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