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