("(n/a) ");
3464   }
3465 
3466   print_on_with_msg(st, nullptr);
3467 
3468   if (WizardMode) {
3469     st->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
3470     st->print(" for method " INTPTR_FORMAT , p2i(method()));
3471     st->print(" { ");
3472     st->print_cr("%s ", state());
3473     st->print_cr("}:");
3474   }
3475   if (size              () > 0) st->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3476                                              p2i(this),
3477                                              p2i(this) + size(),
3478                                              size());
3479   if (consts_size       () > 0) st->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3480                                              p2i(consts_begin()),
3481                                              p2i(consts_end()),
3482                                              consts_size());
3483   if (insts_size        () > 0) st->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3484                                              p2i(insts_begin()),
3485                                              p2i(insts_end()),
3486                                              insts_size());
3487   if (stub_size         () > 0) st->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3488                                              p2i(stub_begin()),
3489                                              p2i(stub_end()),
3490                                              stub_size());
3491   if (oops_size         () > 0) st->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3492                                              p2i(oops_begin()),
3493                                              p2i(oops_end()),
3494                                              oops_size());
3495   if (mutable_data_size () > 0) st->print_cr(" mutable data   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3496                                              p2i(mutable_data_begin()),
3497                                              p2i(mutable_data_end()),
3498                                              mutable_data_size());
3499   if (relocation_size   () > 0) st->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3500                                              p2i(relocation_begin()),
3501                                              p2i(relocation_end()),
3502                                              relocation_size());
3503   if (metadata_size     () > 0) st->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3504                                              p2i(metadata_begin()),
3505                                              p2i(metadata_end()),
3506                                              metadata_size());
3507 #if INCLUDE_JVMCI
3508   if (jvmci_data_size   () > 0) st->print_cr(" JVMCI data     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3509                                              p2i(jvmci_data_begin()),
3510                                              p2i(jvmci_data_end()),
3511                                              jvmci_data_size());
3512 #endif
3513   if (immutable_data_size() > 0) st->print_cr(" immutable data [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3514                                              p2i(immutable_data_begin()),
3515                                              p2i(immutable_data_end()),
3516                                              immutable_data_size());
3517   if (dependencies_size () > 0) st->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3518                                              p2i(dependencies_begin()),
3519                                              p2i(dependencies_end()),
3520                                              dependencies_size());
3521   if (nul_chk_table_size() > 0) st->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3522                                              p2i(nul_chk_table_begin()),
3523                                              p2i(nul_chk_table_end()),
3524                                              nul_chk_table_size());
3525   if (handler_table_size() > 0) st->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3526                                              p2i(handler_table_begin()),
3527                                              p2i(handler_table_end()),
3528                                              handler_table_size());
3529   if (scopes_pcs_size   () > 0) st->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3530                                              p2i(scopes_pcs_begin()),
3531                                              p2i(scopes_pcs_end()),
3532                                              scopes_pcs_size());
3533   if (scopes_data_size  () > 0) st->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3534                                              p2i(scopes_data_begin()),
3535                                              p2i(scopes_data_end()),
3536                                              scopes_data_size());
3537 #if INCLUDE_JVMCI
3538   if (speculations_size () > 0) st->print_cr(" speculations   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3539                                              p2i(speculations_begin()),
3540                                              p2i(speculations_end()),
3541                                              speculations_size());
3542 #endif
3543 }
3544 
3545 void nmethod::print_code() {
3546   ResourceMark m;
3547   ttyLocker ttyl;
3548   // Call the specialized decode method of this class.
3549   decode(tty);
3550 }
3551 
3552 #ifndef PRODUCT  // called InstanceKlass methods are available only then. Declared as PRODUCT_RETURN
3553 
3554 void nmethod::print_dependencies_on(outputStream* out) {
3555   ResourceMark rm;
3556   stringStream st;
3557   st.print_cr("Dependencies:");
3558   for (Dependencies::DepStream deps(this); deps.next(); ) {
3559     deps.print_dependency(&st);
3560     InstanceKlass* ctxk = deps.context_type();
3561     if (ctxk != nullptr) {
3562       if (ctxk->is_dependent_nmethod(this)) {
3563         st.print_cr("   [nmethod<=klass]%s", ctxk->external_name());
3564       }
3565     }
3566     deps.log_dependency();  // put it into the xml log also
3567   }
3568   out->print_raw(st.as_string());
3569 }
3570 #endif
3571 
3572 #if defined(SUPPORT_DATA_STRUCTS)
3573 
3574 // Print the oops from the underlying CodeBlob.
3575 void nmethod::print_oops(outputStream* st) {
3576   ResourceMark m;
3577   st->print("Oops:");
3578   if (oops_begin() < oops_end()) {
3579     st->cr();
3580     for (oop* p = oops_begin(); p < oops_end(); p++) {
3581       Disassembler::print_location((unsigned char*)p, (unsigned char*)oops_begin(), (unsigned char*)oops_end(), st, true, false);
3582       st->print(PTR_FORMAT " ", *((uintptr_t*)p));
3583       if (Universe::contains_non_oop_word(p)) {
3584         st->print_cr("NON_OOP");
3585         continue;  // skip non-oops
3586       }
3587       if (*p == nullptr) {
3588         st->print_cr("nullptr-oop");
3589         continue;  // skip non-oops
3590       }
3591       (*p)->print_value_on(st);
3592       st->cr();
3593     }
3594   } else {
3595     st->print_cr(" <list empty>");
3596   }
3597 }
3598 
3599 // Print metadata pool.
