1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/assembler.inline.hpp"
  26 #include "code/codeCache.hpp"
  27 #include "code/compiledIC.hpp"
  28 #include "code/dependencies.hpp"
  29 #include "code/nativeInst.hpp"
  30 #include "code/nmethod.inline.hpp"
  31 #include "code/scopeDesc.hpp"
  32 #include "code/SCCache.hpp"
  33 #include "compiler/abstractCompiler.hpp"
  34 #include "compiler/compilationLog.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/compileLog.hpp"
  37 #include "compiler/compileTask.hpp"
  38 #include "compiler/compilerDirectives.hpp"
  39 #include "compiler/compilerOracle.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/continuation.hpp"
  64 #include "runtime/atomic.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/resourceHash.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   assert(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 Atomic::load(&_next);
 381 }
 382 
 383 void ExceptionCache::set_next(ExceptionCache *ec) {
 384   Atomic::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     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 397   }
 398 }
 399 
 400 void PcDescCache::init_to(PcDesc* initial_pc_desc) {
 401   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_init);
 402   // initialize the cache by filling it with benign (non-null) values
 403   assert(initial_pc_desc != nullptr && initial_pc_desc->pc_offset() == PcDesc::lower_offset_limit,
 404          "must start with a sentinel");
 405   for (int i = 0; i < cache_size; i++) {
 406     _pc_descs[i] = initial_pc_desc;
 407   }
 408 }
 409 
 410 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 411   // Note: one might think that caching the most recently
 412   // read value separately would be a win, but one would be
 413   // wrong.  When many threads are updating it, the cache
 414   // line it's in would bounce between caches, negating
 415   // any benefit.
 416 
 417   // In order to prevent race conditions do not load cache elements
 418   // repeatedly, but use a local copy:
 419   PcDesc* res;
 420 
 421   // Step one:  Check the most recently added value.
 422   res = _pc_descs[0];
 423   assert(res != nullptr, "PcDesc cache should be initialized already");
 424 
 425   // Approximate only here since PcDescContainer::find_pc_desc() checked for exact case.
 426   if (approximate && match_desc(res, pc_offset, approximate)) {
 427     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 428     return res;
 429   }
 430 
 431   // Step two:  Check the rest of the LRU cache.
 432   for (int i = 1; i < cache_size; ++i) {
 433     res = _pc_descs[i];
 434     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 435     if (match_desc(res, pc_offset, approximate)) {
 436       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 437       return res;
 438     }
 439   }
 440 
 441   // Report failure.
 442   return nullptr;
 443 }
 444 
 445 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 446   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 447   // Update the LRU cache by shifting pc_desc forward.
 448   for (int i = 0; i < cache_size; i++)  {
 449     PcDesc* next = _pc_descs[i];
 450     _pc_descs[i] = pc_desc;
 451     pc_desc = next;
 452   }
 453 }
 454 
 455 // adjust pcs_size so that it is a multiple of both oopSize and
 456 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 457 // of oopSize, then 2*sizeof(PcDesc) is)
 458 static int adjust_pcs_size(int pcs_size) {
 459   int nsize = align_up(pcs_size,   oopSize);
 460   if ((nsize % sizeof(PcDesc)) != 0) {
 461     nsize = pcs_size + sizeof(PcDesc);
 462   }
 463   assert((nsize % oopSize) == 0, "correct alignment");
 464   return nsize;
 465 }
 466 
 467 bool nmethod::is_method_handle_return(address return_pc) {
 468   if (!has_method_handle_invokes())  return false;
 469   PcDesc* pd = pc_desc_at(return_pc);
 470   if (pd == nullptr)
 471     return false;
 472   return pd->is_method_handle_invoke();
 473 }
 474 
 475 // Returns a string version of the method state.
 476 const char* nmethod::state() const {
 477   int state = get_state();
 478   switch (state) {
 479   case not_installed:
 480     return "not installed";
 481   case in_use:
 482     return "in use";
 483   case not_entrant:
 484     return "not_entrant";
 485   default:
 486     fatal("unexpected method state: %d", state);
 487     return nullptr;
 488   }
 489 }
 490 
 491 void nmethod::set_deoptimized_done() {
 492   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 493   if (_deoptimization_status != deoptimize_done) { // can't go backwards
 494     Atomic::store(&_deoptimization_status, deoptimize_done);
 495   }
 496 }
 497 
 498 ExceptionCache* nmethod::exception_cache_acquire() const {
 499   return Atomic::load_acquire(&_exception_cache);
 500 }
 501 
 502 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 503   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 504   assert(new_entry != nullptr,"Must be non null");
 505   assert(new_entry->next() == nullptr, "Must be null");
 506 
 507   for (;;) {
 508     ExceptionCache *ec = exception_cache();
 509     if (ec != nullptr) {
 510       Klass* ex_klass = ec->exception_type();
 511       if (!ex_klass->is_loader_alive()) {
 512         // We must guarantee that entries are not inserted with new next pointer
 513         // edges to ExceptionCache entries with dead klasses, due to bad interactions
 514         // with concurrent ExceptionCache cleanup. Therefore, the inserts roll
 515         // the head pointer forward to the first live ExceptionCache, so that the new
 516         // next pointers always point at live ExceptionCaches, that are not removed due
 517         // to concurrent ExceptionCache cleanup.
 518         ExceptionCache* next = ec->next();
 519         if (Atomic::cmpxchg(&_exception_cache, ec, next) == ec) {
 520           CodeCache::release_exception_cache(ec);
 521         }
 522         continue;
 523       }
 524       ec = exception_cache();
 525       if (ec != nullptr) {
 526         new_entry->set_next(ec);
 527       }
 528     }
 529     if (Atomic::cmpxchg(&_exception_cache, ec, new_entry) == ec) {
 530       return;
 531     }
 532   }
 533 }
 534 
 535 void nmethod::clean_exception_cache() {
 536   // For each nmethod, only a single thread may call this cleanup function
 537   // at the same time, whether called in STW cleanup or concurrent cleanup.
 538   // Note that if the GC is processing exception cache cleaning in a concurrent phase,
 539   // then a single writer may contend with cleaning up the head pointer to the
 540   // first ExceptionCache node that has a Klass* that is alive. That is fine,
 541   // as long as there is no concurrent cleanup of next pointers from concurrent writers.
 542   // And the concurrent writers do not clean up next pointers, only the head.
 543   // Also note that concurrent readers will walk through Klass* pointers that are not
 544   // alive. That does not cause ABA problems, because Klass* is deleted after
 545   // a handshake with all threads, after all stale ExceptionCaches have been
 546   // unlinked. That is also when the CodeCache::exception_cache_purge_list()
 547   // is deleted, with all ExceptionCache entries that were cleaned concurrently.
 548   // That similarly implies that CAS operations on ExceptionCache entries do not
 549   // suffer from ABA problems as unlinking and deletion is separated by a global
 550   // handshake operation.
 551   ExceptionCache* prev = nullptr;
 552   ExceptionCache* curr = exception_cache_acquire();
 553 
 554   while (curr != nullptr) {
 555     ExceptionCache* next = curr->next();
 556 
 557     if (!curr->exception_type()->is_loader_alive()) {
 558       if (prev == nullptr) {
 559         // Try to clean head; this is contended by concurrent inserts, that
 560         // both lazily clean the head, and insert entries at the head. If
 561         // the CAS fails, the operation is restarted.
 562         if (Atomic::cmpxchg(&_exception_cache, curr, next) != curr) {
 563           prev = nullptr;
 564           curr = exception_cache_acquire();
 565           continue;
 566         }
 567       } else {
 568         // It is impossible to during cleanup connect the next pointer to
 569         // an ExceptionCache that has not been published before a safepoint
 570         // prior to the cleanup. Therefore, release is not required.
 571         prev->set_next(next);
 572       }
 573       // prev stays the same.
 574 
 575       CodeCache::release_exception_cache(curr);
 576     } else {
 577       prev = curr;
 578     }
 579 
 580     curr = next;
 581   }
 582 }
 583 
 584 // public method for accessing the exception cache
 585 // These are the public access methods.
 586 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 587   // We never grab a lock to read the exception cache, so we may
 588   // have false negatives. This is okay, as it can only happen during
 589   // the first few exception lookups for a given nmethod.
 590   ExceptionCache* ec = exception_cache_acquire();
 591   while (ec != nullptr) {
 592     address ret_val;
 593     if ((ret_val = ec->match(exception,pc)) != nullptr) {
 594       return ret_val;
 595     }
 596     ec = ec->next();
 597   }
 598   return nullptr;
 599 }
 600 
 601 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 602   // There are potential race conditions during exception cache updates, so we
 603   // must own the ExceptionCache_lock before doing ANY modifications. Because
 604   // we don't lock during reads, it is possible to have several threads attempt
 605   // to update the cache with the same data. We need to check for already inserted
 606   // copies of the current data before adding it.
 607 
 608   MutexLocker ml(ExceptionCache_lock);
 609   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 610 
 611   if (target_entry == nullptr || !target_entry->add_address_and_handler(pc,handler)) {
 612     target_entry = new ExceptionCache(exception,pc,handler);
 613     add_exception_cache_entry(target_entry);
 614   }
 615 }
 616 
 617 // private method for handling exception cache
 618 // These methods are private, and used to manipulate the exception cache
 619 // directly.
 620 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 621   ExceptionCache* ec = exception_cache_acquire();
 622   while (ec != nullptr) {
 623     if (ec->match_exception_with_space(exception)) {
 624       return ec;
 625     }
 626     ec = ec->next();
 627   }
 628   return nullptr;
 629 }
 630 
 631 bool nmethod::is_at_poll_return(address pc) {
 632   RelocIterator iter(this, pc, pc+1);
 633   while (iter.next()) {
 634     if (iter.type() == relocInfo::poll_return_type)
 635       return true;
 636   }
 637   return false;
 638 }
 639 
 640 
 641 bool nmethod::is_at_poll_or_poll_return(address pc) {
 642   RelocIterator iter(this, pc, pc+1);
 643   while (iter.next()) {
 644     relocInfo::relocType t = iter.type();
 645     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
 646       return true;
 647   }
 648   return false;
 649 }
 650 
 651 void nmethod::verify_oop_relocations() {
 652   // Ensure sure that the code matches the current oop values
 653   RelocIterator iter(this, nullptr, nullptr);
 654   while (iter.next()) {
 655     if (iter.type() == relocInfo::oop_type) {
 656       oop_Relocation* reloc = iter.oop_reloc();
 657       if (!reloc->oop_is_immediate()) {
 658         reloc->verify_oop_relocation();
 659       }
 660     }
 661   }
 662 }
 663 
 664 
 665 ScopeDesc* nmethod::scope_desc_at(address pc) {
 666   PcDesc* pd = pc_desc_at(pc);
 667   guarantee(pd != nullptr, "scope must be present");
 668   return new ScopeDesc(this, pd);
 669 }
 670 
 671 ScopeDesc* nmethod::scope_desc_near(address pc) {
 672   PcDesc* pd = pc_desc_near(pc);
 673   guarantee(pd != nullptr, "scope must be present");
 674   return new ScopeDesc(this, pd);
 675 }
 676 
 677 address nmethod::oops_reloc_begin() const {
 678   // If the method is not entrant then a JMP is plastered over the
 679   // first few bytes.  If an oop in the old code was there, that oop
 680   // should not get GC'd.  Skip the first few bytes of oops on
 681   // not-entrant methods.
 682   if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
 683       code_begin() + frame_complete_offset() >
 684       verified_entry_point() + NativeJump::instruction_size)
 685   {
 686     // If we have a frame_complete_offset after the native jump, then there
 687     // is no point trying to look for oops before that. This is a requirement
 688     // for being allowed to scan oops concurrently.
 689     return code_begin() + frame_complete_offset();
 690   }
 691 
 692   address low_boundary = verified_entry_point();
 693   if (!is_in_use()) {
 694     low_boundary += NativeJump::instruction_size;
 695     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
 696     // This means that the low_boundary is going to be a little too high.
 697     // This shouldn't matter, since oops of non-entrant methods are never used.
 698     // In fact, why are we bothering to look at oops in a non-entrant method??
 699   }
 700   return low_boundary;
 701 }
 702 
 703 // Method that knows how to preserve outgoing arguments at call. This method must be
 704 // called with a frame corresponding to a Java invoke
 705 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
 706   if (method() == nullptr) {
 707     return;
 708   }
 709 
 710   // handle the case of an anchor explicitly set in continuation code that doesn't have a callee
 711   JavaThread* thread = reg_map->thread();
 712   if ((thread->has_last_Java_frame() && fr.sp() == thread->last_Java_sp())
 713       JVMTI_ONLY(|| (method()->is_continuation_enter_intrinsic() && thread->on_monitor_waited_event()))) {
 714     return;
 715   }
 716 
 717   if (!method()->is_native()) {
 718     address pc = fr.pc();
 719     bool has_receiver, has_appendix;
 720     Symbol* signature;
 721 
 722     // The method attached by JIT-compilers should be used, if present.
 723     // Bytecode can be inaccurate in such case.
 724     Method* callee = attached_method_before_pc(pc);
 725     if (callee != nullptr) {
 726       has_receiver = !(callee->access_flags().is_static());
 727       has_appendix = false;
 728       signature    = callee->signature();
 729     } else {
 730       SimpleScopeDesc ssd(this, pc);
 731 
 732       Bytecode_invoke call(methodHandle(Thread::current(), ssd.method()), ssd.bci());
 733       has_receiver = call.has_receiver();
 734       has_appendix = call.has_appendix();
 735       signature    = call.signature();
 736     }
 737 
 738     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
 739   } else if (method()->is_continuation_enter_intrinsic()) {
 740     // This method only calls Continuation.enter()
 741     Symbol* signature = vmSymbols::continuationEnter_signature();
 742     fr.oops_compiled_arguments_do(signature, false, false, reg_map, f);
 743   }
 744 }
 745 
 746 Method* nmethod::attached_method(address call_instr) {
 747   assert(code_contains(call_instr), "not part of the nmethod");
 748   RelocIterator iter(this, call_instr, call_instr + 1);
 749   while (iter.next()) {
 750     if (iter.addr() == call_instr) {
 751       switch(iter.type()) {
 752         case relocInfo::static_call_type:      return iter.static_call_reloc()->method_value();
 753         case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
 754         case relocInfo::virtual_call_type:     return iter.virtual_call_reloc()->method_value();
 755         default:                               break;
 756       }
 757     }
 758   }
 759   return nullptr; // not found
 760 }
 761 
 762 Method* nmethod::attached_method_before_pc(address pc) {
 763   if (NativeCall::is_call_before(pc)) {
 764     NativeCall* ncall = nativeCall_before(pc);
 765     return attached_method(ncall->instruction_address());
 766   }
 767   return nullptr; // not a call
 768 }
 769 
 770 void nmethod::clear_inline_caches() {
 771   assert(SafepointSynchronize::is_at_safepoint(), "clearing of IC's only allowed at safepoint");
 772   RelocIterator iter(this);
 773   while (iter.next()) {
 774     iter.reloc()->clear_inline_cache();
 775   }
 776 }
 777 
 778 #ifdef ASSERT
 779 // Check class_loader is alive for this bit of metadata.
 780 class CheckClass : public MetadataClosure {
 781   void do_metadata(Metadata* md) {
 782     Klass* klass = nullptr;
 783     if (md->is_klass()) {
 784       klass = ((Klass*)md);
 785     } else if (md->is_method()) {
 786       klass = ((Method*)md)->method_holder();
 787     } else if (md->is_methodData()) {
 788       klass = ((MethodData*)md)->method()->method_holder();
 789     } else if (md->is_methodCounters()) {
 790       klass = ((MethodCounters*)md)->method()->method_holder();
 791     } else {
 792       md->print();
 793       ShouldNotReachHere();
 794     }
 795     assert(klass->is_loader_alive(), "must be alive");
 796   }
 797 };
 798 #endif // ASSERT
 799 
 800 
 801 static void clean_ic_if_metadata_is_dead(CompiledIC *ic) {
 802   ic->clean_metadata();
 803 }
 804 
 805 // Clean references to unloaded nmethods at addr from this one, which is not unloaded.
 806 template <typename CallsiteT>
 807 static void clean_if_nmethod_is_unloaded(CallsiteT* callsite, nmethod* from,
 808                                          bool clean_all) {
 809   CodeBlob* cb = CodeCache::find_blob(callsite->destination());
 810   if (!cb->is_nmethod()) {
 811     return;
 812   }
 813   nmethod* nm = cb->as_nmethod();
 814   if (clean_all || !nm->is_in_use() || nm->is_unloading() || nm->method()->code() != nm) {
 815     callsite->set_to_clean();
 816   }
 817 }
 818 
 819 // Cleans caches in nmethods that point to either classes that are unloaded
 820 // or nmethods that are unloaded.
 821 //
 822 // Can be called either in parallel by G1 currently or after all
 823 // nmethods are unloaded.  Return postponed=true in the parallel case for
 824 // inline caches found that point to nmethods that are not yet visited during
 825 // the do_unloading walk.
 826 void nmethod::unload_nmethod_caches(bool unloading_occurred) {
 827   ResourceMark rm;
 828 
 829   // Exception cache only needs to be called if unloading occurred
 830   if (unloading_occurred) {
 831     clean_exception_cache();
 832   }
 833 
 834   cleanup_inline_caches_impl(unloading_occurred, false);
 835 
 836 #ifdef ASSERT
 837   // Check that the metadata embedded in the nmethod is alive
 838   CheckClass check_class;
 839   metadata_do(&check_class);
 840 #endif
 841 }
 842 
 843 void nmethod::run_nmethod_entry_barrier() {
 844   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
 845   if (bs_nm != nullptr) {
 846     // We want to keep an invariant that nmethods found through iterations of a Thread's
 847     // nmethods found in safepoints have gone through an entry barrier and are not armed.
