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