3600 void nmethod::print_metadata(outputStream* st) {
3601   ResourceMark m;
3602   st->print("Metadata:");
3603   if (metadata_begin() < metadata_end()) {
3604     st->cr();
3605     for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
3606       Disassembler::print_location((unsigned char*)p, (unsigned char*)metadata_begin(), (unsigned char*)metadata_end(), st, true, false);
3607       st->print(PTR_FORMAT " ", *((uintptr_t*)p));
3608       if (*p && *p != Universe::non_oop_word()) {
3609         (*p)->print_value_on(st);
3610       }
3611       st->cr();
3612     }
3613   } else {
3614     st->print_cr(" <list empty>");
3615   }
3616 }
3617 
3618 #ifndef PRODUCT  // ScopeDesc::print_on() is available only then. Declared as PRODUCT_RETURN
3619 void nmethod::print_scopes_on(outputStream* st) {
3620   // Find the first pc desc for all scopes in the code and print it.
3621   ResourceMark rm;
3622   st->print("scopes:");
3623   if (scopes_pcs_begin() < scopes_pcs_end()) {
3624     st->cr();
3625     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3626       if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
3627         continue;
3628 
3629       ScopeDesc* sd = scope_desc_at(p->real_pc(this));
3630       while (sd != nullptr) {
3631         sd->print_on(st, p);  // print output ends with a newline
3632         sd = sd->sender();
3633       }
3634     }
3635   } else {
3636     st->print_cr(" <list empty>");
3637   }
3638 }
3639 #endif
3640 
3641 #ifndef PRODUCT  // RelocIterator does support printing only then.
3642 void nmethod::print_relocations() {
3643   ResourceMark m;       // in case methods get printed via the debugger
3644   tty->print_cr("relocations:");
3645   RelocIterator iter(this);
3646   iter.print_on(tty);
3647 }
3648 #endif
3649 
3650 void nmethod::print_pcs_on(outputStream* st) {
3651   ResourceMark m;       // in case methods get printed via debugger
3652   st->print("pc-bytecode offsets:");
3653   if (scopes_pcs_begin() < scopes_pcs_end()) {
3654     st->cr();
3655     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3656       p->print_on(st, this);  // print output ends with a newline
3657     }
3658   } else {
3659     st->print_cr(" <list empty>");
3660   }
3661 }
3662 
3663 void nmethod::print_handler_table() {
3664   ExceptionHandlerTable(this).print(code_begin());
3665 }
3666 
3667 void nmethod::print_nul_chk_table() {
3668   ImplicitExceptionTable(this).print(code_begin());
3669 }
3670 
3671 void nmethod::print_recorded_oop(int log_n, int i) {
3672   void* value;
3673 
3674   if (i == 0) {
3675     value = nullptr;
3676   } else {
3677     // Be careful around non-oop words. Don't create an oop
3678     // with that value, or it will assert in verification code.
3679     if (Universe::contains_non_oop_word(oop_addr_at(i))) {
3680       value = Universe::non_oop_word();
3681     } else {
3682       value = oop_at(i);
3683     }
3684   }
3685 
3686   tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(value));
3687 
3688   if (value == Universe::non_oop_word()) {
3689     tty->print("non-oop word");
3690   } else {
3691     if (value == nullptr) {
3692       tty->print("nullptr-oop");
3693     } else {
3694       oop_at(i)->print_value_on(tty);
3695     }
3696   }
3697 
3698   tty->cr();
3699 }
3700 
3701 void nmethod::print_recorded_oops() {
3702   const int n = oops_count();
3703   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
3704   tty->print("Recorded oops:");
3705   if (n > 0) {
3706     tty->cr();
3707     for (int i = 0; i < n; i++) {
3708       print_recorded_oop(log_n, i);
3709     }
3710   } else {
3711     tty->print_cr(" <list empty>");
3712   }
3713 }
3714 
3715 void nmethod::print_recorded_metadata() {
3716   const int n = metadata_count();
3717   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
3718   tty->print("Recorded metadata:");
3719   if (n > 0) {
3720     tty->cr();
3721     for (int i = 0; i < n; i++) {
3722       Metadata* m = metadata_at(i);
3723       tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(m));
3724       if (m == (Metadata*)Universe::non_oop_word()) {
3725         tty->print("non-metadata word");
3726       } else if (m == nullptr) {
3727         tty->print("nullptr-oop");
3728       } else {
3729         Metadata::print_value_on_maybe_null(tty, m);
3730       }
3731       tty->cr();
3732     }
3733   } else {
3734     tty->print_cr(" <list empty>");
3735   }
3736 }
3737 #endif
3738 
3739 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
3740 
3741 void nmethod::print_constant_pool(outputStream* st) {
3742   //-----------------------------------
3743   //---<  Print the constant pool  >---
3744   //-----------------------------------
3745   int consts_size = this->consts_size();
3746   if ( consts_size > 0 ) {
3747     unsigned char* cstart = this->consts_begin();
3748     unsigned char* cp     = cstart;
3749     unsigned char* cend   = cp + consts_size;
3750     unsigned int   bytes_per_line = 4;
3751     unsigned int   CP_alignment   = 8;
3752     unsigned int   n;
3753 
3754     st->cr();
3755 
3756     //---<  print CP header to make clear what's printed  >---
3757     if( ((uintptr_t)cp&(CP_alignment-1)) == 0 ) {
3758       n = bytes_per_line;
3759       st->print_cr("[Constant Pool]");
3760       Disassembler::print_location(cp, cstart, cend, st, true, true);
3761       Disassembler::print_hexdata(cp, n, st, true);
3762       st->cr();
3763     } else {
3764       n = (int)((uintptr_t)cp & (bytes_per_line-1));
3765       st->print_cr("[Constant Pool (unaligned)]");
3766     }
3767 
3768     //---<  print CP contents, bytes_per_line at a time  >---
3769     while (cp < cend) {