 848     // By calling this nmethod entry barrier, it plays along and acts
 849     // like any other nmethod found on the stack of a thread (fewer surprises).
 850     nmethod* nm = this;
 851     bool alive = bs_nm->nmethod_entry_barrier(nm);
 852     assert(alive, "should be alive");
 853   }
 854 }
 855 
 856 // Only called by whitebox test
 857 void nmethod::cleanup_inline_caches_whitebox() {
 858   assert_locked_or_safepoint(CodeCache_lock);
 859   CompiledICLocker ic_locker(this);
 860   cleanup_inline_caches_impl(false /* unloading_occurred */, true /* clean_all */);
 861 }
 862 
 863 address* nmethod::orig_pc_addr(const frame* fr) {
 864   return (address*) ((address)fr->unextended_sp() + orig_pc_offset());
 865 }
 866 
 867 // Called to clean up after class unloading for live nmethods
 868 void nmethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) {
 869   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
 870   ResourceMark rm;
 871 
 872   // Find all calls in an nmethod and clear the ones that point to bad nmethods.
 873   RelocIterator iter(this, oops_reloc_begin());
 874   bool is_in_static_stub = false;
 875   while(iter.next()) {
 876 
 877     switch (iter.type()) {
 878 
 879     case relocInfo::virtual_call_type:
 880       if (unloading_occurred) {
 881         // If class unloading occurred we first clear ICs where the cached metadata
 882         // is referring to an unloaded klass or method.
 883         clean_ic_if_metadata_is_dead(CompiledIC_at(&iter));
 884       }
 885 
 886       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all);
 887       break;
 888 
 889     case relocInfo::opt_virtual_call_type:
 890     case relocInfo::static_call_type:
 891       clean_if_nmethod_is_unloaded(CompiledDirectCall::at(iter.reloc()), this, clean_all);
 892       break;
 893 
 894     case relocInfo::static_stub_type: {
 895       is_in_static_stub = true;
 896       break;
 897     }
 898 
 899     case relocInfo::metadata_type: {
 900       // Only the metadata relocations contained in static/opt virtual call stubs
 901       // contains the Method* passed to c2i adapters. It is the only metadata
 902       // relocation that needs to be walked, as it is the one metadata relocation
 903       // that violates the invariant that all metadata relocations have an oop
 904       // in the compiled method (due to deferred resolution and code patching).
 905 
 906       // This causes dead metadata to remain in compiled methods that are not
 907       // unloading. Unless these slippery metadata relocations of the static
 908       // stubs are at least cleared, subsequent class redefinition operations
 909       // will access potentially free memory, and JavaThread execution
 910       // concurrent to class unloading may call c2i adapters with dead methods.
 911       if (!is_in_static_stub) {
 912         // The first metadata relocation after a static stub relocation is the
 913         // metadata relocation of the static stub used to pass the Method* to
 914         // c2i adapters.
 915         continue;
 916       }
 917       is_in_static_stub = false;
 918       if (is_unloading()) {
 919         // If the nmethod itself is dying, then it may point at dead metadata.
 920         // Nobody should follow that metadata; it is strictly unsafe.
 921         continue;
 922       }
 923       metadata_Relocation* r = iter.metadata_reloc();
 924       Metadata* md = r->metadata_value();
 925       if (md != nullptr && md->is_method()) {
 926         Method* method = static_cast<Method*>(md);
 927         if (!method->method_holder()->is_loader_alive()) {
 928           Atomic::store(r->metadata_addr(), (Method*)nullptr);
 929 
 930           if (!r->metadata_is_immediate()) {
 931             r->fix_metadata_relocation();
 932           }
 933         }
 934       }
 935       break;
 936     }
 937 
 938     default:
 939       break;
 940     }
 941   }
 942 }
 943 
 944 address nmethod::continuation_for_implicit_exception(address pc, bool for_div0_check) {
 945   // Exception happened outside inline-cache check code => we are inside
 946   // an active nmethod => use cpc to determine a return address
 947   int exception_offset = int(pc - code_begin());
 948   int cont_offset = ImplicitExceptionTable(this).continuation_offset( exception_offset );
 949 #ifdef ASSERT
 950   if (cont_offset == 0) {
 951     Thread* thread = Thread::current();
 952     ResourceMark rm(thread);
 953     CodeBlob* cb = CodeCache::find_blob(pc);
 954     assert(cb != nullptr && cb == this, "");
 955 
 956     // Keep tty output consistent. To avoid ttyLocker, we buffer in stream, and print all at once.
 957     stringStream ss;
 958     ss.print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
 959     print_on(&ss);
 960     method()->print_codes_on(&ss);
 961     print_code_on(&ss);
 962     print_pcs_on(&ss);
 963     tty->print("%s", ss.as_string()); // print all at once
 964   }
 965 #endif
 966   if (cont_offset == 0) {
 967     // Let the normal error handling report the exception
 968     return nullptr;
 969   }
 970   if (cont_offset == exception_offset) {
 971 #if INCLUDE_JVMCI
 972     Deoptimization::DeoptReason deopt_reason = for_div0_check ? Deoptimization::Reason_div0_check : Deoptimization::Reason_null_check;
 973     JavaThread *thread = JavaThread::current();
 974     thread->set_jvmci_implicit_exception_pc(pc);
 975     thread->set_pending_deoptimization(Deoptimization::make_trap_request(deopt_reason,
 976                                                                          Deoptimization::Action_reinterpret));
 977     return (SharedRuntime::deopt_blob()->implicit_exception_uncommon_trap());
 978 #else
 979     ShouldNotReachHere();
 980 #endif
 981   }
 982   return code_begin() + cont_offset;
 983 }
 984 
 985 class HasEvolDependency : public MetadataClosure {
 986   bool _has_evol_dependency;
 987  public:
 988   HasEvolDependency() : _has_evol_dependency(false) {}
 989   void do_metadata(Metadata* md) {
 990     if (md->is_method()) {
 991       Method* method = (Method*)md;
 992       if (method->is_old()) {
 993         _has_evol_dependency = true;
 994       }
 995     }
 996   }
 997   bool has_evol_dependency() const { return _has_evol_dependency; }
 998 };
 999 
1000 bool nmethod::has_evol_metadata() {
1001   // Check the metadata in relocIter and CompiledIC and also deoptimize
1002   // any nmethod that has reference to old methods.
1003   HasEvolDependency check_evol;
1004   metadata_do(&check_evol);
1005   if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)) {
1006     ResourceMark rm;
1007     log_debug(redefine, class, nmethod)
1008             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata",
1009              _method->method_holder()->external_name(),
1010              _method->name()->as_C_string(),
1011              _method->signature()->as_C_string(),
1012              compile_id());
1013   }
1014   return check_evol.has_evol_dependency();
1015 }
1016 
1017 int nmethod::total_size() const {
1018   return
1019     consts_size()        +
1020     insts_size()         +
1021     stub_size()          +
1022     scopes_data_size()   +
1023     scopes_pcs_size()    +
1024     handler_table_size() +
1025     nul_chk_table_size();
1026 }
1027 
1028 const char* nmethod::compile_kind() const {
1029   if (is_osr_method())     return "osr";
1030   if (method() != nullptr && is_native_method()) {
1031     if (method()->is_continuation_native_intrinsic()) {
1032       return "cnt";
1033     }
1034     return "c2n";
1035   }
1036   return nullptr;
1037 }
1038 
1039 const char* nmethod::compiler_name() const {
1040   return compilertype2name(_compiler_type);
1041 }
1042 
1043 #ifdef ASSERT
1044 class CheckForOopsClosure : public OopClosure {
1045   bool _found_oop = false;
1046  public:
1047   virtual void do_oop(oop* o) { _found_oop = true; }
1048   virtual void do_oop(narrowOop* o) { _found_oop = true; }
1049   bool found_oop() { return _found_oop; }
1050 };
1051 class CheckForMetadataClosure : public MetadataClosure {
1052   bool _found_metadata = false;
1053   Metadata* _ignore = nullptr;
1054  public:
1055   CheckForMetadataClosure(Metadata* ignore) : _ignore(ignore) {}
1056   virtual void do_metadata(Metadata* md) { if (md != _ignore) _found_metadata = true; }
1057   bool found_metadata() { return _found_metadata; }
1058 };
1059 
1060 static void assert_no_oops_or_metadata(nmethod* nm) {
1061   if (nm == nullptr) return;
1062   assert(nm->oop_maps() == nullptr, "expectation");
1063 
1064   CheckForOopsClosure cfo;
1065   nm->oops_do(&cfo);
1066   assert(!cfo.found_oop(), "no oops allowed");
1067 
1068   // We allow an exception for the own Method, but require its class to be permanent.
1069   Method* own_method = nm->method();
1070   CheckForMetadataClosure cfm(/* ignore reference to own Method */ own_method);
1071   nm->metadata_do(&cfm);
1072   assert(!cfm.found_metadata(), "no metadata allowed");
1073 
1074   assert(own_method->method_holder()->class_loader_data()->is_permanent_class_loader_data(),
1075          "Method's class needs to be permanent");
1076 }
1077 #endif
1078 
1079 static int required_mutable_data_size(CodeBuffer* code_buffer,
1080                                       int jvmci_data_size = 0) {
1081   return align_up(code_buffer->total_relocation_size(), oopSize) +
1082          align_up(code_buffer->total_metadata_size(), oopSize) +
1083          align_up(jvmci_data_size, oopSize);
1084 }
1085 
1086 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
1087   int compile_id,
1088   CodeBuffer *code_buffer,
1089   int vep_offset,
1090   int frame_complete,
1091   int frame_size,
1092   ByteSize basic_lock_owner_sp_offset,
1093   ByteSize basic_lock_sp_offset,
1094   OopMapSet* oop_maps,
1095   int exception_handler) {
1096   code_buffer->finalize_oop_references(method);
1097   // create nmethod
1098   nmethod* nm = nullptr;
1099   int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
1100   {
1101     MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1102 
1103     CodeOffsets offsets;
1104     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
1105     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
1106     if (exception_handler != -1) {
1107       offsets.set_value(CodeOffsets::Exceptions, exception_handler);
1108     }
1109 
1110     int mutable_data_size = required_mutable_data_size(code_buffer);
1111 
1112     // MH intrinsics are dispatch stubs which are compatible with NonNMethod space.
1113     // IsUnloadingBehaviour::is_unloading needs to handle them separately.
1114     bool allow_NonNMethod_space = method->can_be_allocated_in_NonNMethod_space();
1115     nm = new (native_nmethod_size, allow_NonNMethod_space)
1116     nmethod(method(), compiler_none, native_nmethod_size,
1117             compile_id, &offsets,
1118             code_buffer, frame_size,
1119             basic_lock_owner_sp_offset,
1120             basic_lock_sp_offset,
1121             oop_maps, mutable_data_size);
1122     DEBUG_ONLY( if (allow_NonNMethod_space) assert_no_oops_or_metadata(nm); )
1123     NOT_PRODUCT(if (nm != nullptr) native_nmethod_stats.note_native_nmethod(nm));
1124   }
1125 
1126   if (nm != nullptr) {
1127     // verify nmethod
1128     debug_only(nm->verify();) // might block
1129 
1130     nm->log_new_nmethod();
1131   }
1132   return nm;
1133 }
1134 
1135 nmethod* nmethod::new_nmethod(const methodHandle& method,
1136   int compile_id,
1137   int entry_bci,
1138   CodeOffsets* offsets,
1139   int orig_pc_offset,
1140   DebugInformationRecorder* debug_info,
1141   Dependencies* dependencies,
1142   CodeBuffer* code_buffer, int frame_size,
1143   OopMapSet* oop_maps,
1144   ExceptionHandlerTable* handler_table,
1145   ImplicitExceptionTable* nul_chk_table,
1146   AbstractCompiler* compiler,
1147   CompLevel comp_level
1148   , SCCEntry* scc_entry
1149 #if INCLUDE_JVMCI
1150   , char* speculations,
1151   int speculations_len,
1152   JVMCINMethodData* jvmci_data
1153 #endif
1154 )
1155 {
1156   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
1157   code_buffer->finalize_oop_references(method);
1158   // create nmethod
1159   nmethod* nm = nullptr;
1160   int nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
1161 
1162   int immutable_data_size =
1163       adjust_pcs_size(debug_info->pcs_size())
1164     + align_up((int)dependencies->size_in_bytes(), oopSize)
1165     + align_up(handler_table->size_in_bytes()    , oopSize)
1166     + align_up(nul_chk_table->size_in_bytes()    , oopSize)
1167 #if INCLUDE_JVMCI
1168     + align_up(speculations_len                  , oopSize)
1169 #endif
1170     + align_up(debug_info->data_size()           , oopSize);
1171 
1172   // First, allocate space for immutable data in C heap.
1173   address immutable_data = nullptr;
1174   if (immutable_data_size > 0) {
1175     immutable_data = (address)os::malloc(immutable_data_size, mtCode);
1176     if (immutable_data == nullptr) {
1177       vm_exit_out_of_memory(immutable_data_size, OOM_MALLOC_ERROR, "nmethod: no space for immutable data");
1178       return nullptr;
1179     }
1180   }
1181 
1182   int mutable_data_size = required_mutable_data_size(code_buffer
1183     JVMCI_ONLY(COMMA (compiler->is_jvmci() ? jvmci_data->size() : 0)));
1184 
1185   {
1186     MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1187 
1188     nm = new (nmethod_size, comp_level)
1189     nmethod(method(), compiler->type(), nmethod_size, immutable_data_size, mutable_data_size,
1190             compile_id, entry_bci, immutable_data, offsets, orig_pc_offset,
1191             debug_info, dependencies, code_buffer, frame_size, oop_maps,
1192             handler_table, nul_chk_table, compiler, comp_level, scc_entry
1193 #if INCLUDE_JVMCI
1194             , speculations,
1195             speculations_len,
1196             jvmci_data
1197 #endif
1198             );
1199 
1200     if (nm != nullptr) {
1201       // To make dependency checking during class loading fast, record
1202       // the nmethod dependencies in the classes it is dependent on.
1203       // This allows the dependency checking code to simply walk the
1204       // class hierarchy above the loaded class, checking only nmethods
1205       // which are dependent on those classes.  The slow way is to
1206       // check every nmethod for dependencies which makes it linear in
1207       // the number of methods compiled.  For applications with a lot
1208       // classes the slow way is too slow.
1209       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1210         if (deps.type() == Dependencies::call_site_target_value) {
1211           // CallSite dependencies are managed on per-CallSite instance basis.
1212           oop call_site = deps.argument_oop(0);
1213           MethodHandles::add_dependent_nmethod(call_site, nm);
1214         } else {
1215           InstanceKlass* ik = deps.context_type();
1216           if (ik == nullptr) {
1217             continue;  // ignore things like evol_method
1218           }
1219           // record this nmethod as dependent on this klass
1220           ik->add_dependent_nmethod(nm);
1221         }
1222       }
1223       NOT_PRODUCT(if (nm != nullptr)  note_java_nmethod(nm));
1224     }
1225   }
1226   // Do verification and logging outside CodeCache_lock.
1227   if (nm != nullptr) {
1228 
1229 #ifdef ASSERT
1230     LogTarget(Debug, scc, nmethod) log;
1231     if (log.is_enabled()) {
1232       LogStream out(log);
1233       out.print_cr("== new_nmethod 2");
1234       FlagSetting fs(PrintRelocations, true);
1235       nm->print_on_impl(&out);
1236       nm->decode(&out);
1237     }
1238 #endif
1239 
1240     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
1241     DEBUG_ONLY(nm->verify();)
1242     nm->log_new_nmethod();
1243   }
1244   return nm;
1245 }
1246 
1247 // Fill in default values for various fields
1248 void nmethod::init_defaults(CodeBuffer *code_buffer, CodeOffsets* offsets) {
1249   // avoid uninitialized fields, even for short time periods
1250   _exception_cache            = nullptr;
1251   _gc_data                    = nullptr;
1252   _oops_do_mark_link          = nullptr;
1253   _compiled_ic_data           = nullptr;
1254 
1255   _is_unloading_state         = 0;
1256   _state                      = not_installed;
1257 
1258   _has_unsafe_access          = 0;
1259   _has_method_handle_invokes  = 0;
1260   _has_wide_vectors           = 0;
1261   _has_monitors               = 0;
1262   _has_scoped_access          = 0;
1263   _has_flushed_dependencies   = 0;
1264   _is_unlinked                = 0;
1265   _load_reported              = 0; // jvmti state
1266   _preloaded                  = 0;
1267   _has_clinit_barriers        = 0;
1268 
1269   _used                       = false;
1270   _deoptimization_status      = not_marked;
1271 
1272   // SECT_CONSTS is first in code buffer so the offset should be 0.
