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