3770       Disassembler::print_location(cp, cstart, cend, st, true, false);
3771       Disassembler::print_hexdata(cp, n, st, false);
3772       cp += n;
3773       n   = bytes_per_line;
3774       st->cr();
3775     }
3776 
3777     //---<  Show potential alignment gap between constant pool and code  >---
3778     cend = code_begin();
3779     if( cp < cend ) {
3780       n = 4;
3781       st->print_cr("[Code entry alignment]");
3782       while (cp < cend) {
3783         Disassembler::print_location(cp, cstart, cend, st, false, false);
3784         cp += n;
3785         st->cr();
3786       }
3787     }
3788   } else {
3789     st->print_cr("[Constant Pool (empty)]");
3790   }
3791   st->cr();
3792 }
3793 
3794 #endif
3795 
3796 // Disassemble this nmethod.
3797 // Print additional debug information, if requested. This could be code
3798 // comments, block comments, profiling counters, etc.
3799 // The undisassembled format is useful no disassembler library is available.
3800 // The resulting hex dump (with markers) can be disassembled later, or on
3801 // another system, when/where a disassembler library is available.
3802 void nmethod::decode2(outputStream* ost) const {
3803 
3804   // Called from frame::back_trace_with_decode without ResourceMark.
3805   ResourceMark rm;
3806 
3807   // Make sure we have a valid stream to print on.
3808   outputStream* st = ost ? ost : tty;
3809 
3810 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) && ! defined(SUPPORT_ASSEMBLY)
3811   const bool use_compressed_format    = true;
3812   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
3813                                                                   AbstractDisassembler::show_block_comment());
3814 #else
3815   const bool use_compressed_format    = Disassembler::is_abstract();
3816   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
3817                                                                   AbstractDisassembler::show_block_comment());
3818 #endif
3819 
3820   st->cr();
3821   this->print_on(st);
3822   st->cr();
3823 
3824 #if defined(SUPPORT_ASSEMBLY)
3825   //----------------------------------
3826   //---<  Print real disassembly  >---
3827   //----------------------------------
3828   if (! use_compressed_format) {
3829     st->print_cr("[Disassembly]");
3830     Disassembler::decode(const_cast<nmethod*>(this), st);
3831     st->bol();
3832     st->print_cr("[/Disassembly]");
3833     return;
3834   }
3835 #endif
3836 
3837 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3838 
3839   // Compressed undisassembled disassembly format.
3840   // The following status values are defined/supported:
3841   //   = 0 - currently at bol() position, nothing printed yet on current line.
3842   //   = 1 - currently at position after print_location().
3843   //   > 1 - in the midst of printing instruction stream bytes.
3844   int        compressed_format_idx    = 0;
3845   int        code_comment_column      = 0;
3846   const int  instr_maxlen             = Assembler::instr_maxlen();
3847   const uint tabspacing               = 8;
3848   unsigned char* start = this->code_begin();
3849   unsigned char* p     = this->code_begin();
3850   unsigned char* end   = this->code_end();
3851   unsigned char* pss   = p; // start of a code section (used for offsets)
3852 
3853   if ((start == nullptr) || (end == nullptr)) {
3854     st->print_cr("PrintAssembly not possible due to uninitialized section pointers");
3855     return;
3856   }
3857 #endif
3858 
3859 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3860   //---<  plain abstract disassembly, no comments or anything, just section headers  >---
3861   if (use_compressed_format && ! compressed_with_comments) {
3862     const_cast<nmethod*>(this)->print_constant_pool(st);
3863 
3864     st->bol();
3865     st->cr();
3866     st->print_cr("Loading hsdis library failed, undisassembled code is shown in MachCode section");
3867     //---<  Open the output (Marker for post-mortem disassembler)  >---
3868     st->print_cr("[MachCode]");
3869     const char* header = nullptr;
3870     address p0 = p;
3871     while (p < end) {
3872       address pp = p;
3873       while ((p < end) && (header == nullptr)) {
3874         header = nmethod_section_label(p);
3875         pp  = p;
3876         p  += Assembler::instr_len(p);
3877       }
3878       if (pp > p0) {
3879         AbstractDisassembler::decode_range_abstract(p0, pp, start, end, st, Assembler::instr_maxlen());
3880         p0 = pp;
3881         p  = pp;
3882         header = nullptr;
3883       } else if (header != nullptr) {
3884         st->bol();
3885         st->print_cr("%s", header);
3886         header = nullptr;
3887       }
3888     }
3889     //---<  Close the output (Marker for post-mortem disassembler)  >---
3890     st->bol();
3891     st->print_cr("[/MachCode]");
3892     return;
3893   }
3894 #endif
3895 
3896 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3897   //---<  abstract disassembly with comments and section headers merged in  >---
3898   if (compressed_with_comments) {
3899     const_cast<nmethod*>(this)->print_constant_pool(st);
3900 
3901     st->bol();
3902     st->cr();
3903     st->print_cr("Loading hsdis library failed, undisassembled code is shown in MachCode section");
3904     //---<  Open the output (Marker for post-mortem disassembler)  >---
3905     st->print_cr("[MachCode]");
3906     while ((p < end) && (p != nullptr)) {
3907       const int instruction_size_in_bytes = Assembler::instr_len(p);
3908 
3909       //---<  Block comments for nmethod. Interrupts instruction stream, if any.  >---
3910       // Outputs a bol() before and a cr() after, but only if a comment is printed.