1273   int consts_offset = code_buffer->total_offset_of(code_buffer->consts());
1274   assert(consts_offset == 0, "const_offset: %d", consts_offset);
1275 
1276   _stub_offset = content_offset() + code_buffer->total_offset_of(code_buffer->stubs());
1277 
1278   CHECKED_CAST(_entry_offset,              uint16_t, (offsets->value(CodeOffsets::Entry)));
1279   CHECKED_CAST(_verified_entry_offset,     uint16_t, (offsets->value(CodeOffsets::Verified_Entry)));
1280 
1281   _skipped_instructions_size = code_buffer->total_skipped_instructions_size();
1282 }
1283 
1284 // Post initialization
1285 void nmethod::post_init() {
1286   clear_unloading_state();
1287 
1288   finalize_relocations();
1289 
1290   Universe::heap()->register_nmethod(this);
1291   debug_only(Universe::heap()->verify_nmethod(this));
1292 
1293   CodeCache::commit(this);
1294 }
1295 
1296 // For native wrappers
1297 nmethod::nmethod(
1298   Method* method,
1299   CompilerType type,
1300   int nmethod_size,
1301   int compile_id,
1302   CodeOffsets* offsets,
1303   CodeBuffer* code_buffer,
1304   int frame_size,
1305   ByteSize basic_lock_owner_sp_offset,
1306   ByteSize basic_lock_sp_offset,
1307   OopMapSet* oop_maps,
1308   int mutable_data_size)
1309   : CodeBlob("native nmethod", CodeBlobKind::Nmethod, code_buffer, nmethod_size, sizeof(nmethod),
1310              offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false, mutable_data_size),
1311   _deoptimization_generation(0),
1312   _gc_epoch(CodeCache::gc_epoch()),
1313   _method(method),
1314   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
1315   _native_basic_lock_sp_offset(basic_lock_sp_offset)
1316 {
1317   {
1318     debug_only(NoSafepointVerifier nsv;)
1319     assert_locked_or_safepoint(CodeCache_lock);
1320 
1321     init_defaults(code_buffer, offsets);
1322 
1323     _osr_entry_point         = nullptr;
1324     _pc_desc_container       = nullptr;
1325     _entry_bci               = InvocationEntryBci;
1326     _compile_id              = compile_id;
1327     _comp_level              = CompLevel_none;
1328     _compiler_type           = type;
1329     _orig_pc_offset          = 0;
1330     _num_stack_arg_slots     = 0;
1331 
1332     if (offsets->value(CodeOffsets::Exceptions) != -1) {
1333       // Continuation enter intrinsic
1334       _exception_offset      = code_offset() + offsets->value(CodeOffsets::Exceptions);
1335     } else {
1336       _exception_offset      = 0;
1337     }
1338     // Native wrappers do not have deopt handlers. Make the values
1339     // something that will never match a pc like the nmethod vtable entry
1340     _deopt_handler_offset    = 0;
1341     _deopt_mh_handler_offset = 0;
1342     _scc_entry               = nullptr;
1343     _method_profiling_count  = 0;
1344     _unwind_handler_offset   = 0;
1345 
1346     CHECKED_CAST(_oops_size, uint16_t, align_up(code_buffer->total_oop_size(), oopSize));
1347     int metadata_size = align_up(code_buffer->total_metadata_size(), wordSize);
1348     JVMCI_ONLY( _jvmci_data_size = 0; )
1349     assert(_mutable_data_size == _relocation_size + metadata_size,
1350            "wrong mutable data size: %d != %d + %d",
1351            _mutable_data_size, _relocation_size, metadata_size);
1352 
1353     // native wrapper does not have read-only data but we need unique not null address
1354     _immutable_data          = blob_end();
1355     _immutable_data_size     = 0;
1356     _nul_chk_table_offset    = 0;
1357     _handler_table_offset    = 0;
1358     _scopes_pcs_offset       = 0;
1359     _scopes_data_offset      = 0;
1360 #if INCLUDE_JVMCI
1361     _speculations_offset     = 0;
1362 #endif
1363 
1364     code_buffer->copy_code_and_locs_to(this);
1365     code_buffer->copy_values_to(this);
1366 
1367     post_init();
1368   }
1369 
1370   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
1371     ttyLocker ttyl;  // keep the following output all in one block
1372     // This output goes directly to the tty, not the compiler log.
1373     // To enable tools to match it up with the compilation activity,
1374     // be sure to tag this tty output with the compile ID.
1375     if (xtty != nullptr) {
1376       xtty->begin_head("print_native_nmethod");
1377       xtty->method(_method);
1378       xtty->stamp();
1379       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
1380     }
1381     // Print the header part, then print the requested information.
1382     // This is both handled in decode2(), called via print_code() -> decode()
1383     if (PrintNativeNMethods) {
1384       tty->print_cr("-------------------------- Assembly (native nmethod) ---------------------------");
1385       print_code();
1386       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1387 #if defined(SUPPORT_DATA_STRUCTS)
1388       if (AbstractDisassembler::show_structs()) {
1389         if (oop_maps != nullptr) {
1390           tty->print("oop maps:"); // oop_maps->print_on(tty) outputs a cr() at the beginning
1391           oop_maps->print_on(tty);
1392           tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1393         }
1394       }
1395 #endif
1396     } else {
1397       print(); // print the header part only.
1398     }
1399 #if defined(SUPPORT_DATA_STRUCTS)
1400     if (AbstractDisassembler::show_structs()) {
1401       if (PrintRelocations) {
1402         print_relocations_on(tty);
1403         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1404       }
1405     }
1406 #endif
1407     if (xtty != nullptr) {
1408       xtty->tail("print_native_nmethod");
1409     }
1410   }
1411 }
1412 
1413 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
1414   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
1415 }
1416 
1417 void* nmethod::operator new(size_t size, int nmethod_size, bool allow_NonNMethod_space) throw () {
1418   // Try MethodNonProfiled and MethodProfiled.
1419   void* return_value = CodeCache::allocate(nmethod_size, CodeBlobType::MethodNonProfiled);
1420   if (return_value != nullptr || !allow_NonNMethod_space) return return_value;
1421   // Try NonNMethod or give up.
1422   return CodeCache::allocate(nmethod_size, CodeBlobType::NonNMethod);
1423 }
1424 
1425 // For normal JIT compiled code
1426 nmethod::nmethod(
1427   Method* method,
1428   CompilerType type,
1429   int nmethod_size,
1430   int immutable_data_size,
1431   int mutable_data_size,
1432   int compile_id,
1433   int entry_bci,
1434   address immutable_data,
1435   CodeOffsets* offsets,
1436   int orig_pc_offset,
1437   DebugInformationRecorder* debug_info,
1438   Dependencies* dependencies,
1439   CodeBuffer *code_buffer,
1440   int frame_size,
1441   OopMapSet* oop_maps,
1442   ExceptionHandlerTable* handler_table,
1443   ImplicitExceptionTable* nul_chk_table,
1444   AbstractCompiler* compiler,
1445   CompLevel comp_level
1446   , SCCEntry* scc_entry
1447 #if INCLUDE_JVMCI
1448   , char* speculations,
1449   int speculations_len,
1450   JVMCINMethodData* jvmci_data
1451 #endif
1452   )
1453   : CodeBlob("nmethod", CodeBlobKind::Nmethod, code_buffer, nmethod_size, sizeof(nmethod),
1454              offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false, mutable_data_size),
1455   _deoptimization_generation(0),
1456   _gc_epoch(CodeCache::gc_epoch()),
1457   _method(method),
1458   _osr_link(nullptr)
1459 {
1460   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
1461   {
1462     debug_only(NoSafepointVerifier nsv;)
1463     assert_locked_or_safepoint(CodeCache_lock);
1464 
1465     init_defaults(code_buffer, offsets);
1466     _scc_entry      = scc_entry;
1467     _method_profiling_count  = 0;
1468 
1469     _osr_entry_point = code_begin() + offsets->value(CodeOffsets::OSR_Entry);
1470     _entry_bci       = entry_bci;
1471     _compile_id      = compile_id;
1472     _comp_level      = comp_level;
1473     _compiler_type   = type;
1474     _orig_pc_offset  = orig_pc_offset;
1475 
1476     _num_stack_arg_slots = entry_bci != InvocationEntryBci ? 0 : _method->constMethod()->num_stack_arg_slots();
1477 
1478     set_ctable_begin(header_begin() + content_offset());
1479 
1480 #if INCLUDE_JVMCI
1481     if (compiler->is_jvmci()) {
1482       // JVMCI might not produce any stub sections
1483       if (offsets->value(CodeOffsets::Exceptions) != -1) {
1484         _exception_offset        = code_offset() + offsets->value(CodeOffsets::Exceptions);
1485       } else {
1486         _exception_offset        = -1;
1487       }
1488       if (offsets->value(CodeOffsets::Deopt) != -1) {
1489         _deopt_handler_offset    = code_offset() + offsets->value(CodeOffsets::Deopt);
1490       } else {
1491         _deopt_handler_offset    = -1;
1492       }
1493       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
1494         _deopt_mh_handler_offset = code_offset() + offsets->value(CodeOffsets::DeoptMH);
1495       } else {
1496         _deopt_mh_handler_offset = -1;
1497       }
1498     } else
1499 #endif
1500     {
1501       // Exception handler and deopt handler are in the stub section
1502       assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
1503       assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
1504 
1505       _exception_offset          = _stub_offset + offsets->value(CodeOffsets::Exceptions);
1506       _deopt_handler_offset      = _stub_offset + offsets->value(CodeOffsets::Deopt);
1507       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
1508         _deopt_mh_handler_offset = _stub_offset + offsets->value(CodeOffsets::DeoptMH);
1509       } else {
1510         _deopt_mh_handler_offset = -1;
1511       }
1512     }
1513     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
1514       // C1 generates UnwindHandler at the end of instructions section.
1515       // Calculate positive offset as distance between the start of stubs section
1516       // (which is also the end of instructions section) and the start of the handler.
1517       int unwind_handler_offset = code_offset() + offsets->value(CodeOffsets::UnwindHandler);
1518       CHECKED_CAST(_unwind_handler_offset, int16_t, (_stub_offset - unwind_handler_offset));
1519     } else {
1520       _unwind_handler_offset = -1;
1521     }
1522 
1523     CHECKED_CAST(_oops_size, uint16_t, align_up(code_buffer->total_oop_size(), oopSize));
1524     uint16_t metadata_size = (uint16_t)align_up(code_buffer->total_metadata_size(), wordSize);
1525     JVMCI_ONLY(CHECKED_CAST(_jvmci_data_size, uint16_t, align_up(compiler->is_jvmci() ? jvmci_data->size() : 0, oopSize)));
1526     int jvmci_data_size = 0 JVMCI_ONLY(+ _jvmci_data_size);
1527     assert(_mutable_data_size == _relocation_size + metadata_size + jvmci_data_size,
1528            "wrong mutable data size: %d != %d + %d + %d",
1529            _mutable_data_size, _relocation_size, metadata_size, jvmci_data_size);
1530     assert(nmethod_size == data_end() - header_begin(), "wrong nmethod size: %d != %d",
1531            nmethod_size, (int)(code_end() - header_begin()));
1532 
1533     _immutable_data_size  = immutable_data_size;
1534     if (immutable_data_size > 0) {
1535       assert(immutable_data != nullptr, "required");
1536       _immutable_data     = immutable_data;
1537     } else {
1538       // We need unique not null address
1539       _immutable_data     = blob_end();
1540     }
1541     CHECKED_CAST(_nul_chk_table_offset, uint16_t, (align_up((int)dependencies->size_in_bytes(), oopSize)));
1542     CHECKED_CAST(_handler_table_offset, uint16_t, (_nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize)));
1543     _scopes_pcs_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
1544     _scopes_data_offset   = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
1545 
1546 #if INCLUDE_JVMCI
1547     _speculations_offset  = _scopes_data_offset   + align_up(debug_info->data_size(), oopSize);
1548     DEBUG_ONLY( int immutable_data_end_offset = _speculations_offset  + align_up(speculations_len, oopSize); )
1549 #else
1550     DEBUG_ONLY( int immutable_data_end_offset = _scopes_data_offset + align_up(debug_info->data_size(), oopSize); )
1551 #endif
1552     assert(immutable_data_end_offset <= immutable_data_size, "wrong read-only data size: %d > %d",
1553            immutable_data_end_offset, immutable_data_size);
1554 
1555     // Copy code and relocation info
1556     code_buffer->copy_code_and_locs_to(this);
1557     // Copy oops and metadata
1558     code_buffer->copy_values_to(this);
1559     dependencies->copy_to(this);
1560     // Copy PcDesc and ScopeDesc data
1561     debug_info->copy_to(this);
1562 
1563     // Create cache after PcDesc data is copied - it will be used to initialize cache
1564     _pc_desc_container = new PcDescContainer(scopes_pcs_begin());
1565 
1566 #if INCLUDE_JVMCI
1567     if (compiler->is_jvmci()) {
1568       // Initialize the JVMCINMethodData object inlined into nm
1569       jvmci_nmethod_data()->copy(jvmci_data);
1570     }
1571 #endif
1572 
1573     // Copy contents of ExceptionHandlerTable to nmethod
1574     handler_table->copy_to(this);
1575     nul_chk_table->copy_to(this);
1576 
1577 #if INCLUDE_JVMCI
1578     // Copy speculations to nmethod
1579     if (speculations_size() != 0) {
1580       memcpy(speculations_begin(), speculations, speculations_len);
1581     }
1582 #endif
1583 
1584     post_init();
1585 
1586     // we use the information of entry points to find out if a method is
1587     // static or non static
1588     assert(compiler->is_c2() || compiler->is_jvmci() ||
1589            _method->is_static() == (entry_point() == verified_entry_point()),
1590            " entry points must be same for static methods and vice versa");
1591   }
1592 }
1593 
1594 // Print a short set of xml attributes to identify this nmethod.  The
1595 // output should be embedded in some other element.
1596 void nmethod::log_identity(xmlStream* log) const {
1597   assert(log->inside_attrs_or_error(), "printing attributes");
1598   log->print(" code_compile_id='%d'", compile_id());
1599   const char* nm_kind = compile_kind();
1600   if (nm_kind != nullptr)  log->print(" code_compile_kind='%s'", nm_kind);
1601   log->print(" code_compiler='%s'", compiler_name());
1602   if (TieredCompilation) {
1603     log->print(" code_compile_level='%d'", comp_level());
1604   }
1605 #if INCLUDE_JVMCI
1606   if (jvmci_nmethod_data() != nullptr) {
1607     const char* jvmci_name = jvmci_nmethod_data()->name();
1608     if (jvmci_name != nullptr) {
1609       log->print(" jvmci_mirror_name='");
1610       log->text("%s", jvmci_name);
1611       log->print("'");
1612     }
1613   }
1614 #endif
1615 }
1616 
1617 
1618 #define LOG_OFFSET(log, name)                    \
1619   if (p2i(name##_end()) - p2i(name##_begin())) \
1620     log->print(" " XSTR(name) "_offset='%zd'"    , \
1621                p2i(name##_begin()) - p2i(this))
1622 
1623 
1624 void nmethod::log_new_nmethod() const {
1625   if (LogCompilation && xtty != nullptr) {
1626     ttyLocker ttyl;
1627     xtty->begin_elem("nmethod");
1628     log_identity(xtty);
1629     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
1630     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
1631 
1632     LOG_OFFSET(xtty, relocation);
1633     LOG_OFFSET(xtty, consts);
1634     LOG_OFFSET(xtty, insts);
1635     LOG_OFFSET(xtty, stub);
1636     LOG_OFFSET(xtty, scopes_data);
1637     LOG_OFFSET(xtty, scopes_pcs);
1638     LOG_OFFSET(xtty, dependencies);
1639     LOG_OFFSET(xtty, handler_table);
1640     LOG_OFFSET(xtty, nul_chk_table);
1641     LOG_OFFSET(xtty, oops);
1642     LOG_OFFSET(xtty, metadata);
1643 
1644     xtty->method(method());
1645     xtty->stamp();
1646     xtty->end_elem();
1647   }
1648 }
1649 
1650 #undef LOG_OFFSET
1651 
1652 
1653 // Print out more verbose output usually for a newly created nmethod.
1654 void nmethod::print_on_with_msg(outputStream* st, const char* msg) const {
1655   if (st != nullptr) {
1656     ttyLocker ttyl;
1657     if (WizardMode) {
1658       CompileTask::print(st, this, msg, /*short_form:*/ true);
1659       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
1660     } else {
1661       CompileTask::print(st, this, msg, /*short_form:*/ false);
1662     }
1663   }
1664 }
1665 
1666 void nmethod::maybe_print_nmethod(const DirectiveSet* directive) {
1667   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
1668   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
1669     print_nmethod(printnmethods);
1670   }
1671 }
1672 
1673 void nmethod::print_nmethod(bool printmethod) {
1674   ttyLocker ttyl;  // keep the following output all in one block
1675   if (xtty != nullptr) {
1676     xtty->begin_head("print_nmethod");
1677     log_identity(xtty);
1678     xtty->stamp();
1679     xtty->end_head();
1680   }
1681   // Print the header part, then print the requested information.
1682   // This is both handled in decode2().
1683   if (printmethod) {
1684     ResourceMark m;
1685     if (is_compiled_by_c1()) {
1686       tty->cr();
1687       tty->print_cr("============================= C1-compiled nmethod ==============================");
1688     }
1689     if (is_compiled_by_jvmci()) {
1690       tty->cr();
1691       tty->print_cr("=========================== JVMCI-compiled nmethod =============================");
1692     }
1693     tty->print_cr("----------------------------------- Assembly -----------------------------------");
1694     decode2(tty);
1695 #if defined(SUPPORT_DATA_STRUCTS)
1696     if (AbstractDisassembler::show_structs()) {
1697       // Print the oops from the underlying CodeBlob as well.
1698       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1699       print_oops(tty);
1700       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1701       print_metadata(tty);
1702       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1703       print_pcs_on(tty);
1704       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1705       if (oop_maps() != nullptr) {
1706         tty->print("oop maps:"); // oop_maps()->print_on(tty) outputs a cr() at the beginning
1707         oop_maps()->print_on(tty);
1708         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1709       }
1710     }
1711 #endif
1712   } else {
1713     print(); // print the header part only.
1714   }
1715 
1716 #if defined(SUPPORT_DATA_STRUCTS)
1717   if (AbstractDisassembler::show_structs()) {
1718     methodHandle mh(Thread::current(), _method);
1719     if (printmethod || PrintDebugInfo || CompilerOracle::has_option(mh, CompileCommandEnum::PrintDebugInfo)) {
1720       print_scopes();
1721       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1722     }
1723     if (printmethod || PrintRelocations || CompilerOracle::has_option(mh, CompileCommandEnum::PrintRelocations)) {
1724       print_relocations_on(tty);
1725       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1726     }
1727     if (printmethod || PrintDependencies || CompilerOracle::has_option(mh, CompileCommandEnum::PrintDependencies)) {
1728       print_dependencies_on(tty);
1729       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1730     }
1731     if (printmethod || PrintExceptionHandlers) {
1732       print_handler_table();
1733       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1734       print_nul_chk_table();
1735       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1736     }
1737 
1738     if (printmethod) {
1739       print_recorded_oops();
1740       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1741       print_recorded_metadata();
1742       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
1743     }
1744   }
1745 #endif
1746 
1747   if (xtty != nullptr) {
1748     xtty->tail("print_nmethod");
1749   }
1750 }
1751 
1752 
1753 // Promote one word from an assembly-time handle to a live embedded oop.
