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