3911       // Prints nmethod_section_label as well.
3912       if (AbstractDisassembler::show_block_comment()) {
3913         print_block_comment(st, p);
3914         if (st->position() == 0) {
3915           compressed_format_idx = 0;
3916         }
3917       }
3918 
3919       //---<  New location information after line break  >---
3920       if (compressed_format_idx == 0) {
3921         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
3922         compressed_format_idx = 1;
3923       }
3924 
3925       //---<  Code comment for current instruction. Address range [p..(p+len))  >---
3926       unsigned char* p_end = p + (ssize_t)instruction_size_in_bytes;
3927       S390_ONLY(if (p_end > end) p_end = end;) // avoid getting past the end
3928 
3929       if (AbstractDisassembler::show_comment() && const_cast<nmethod*>(this)->has_code_comment(p, p_end)) {
3930         //---<  interrupt instruction byte stream for code comment  >---
3931         if (compressed_format_idx > 1) {
3932           st->cr();  // interrupt byte stream
3933           st->cr();  // add an empty line
3934           code_comment_column = Disassembler::print_location(p, pss, end, st, false, false);
3935         }
3936         const_cast<nmethod*>(this)->print_code_comment_on(st, code_comment_column, p, p_end );
3937         st->bol();
3938         compressed_format_idx = 0;
3939       }
3940 
3941       //---<  New location information after line break  >---
3942       if (compressed_format_idx == 0) {
3943         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
3944         compressed_format_idx = 1;
3945       }
3946 
3947       //---<  Nicely align instructions for readability  >---
3948       if (compressed_format_idx > 1) {
3949         Disassembler::print_delimiter(st);
3950       }
3951 
3952       //---<  Now, finally, print the actual instruction bytes  >---
3953       unsigned char* p0 = p;
3954       p = Disassembler::decode_instruction_abstract(p, st, instruction_size_in_bytes, instr_maxlen);
3955       compressed_format_idx += (int)(p - p0);
3956 
3957       if (Disassembler::start_newline(compressed_format_idx-1)) {
3958         st->cr();
3959         compressed_format_idx = 0;
3960       }
3961     }
3962     //---<  Close the output (Marker for post-mortem disassembler)  >---
3963     st->bol();
3964     st->print_cr("[/MachCode]");
3965     return;
3966   }
3967 #endif
3968 }
3969 
3970 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
3971 
3972 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
3973   RelocIterator iter(this, begin, end);
3974   bool have_one = false;
3975   while (iter.next()) {
3976     have_one = true;
3977     switch (iter.type()) {
3978         case relocInfo::none: {
3979           // Skip it and check next
3980           break;
3981         }
3982         case relocInfo::oop_type: {
3983           // Get a non-resizable resource-allocated stringStream.
3984           // Our callees make use of (nested) ResourceMarks.