1754 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1755   if (handle == nullptr ||
1756       // As a special case, IC oops are initialized to 1 or -1.
1757       handle == (jobject) Universe::non_oop_word()) {
1758     *(void**)dest = handle;
1759   } else {
1760     *dest = JNIHandles::resolve_non_null(handle);
1761   }
1762 }
1763 
1764 
1765 // Have to have the same name because it's called by a template
1766 void nmethod::copy_values(GrowableArray<jobject>* array) {
1767   int length = array->length();
1768   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
1769   oop* dest = oops_begin();
1770   for (int index = 0 ; index < length; index++) {
1771     initialize_immediate_oop(&dest[index], array->at(index));
1772   }
1773 
1774   // Now we can fix up all the oops in the code.  We need to do this
1775   // in the code because the assembler uses jobjects as placeholders.
1776   // The code and relocations have already been initialized by the
1777   // CodeBlob constructor, so it is valid even at this early point to
1778   // iterate over relocations and patch the code.
1779   fix_oop_relocations(nullptr, nullptr, /*initialize_immediates=*/ true);
1780 }
1781 
1782 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
1783   int length = array->length();
1784   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
1785   Metadata** dest = metadata_begin();
1786   for (int index = 0 ; index < length; index++) {
1787     dest[index] = array->at(index);
1788   }
1789 }
1790 
1791 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1792   // re-patch all oop-bearing instructions, just in case some oops moved
1793   RelocIterator iter(this, begin, end);
1794   while (iter.next()) {
1795     if (iter.type() == relocInfo::oop_type) {
1796       oop_Relocation* reloc = iter.oop_reloc();
1797       if (initialize_immediates && reloc->oop_is_immediate()) {
1798         oop* dest = reloc->oop_addr();
1799         jobject obj = *reinterpret_cast<jobject*>(dest);
1800         initialize_immediate_oop(dest, obj);
1801       }
1802       // Refresh the oop-related bits of this instruction.
1803       reloc->fix_oop_relocation();
1804     } else if (iter.type() == relocInfo::metadata_type) {
1805       metadata_Relocation* reloc = iter.metadata_reloc();
1806       reloc->fix_metadata_relocation();
1807     }
1808   }
1809 }
1810 
1811 static void install_post_call_nop_displacement(nmethod* nm, address pc) {
1812   NativePostCallNop* nop = nativePostCallNop_at((address) pc);
1813   intptr_t cbaddr = (intptr_t) nm;
1814   intptr_t offset = ((intptr_t) pc) - cbaddr;
1815 
1816   int oopmap_slot = nm->oop_maps()->find_slot_for_offset(int((intptr_t) pc - (intptr_t) nm->code_begin()));
1817   if (oopmap_slot < 0) { // this can happen at asynchronous (non-safepoint) stackwalks
1818     log_debug(codecache)("failed to find oopmap for cb: " INTPTR_FORMAT " offset: %d", cbaddr, (int) offset);
1819   } else if (!nop->patch(oopmap_slot, offset)) {
1820     log_debug(codecache)("failed to encode %d %d", oopmap_slot, (int) offset);
1821   }
1822 }
1823 
1824 void nmethod::finalize_relocations() {
1825   NoSafepointVerifier nsv;
1826 
1827   GrowableArray<NativeMovConstReg*> virtual_call_data;
1828 
1829   // Make sure that post call nops fill in nmethod offsets eagerly so
1830   // we don't have to race with deoptimization
1831   RelocIterator iter(this);
1832   while (iter.next()) {
1833     if (iter.type() == relocInfo::virtual_call_type) {
1834       virtual_call_Relocation* r = iter.virtual_call_reloc();
1835       NativeMovConstReg* value = nativeMovConstReg_at(r->cached_value());
1836       virtual_call_data.append(value);
1837     } else if (iter.type() == relocInfo::post_call_nop_type) {
1838       post_call_nop_Relocation* const reloc = iter.post_call_nop_reloc();
1839       address pc = reloc->addr();
1840       install_post_call_nop_displacement(this, pc);
1841     }
1842   }
1843 
1844   if (virtual_call_data.length() > 0) {
1845     // We allocate a block of CompiledICData per nmethod so the GC can purge this faster.
1846     _compiled_ic_data = new CompiledICData[virtual_call_data.length()];
1847     CompiledICData* next_data = _compiled_ic_data;
1848 
1849     for (NativeMovConstReg* value : virtual_call_data) {
1850       value->set_data((intptr_t)next_data);
1851       next_data++;
1852     }
1853   }
1854 }
1855 
1856 void nmethod::make_deoptimized() {
1857   if (!Continuations::enabled()) {
1858     // Don't deopt this again.
1859     set_deoptimized_done();
1860     return;
1861   }
1862 
1863   assert(method() == nullptr || can_be_deoptimized(), "");
1864 
1865   CompiledICLocker ml(this);
1866   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
1867 
1868   // If post call nops have been already patched, we can just bail-out.
1869   if (has_been_deoptimized()) {
1870     return;
1871   }
1872 
1873   ResourceMark rm;
1874   RelocIterator iter(this, oops_reloc_begin());
1875 
1876   while (iter.next()) {
1877 
1878     switch (iter.type()) {
1879       case relocInfo::virtual_call_type: {
1880         CompiledIC *ic = CompiledIC_at(&iter);
1881         address pc = ic->end_of_call();
1882         NativePostCallNop* nop = nativePostCallNop_at(pc);
1883         if (nop != nullptr) {
1884           nop->make_deopt();
1885         }
1886         assert(NativeDeoptInstruction::is_deopt_at(pc), "check");
1887         break;
1888       }
1889       case relocInfo::static_call_type:
1890       case relocInfo::opt_virtual_call_type: {
1891         CompiledDirectCall *csc = CompiledDirectCall::at(iter.reloc());
1892         address pc = csc->end_of_call();
1893         NativePostCallNop* nop = nativePostCallNop_at(pc);
1894         //tty->print_cr(" - static pc %p", pc);
1895         if (nop != nullptr) {
1896           nop->make_deopt();
1897         }
1898         // We can't assert here, there are some calls to stubs / runtime
1899         // that have reloc data and doesn't have a post call NOP.
1900         //assert(NativeDeoptInstruction::is_deopt_at(pc), "check");
1901         break;
1902       }
1903       default:
1904         break;
1905     }
1906   }
1907   // Don't deopt this again.
1908   set_deoptimized_done();
1909 }
1910 
1911 void nmethod::verify_clean_inline_caches() {
1912   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
1913 
1914   ResourceMark rm;
1915   RelocIterator iter(this, oops_reloc_begin());
1916   while(iter.next()) {
1917     switch(iter.type()) {
1918       case relocInfo::virtual_call_type: {
1919         CompiledIC *ic = CompiledIC_at(&iter);
1920         CodeBlob *cb = CodeCache::find_blob(ic->destination());
1921         assert(cb != nullptr, "destination not in CodeBlob?");
1922         nmethod* nm = cb->as_nmethod_or_null();
1923         if (nm != nullptr) {
1924           // Verify that inline caches pointing to bad nmethods are clean
1925           if (!nm->is_in_use() || nm->is_unloading()) {
1926             assert(ic->is_clean(), "IC should be clean");
1927           }
1928         }
1929         break;
1930       }
1931       case relocInfo::static_call_type:
1932       case relocInfo::opt_virtual_call_type: {
1933         CompiledDirectCall *cdc = CompiledDirectCall::at(iter.reloc());
1934         CodeBlob *cb = CodeCache::find_blob(cdc->destination());
1935         assert(cb != nullptr, "destination not in CodeBlob?");
1936         nmethod* nm = cb->as_nmethod_or_null();
1937         if (nm != nullptr) {
1938           // Verify that inline caches pointing to bad nmethods are clean
1939           if (!nm->is_in_use() || nm->is_unloading() || nm->method()->code() != nm) {
1940             assert(cdc->is_clean(), "IC should be clean");
1941           }
1942         }
1943         break;
1944       }
1945       default:
1946         break;
1947     }
1948   }
1949 }
1950 
1951 void nmethod::mark_as_maybe_on_stack() {
1952   Atomic::store(&_gc_epoch, CodeCache::gc_epoch());
1953 }
1954 
1955 bool nmethod::is_maybe_on_stack() {
1956   // If the condition below is true, it means that the nmethod was found to
1957   // be alive the previous completed marking cycle.
1958   return Atomic::load(&_gc_epoch) >= CodeCache::previous_completed_gc_marking_cycle();
1959 }
1960 
1961 void nmethod::inc_decompile_count() {
1962   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1963   // Could be gated by ProfileTraps, but do not bother...
1964   Method* m = method();
1965   if (m == nullptr)  return;
1966   MethodData* mdo = m->method_data();
1967   if (mdo == nullptr)  return;
1968   // There is a benign race here.  See comments in methodData.hpp.
1969   mdo->inc_decompile_count();
1970 }
1971 
1972 void nmethod::inc_method_profiling_count() {
1973   Atomic::inc(&_method_profiling_count);
1974 }
1975 
1976 uint64_t nmethod::method_profiling_count() {
1977   return _method_profiling_count;
1978 }
1979 
1980 bool nmethod::try_transition(signed char new_state_int) {
1981   signed char new_state = new_state_int;
1982   assert_lock_strong(NMethodState_lock);
1983   signed char old_state = _state;
1984   if (old_state >= new_state) {
1985     // Ensure monotonicity of transitions.
1986     return false;
1987   }
1988   Atomic::store(&_state, new_state);
1989   return true;
1990 }
1991 
1992 void nmethod::invalidate_osr_method() {
1993   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1994   // Remove from list of active nmethods
1995   if (method() != nullptr) {
1996     method()->method_holder()->remove_osr_nmethod(this);
1997   }
1998 }
1999 
2000 void nmethod::log_state_change(const char* reason) const {
2001   assert(reason != nullptr, "Must provide a reason");
2002 
2003   if (LogCompilation) {
2004     if (xtty != nullptr) {
2005       ttyLocker ttyl;  // keep the following output all in one block
2006       xtty->begin_elem("make_not_entrant thread='%zu' reason='%s'",
2007                        os::current_thread_id(), reason);
2008       log_identity(xtty);
2009       xtty->stamp();
2010       xtty->end_elem();
2011     }
2012   }
2013 
2014   ResourceMark rm;
2015   stringStream ss(NEW_RESOURCE_ARRAY(char, 256), 256);
2016   ss.print("made not entrant: %s", reason);
2017 
2018   CompileTask::print_ul(this, ss.freeze());
2019   if (PrintCompilation) {
2020     print_on_with_msg(tty, ss.freeze());
2021   }
2022 }
2023 
2024 void nmethod::unlink_from_method() {
2025   if (method() != nullptr) {
2026     method()->unlink_code(this);
2027   }
2028 }
2029 
2030 // Invalidate code
2031 bool nmethod::make_not_entrant(const char* reason, bool make_not_entrant) {
2032   assert(reason != nullptr, "Must provide a reason");
2033 
2034   // This can be called while the system is already at a safepoint which is ok
2035   NoSafepointVerifier nsv;
2036 
2037   if (is_unloading()) {
2038     // If the nmethod is unloading, then it is already not entrant through
2039     // the nmethod entry barriers. No need to do anything; GC will unload it.
2040     return false;
2041   }
2042 
2043   if (Atomic::load(&_state) == not_entrant) {
2044     // Avoid taking the lock if already in required state.
2045     // This is safe from races because the state is an end-state,
2046     // which the nmethod cannot back out of once entered.
2047     // No need for fencing either.
2048     return false;
2049   }
2050 
2051   {
2052     // Enter critical section.  Does not block for safepoint.
2053     ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
2054 
2055     if (Atomic::load(&_state) == not_entrant) {
2056       // another thread already performed this transition so nothing
2057       // to do, but return false to indicate this.
2058       return false;
2059     }
2060 
2061     if (is_osr_method()) {
2062       // This logic is equivalent to the logic below for patching the
2063       // verified entry point of regular methods.
2064       // this effectively makes the osr nmethod not entrant
2065       invalidate_osr_method();
2066     } else {
2067       // The caller can be calling the method statically or through an inline
2068       // cache call.
2069       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
2070                                        SharedRuntime::get_handle_wrong_method_stub());
2071     }
2072 
2073     if (update_recompile_counts()) {
2074       // Mark the method as decompiled.
2075       inc_decompile_count();
2076     }
2077 
2078     BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2079     if (bs_nm == nullptr || !bs_nm->supports_entry_barrier(this)) {
2080       // If nmethod entry barriers are not supported, we won't mark
2081       // nmethods as on-stack when they become on-stack. So we
2082       // degrade to a less accurate flushing strategy, for now.
2083       mark_as_maybe_on_stack();
2084     }
2085 
2086     // Change state
2087     bool success = try_transition(not_entrant);
2088     assert(success, "Transition can't fail");
2089 
2090     // Log the transition once
2091     log_state_change(reason);
2092 
2093     // Remove nmethod from method.
2094     unlink_from_method();
2095 
2096     if (make_not_entrant) {
2097       // Keep cached code if it was simply replaced
2098       // otherwise make it not entrant too.
2099       SCCache::invalidate(_scc_entry);
2100     }
2101 
2102     CompileBroker::log_not_entrant(this);
2103   } // leave critical region under NMethodState_lock
2104 
2105 #if INCLUDE_JVMCI
2106   // Invalidate can't occur while holding the NMethodState_lock
2107   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
2108   if (nmethod_data != nullptr) {
2109     nmethod_data->invalidate_nmethod_mirror(this);
2110   }
2111 #endif
2112 
2113 #ifdef ASSERT
2114   if (is_osr_method() && method() != nullptr) {
2115     // Make sure osr nmethod is invalidated, i.e. not on the list
2116     bool found = method()->method_holder()->remove_osr_nmethod(this);
2117     assert(!found, "osr nmethod should have been invalidated");
2118   }
2119 #endif
2120 
2121   return true;
2122 }
2123 
2124 // For concurrent GCs, there must be a handshake between unlink and flush
2125 void nmethod::unlink() {
2126   if (is_unlinked()) {
2127     // Already unlinked.
2128     return;
2129   }
2130 
2131   flush_dependencies();
2132 
2133   // unlink_from_method will take the NMethodState_lock.
2134   // In this case we don't strictly need it when unlinking nmethods from
2135   // the Method, because it is only concurrently unlinked by
2136   // the entry barrier, which acquires the per nmethod lock.
2137   unlink_from_method();
2138 
2139   if (is_osr_method()) {
2140     invalidate_osr_method();
2141   }
2142 
2143 #if INCLUDE_JVMCI
2144   // Clear the link between this nmethod and a HotSpotNmethod mirror
2145   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
2146   if (nmethod_data != nullptr) {
2147     nmethod_data->invalidate_nmethod_mirror(this);
2148   }
2149 #endif
2150 
2151   // Post before flushing as jmethodID is being used
2152   post_compiled_method_unload();
2153 
2154   // Register for flushing when it is safe. For concurrent class unloading,
2155   // that would be after the unloading handshake, and for STW class unloading
2156   // that would be when getting back to the VM thread.
2157   ClassUnloadingContext::context()->register_unlinked_nmethod(this);
2158 }
2159 
2160 void nmethod::purge(bool unregister_nmethod) {
2161 
2162   MutexLocker ml(CodeCache_lock, Mutex::_no_safepoint_check_flag);
2163 
2164   // completely deallocate this method
2165   Events::log_nmethod_flush(Thread::current(), "flushing %s nmethod " INTPTR_FORMAT, is_osr_method() ? "osr" : "", p2i(this));
2166   log_debug(codecache)("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
2167                        "/Free CodeCache:%zuKb",
2168                        is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
2169                        CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
2170 
2171   // We need to deallocate any ExceptionCache data.
2172   // Note that we do not need to grab the nmethod lock for this, it
2173   // better be thread safe if we're disposing of it!
2174   ExceptionCache* ec = exception_cache();
2175   while(ec != nullptr) {
2176     ExceptionCache* next = ec->next();
2177     delete ec;
2178     ec = next;
2179   }
2180   if (_pc_desc_container != nullptr) {
2181     delete _pc_desc_container;
2182   }
2183   delete[] _compiled_ic_data;
2184 
2185   if (_immutable_data != blob_end()) {
2186     os::free(_immutable_data);
2187     _immutable_data = blob_end(); // Valid not null address
2188   }
2189   if (unregister_nmethod) {
2190     Universe::heap()->unregister_nmethod(this);
2191   }
2192   CodeCache::unregister_old_nmethod(this);
2193 
2194   CodeBlob::purge();
2195 }
2196 
2197 oop nmethod::oop_at(int index) const {
2198   if (index == 0) {
2199     return nullptr;
2200   }
2201 
2202   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2203   return bs_nm->oop_load_no_keepalive(this, index);
2204 }
2205 
2206 oop nmethod::oop_at_phantom(int index) const {
2207   if (index == 0) {
2208     return nullptr;
2209   }
2210 
2211   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2212   return bs_nm->oop_load_phantom(this, index);
2213 }
2214 
2215 //
2216 // Notify all classes this nmethod is dependent on that it is no
2217 // longer dependent.
