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