3985           stringStream st(NEW_RESOURCE_ARRAY(char, 1024), 1024);
3986           oop_Relocation* r = iter.oop_reloc();
3987           oop obj = r->oop_value();
3988           st.print("oop(");
3989           if (obj == nullptr) st.print("nullptr");
3990           else obj->print_value_on(&st);
3991           st.print(")");
3992           return st.as_string();
3993         }
3994         case relocInfo::metadata_type: {
3995           stringStream st;
3996           metadata_Relocation* r = iter.metadata_reloc();
3997           Metadata* obj = r->metadata_value();
3998           st.print("metadata(");
3999           if (obj == nullptr) st.print("nullptr");
4000           else obj->print_value_on(&st);
4001           st.print(")");
4002           return st.as_string();
4003         }
4004         case relocInfo::runtime_call_type:
4005         case relocInfo::runtime_call_w_cp_type: {
4006           stringStream st;
4007           st.print("runtime_call");
4008           CallRelocation* r = (CallRelocation*)iter.reloc();
4009           address dest = r->destination();
4010           if (StubRoutines::contains(dest)) {
4011             StubCodeDesc* desc = StubCodeDesc::desc_for(dest);
4012             if (desc == nullptr) {
4013               desc = StubCodeDesc::desc_for(dest + frame::pc_return_offset);
4014             }
4015             if (desc != nullptr) {
4016               st.print(" Stub::%s", desc->name());
4017               return st.as_string();
4018             }
4019           }
4020           CodeBlob* cb = CodeCache::find_blob(dest);
4021           if (cb != nullptr) {
4022             st.print(" %s", cb->name());
4023           } else {
4024             ResourceMark rm;
4025             const int buflen = 1024;
4026             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
4027             int offset;
4028             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
4029               st.print(" %s", buf);
4030               if (offset != 0) {
4031                 st.print("+%d", offset);
4032               }
4033             }
4034           }
4035           return st.as_string();
4036         }
4037         case relocInfo::virtual_call_type: {
4038           stringStream st;
4039           st.print_raw("virtual_call");
4040           virtual_call_Relocation* r = iter.virtual_call_reloc();
4041           Method* m = r->method_value();
4042           if (m != nullptr) {
4043             assert(m->is_method(), "");
4044             m->print_short_name(&st);
4045           }
4046           return st.as_string();
4047         }
4048         case relocInfo::opt_virtual_call_type: {
4049           stringStream st;
4050           st.print_raw("optimized virtual_call");
4051           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
4052           Method* m = r->method_value();
4053           if (m != nullptr) {
4054             assert(m->is_method(), "");
4055             m->print_short_name(&st);
4056           }
4057           return st.as_string();
4058         }
4059         case relocInfo::static_call_type: {
4060           stringStream st;
4061           st.print_raw("static_call");
4062           static_call_Relocation* r = iter.static_call_reloc();
4063           Method* m = r->method_value();
4064           if (m != nullptr) {
4065             assert(m->is_method(), "");
4066             m->print_short_name(&st);
4067           }
4068           return st.as_string();
4069         }
4070         case relocInfo::static_stub_type:      return "static_stub";
4071         case relocInfo::external_word_type:    return "external_word";
4072         case relocInfo::internal_word_type:    return "internal_word";
4073         case relocInfo::section_word_type:     return "section_word";
4074         case relocInfo::poll_type:             return "poll";
4075         case relocInfo::poll_return_type:      return "poll_return";
4076         case relocInfo::trampoline_stub_type:  return "trampoline_stub";
4077         case relocInfo::entry_guard_type:      return "entry_guard";
4078         case relocInfo::post_call_nop_type:    return "post_call_nop";
4079         case relocInfo::barrier_type: {
4080           barrier_Relocation* const reloc = iter.barrier_reloc();
4081           stringStream st;
4082           st.print("barrier format=%d", reloc->format());
4083           return st.as_string();
4084         }
4085 
4086         case relocInfo::type_mask:             return "type_bit_mask";
4087 
4088         default: {
4089           stringStream st;
4090           st.print("unknown relocInfo=%d", (int) iter.type());
4091           return st.as_string();
4092         }
4093     }
4094   }
4095   return have_one ? "other" : nullptr;
4096 }
4097 
4098 // Return the last scope in (begin..end]
4099 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
4100   PcDesc* p = pc_desc_near(begin+1);
4101   if (p != nullptr && p->real_pc(this) <= end) {
4102     return new ScopeDesc(this, p);
4103   }
4104   return nullptr;
4105 }
4106 
4107 const char* nmethod::nmethod_section_label(address pos) const {
4108   const char* label = nullptr;
4109   if (pos == code_begin())                                              label = "[Instructions begin]";
4110   if (pos == entry_point())                                             label = "[Entry Point]";
4111   if (pos == inline_entry_point())                                      label = "[Inline Entry Point]";
4112   if (pos == verified_entry_point())                                    label = "[Verified Entry Point]";
4113   if (pos == verified_inline_entry_point())                             label = "[Verified Inline Entry Point]";
4114   if (pos == verified_inline_ro_entry_point())                          label = "[Verified Inline Entry Point (RO)]";
4115   if (pos == consts_begin() && pos != insts_begin())                    label = "[Constants]";
4116   // Check stub_code before checking exception_handler or deopt_handler.
4117   if (pos == this->stub_begin())                                        label = "[Stub Code]";
4118   if (JVMCI_ONLY(_exception_offset >= 0 &&) pos == exception_begin())          label = "[Exception Handler]";
4119   if (JVMCI_ONLY(_deopt_handler_entry_offset != -1 &&) pos == deopt_handler_entry()) label = "[Deopt Handler Entry Point]";
4120   return label;
4121 }
4122 
4123 static int maybe_print_entry_label(outputStream* stream, address pos, address entry, const char* label) {
4124   if (pos == entry) {
4125     stream->bol();
4126     stream->print_cr("%s", label);
4127     return 1;
4128   } else {
4129     return 0;
4130   }
4131 }
4132 
4133 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels) const {
4134   if (print_section_labels) {
4135     int n = 0;
4136     // Multiple entry points may be at the same position. Print them all.
4137     n += maybe_print_entry_label(stream, block_begin, entry_point(),                    "[Entry Point]");
4138     n += maybe_print_entry_label(stream, block_begin, inline_entry_point(),             "[Inline Entry Point]");
4139     n += maybe_print_entry_label(stream, block_begin, verified_entry_point(),           "[Verified Entry Point]");
4140     n += maybe_print_entry_label(stream, block_begin, verified_inline_entry_point(),    "[Verified Inline Entry Point]");
4141     n += maybe_print_entry_label(stream, block_begin, verified_inline_ro_entry_point(), "[Verified Inline Entry Point (RO)]");
4142     if (n == 0) {
4143       const char* label = nmethod_section_label(block_begin);
4144       if (label != nullptr) {
4145         stream->bol();
4146         stream->print_cr("%s", label);
4147       }
4148     }
4149   }
4150 
4151   Method* m = method();
4152   if (m == nullptr || is_osr_method()) {
4153     return;
4154   }
4155 
4156   // Print the name of the method (only once)
4157   address low = MIN3(entry_point(),
4158                      verified_entry_point(),
4159                      inline_entry_point());
4160   // The verified inline entry point and verified inline RO entry point are not always
4161   // used. When they are unused. CodeOffsets::Verified_Inline_Entry(_RO) is -1. Hence,
4162   // the calculated entry point is smaller than the block they are offsetting into.