2218 
2219 void nmethod::flush_dependencies() {
2220   if (!has_flushed_dependencies()) {
2221     set_has_flushed_dependencies(true);
2222     for (Dependencies::DepStream deps(this); deps.next(); ) {
2223       if (deps.type() == Dependencies::call_site_target_value) {
2224         // CallSite dependencies are managed on per-CallSite instance basis.
2225         oop call_site = deps.argument_oop(0);
2226         MethodHandles::clean_dependency_context(call_site);
2227       } else {
2228         InstanceKlass* ik = deps.context_type();
2229         if (ik == nullptr) {
2230           continue;  // ignore things like evol_method
2231         }
2232         // During GC liveness of dependee determines class that needs to be updated.
2233         // The GC may clean dependency contexts concurrently and in parallel.
2234         ik->clean_dependency_context();
2235       }
2236     }
2237   }
2238 }
2239 
2240 void nmethod::post_compiled_method(CompileTask* task) {
2241   task->mark_success();
2242   task->set_nm_content_size(content_size());
2243   task->set_nm_insts_size(insts_size());
2244   task->set_nm_total_size(total_size());
2245 
2246   // task->is_scc() is true only for loaded cached code.
2247   // nmethod::_scc_entry is set for loaded and stored cached code
2248   // to invalidate the entry when nmethod is deoptimized.
2249   // There is option to not store in archive cached code.
2250   guarantee((_scc_entry != nullptr) || !task->is_scc() || VerifyCachedCode, "sanity");
2251 
2252   // JVMTI -- compiled method notification (must be done outside lock)
2253   post_compiled_method_load_event();
2254 
2255   if (CompilationLog::log() != nullptr) {
2256     CompilationLog::log()->log_nmethod(JavaThread::current(), this);
2257   }
2258 
2259   const DirectiveSet* directive = task->directive();
2260   maybe_print_nmethod(directive);
2261 }
2262 
2263 // ------------------------------------------------------------------
2264 // post_compiled_method_load_event
2265 // new method for install_code() path
2266 // Transfer information from compilation to jvmti
2267 void nmethod::post_compiled_method_load_event(JvmtiThreadState* state) {
2268   // This is a bad time for a safepoint.  We don't want
2269   // this nmethod to get unloaded while we're queueing the event.
2270   NoSafepointVerifier nsv;
2271 
2272   Method* m = method();
2273   HOTSPOT_COMPILED_METHOD_LOAD(
2274       (char *) m->klass_name()->bytes(),
2275       m->klass_name()->utf8_length(),
2276       (char *) m->name()->bytes(),
2277       m->name()->utf8_length(),
2278       (char *) m->signature()->bytes(),
2279       m->signature()->utf8_length(),
2280       insts_begin(), insts_size());
2281 
2282 
2283   if (JvmtiExport::should_post_compiled_method_load()) {
2284     // Only post unload events if load events are found.
2285     set_load_reported();
2286     // If a JavaThread hasn't been passed in, let the Service thread
2287     // (which is a real Java thread) post the event
2288     JvmtiDeferredEvent event = JvmtiDeferredEvent::compiled_method_load_event(this);
2289     if (state == nullptr) {
2290       // Execute any barrier code for this nmethod as if it's called, since
2291       // keeping it alive looks like stack walking.
2292       run_nmethod_entry_barrier();
2293       ServiceThread::enqueue_deferred_event(&event);
2294     } else {
2295       // This enters the nmethod barrier outside in the caller.
2296       state->enqueue_event(&event);
2297     }
2298   }
2299 }
2300 
2301 void nmethod::post_compiled_method_unload() {
2302   assert(_method != nullptr, "just checking");
2303   DTRACE_METHOD_UNLOAD_PROBE(method());
2304 
2305   // If a JVMTI agent has enabled the CompiledMethodUnload event then
2306   // post the event. The Method* will not be valid when this is freed.
2307 
2308   // Don't bother posting the unload if the load event wasn't posted.
2309   if (load_reported() && JvmtiExport::should_post_compiled_method_unload()) {
2310     JvmtiDeferredEvent event =
2311       JvmtiDeferredEvent::compiled_method_unload_event(
2312           method()->jmethod_id(), insts_begin());
2313     ServiceThread::enqueue_deferred_event(&event);
2314   }
2315 }
2316 
2317 // Iterate over metadata calling this function.   Used by RedefineClasses
2318 void nmethod::metadata_do(MetadataClosure* f) {
2319   {
2320     // Visit all immediate references that are embedded in the instruction stream.
2321     RelocIterator iter(this, oops_reloc_begin());
2322     while (iter.next()) {
2323       if (iter.type() == relocInfo::metadata_type) {
2324         metadata_Relocation* r = iter.metadata_reloc();
2325         // In this metadata, we must only follow those metadatas directly embedded in
2326         // the code.  Other metadatas (oop_index>0) are seen as part of
2327         // the metadata section below.
2328         assert(1 == (r->metadata_is_immediate()) +
2329                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
2330                "metadata must be found in exactly one place");
2331         if (r->metadata_is_immediate() && r->metadata_value() != nullptr) {
2332           Metadata* md = r->metadata_value();
2333           if (md != _method) f->do_metadata(md);
2334         }
2335       } else if (iter.type() == relocInfo::virtual_call_type) {
2336         // Check compiledIC holders associated with this nmethod
2337         ResourceMark rm;
2338         CompiledIC *ic = CompiledIC_at(&iter);
2339         ic->metadata_do(f);
2340       }
2341     }
2342   }
2343 
2344   // Visit the metadata section
2345   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
2346     if (*p == Universe::non_oop_word() || *p == nullptr)  continue;  // skip non-oops
2347     Metadata* md = *p;
2348     f->do_metadata(md);
2349   }
2350 
2351   // Visit metadata not embedded in the other places.
2352   if (_method != nullptr) f->do_metadata(_method);
2353 }
2354 
2355 // Heuristic for nuking nmethods even though their oops are live.
2356 // Main purpose is to reduce code cache pressure and get rid of
2357 // nmethods that don't seem to be all that relevant any longer.
2358 bool nmethod::is_cold() {
2359   if (!MethodFlushing || is_native_method() || is_not_installed()) {
2360     // No heuristic unloading at all
2361     return false;
2362   }
2363 
2364   if (!is_maybe_on_stack() && is_not_entrant()) {
2365     // Not entrant nmethods that are not on any stack can just
2366     // be removed
2367     return true;
2368   }
2369 
2370   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2371   if (bs_nm == nullptr || !bs_nm->supports_entry_barrier(this)) {
2372     // On platforms that don't support nmethod entry barriers, we can't
2373     // trust the temporal aspect of the gc epochs. So we can't detect
2374     // cold nmethods on such platforms.
2375     return false;
2376   }
2377 
2378   if (!UseCodeCacheFlushing) {
2379     // Bail out if we don't heuristically remove nmethods
2380     return false;
2381   }
2382 
2383   // Other code can be phased out more gradually after N GCs
2384   return CodeCache::previous_completed_gc_marking_cycle() > _gc_epoch + 2 * CodeCache::cold_gc_count();
2385 }
2386 
2387 // The _is_unloading_state encodes a tuple comprising the unloading cycle
2388 // and the result of IsUnloadingBehaviour::is_unloading() for that cycle.
2389 // This is the bit layout of the _is_unloading_state byte: 00000CCU
2390 // CC refers to the cycle, which has 2 bits, and U refers to the result of
2391 // IsUnloadingBehaviour::is_unloading() for that unloading cycle.
2392 
2393 class IsUnloadingState: public AllStatic {
2394   static const uint8_t _is_unloading_mask = 1;
2395   static const uint8_t _is_unloading_shift = 0;
2396   static const uint8_t _unloading_cycle_mask = 6;
2397   static const uint8_t _unloading_cycle_shift = 1;
2398 
2399   static uint8_t set_is_unloading(uint8_t state, bool value) {
2400     state &= (uint8_t)~_is_unloading_mask;
2401     if (value) {
2402       state |= 1 << _is_unloading_shift;
2403     }
2404     assert(is_unloading(state) == value, "unexpected unloading cycle overflow");
2405     return state;
2406   }
2407 
2408   static uint8_t set_unloading_cycle(uint8_t state, uint8_t value) {
2409     state &= (uint8_t)~_unloading_cycle_mask;
2410     state |= (uint8_t)(value << _unloading_cycle_shift);
2411     assert(unloading_cycle(state) == value, "unexpected unloading cycle overflow");
2412     return state;
2413   }
2414 
2415 public:
2416   static bool is_unloading(uint8_t state) { return (state & _is_unloading_mask) >> _is_unloading_shift == 1; }
2417   static uint8_t unloading_cycle(uint8_t state) { return (state & _unloading_cycle_mask) >> _unloading_cycle_shift; }
2418 
2419   static uint8_t create(bool is_unloading, uint8_t unloading_cycle) {
2420     uint8_t state = 0;
2421     state = set_is_unloading(state, is_unloading);
2422     state = set_unloading_cycle(state, unloading_cycle);
2423     return state;
2424   }
2425 };
2426 
2427 bool nmethod::is_unloading() {
2428   uint8_t state = Atomic::load(&_is_unloading_state);
2429   bool state_is_unloading = IsUnloadingState::is_unloading(state);
2430   if (state_is_unloading) {
2431     return true;
2432   }
2433   uint8_t state_unloading_cycle = IsUnloadingState::unloading_cycle(state);
2434   uint8_t current_cycle = CodeCache::unloading_cycle();
2435   if (state_unloading_cycle == current_cycle) {
2436     return false;
2437   }
2438 
2439   // The IsUnloadingBehaviour is responsible for calculating if the nmethod
2440   // should be unloaded. This can be either because there is a dead oop,
2441   // or because is_cold() heuristically determines it is time to unload.
2442   state_unloading_cycle = current_cycle;
2443   state_is_unloading = IsUnloadingBehaviour::is_unloading(this);
2444   uint8_t new_state = IsUnloadingState::create(state_is_unloading, state_unloading_cycle);
2445 
2446   // Note that if an nmethod has dead oops, everyone will agree that the
2447   // nmethod is_unloading. However, the is_cold heuristics can yield
2448   // different outcomes, so we guard the computed result with a CAS
2449   // to ensure all threads have a shared view of whether an nmethod
2450   // is_unloading or not.
2451   uint8_t found_state = Atomic::cmpxchg(&_is_unloading_state, state, new_state, memory_order_relaxed);
2452 
2453   if (found_state == state) {
2454     // First to change state, we win
2455     return state_is_unloading;
2456   } else {
2457     // State already set, so use it
2458     return IsUnloadingState::is_unloading(found_state);
2459   }
2460 }
2461 
2462 void nmethod::clear_unloading_state() {
2463   uint8_t state = IsUnloadingState::create(false, CodeCache::unloading_cycle());
2464   Atomic::store(&_is_unloading_state, state);
2465 }
2466 
2467 
2468 // This is called at the end of the strong tracing/marking phase of a
2469 // GC to unload an nmethod if it contains otherwise unreachable
2470 // oops or is heuristically found to be not important.
2471 void nmethod::do_unloading(bool unloading_occurred) {
2472   // Make sure the oop's ready to receive visitors
2473   if (is_unloading()) {
2474     unlink();
2475   } else {
2476     unload_nmethod_caches(unloading_occurred);
2477     BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2478     if (bs_nm != nullptr) {
2479       bs_nm->disarm(this);
2480     }
2481   }
2482 }
2483 
2484 void nmethod::oops_do(OopClosure* f, bool allow_dead) {
2485   // Prevent extra code cache walk for platforms that don't have immediate oops.
2486   if (relocInfo::mustIterateImmediateOopsInCode()) {
2487     RelocIterator iter(this, oops_reloc_begin());
2488 
2489     while (iter.next()) {
2490       if (iter.type() == relocInfo::oop_type ) {
2491         oop_Relocation* r = iter.oop_reloc();
2492         // In this loop, we must only follow those oops directly embedded in
2493         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
2494         assert(1 == (r->oop_is_immediate()) +
2495                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
2496                "oop must be found in exactly one place");
2497         if (r->oop_is_immediate() && r->oop_value() != nullptr) {
2498           f->do_oop(r->oop_addr());
2499         }
2500       }
2501     }
2502   }
2503 
2504   // Scopes
2505   // This includes oop constants not inlined in the code stream.
2506   for (oop* p = oops_begin(); p < oops_end(); p++) {
2507     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
2508     f->do_oop(p);
2509   }
2510 }
2511 
2512 void nmethod::follow_nmethod(OopIterateClosure* cl) {
2513   // Process oops in the nmethod
2514   oops_do(cl);
2515 
2516   // CodeCache unloading support
2517   mark_as_maybe_on_stack();
2518 
2519   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
2520   bs_nm->disarm(this);
2521 
2522   // There's an assumption made that this function is not used by GCs that
2523   // relocate objects, and therefore we don't call fix_oop_relocations.
2524 }
2525 
2526 nmethod* volatile nmethod::_oops_do_mark_nmethods;
2527 
2528 void nmethod::oops_do_log_change(const char* state) {
2529   LogTarget(Trace, gc, nmethod) lt;
2530   if (lt.is_enabled()) {
2531     LogStream ls(lt);
2532     CompileTask::print(&ls, this, state, true /* short_form */);
2533   }
2534 }
2535 
2536 bool nmethod::oops_do_try_claim() {
2537   if (oops_do_try_claim_weak_request()) {
2538     nmethod* result = oops_do_try_add_to_list_as_weak_done();
2539     assert(result == nullptr, "adding to global list as weak done must always succeed.");
2540     return true;
2541   }
2542   return false;
2543 }
2544 
2545 bool nmethod::oops_do_try_claim_weak_request() {
2546   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2547 
2548   if ((_oops_do_mark_link == nullptr) &&
2549       (Atomic::replace_if_null(&_oops_do_mark_link, mark_link(this, claim_weak_request_tag)))) {
2550     oops_do_log_change("oops_do, mark weak request");
2551     return true;
2552   }
2553   return false;
2554 }
2555 
2556 void nmethod::oops_do_set_strong_done(nmethod* old_head) {
2557   _oops_do_mark_link = mark_link(old_head, claim_strong_done_tag);
2558 }
2559 
2560 nmethod::oops_do_mark_link* nmethod::oops_do_try_claim_strong_done() {
2561   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2562 
2563   oops_do_mark_link* old_next = Atomic::cmpxchg(&_oops_do_mark_link, mark_link(nullptr, claim_weak_request_tag), mark_link(this, claim_strong_done_tag));
2564   if (old_next == nullptr) {
2565     oops_do_log_change("oops_do, mark strong done");
2566   }
2567   return old_next;
2568 }
2569 
2570 nmethod::oops_do_mark_link* nmethod::oops_do_try_add_strong_request(nmethod::oops_do_mark_link* next) {
2571   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2572   assert(next == mark_link(this, claim_weak_request_tag), "Should be claimed as weak");
2573 
2574   oops_do_mark_link* old_next = Atomic::cmpxchg(&_oops_do_mark_link, next, mark_link(this, claim_strong_request_tag));
2575   if (old_next == next) {
2576     oops_do_log_change("oops_do, mark strong request");
2577   }
2578   return old_next;
2579 }
2580 
2581 bool nmethod::oops_do_try_claim_weak_done_as_strong_done(nmethod::oops_do_mark_link* next) {
2582   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2583   assert(extract_state(next) == claim_weak_done_tag, "Should be claimed as weak done");
2584 
2585   oops_do_mark_link* old_next = Atomic::cmpxchg(&_oops_do_mark_link, next, mark_link(extract_nmethod(next), claim_strong_done_tag));
2586   if (old_next == next) {
2587     oops_do_log_change("oops_do, mark weak done -> mark strong done");
2588     return true;
2589   }
2590   return false;
2591 }
2592 
2593 nmethod* nmethod::oops_do_try_add_to_list_as_weak_done() {
2594   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2595 
2596   assert(extract_state(_oops_do_mark_link) == claim_weak_request_tag ||
2597          extract_state(_oops_do_mark_link) == claim_strong_request_tag,
2598          "must be but is nmethod " PTR_FORMAT " %u", p2i(extract_nmethod(_oops_do_mark_link)), extract_state(_oops_do_mark_link));
2599 
2600   nmethod* old_head = Atomic::xchg(&_oops_do_mark_nmethods, this);
2601   // Self-loop if needed.
2602   if (old_head == nullptr) {
2603     old_head = this;
2604   }
2605   // Try to install end of list and weak done tag.
2606   if (Atomic::cmpxchg(&_oops_do_mark_link, mark_link(this, claim_weak_request_tag), mark_link(old_head, claim_weak_done_tag)) == mark_link(this, claim_weak_request_tag)) {
2607     oops_do_log_change("oops_do, mark weak done");
2608     return nullptr;
2609   } else {
2610     return old_head;
2611   }
2612 }
2613 
2614 void nmethod::oops_do_add_to_list_as_strong_done() {
2615   assert(SafepointSynchronize::is_at_safepoint(), "only at safepoint");
2616 
2617   nmethod* old_head = Atomic::xchg(&_oops_do_mark_nmethods, this);
2618   // Self-loop if needed.
2619   if (old_head == nullptr) {
2620     old_head = this;
2621   }
2622   assert(_oops_do_mark_link == mark_link(this, claim_strong_done_tag), "must be but is nmethod " PTR_FORMAT " state %u",
2623          p2i(extract_nmethod(_oops_do_mark_link)), extract_state(_oops_do_mark_link));
2624 
2625   oops_do_set_strong_done(old_head);
2626 }
2627 
2628 void nmethod::oops_do_process_weak(OopsDoProcessor* p) {
2629   if (!oops_do_try_claim_weak_request()) {
2630     // Failed to claim for weak processing.
2631     oops_do_log_change("oops_do, mark weak request fail");
2632     return;
2633   }
2634 
2635   p->do_regular_processing(this);
2636 
2637   nmethod* old_head = oops_do_try_add_to_list_as_weak_done();
2638   if (old_head == nullptr) {
2639     return;
2640   }
2641   oops_do_log_change("oops_do, mark weak done fail");
2642   // Adding to global list failed, another thread added a strong request.