4163   if (verified_inline_entry_point() >= block_begin) {
4164     low = MIN2(low, verified_inline_entry_point());
4165   }
4166   if (verified_inline_ro_entry_point() >= block_begin) {
4167     low = MIN2(low, verified_inline_ro_entry_point());
4168   }
4169   assert(low != nullptr, "sanity");
4170   if (block_begin == low) {
4171     stream->print("  # ");
4172     m->print_value_on(stream);
4173     stream->cr();
4174   }
4175 
4176   // Print the arguments for the 3 types of verified entry points
4177   CompiledEntrySignature ces(m);
4178   ces.compute_calling_conventions(false);
4179   const GrowableArray<SigEntry>* sig_cc;
4180   const VMRegPair* regs;
4181   if (block_begin == verified_entry_point()) {
4182     sig_cc = ces.sig_cc();
4183     regs = ces.regs_cc();
4184   } else if (block_begin == verified_inline_entry_point()) {
4185     sig_cc = ces.sig();
4186     regs = ces.regs();
4187   } else if (block_begin == verified_inline_ro_entry_point()) {
4188     sig_cc = ces.sig_cc_ro();
4189     regs = ces.regs_cc_ro();
4190   } else {
4191     return;
4192   }
4193 
4194   bool has_this = !m->is_static();
4195   if (ces.has_inline_recv() && block_begin == verified_entry_point()) {
4196     // <this> argument is scalarized for verified_entry_point()
4197     has_this = false;
4198   }
4199   const char* spname = "sp"; // make arch-specific?
4200   int stack_slot_offset = this->frame_size() * wordSize;
4201   int tab1 = 14, tab2 = 24;
4202   int sig_index = 0;
4203   int arg_index = has_this ? -1 : 0;
4204   bool did_old_sp = false;
4205   for (ExtendedSignature sig = ExtendedSignature(sig_cc, SigEntryFilter()); !sig.at_end(); ++sig) {
4206     bool at_this = (arg_index == -1);
4207     bool at_old_sp = false;
4208     BasicType t = (*sig)._bt;
4209     if (at_this) {
4210       stream->print("  # this: ");
4211     } else {
4212       stream->print("  # parm%d: ", arg_index);
4213     }
4214     stream->move_to(tab1);
4215     VMReg fst = regs[sig_index].first();
4216     VMReg snd = regs[sig_index].second();
4217     if (fst->is_reg()) {
4218       stream->print("%s", fst->name());
4219       if (snd->is_valid())  {
4220         stream->print(":%s", snd->name());
4221       }
4222     } else if (fst->is_stack()) {
4223       int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
4224       if (offset == stack_slot_offset)  at_old_sp = true;
4225       stream->print("[%s+0x%x]", spname, offset);
4226     } else {
4227       stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
4228     }
4229     stream->print(" ");
4230     stream->move_to(tab2);
4231     stream->print("= ");
4232     if (at_this) {
4233       m->method_holder()->print_value_on(stream);
4234     } else {
4235       bool did_name = false;
4236       if (is_reference_type(t) && !(*sig)._vt_oop) {
4237         Symbol* name = (*sig)._name;
4238         name->print_value_on(stream);
4239         did_name = true;
4240       }
4241       if (!did_name)
4242         stream->print("%s", type2name(t));
4243       if ((*sig)._null_marker) {
4244         stream->print(" (null marker)");
4245       }
4246       if ((*sig)._vt_oop) {
4247         stream->print(" (VT OOP)");
4248       }
4249     }
4250     if (at_old_sp) {
4251       stream->print("  (%s of caller)", spname);
4252       did_old_sp = true;
4253     }
4254     stream->cr();
4255     sig_index += type2size[t];
4256     arg_index += 1;
4257   }
4258   if (!did_old_sp) {
4259     stream->print("  # ");
4260     stream->move_to(tab1);
4261     stream->print("[%s+0x%x]", spname, stack_slot_offset);
4262     stream->print("  (%s of caller)", spname);
4263     stream->cr();
4264   }
4265 }
4266 
4267 // Returns whether this nmethod has code comments.
4268 bool nmethod::has_code_comment(address begin, address end) {
4269   // scopes?
4270   ScopeDesc* sd  = scope_desc_in(begin, end);
4271   if (sd != nullptr) return true;
4272 
4273   // relocations?
4274   const char* str = reloc_string_for(begin, end);
4275   if (str != nullptr) return true;
4276 
4277   // implicit exceptions?