2643   assert(extract_state(_oops_do_mark_link) == claim_strong_request_tag,
2644          "must be but is %u", extract_state(_oops_do_mark_link));
2645 
2646   oops_do_log_change("oops_do, mark weak request -> mark strong done");
2647 
2648   oops_do_set_strong_done(old_head);
2649   // Do missing strong processing.
2650   p->do_remaining_strong_processing(this);
2651 }
2652 
2653 void nmethod::oops_do_process_strong(OopsDoProcessor* p) {
2654   oops_do_mark_link* next_raw = oops_do_try_claim_strong_done();
2655   if (next_raw == nullptr) {
2656     p->do_regular_processing(this);
2657     oops_do_add_to_list_as_strong_done();
2658     return;
2659   }
2660   // Claim failed. Figure out why and handle it.
2661   if (oops_do_has_weak_request(next_raw)) {
2662     oops_do_mark_link* old = next_raw;
2663     // Claim failed because being weak processed (state == "weak request").
2664     // Try to request deferred strong processing.
2665     next_raw = oops_do_try_add_strong_request(old);
2666     if (next_raw == old) {
2667       // Successfully requested deferred strong processing.
2668       return;
2669     }
2670     // Failed because of a concurrent transition. No longer in "weak request" state.
2671   }
2672   if (oops_do_has_any_strong_state(next_raw)) {
2673     // Already claimed for strong processing or requested for such.
2674     return;
2675   }
2676   if (oops_do_try_claim_weak_done_as_strong_done(next_raw)) {
2677     // Successfully claimed "weak done" as "strong done". Do the missing marking.
2678     p->do_remaining_strong_processing(this);
2679     return;
2680   }
2681   // Claim failed, some other thread got it.
2682 }
2683 
2684 void nmethod::oops_do_marking_prologue() {
2685   assert_at_safepoint();
2686 
2687   log_trace(gc, nmethod)("oops_do_marking_prologue");
2688   assert(_oops_do_mark_nmethods == nullptr, "must be empty");
2689 }
2690 
2691 void nmethod::oops_do_marking_epilogue() {
2692   assert_at_safepoint();
2693 
2694   nmethod* next = _oops_do_mark_nmethods;
2695   _oops_do_mark_nmethods = nullptr;
2696   if (next != nullptr) {
2697     nmethod* cur;
2698     do {
2699       cur = next;
2700       next = extract_nmethod(cur->_oops_do_mark_link);
2701       cur->_oops_do_mark_link = nullptr;
2702       DEBUG_ONLY(cur->verify_oop_relocations());
2703 
2704       LogTarget(Trace, gc, nmethod) lt;
2705       if (lt.is_enabled()) {
2706         LogStream ls(lt);
2707         CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
2708       }
2709       // End if self-loop has been detected.
2710     } while (cur != next);
2711   }
2712   log_trace(gc, nmethod)("oops_do_marking_epilogue");
2713 }
2714 
2715 inline bool includes(void* p, void* from, void* to) {
2716   return from <= p && p < to;
2717 }
2718 
2719 
2720 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
2721   assert(count >= 2, "must be sentinel values, at least");
2722 
2723 #ifdef ASSERT
2724   // must be sorted and unique; we do a binary search in find_pc_desc()
2725   int prev_offset = pcs[0].pc_offset();
2726   assert(prev_offset == PcDesc::lower_offset_limit,
2727          "must start with a sentinel");
2728   for (int i = 1; i < count; i++) {
2729     int this_offset = pcs[i].pc_offset();
2730     assert(this_offset > prev_offset, "offsets must be sorted");
2731     prev_offset = this_offset;
2732   }
2733   assert(prev_offset == PcDesc::upper_offset_limit,
2734          "must end with a sentinel");
2735 #endif //ASSERT
2736 
2737   // Search for MethodHandle invokes and tag the nmethod.
2738   for (int i = 0; i < count; i++) {
2739     if (pcs[i].is_method_handle_invoke()) {
2740       set_has_method_handle_invokes(true);
2741       break;
2742     }
2743   }
2744   assert(has_method_handle_invokes() == (_deopt_mh_handler_offset != -1), "must have deopt mh handler");
2745 
2746   int size = count * sizeof(PcDesc);
2747   assert(scopes_pcs_size() >= size, "oob");
2748   memcpy(scopes_pcs_begin(), pcs, size);
2749 
2750   // Adjust the final sentinel downward.
2751   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
2752   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
2753   last_pc->set_pc_offset(content_size() + 1);
2754   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
2755     // Fill any rounding gaps with copies of the last record.
2756     last_pc[1] = last_pc[0];
2757   }
2758   // The following assert could fail if sizeof(PcDesc) is not
2759   // an integral multiple of oopSize (the rounding term).
2760   // If it fails, change the logic to always allocate a multiple
2761   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
2762   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
2763 }
2764 
2765 void nmethod::copy_scopes_data(u_char* buffer, int size) {
2766   assert(scopes_data_size() >= size, "oob");
2767   memcpy(scopes_data_begin(), buffer, size);
2768 }
2769 
2770 #ifdef ASSERT
2771 static PcDesc* linear_search(int pc_offset, bool approximate, PcDesc* lower, PcDesc* upper) {
2772   PcDesc* res = nullptr;
2773   assert(lower != nullptr && lower->pc_offset() == PcDesc::lower_offset_limit,
2774          "must start with a sentinel");
2775   // lower + 1 to exclude initial sentinel
2776   for (PcDesc* p = lower + 1; p < upper; p++) {
2777     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
2778     if (match_desc(p, pc_offset, approximate)) {
2779       if (res == nullptr) {
2780         res = p;
2781       } else {
2782         res = (PcDesc*) badAddress;
2783       }
2784     }
2785   }
2786   return res;
2787 }
2788 #endif
2789 
2790 
2791 #ifndef PRODUCT
2792 // Version of method to collect statistic
2793 PcDesc* PcDescContainer::find_pc_desc(address pc, bool approximate, address code_begin,
2794                                       PcDesc* lower, PcDesc* upper) {
2795   ++pc_nmethod_stats.pc_desc_queries;
2796   if (approximate) ++pc_nmethod_stats.pc_desc_approx;
2797 
2798   PcDesc* desc = _pc_desc_cache.last_pc_desc();
2799   assert(desc != nullptr, "PcDesc cache should be initialized already");
2800   if (desc->pc_offset() == (pc - code_begin)) {
2801     // Cached value matched
2802     ++pc_nmethod_stats.pc_desc_tests;
2803     ++pc_nmethod_stats.pc_desc_repeats;
2804     return desc;
2805   }
2806   return find_pc_desc_internal(pc, approximate, code_begin, lower, upper);
2807 }
2808 #endif
2809 
2810 // Finds a PcDesc with real-pc equal to "pc"
2811 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, address code_begin,
2812                                                PcDesc* lower_incl, PcDesc* upper_incl) {
2813   if ((pc < code_begin) ||
2814       (pc - code_begin) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
2815     return nullptr;  // PC is wildly out of range
2816   }
2817   int pc_offset = (int) (pc - code_begin);
2818 
2819   // Check the PcDesc cache if it contains the desired PcDesc
2820   // (This as an almost 100% hit rate.)
2821   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
2822   if (res != nullptr) {
2823     assert(res == linear_search(pc_offset, approximate, lower_incl, upper_incl), "cache ok");
2824     return res;
2825   }
2826 
2827   // Fallback algorithm: quasi-linear search for the PcDesc
2828   // Find the last pc_offset less than the given offset.
2829   // The successor must be the required match, if there is a match at all.
2830   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
2831   PcDesc* lower = lower_incl;     // this is initial sentinel
2832   PcDesc* upper = upper_incl - 1; // exclude final sentinel
2833   if (lower >= upper)  return nullptr;  // no PcDescs at all
2834 
2835 #define assert_LU_OK \
2836   /* invariant on lower..upper during the following search: */ \
2837   assert(lower->pc_offset() <  pc_offset, "sanity"); \
2838   assert(upper->pc_offset() >= pc_offset, "sanity")
2839   assert_LU_OK;
2840 
2841   // Use the last successful return as a split point.
2842   PcDesc* mid = _pc_desc_cache.last_pc_desc();
2843   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2844   if (mid->pc_offset() < pc_offset) {
2845     lower = mid;
2846   } else {
2847     upper = mid;
2848   }
2849 
2850   // Take giant steps at first (4096, then 256, then 16, then 1)
2851   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
2852   const int RADIX = (1 << LOG2_RADIX);
2853   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
2854     while ((mid = lower + step) < upper) {
2855       assert_LU_OK;
2856       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2857       if (mid->pc_offset() < pc_offset) {
2858         lower = mid;
2859       } else {
2860         upper = mid;
2861         break;
2862       }
2863     }
2864     assert_LU_OK;
2865   }
2866 
2867   // Sneak up on the value with a linear search of length ~16.
2868   while (true) {
2869     assert_LU_OK;
2870     mid = lower + 1;
2871     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2872     if (mid->pc_offset() < pc_offset) {
2873       lower = mid;
2874     } else {
2875       upper = mid;
2876       break;
2877     }
2878   }
2879 #undef assert_LU_OK
2880 
2881   if (match_desc(upper, pc_offset, approximate)) {
2882     assert(upper == linear_search(pc_offset, approximate, lower_incl, upper_incl), "search mismatch");
2883     if (!Thread::current_in_asgct()) {
2884       // we don't want to modify the cache if we're in ASGCT
2885       // which is typically called in a signal handler
2886       _pc_desc_cache.add_pc_desc(upper);
2887     }
2888     return upper;
2889   } else {
2890     assert(nullptr == linear_search(pc_offset, approximate, lower_incl, upper_incl), "search mismatch");
2891     return nullptr;
2892   }
2893 }
2894 
2895 bool nmethod::check_dependency_on(DepChange& changes) {
2896   // What has happened:
2897   // 1) a new class dependee has been added
2898   // 2) dependee and all its super classes have been marked
2899   bool found_check = false;  // set true if we are upset
2900   for (Dependencies::DepStream deps(this); deps.next(); ) {
2901     // Evaluate only relevant dependencies.
2902     if (deps.spot_check_dependency_at(changes) != nullptr) {
2903       found_check = true;
2904       NOT_DEBUG(break);
2905     }
2906   }
2907   return found_check;
2908 }
2909 
2910 // Called from mark_for_deoptimization, when dependee is invalidated.
2911 bool nmethod::is_dependent_on_method(Method* dependee) {
2912   for (Dependencies::DepStream deps(this); deps.next(); ) {
2913     if (deps.type() != Dependencies::evol_method)
2914       continue;
2915     Method* method = deps.method_argument(0);
2916     if (method == dependee) return true;
2917   }
2918   return false;
2919 }
2920 
2921 void nmethod_init() {
2922   // make sure you didn't forget to adjust the filler fields
2923   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2924 }
2925 
2926 // -----------------------------------------------------------------------------
2927 // Verification
2928 
2929 class VerifyOopsClosure: public OopClosure {
2930   nmethod* _nm;
2931   bool     _ok;
2932 public:
2933   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2934   bool ok() { return _ok; }
2935   virtual void do_oop(oop* p) {
2936     if (oopDesc::is_oop_or_null(*p)) return;
2937     // Print diagnostic information before calling print_nmethod().
2938     // Assertions therein might prevent call from returning.
2939     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2940                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2941     if (_ok) {
2942       _nm->print_nmethod(true);
2943       _ok = false;
2944     }
2945   }
2946   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2947 };
2948 
2949 class VerifyMetadataClosure: public MetadataClosure {
2950  public:
2951   void do_metadata(Metadata* md) {
2952     if (md->is_method()) {
2953       Method* method = (Method*)md;
2954       assert(!method->is_old(), "Should not be installing old methods");
2955     }
2956   }
2957 };
2958 
2959 
2960 void nmethod::verify() {
2961   if (is_not_entrant())
2962     return;
2963 
2964   // Make sure all the entry points are correctly aligned for patching.
2965   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2966 
2967   // assert(oopDesc::is_oop(method()), "must be valid");
2968 
2969   ResourceMark rm;
2970 
2971   if (!CodeCache::contains(this)) {
2972     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2973   }
2974 
2975   if(is_native_method() )
2976     return;
2977 
2978   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2979   if (nm != this) {
2980     fatal("find_nmethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2981   }
2982 
2983   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2984     if (! p->verify(this)) {
2985       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2986     }
2987   }
2988 
2989 #ifdef ASSERT
2990 #if INCLUDE_JVMCI
2991   {
2992     // Verify that implicit exceptions that deoptimize have a PcDesc and OopMap
2993     ImmutableOopMapSet* oms = oop_maps();
2994     ImplicitExceptionTable implicit_table(this);
2995     for (uint i = 0; i < implicit_table.len(); i++) {
2996       int exec_offset = (int) implicit_table.get_exec_offset(i);
2997       if (implicit_table.get_exec_offset(i) == implicit_table.get_cont_offset(i)) {
2998         assert(pc_desc_at(code_begin() + exec_offset) != nullptr, "missing PcDesc");
2999         bool found = false;
3000         for (int i = 0, imax = oms->count(); i < imax; i++) {
3001           if (oms->pair_at(i)->pc_offset() == exec_offset) {
3002             found = true;
3003             break;
3004           }
3005         }
3006         assert(found, "missing oopmap");
3007       }
3008     }
3009   }
3010 #endif
3011 #endif
3012 
3013   VerifyOopsClosure voc(this);
3014   oops_do(&voc);
3015   assert(voc.ok(), "embedded oops must be OK");
3016   Universe::heap()->verify_nmethod(this);
3017 
3018   assert(_oops_do_mark_link == nullptr, "_oops_do_mark_link for %s should be nullptr but is " PTR_FORMAT,
3019          nm->method()->external_name(), p2i(_oops_do_mark_link));
3020   verify_scopes();
3021 
3022   CompiledICLocker nm_verify(this);
3023   VerifyMetadataClosure vmc;
3024   metadata_do(&vmc);
3025 }
3026 
3027 
3028 void nmethod::verify_interrupt_point(address call_site, bool is_inline_cache) {
3029 
3030   // Verify IC only when nmethod installation is finished.
3031   if (!is_not_installed()) {
3032     if (CompiledICLocker::is_safe(this)) {
3033       if (is_inline_cache) {
3034         CompiledIC_at(this, call_site);
3035       } else {
3036         CompiledDirectCall::at(call_site);
3037       }
3038     } else {
3039       CompiledICLocker ml_verify(this);
3040       if (is_inline_cache) {
3041         CompiledIC_at(this, call_site);
3042       } else {
3043         CompiledDirectCall::at(call_site);
3044       }
3045     }
3046   }
3047 
3048   HandleMark hm(Thread::current());
3049 
3050   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
3051   assert(pd != nullptr, "PcDesc must exist");
3052   for (ScopeDesc* sd = new ScopeDesc(this, pd);
3053        !sd->is_top(); sd = sd->sender()) {
3054     sd->verify();
3055   }
3056 }
3057 
3058 void nmethod::verify_scopes() {
3059   if( !method() ) return;       // Runtime stubs have no scope
3060   if (method()->is_native()) return; // Ignore stub methods.
3061   // iterate through all interrupt point
3062   // and verify the debug information is valid.
3063   RelocIterator iter(this);
3064   while (iter.next()) {
3065     address stub = nullptr;
3066     switch (iter.type()) {
3067       case relocInfo::virtual_call_type:
3068         verify_interrupt_point(iter.addr(), true /* is_inline_cache */);
3069         break;
3070       case relocInfo::opt_virtual_call_type:
3071         stub = iter.opt_virtual_call_reloc()->static_stub();
3072         verify_interrupt_point(iter.addr(), false /* is_inline_cache */);
3073         break;
3074       case relocInfo::static_call_type:
3075         stub = iter.static_call_reloc()->static_stub();
3076         verify_interrupt_point(iter.addr(), false /* is_inline_cache */);
3077         break;
3078       case relocInfo::runtime_call_type:
3079       case relocInfo::runtime_call_w_cp_type: {
3080         address destination = iter.reloc()->value();
3081         // Right now there is no way to find out which entries support
3082         // an interrupt point.  It would be nice if we had this
3083         // information in a table.