4278   int cont_offset = ImplicitExceptionTable(this).continuation_offset((uint)(begin - code_begin()));
4279   if (cont_offset != 0) return true;
4280 
4281   return false;
4282 }
4283 
4284 void nmethod::print_code_comment_on(outputStream* st, int column, address begin, address end) {
4285   ImplicitExceptionTable implicit_table(this);
4286   int pc_offset = (int)(begin - code_begin());
4287   int cont_offset = implicit_table.continuation_offset(pc_offset);
4288   bool oop_map_required = false;
4289   if (cont_offset != 0) {
4290     st->move_to(column, 6, 0);
4291     if (pc_offset == cont_offset) {
4292       st->print("; implicit exception: deoptimizes");
4293       oop_map_required = true;
4294     } else {
4295       st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
4296     }
4297   }
4298 
4299   // Find an oopmap in (begin, end].  We use the odd half-closed
4300   // interval so that oop maps and scope descs which are tied to the
4301   // byte after a call are printed with the call itself.  OopMaps
4302   // associated with implicit exceptions are printed with the implicit
4303   // instruction.
4304   address base = code_begin();
4305   ImmutableOopMapSet* oms = oop_maps();
4306   if (oms != nullptr) {
4307     for (int i = 0, imax = oms->count(); i < imax; i++) {
4308       const ImmutableOopMapPair* pair = oms->pair_at(i);
4309       const ImmutableOopMap* om = pair->get_from(oms);
4310       address pc = base + pair->pc_offset();
4311       if (pc >= begin) {
4312 #if INCLUDE_JVMCI
4313         bool is_implicit_deopt = implicit_table.continuation_offset(pair->pc_offset()) == (uint) pair->pc_offset();
4314 #else
4315         bool is_implicit_deopt = false;
4316 #endif
4317         if (is_implicit_deopt ? pc == begin : pc > begin && pc <= end) {
4318           st->move_to(column, 6, 0);
4319           st->print("; ");
4320           om->print_on(st);
4321           oop_map_required = false;
4322         }
4323       }
4324       if (pc > end) {
4325         break;
4326       }
4327     }
4328   }
4329   assert(!oop_map_required, "missed oopmap");
4330 
4331   Thread* thread = Thread::current();
4332 
4333   // Print any debug info present at this pc.
4334   ScopeDesc* sd  = scope_desc_in(begin, end);
4335   if (sd != nullptr) {
4336     st->move_to(column, 6, 0);
4337     if (sd->bci() == SynchronizationEntryBCI) {
4338       st->print(";*synchronization entry");
4339     } else if (sd->bci() == AfterBci) {
4340       st->print(";* method exit (unlocked if synchronized)");
4341     } else if (sd->bci() == UnwindBci) {
4342       st->print(";* unwind (locked if synchronized)");
4343     } else if (sd->bci() == AfterExceptionBci) {
4344       st->print(";* unwind (unlocked if synchronized)");
4345     } else if (sd->bci() == UnknownBci) {
4346       st->print(";* unknown");
4347     } else if (sd->bci() == InvalidFrameStateBci) {
4348       st->print(";* invalid frame state");
4349     } else {
4350       if (sd->method() == nullptr) {
4351         st->print("method is nullptr");
4352       } else if (sd->method()->is_native()) {
4353         st->print("method is native");
4354       } else {
4355         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
4356         st->print(";*%s", Bytecodes::name(bc));
4357         switch (bc) {
4358         case Bytecodes::_invokevirtual:
4359         case Bytecodes::_invokespecial:
4360         case Bytecodes::_invokestatic:
4361         case Bytecodes::_invokeinterface:
4362           {
4363             Bytecode_invoke invoke(methodHandle(thread, sd->method()), sd->bci());
4364             st->print(" ");
4365             if (invoke.name() != nullptr)
4366               invoke.name()->print_symbol_on(st);
4367             else
4368               st->print("<UNKNOWN>");
4369             break;
4370           }
4371         case Bytecodes::_getfield:
4372         case Bytecodes::_putfield:
4373         case Bytecodes::_getstatic:
4374         case Bytecodes::_putstatic:
4375           {
4376             Bytecode_field field(methodHandle(thread, sd->method()), sd->bci());
4377             st->print(" ");
4378             if (field.name() != nullptr)
4379               field.name()->print_symbol_on(st);
4380             else
4381               st->print("<UNKNOWN>");
4382           }
4383         default:
4384           break;
4385         }
4386       }
4387       st->print(" {reexecute=%d rethrow=%d return_oop=%d return_scalarized=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop(), sd->return_scalarized());
4388     }
4389 
4390     // Print all scopes
4391     for (;sd != nullptr; sd = sd->sender()) {
4392       st->move_to(column, 6, 0);
4393       st->print("; -");
4394       if (sd->should_reexecute()) {
4395         st->print(" (reexecute)");
4396       }
4397       if (sd->method() == nullptr) {
4398         st->print("method is nullptr");
4399       } else {
4400         sd->method()->print_short_name(st);
4401       }
4402       int lineno = sd->method()->line_number_from_bci(sd->bci());
4403       if (lineno != -1) {
4404         st->print("@%d (line %d)", sd->bci(), lineno);
4405       } else {
4406         st->print("@%d", sd->bci());
4407       }
4408       st->cr();
4409     }
4410   }
4411 
4412   // Print relocation information
4413   // Prevent memory leak: allocating without ResourceMark.