3084         break;
3085       }
3086       default:
3087         break;
3088     }
3089     assert(stub == nullptr || stub_contains(stub), "static call stub outside stub section");
3090   }
3091 }
3092 
3093 
3094 // -----------------------------------------------------------------------------
3095 // Printing operations
3096 
3097 void nmethod::print_on_impl(outputStream* st) const {
3098   ResourceMark rm;
3099 
3100   st->print("Compiled method ");
3101 
3102   if (is_compiled_by_c1()) {
3103     st->print("(c1) ");
3104   } else if (is_compiled_by_c2()) {
3105     st->print("(c2) ");
3106   } else if (is_compiled_by_jvmci()) {
3107     st->print("(JVMCI) ");
3108   } else {
3109     st->print("(n/a) ");
3110   }
3111 
3112   print_on_with_msg(st, nullptr);
3113 
3114   if (WizardMode) {
3115     st->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
3116     st->print(" for method " INTPTR_FORMAT , p2i(method()));
3117     st->print(" { ");
3118     st->print_cr("%s ", state());
3119     st->print_cr("}:");
3120   }
3121   if (size              () > 0) st->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3122                                              p2i(this),
3123                                              p2i(this) + size(),
3124                                              size());
3125   if (consts_size       () > 0) st->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3126                                              p2i(consts_begin()),
3127                                              p2i(consts_end()),
3128                                              consts_size());
3129   if (insts_size        () > 0) st->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3130                                              p2i(insts_begin()),
3131                                              p2i(insts_end()),
3132                                              insts_size());
3133   if (stub_size         () > 0) st->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3134                                              p2i(stub_begin()),
3135                                              p2i(stub_end()),
3136                                              stub_size());
3137   if (oops_size         () > 0) st->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3138                                              p2i(oops_begin()),
3139                                              p2i(oops_end()),
3140                                              oops_size());
3141   if (mutable_data_size() > 0) st->print_cr(" mutable data [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3142                                              p2i(mutable_data_begin()),
3143                                              p2i(mutable_data_end()),
3144                                              mutable_data_size());
3145   if (relocation_size() > 0)   st->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3146                                              p2i(relocation_begin()),
3147                                              p2i(relocation_end()),
3148                                              relocation_size());
3149   if (metadata_size     () > 0) st->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3150                                              p2i(metadata_begin()),
3151                                              p2i(metadata_end()),
3152                                              metadata_size());
3153 #if INCLUDE_JVMCI
3154   if (jvmci_data_size   () > 0) st->print_cr(" JVMCI data     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3155                                              p2i(jvmci_data_begin()),
3156                                              p2i(jvmci_data_end()),
3157                                              jvmci_data_size());
3158 #endif
3159   if (immutable_data_size() > 0) st->print_cr(" immutable data [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3160                                              p2i(immutable_data_begin()),
3161                                              p2i(immutable_data_end()),
3162                                              immutable_data_size());
3163   if (dependencies_size () > 0) st->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3164                                              p2i(dependencies_begin()),
3165                                              p2i(dependencies_end()),
3166                                              dependencies_size());
3167   if (nul_chk_table_size() > 0) st->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3168                                              p2i(nul_chk_table_begin()),
3169                                              p2i(nul_chk_table_end()),
3170                                              nul_chk_table_size());
3171   if (handler_table_size() > 0) st->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3172                                              p2i(handler_table_begin()),
3173                                              p2i(handler_table_end()),
3174                                              handler_table_size());
3175   if (scopes_pcs_size   () > 0) st->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3176                                              p2i(scopes_pcs_begin()),
3177                                              p2i(scopes_pcs_end()),
3178                                              scopes_pcs_size());
3179   if (scopes_data_size  () > 0) st->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3180                                              p2i(scopes_data_begin()),
3181                                              p2i(scopes_data_end()),
3182                                              scopes_data_size());
3183 #if INCLUDE_JVMCI
3184   if (speculations_size () > 0) st->print_cr(" speculations   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
3185                                              p2i(speculations_begin()),
3186                                              p2i(speculations_end()),
3187                                              speculations_size());
3188 #endif
3189   if (SCCache::is_on() && _scc_entry != nullptr) {
3190     _scc_entry->print(st);
3191   }
3192 }
3193 
3194 void nmethod::print_code() {
3195   ResourceMark m;
3196   ttyLocker ttyl;
3197   // Call the specialized decode method of this class.
3198   decode(tty);
3199 }
3200 
3201 #ifndef PRODUCT  // called InstanceKlass methods are available only then. Declared as PRODUCT_RETURN
3202 
3203 void nmethod::print_dependencies_on(outputStream* out) {
3204   ResourceMark rm;
3205   stringStream st;
3206   st.print_cr("Dependencies:");
3207   for (Dependencies::DepStream deps(this); deps.next(); ) {
3208     deps.print_dependency(&st);
3209     InstanceKlass* ctxk = deps.context_type();
3210     if (ctxk != nullptr) {
3211       if (ctxk->is_dependent_nmethod(this)) {
3212         st.print_cr("   [nmethod<=klass]%s", ctxk->external_name());
3213       }
3214     }
3215     deps.log_dependency();  // put it into the xml log also
3216   }
3217   out->print_raw(st.as_string());
3218 }
3219 #endif
3220 
3221 #if defined(SUPPORT_DATA_STRUCTS)
3222 
3223 // Print the oops from the underlying CodeBlob.
3224 void nmethod::print_oops(outputStream* st) {
3225   ResourceMark m;
3226   st->print("Oops:");
3227   if (oops_begin() < oops_end()) {
3228     st->cr();
3229     for (oop* p = oops_begin(); p < oops_end(); p++) {
3230       Disassembler::print_location((unsigned char*)p, (unsigned char*)oops_begin(), (unsigned char*)oops_end(), st, true, false);
3231       st->print(PTR_FORMAT " ", *((uintptr_t*)p));
3232       if (Universe::contains_non_oop_word(p)) {
3233         st->print_cr("NON_OOP");
3234         continue;  // skip non-oops
3235       }
3236       if (*p == nullptr) {
3237         st->print_cr("nullptr-oop");
3238         continue;  // skip non-oops
3239       }
3240       (*p)->print_value_on(st);
3241       st->cr();
3242     }
3243   } else {
3244     st->print_cr(" <list empty>");
3245   }
3246 }
3247 
3248 // Print metadata pool.
3249 void nmethod::print_metadata(outputStream* st) {
3250   ResourceMark m;
3251   st->print("Metadata:");
3252   if (metadata_begin() < metadata_end()) {
3253     st->cr();
3254     for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
3255       Disassembler::print_location((unsigned char*)p, (unsigned char*)metadata_begin(), (unsigned char*)metadata_end(), st, true, false);
3256       st->print(PTR_FORMAT " ", *((uintptr_t*)p));
3257       if (*p && *p != Universe::non_oop_word()) {
3258         (*p)->print_value_on(st);
3259       }
3260       st->cr();
3261     }
3262   } else {
3263     st->print_cr(" <list empty>");
3264   }
3265 }
3266 
3267 #ifndef PRODUCT  // ScopeDesc::print_on() is available only then. Declared as PRODUCT_RETURN
3268 void nmethod::print_scopes_on(outputStream* st) {
3269   // Find the first pc desc for all scopes in the code and print it.
3270   ResourceMark rm;
3271   st->print("scopes:");
3272   if (scopes_pcs_begin() < scopes_pcs_end()) {
3273     st->cr();
3274     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3275       if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
3276         continue;
3277 
3278       ScopeDesc* sd = scope_desc_at(p->real_pc(this));
3279       while (sd != nullptr) {
3280         sd->print_on(st, p);  // print output ends with a newline
3281         sd = sd->sender();
3282       }
3283     }
3284   } else {
3285     st->print_cr(" <list empty>");
3286   }
3287 }
3288 #endif
3289 
3290 #ifndef PRODUCT  // RelocIterator does support printing only then.
3291 void nmethod::print_relocations_on(outputStream* st) {
3292   ResourceMark m;       // in case methods get printed via the debugger
3293   st->print_cr("relocations:");
3294   RelocIterator iter(this);
3295   iter.print_on(st);
3296 }
3297 #endif
3298 
3299 void nmethod::print_pcs_on(outputStream* st) {
3300   ResourceMark m;       // in case methods get printed via debugger
3301   st->print("pc-bytecode offsets:");
3302   if (scopes_pcs_begin() < scopes_pcs_end()) {
3303     st->cr();
3304     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3305       p->print_on(st, this);  // print output ends with a newline
3306     }
3307   } else {
3308     st->print_cr(" <list empty>");
3309   }
3310 }
3311 
3312 void nmethod::print_handler_table() {
3313   ExceptionHandlerTable(this).print(code_begin());
3314 }
3315 
3316 void nmethod::print_nul_chk_table() {
3317   ImplicitExceptionTable(this).print(code_begin());
3318 }
3319 
3320 void nmethod::print_recorded_oop(int log_n, int i) {
3321   void* value;
3322 
3323   if (i == 0) {
3324     value = nullptr;
3325   } else {
3326     // Be careful around non-oop words. Don't create an oop
3327     // with that value, or it will assert in verification code.
3328     if (Universe::contains_non_oop_word(oop_addr_at(i))) {
3329       value = Universe::non_oop_word();
3330     } else {
3331       value = oop_at(i);
3332     }
3333   }
3334 
3335   tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(value));
3336 
3337   if (value == Universe::non_oop_word()) {
3338     tty->print("non-oop word");
3339   } else {
3340     if (value == nullptr) {
3341       tty->print("nullptr-oop");
3342     } else {
3343       oop_at(i)->print_value_on(tty);
3344     }
3345   }
3346 
3347   tty->cr();
3348 }
3349 
3350 void nmethod::print_recorded_oops() {
3351   const int n = oops_count();
3352   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
3353   tty->print("Recorded oops:");
3354   if (n > 0) {
3355     tty->cr();
3356     for (int i = 0; i < n; i++) {
3357       print_recorded_oop(log_n, i);
3358     }
3359   } else {
3360     tty->print_cr(" <list empty>");
3361   }
3362 }
3363 
3364 void nmethod::print_recorded_metadata() {
3365   const int n = metadata_count();
3366   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
3367   tty->print("Recorded metadata:");
3368   if (n > 0) {
3369     tty->cr();
3370     for (int i = 0; i < n; i++) {
3371       Metadata* m = metadata_at(i);
3372       tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(m));
3373       if (m == (Metadata*)Universe::non_oop_word()) {
3374         tty->print("non-metadata word");
3375       } else if (m == nullptr) {
3376         tty->print("nullptr-oop");
3377       } else {
3378         Metadata::print_value_on_maybe_null(tty, m);
3379       }
3380       tty->cr();
3381     }
3382   } else {
3383     tty->print_cr(" <list empty>");
3384   }
3385 }
3386 #endif
3387 
3388 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
3389 
3390 void nmethod::print_constant_pool(outputStream* st) {
3391   //-----------------------------------
3392   //---<  Print the constant pool  >---
3393   //-----------------------------------
3394   int consts_size = this->consts_size();
3395   if ( consts_size > 0 ) {
3396     unsigned char* cstart = this->consts_begin();
3397     unsigned char* cp     = cstart;
3398     unsigned char* cend   = cp + consts_size;
3399     unsigned int   bytes_per_line = 4;
3400     unsigned int   CP_alignment   = 8;
3401     unsigned int   n;
3402 
3403     st->cr();
3404 
3405     //---<  print CP header to make clear what's printed  >---
3406     if( ((uintptr_t)cp&(CP_alignment-1)) == 0 ) {
3407       n = bytes_per_line;
3408       st->print_cr("[Constant Pool]");
3409       Disassembler::print_location(cp, cstart, cend, st, true, true);
3410       Disassembler::print_hexdata(cp, n, st, true);
3411       st->cr();
3412     } else {
3413       n = (int)((uintptr_t)cp & (bytes_per_line-1));
3414       st->print_cr("[Constant Pool (unaligned)]");
3415     }
3416 
3417     //---<  print CP contents, bytes_per_line at a time  >---
3418     while (cp < cend) {
3419       Disassembler::print_location(cp, cstart, cend, st, true, false);
3420       Disassembler::print_hexdata(cp, n, st, false);
3421       cp += n;
3422       n   = bytes_per_line;
3423       st->cr();
3424     }
3425 
3426     //---<  Show potential alignment gap between constant pool and code  >---
3427     cend = code_begin();
3428     if( cp < cend ) {
3429       n = 4;
3430       st->print_cr("[Code entry alignment]");
3431       while (cp < cend) {
3432         Disassembler::print_location(cp, cstart, cend, st, false, false);
3433         cp += n;
3434         st->cr();
3435       }
3436     }
3437   } else {
3438     st->print_cr("[Constant Pool (empty)]");
3439   }
3440   st->cr();
3441 }
3442 
3443 #endif
3444 
3445 // Disassemble this nmethod.
3446 // Print additional debug information, if requested. This could be code
3447 // comments, block comments, profiling counters, etc.
3448 // The undisassembled format is useful no disassembler library is available.
3449 // The resulting hex dump (with markers) can be disassembled later, or on
3450 // another system, when/where a disassembler library is available.
3451 void nmethod::decode2(outputStream* ost) const {
3452 
3453   // Called from frame::back_trace_with_decode without ResourceMark.
3454   ResourceMark rm;
3455 
3456   // Make sure we have a valid stream to print on.
3457   outputStream* st = ost ? ost : tty;
3458 
3459 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) && ! defined(SUPPORT_ASSEMBLY)
3460   const bool use_compressed_format    = true;
3461   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
3462                                                                   AbstractDisassembler::show_block_comment());
3463 #else
3464   const bool use_compressed_format    = Disassembler::is_abstract();
3465   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
3466                                                                   AbstractDisassembler::show_block_comment());
3467 #endif
3468 
3469   st->cr();
3470   this->print_on(st);
3471   st->cr();
3472 
3473 #if defined(SUPPORT_ASSEMBLY)
3474   //----------------------------------
3475   //---<  Print real disassembly  >---
3476   //----------------------------------
3477   if (! use_compressed_format) {
3478     st->print_cr("[Disassembly]");
3479     Disassembler::decode(const_cast<nmethod*>(this), st);
3480     st->bol();
3481     st->print_cr("[/Disassembly]");
3482     return;
3483   }
3484 #endif
3485 
3486 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3487 
3488   // Compressed undisassembled disassembly format.
3489   // The following status values are defined/supported:
3490   //   = 0 - currently at bol() position, nothing printed yet on current line.
3491   //   = 1 - currently at position after print_location().
3492   //   > 1 - in the midst of printing instruction stream bytes.
3493   int        compressed_format_idx    = 0;
3494   int        code_comment_column      = 0;
3495   const int  instr_maxlen             = Assembler::instr_maxlen();
3496   const uint tabspacing               = 8;
3497   unsigned char* start = this->code_begin();
3498   unsigned char* p     = this->code_begin();
3499   unsigned char* end   = this->code_end();
3500   unsigned char* pss   = p; // start of a code section (used for offsets)
3501 
3502   if ((start == nullptr) || (end == nullptr)) {
3503     st->print_cr("PrintAssembly not possible due to uninitialized section pointers");
3504     return;
3505   }
3506 #endif
3507 
3508 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3509   //---<  plain abstract disassembly, no comments or anything, just section headers  >---
3510   if (use_compressed_format && ! compressed_with_comments) {
3511     const_cast<nmethod*>(this)->print_constant_pool(st);
3512 
3513     //---<  Open the output (Marker for post-mortem disassembler)  >---
3514     st->print_cr("[MachCode]");
3515     const char* header = nullptr;
3516     address p0 = p;
3517     while (p < end) {
3518       address pp = p;
3519       while ((p < end) && (header == nullptr)) {
3520         header = nmethod_section_label(p);
3521         pp  = p;
3522         p  += Assembler::instr_len(p);
3523       }
3524       if (pp > p0) {
3525         AbstractDisassembler::decode_range_abstract(p0, pp, start, end, st, Assembler::instr_maxlen());
3526         p0 = pp;
3527         p  = pp;
3528         header = nullptr;
3529       } else if (header != nullptr) {
3530         st->bol();
3531         st->print_cr("%s", header);
3532         header = nullptr;
3533       }
3534     }
3535     //---<  Close the output (Marker for post-mortem disassembler)  >---
3536     st->bol();
3537     st->print_cr("[/MachCode]");
3538     return;
3539   }
3540 #endif
3541 
3542 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
3543   //---<  abstract disassembly with comments and section headers merged in  >---
3544   if (compressed_with_comments) {
3545     const_cast<nmethod*>(this)->print_constant_pool(st);
3546 
3547     //---<  Open the output (Marker for post-mortem disassembler)  >---
3548     st->print_cr("[MachCode]");
3549     while ((p < end) && (p != nullptr)) {
3550       const int instruction_size_in_bytes = Assembler::instr_len(p);
3551 
3552       //---<  Block comments for nmethod. Interrupts instruction stream, if any.  >---
3553       // Outputs a bol() before and a cr() after, but only if a comment is printed.
3554       // Prints nmethod_section_label as well.
3555       if (AbstractDisassembler::show_block_comment()) {
3556         print_block_comment(st, p);
3557         if (st->position() == 0) {
3558           compressed_format_idx = 0;
3559         }
3560       }
3561 
3562       //---<  New location information after line break  >---
3563       if (compressed_format_idx == 0) {
3564         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
3565         compressed_format_idx = 1;
3566       }
3567 
3568       //---<  Code comment for current instruction. Address range [p..(p+len))  >---
3569       unsigned char* p_end = p + (ssize_t)instruction_size_in_bytes;
3570       S390_ONLY(if (p_end > end) p_end = end;) // avoid getting past the end
3571 
3572       if (AbstractDisassembler::show_comment() && const_cast<nmethod*>(this)->has_code_comment(p, p_end)) {
3573         //---<  interrupt instruction byte stream for code comment  >---
3574         if (compressed_format_idx > 1) {
3575           st->cr();  // interrupt byte stream
3576           st->cr();  // add an empty line
3577           code_comment_column = Disassembler::print_location(p, pss, end, st, false, false);
3578         }
3579         const_cast<nmethod*>(this)->print_code_comment_on(st, code_comment_column, p, p_end );
3580         st->bol();
3581         compressed_format_idx = 0;
3582       }
3583 
3584       //---<  New location information after line break  >---
3585       if (compressed_format_idx == 0) {
3586         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
3587         compressed_format_idx = 1;
3588       }
3589 
3590       //---<  Nicely align instructions for readability  >---
3591       if (compressed_format_idx > 1) {
3592         Disassembler::print_delimiter(st);
3593       }
3594 
3595       //---<  Now, finally, print the actual instruction bytes  >---
3596       unsigned char* p0 = p;
3597       p = Disassembler::decode_instruction_abstract(p, st, instruction_size_in_bytes, instr_maxlen);
3598       compressed_format_idx += (int)(p - p0);
3599 
3600       if (Disassembler::start_newline(compressed_format_idx-1)) {
3601         st->cr();
3602         compressed_format_idx = 0;
3603       }
3604     }
3605     //---<  Close the output (Marker for post-mortem disassembler)  >---
3606     st->bol();
3607     st->print_cr("[/MachCode]");
3608     return;
3609   }
3610 #endif
3611 }
3612 
3613 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
3614 
3615 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
3616   RelocIterator iter(this, begin, end);
3617   bool have_one = false;
3618   while (iter.next()) {
3619     have_one = true;
3620     switch (iter.type()) {
3621         case relocInfo::none: {
3622           // Skip it and check next
3623           break;
3624         }
3625         case relocInfo::oop_type: {
3626           // Get a non-resizable resource-allocated stringStream.
3627           // Our callees make use of (nested) ResourceMarks.
3628           stringStream st(NEW_RESOURCE_ARRAY(char, 1024), 1024);
3629           oop_Relocation* r = iter.oop_reloc();
3630           oop obj = r->oop_value();
3631           st.print("oop(");
3632           if (obj == nullptr) st.print("nullptr");
3633           else obj->print_value_on(&st);
3634           st.print(")");
3635           return st.as_string();
3636         }
3637         case relocInfo::metadata_type: {
3638           stringStream st;
3639           metadata_Relocation* r = iter.metadata_reloc();
3640           Metadata* obj = r->metadata_value();
3641           st.print("metadata(");
3642           if (obj == nullptr) st.print("nullptr");
3643           else obj->print_value_on(&st);
3644           st.print(")");
3645           return st.as_string();
3646         }
3647         case relocInfo::runtime_call_type:
3648         case relocInfo::runtime_call_w_cp_type: {
3649           stringStream st;
3650           st.print("runtime_call");
3651           CallRelocation* r = (CallRelocation*)iter.reloc();
3652           address dest = r->destination();
3653           if (StubRoutines::contains(dest)) {
3654             StubCodeDesc* desc = StubCodeDesc::desc_for(dest);
3655             if (desc == nullptr) {
3656               desc = StubCodeDesc::desc_for(dest + frame::pc_return_offset);
3657             }
3658             if (desc != nullptr) {
3659               st.print(" Stub::%s", desc->name());
3660               return st.as_string();
3661             }
3662           }
3663           CodeBlob* cb = CodeCache::find_blob(dest);
3664           if (cb != nullptr) {
3665             st.print(" %s", cb->name());
3666           } else {
3667             ResourceMark rm;
3668             const int buflen = 1024;
3669             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
3670             int offset;
3671             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
3672               st.print(" %s", buf);
3673               if (offset != 0) {
3674                 st.print("+%d", offset);
3675               }
3676             }
3677           }
3678           return st.as_string();
3679         }
3680         case relocInfo::virtual_call_type: {
3681           stringStream st;
3682           st.print_raw("virtual_call");
3683           virtual_call_Relocation* r = iter.virtual_call_reloc();
3684           Method* m = r->method_value();
3685           if (m != nullptr) {
3686             assert(m->is_method(), "");
3687             m->print_short_name(&st);
3688           }
3689           return st.as_string();
3690         }
3691         case relocInfo::opt_virtual_call_type: {
3692           stringStream st;
3693           st.print_raw("optimized virtual_call");
3694           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
3695           Method* m = r->method_value();
3696           if (m != nullptr) {
3697             assert(m->is_method(), "");
3698             m->print_short_name(&st);
3699           }
3700           return st.as_string();
3701         }
3702         case relocInfo::static_call_type: {
3703           stringStream st;
3704           st.print_raw("static_call");
3705           static_call_Relocation* r = iter.static_call_reloc();
3706           Method* m = r->method_value();
3707           if (m != nullptr) {
3708             assert(m->is_method(), "");
3709             m->print_short_name(&st);
3710           }
3711           return st.as_string();
3712         }
3713         case relocInfo::static_stub_type:      return "static_stub";
3714         case relocInfo::external_word_type:    return "external_word";
3715         case relocInfo::internal_word_type:    return "internal_word";
3716         case relocInfo::section_word_type:     return "section_word";
3717         case relocInfo::poll_type:             return "poll";
3718         case relocInfo::poll_return_type:      return "poll_return";
3719         case relocInfo::trampoline_stub_type:  return "trampoline_stub";
3720         case relocInfo::entry_guard_type:      return "entry_guard";
3721         case relocInfo::post_call_nop_type:    return "post_call_nop";
3722         case relocInfo::barrier_type: {
3723           barrier_Relocation* const reloc = iter.barrier_reloc();
3724           stringStream st;
3725           st.print("barrier format=%d", reloc->format());
3726           return st.as_string();
3727         }
3728 
3729         case relocInfo::type_mask:             return "type_bit_mask";
3730 
3731         default: {
3732           stringStream st;
3733           st.print("unknown relocInfo=%d", (int) iter.type());
3734           return st.as_string();
3735         }
3736     }
3737   }
3738   return have_one ? "other" : nullptr;
3739 }
3740 
3741 // Return the last scope in (begin..end]
3742 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
3743   PcDesc* p = pc_desc_near(begin+1);
3744   if (p != nullptr && p->real_pc(this) <= end) {
3745     return new ScopeDesc(this, p);
3746   }
3747   return nullptr;
3748 }
3749 
3750 const char* nmethod::nmethod_section_label(address pos) const {
3751   const char* label = nullptr;
3752   if (pos == code_begin())                                              label = "[Instructions begin]";
3753   if (pos == entry_point())                                             label = "[Entry Point]";
3754   if (pos == verified_entry_point())                                    label = "[Verified Entry Point]";
3755   if (has_method_handle_invokes() && (pos == deopt_mh_handler_begin())) label = "[Deopt MH Handler Code]";
3756   if (pos == consts_begin() && pos != insts_begin())                    label = "[Constants]";
3757   // Check stub_code before checking exception_handler or deopt_handler.
3758   if (pos == this->stub_begin())                                        label = "[Stub Code]";
3759   if (JVMCI_ONLY(_exception_offset >= 0 &&) pos == exception_begin())          label = "[Exception Handler]";
3760   if (JVMCI_ONLY(_deopt_handler_offset != -1 &&) pos == deopt_handler_begin()) label = "[Deopt Handler Code]";
3761   return label;
3762 }
3763 
3764 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels) const {
3765   if (print_section_labels) {
3766     const char* label = nmethod_section_label(block_begin);
3767     if (label != nullptr) {
3768       stream->bol();
3769       stream->print_cr("%s", label);
3770     }
3771   }
3772 
3773   if (block_begin == entry_point()) {
3774     Method* m = method();
3775     if (m != nullptr) {
3776       stream->print("  # ");
3777       m->print_value_on(stream);
3778       stream->cr();
3779     }
3780     if (m != nullptr && !is_osr_method()) {
3781       ResourceMark rm;
3782       int sizeargs = m->size_of_parameters();
3783       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
3784       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
3785       {
3786         int sig_index = 0;
3787         if (!m->is_static())
3788           sig_bt[sig_index++] = T_OBJECT; // 'this'
3789         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
3790           BasicType t = ss.type();
3791           sig_bt[sig_index++] = t;
3792           if (type2size[t] == 2) {
3793             sig_bt[sig_index++] = T_VOID;
3794           } else {
3795             assert(type2size[t] == 1, "size is 1 or 2");
3796           }
3797         }
3798         assert(sig_index == sizeargs, "");
3799       }
3800       const char* spname = "sp"; // make arch-specific?
3801       SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs);
3802       int stack_slot_offset = this->frame_size() * wordSize;
3803       int tab1 = 14, tab2 = 24;
3804       int sig_index = 0;
3805       int arg_index = (m->is_static() ? 0 : -1);
3806       bool did_old_sp = false;
3807       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
3808         bool at_this = (arg_index == -1);
3809         bool at_old_sp = false;
3810         BasicType t = (at_this ? T_OBJECT : ss.type());
3811         assert(t == sig_bt[sig_index], "sigs in sync");
3812         if (at_this)
3813           stream->print("  # this: ");
3814         else
3815           stream->print("  # parm%d: ", arg_index);
3816         stream->move_to(tab1);
3817         VMReg fst = regs[sig_index].first();
3818         VMReg snd = regs[sig_index].second();
3819         if (fst->is_reg()) {
3820           stream->print("%s", fst->name());
3821           if (snd->is_valid())  {
3822             stream->print(":%s", snd->name());
3823           }
3824         } else if (fst->is_stack()) {
3825           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
3826           if (offset == stack_slot_offset)  at_old_sp = true;
3827           stream->print("[%s+0x%x]", spname, offset);
3828         } else {
3829           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
3830         }
3831         stream->print(" ");
3832         stream->move_to(tab2);
3833         stream->print("= ");
3834         if (at_this) {
3835           m->method_holder()->print_value_on(stream);
3836         } else {
3837           bool did_name = false;
3838           if (!at_this && ss.is_reference()) {
3839             Symbol* name = ss.as_symbol();
3840             name->print_value_on(stream);
3841             did_name = true;
3842           }
3843           if (!did_name)
3844             stream->print("%s", type2name(t));
3845         }
3846         if (at_old_sp) {
3847           stream->print("  (%s of caller)", spname);
3848           did_old_sp = true;
3849         }
3850         stream->cr();
3851         sig_index += type2size[t];
3852         arg_index += 1;
3853         if (!at_this)  ss.next();
3854       }
3855       if (!did_old_sp) {
3856         stream->print("  # ");
3857         stream->move_to(tab1);
3858         stream->print("[%s+0x%x]", spname, stack_slot_offset);
3859         stream->print("  (%s of caller)", spname);
3860         stream->cr();
3861       }
3862     }
3863   }
3864 }
3865 
3866 // Returns whether this nmethod has code comments.
3867 bool nmethod::has_code_comment(address begin, address end) {
3868   // scopes?
3869   ScopeDesc* sd  = scope_desc_in(begin, end);
3870   if (sd != nullptr) return true;
3871 
3872   // relocations?
3873   const char* str = reloc_string_for(begin, end);
3874   if (str != nullptr) return true;
3875 
3876   // implicit exceptions?
3877   int cont_offset = ImplicitExceptionTable(this).continuation_offset((uint)(begin - code_begin()));
3878   if (cont_offset != 0) return true;
3879 
3880   return false;
3881 }
3882 
3883 void nmethod::print_code_comment_on(outputStream* st, int column, address begin, address end) {
3884   ImplicitExceptionTable implicit_table(this);
3885   int pc_offset = (int)(begin - code_begin());
3886   int cont_offset = implicit_table.continuation_offset(pc_offset);
3887   bool oop_map_required = false;
3888   if (cont_offset != 0) {
3889     st->move_to(column, 6, 0);
3890     if (pc_offset == cont_offset) {
3891       st->print("; implicit exception: deoptimizes");
3892       oop_map_required = true;
3893     } else {
3894       st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
3895     }
3896   }
3897 
3898   // Find an oopmap in (begin, end].  We use the odd half-closed
3899   // interval so that oop maps and scope descs which are tied to the
3900   // byte after a call are printed with the call itself.  OopMaps
3901   // associated with implicit exceptions are printed with the implicit
3902   // instruction.
3903   address base = code_begin();
3904   ImmutableOopMapSet* oms = oop_maps();
3905   if (oms != nullptr) {
3906     for (int i = 0, imax = oms->count(); i < imax; i++) {
3907       const ImmutableOopMapPair* pair = oms->pair_at(i);
3908       const ImmutableOopMap* om = pair->get_from(oms);
3909       address pc = base + pair->pc_offset();
3910       if (pc >= begin) {
3911 #if INCLUDE_JVMCI
3912         bool is_implicit_deopt = implicit_table.continuation_offset(pair->pc_offset()) == (uint) pair->pc_offset();
3913 #else
3914         bool is_implicit_deopt = false;
3915 #endif
3916         if (is_implicit_deopt ? pc == begin : pc > begin && pc <= end) {
3917           st->move_to(column, 6, 0);
3918           st->print("; ");
3919           om->print_on(st);
3920           oop_map_required = false;
3921         }
3922       }
3923       if (pc > end) {
3924         break;
3925       }
3926     }
3927   }
3928   assert(!oop_map_required, "missed oopmap");
3929 
3930   Thread* thread = Thread::current();
3931 
3932   // Print any debug info present at this pc.
3933   ScopeDesc* sd  = scope_desc_in(begin, end);
3934   if (sd != nullptr) {
3935     st->move_to(column, 6, 0);
3936     if (sd->bci() == SynchronizationEntryBCI) {
3937       st->print(";*synchronization entry");
3938     } else if (sd->bci() == AfterBci) {
3939       st->print(";* method exit (unlocked if synchronized)");
3940     } else if (sd->bci() == UnwindBci) {
3941       st->print(";* unwind (locked if synchronized)");
3942     } else if (sd->bci() == AfterExceptionBci) {
3943       st->print(";* unwind (unlocked if synchronized)");
3944     } else if (sd->bci() == UnknownBci) {
3945       st->print(";* unknown");
3946     } else if (sd->bci() == InvalidFrameStateBci) {
3947       st->print(";* invalid frame state");
3948     } else {
3949       if (sd->method() == nullptr) {
3950         st->print("method is nullptr");
3951       } else if (sd->method()->is_native()) {
3952         st->print("method is native");
3953       } else {
3954         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
3955         st->print(";*%s", Bytecodes::name(bc));
3956         switch (bc) {
3957         case Bytecodes::_invokevirtual:
3958         case Bytecodes::_invokespecial:
3959         case Bytecodes::_invokestatic:
3960         case Bytecodes::_invokeinterface:
3961           {
3962             Bytecode_invoke invoke(methodHandle(thread, sd->method()), sd->bci());
3963             st->print(" ");
3964             if (invoke.name() != nullptr)
3965               invoke.name()->print_symbol_on(st);
3966             else
3967               st->print("<UNKNOWN>");
3968             break;
3969           }
3970         case Bytecodes::_getfield:
3971         case Bytecodes::_putfield:
3972         case Bytecodes::_getstatic:
3973         case Bytecodes::_putstatic:
3974           {
3975             Bytecode_field field(methodHandle(thread, sd->method()), sd->bci());
3976             st->print(" ");
3977             if (field.name() != nullptr)
3978               field.name()->print_symbol_on(st);
3979             else
3980               st->print("<UNKNOWN>");
3981           }
3982         default:
3983           break;
3984         }
3985       }
3986       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
3987     }
3988 
3989     // Print all scopes
3990     for (;sd != nullptr; sd = sd->sender()) {
3991       st->move_to(column, 6, 0);
3992       st->print("; -");
3993       if (sd->should_reexecute()) {
3994         st->print(" (reexecute)");
3995       }
3996       if (sd->method() == nullptr) {
3997         st->print("method is nullptr");
3998       } else {
3999         sd->method()->print_short_name(st);
4000       }
4001       int lineno = sd->method()->line_number_from_bci(sd->bci());
4002       if (lineno != -1) {
4003         st->print("@%d (line %d)", sd->bci(), lineno);
4004       } else {
4005         st->print("@%d", sd->bci());
4006       }
4007       st->cr();
4008     }
4009   }
4010 
4011   // Print relocation information
4012   // Prevent memory leak: allocating without ResourceMark.
4013   ResourceMark rm;
4014   const char* str = reloc_string_for(begin, end);
4015   if (str != nullptr) {
4016     if (sd != nullptr) st->cr();
4017     st->move_to(column, 6, 0);
4018     st->print(";   {%s}", str);
4019   }
4020 }
4021 
4022 #endif
4023 
4024 address nmethod::call_instruction_address(address pc) const {
4025   if (NativeCall::is_call_before(pc)) {
4026     NativeCall *ncall = nativeCall_before(pc);
4027     return ncall->instruction_address();
4028   }
4029   return nullptr;
4030 }
4031 
4032 void nmethod::print_value_on_impl(outputStream* st) const {
4033   st->print_cr("nmethod");
4034 #if defined(SUPPORT_DATA_STRUCTS)
4035   print_on_with_msg(st, nullptr);
4036 #endif
4037 }
4038 
4039 #ifndef PRODUCT
4040 
4041 void nmethod::print_calls(outputStream* st) {
4042   RelocIterator iter(this);
4043   while (iter.next()) {
4044     switch (iter.type()) {
4045     case relocInfo::virtual_call_type: {
4046       CompiledICLocker ml_verify(this);
4047       CompiledIC_at(&iter)->print();
4048       break;
4049     }
4050     case relocInfo::static_call_type:
4051     case relocInfo::opt_virtual_call_type:
4052       st->print_cr("Direct call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
4053       CompiledDirectCall::at(iter.reloc())->print();
4054       break;
4055     default:
4056       break;
4057     }
4058   }
4059 }
4060 
4061 void nmethod::print_statistics() {
4062   ttyLocker ttyl;
4063   if (xtty != nullptr)  xtty->head("statistics type='nmethod'");
4064   native_nmethod_stats.print_native_nmethod_stats();
4065 #ifdef COMPILER1
4066   c1_java_nmethod_stats.print_nmethod_stats("C1");
4067 #endif
4068 #ifdef COMPILER2
4069   c2_java_nmethod_stats.print_nmethod_stats("C2");
4070 #endif
4071 #if INCLUDE_JVMCI
4072   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
4073 #endif
4074   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
4075   DebugInformationRecorder::print_statistics();
4076   pc_nmethod_stats.print_pc_stats();
4077   Dependencies::print_statistics();
4078   ExternalsRecorder::print_statistics();
4079   if (xtty != nullptr)  xtty->tail("statistics");
4080 }
4081 
4082 #endif // !PRODUCT
4083 
4084 #if INCLUDE_JVMCI
4085 void nmethod::update_speculation(JavaThread* thread) {
4086   jlong speculation = thread->pending_failed_speculation();
4087   if (speculation != 0) {
4088     guarantee(jvmci_nmethod_data() != nullptr, "failed speculation in nmethod without failed speculation list");
4089     jvmci_nmethod_data()->add_failed_speculation(this, speculation);
4090     thread->set_pending_failed_speculation(0);
4091   }
4092 }
4093 
4094 const char* nmethod::jvmci_name() {
4095   if (jvmci_nmethod_data() != nullptr) {
4096     return jvmci_nmethod_data()->name();
4097   }
4098   return nullptr;
4099 }
4100 #endif