4414   ResourceMark rm;
4415   const char* str = reloc_string_for(begin, end);
4416   if (str != nullptr) {
4417     if (sd != nullptr) st->cr();
4418     st->move_to(column, 6, 0);
4419     st->print(";   {%s}", str);
4420   }
4421 }
4422 
4423 #endif
4424 
4425 address nmethod::call_instruction_address(address pc) const {
4426   if (NativeCall::is_call_before(pc)) {
4427     NativeCall *ncall = nativeCall_before(pc);
4428     return ncall->instruction_address();
4429   }
4430   return nullptr;
4431 }
4432 
4433 void nmethod::print_value_on_impl(outputStream* st) const {
4434   st->print_cr("nmethod");
4435 #if defined(SUPPORT_DATA_STRUCTS)
4436   print_on_with_msg(st, nullptr);
4437 #endif
4438 }
4439 
4440 void nmethod::print_code_snippet(outputStream* st, address addr) const {
4441   if (entry_point() <= addr && addr < code_end()) {
4442     // Pointing into the nmethod's code. Try to disassemble some instructions around addr.
4443     // Determine conservative start and end points.
4444     address start;
4445     if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
4446         addr >= code_begin() + frame_complete_offset()) {
4447       start = code_begin() + frame_complete_offset();
4448     } else {
4449       start = (addr < verified_entry_point()) ? entry_point() : verified_entry_point();
4450     }
4451     address start_for_hex_dump = start; // We can choose a different starting point for hex dump, below.
4452     address end = code_end();
4453 
4454     // Try using relocations to find closer instruction start and end points.
4455     // (Some platforms have variable length instructions and can only
4456     // disassemble correctly at instruction start addresses.)
4457     RelocIterator iter((nmethod*)this, start);
4458     while (iter.next() && iter.addr() < addr) { // find relocation before addr
4459       // Note: There's a relocation which doesn't point to an instruction start:
4460       // ZBarrierRelocationFormatStoreGoodAfterMov with ZGC on x86_64
4461       // We could detect and skip it, but hex dump is still usable when
4462       // disassembler produces garbage in such a very rare case.
4463       start = iter.addr();
4464       // We want at least 64 Bytes ahead in hex dump.
4465       if (iter.addr() <= (addr - 64)) start_for_hex_dump = iter.addr();
4466     }
4467     if (iter.has_current()) {
4468       if (iter.addr() == addr) iter.next(); // find relocation after addr
4469       if (iter.has_current()) end = iter.addr();
4470     }
4471 
4472     // Always print hex. Disassembler may still have problems when hitting an incorrect instruction start.
4473     os::print_hex_dump(st, start_for_hex_dump, end, 1, /* print_ascii=*/false);
4474     if (!Disassembler::is_abstract()) {
4475       Disassembler::decode(start, end, st);
4476     }
4477   }
4478 }
4479 
4480 #ifndef PRODUCT
4481 
4482 void nmethod::print_calls(outputStream* st) {
4483   RelocIterator iter(this);
4484   while (iter.next()) {
4485     switch (iter.type()) {
4486     case relocInfo::virtual_call_type: {
4487       CompiledICLocker ml_verify(this);
4488       CompiledIC_at(&iter)->print();
4489       break;
4490     }
4491     case relocInfo::static_call_type:
4492     case relocInfo::opt_virtual_call_type:
4493       st->print_cr("Direct call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
4494       CompiledDirectCall::at(iter.reloc())->print();
4495       break;
4496     default:
4497       break;
4498     }
4499   }
4500 }
4501 
4502 void nmethod::print_statistics() {
4503   ttyLocker ttyl;
4504   if (xtty != nullptr)  xtty->head("statistics type='nmethod'");
4505   native_nmethod_stats.print_native_nmethod_stats();
4506 #ifdef COMPILER1
4507   c1_java_nmethod_stats.print_nmethod_stats("C1");
4508 #endif
4509 #ifdef COMPILER2
4510   c2_java_nmethod_stats.print_nmethod_stats("C2");
4511 #endif
4512 #if INCLUDE_JVMCI
4513   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
4514 #endif
4515   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
4516   DebugInformationRecorder::print_statistics();
4517   pc_nmethod_stats.print_pc_stats();
4518   Dependencies::print_statistics();
4519   ExternalsRecorder::print_statistics();
4520   if (xtty != nullptr)  xtty->tail("statistics");
4521 }
4522 
4523 #endif // !PRODUCT
4524 
4525 #if INCLUDE_JVMCI
4526 void nmethod::update_speculation(JavaThread* thread) {
4527   jlong speculation = thread->pending_failed_speculation();
4528   if (speculation != 0) {
4529     guarantee(jvmci_nmethod_data() != nullptr, "failed speculation in nmethod without failed speculation list");
4530     jvmci_nmethod_data()->add_failed_speculation(this, speculation);
4531     thread->set_pending_failed_speculation(0);
4532   }
4533 }
4534 
4535 const char* nmethod::jvmci_name() {
4536   if (jvmci_nmethod_data() != nullptr) {
4537     return jvmci_nmethod_data()->name();
4538   }
4539   return nullptr;
4540 }
4541 
4542 bool nmethod::jvmci_skip_profile_deopt() const {
4543   return jvmci_nmethod_data() != nullptr && !jvmci_nmethod_data()->profile_deopt();
4544 }
4545 #endif