1 /*
   2  * Copyright (c) 1997, 2018, 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 "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "code/codeCache.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/compiledMethod.inline.hpp"
  30 #include "code/dependencies.hpp"
  31 #include "code/nativeInst.hpp"
  32 #include "code/nmethod.hpp"
  33 #include "code/scopeDesc.hpp"
  34 #include "compiler/abstractCompiler.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/compileLog.hpp"
  37 #include "compiler/compilerDirectives.hpp"
  38 #include "compiler/directivesParser.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "interpreter/bytecode.hpp"
  41 #include "logging/log.hpp"
  42 #include "logging/logStream.hpp"
  43 #include "memory/allocation.inline.hpp"
  44 #include "memory/resourceArea.hpp"
  45 #include "oops/method.inline.hpp"
  46 #include "oops/methodData.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "prims/jvmtiImpl.hpp"
  49 #include "runtime/atomic.hpp"
  50 #include "runtime/flags/flagSetting.hpp"
  51 #include "runtime/frame.inline.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/jniHandles.inline.hpp"
  54 #include "runtime/orderAccess.hpp"
  55 #include "runtime/os.hpp"
  56 #include "runtime/safepointVerifiers.hpp"
  57 #include "runtime/sharedRuntime.hpp"
  58 #include "runtime/sweeper.hpp"
  59 #include "runtime/vmThread.hpp"
  60 #include "utilities/align.hpp"
  61 #include "utilities/dtrace.hpp"
  62 #include "utilities/events.hpp"
  63 #include "utilities/resourceHash.hpp"
  64 #include "utilities/xmlstream.hpp"
  65 #if INCLUDE_JVMCI
  66 #include "jvmci/jvmciJavaClasses.hpp"
  67 #endif
  68 
  69 #ifdef DTRACE_ENABLED
  70 
  71 // Only bother with this argument setup if dtrace is available
  72 
  73 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  74   {                                                                       \
  75     Method* m = (method);                                                 \
  76     if (m != NULL) {                                                      \
  77       Symbol* klass_name = m->klass_name();                               \
  78       Symbol* name = m->name();                                           \
  79       Symbol* signature = m->signature();                                 \
  80       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  81         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  82         (char *) name->bytes(), name->utf8_length(),                               \
  83         (char *) signature->bytes(), signature->utf8_length());                    \
  84     }                                                                     \
  85   }
  86 
  87 #else //  ndef DTRACE_ENABLED
  88 
  89 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  90 
  91 #endif
  92 
  93 //---------------------------------------------------------------------------------
  94 // NMethod statistics
  95 // They are printed under various flags, including:
  96 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  97 // (In the latter two cases, they like other stats are printed to the log only.)
  98 
  99 #ifndef PRODUCT
 100 // These variables are put into one block to reduce relocations
 101 // and make it simpler to print from the debugger.
 102 struct java_nmethod_stats_struct {
 103   int nmethod_count;
 104   int total_size;
 105   int relocation_size;
 106   int consts_size;
 107   int insts_size;
 108   int stub_size;
 109   int scopes_data_size;
 110   int scopes_pcs_size;
 111   int dependencies_size;
 112   int handler_table_size;
 113   int nul_chk_table_size;
 114   int oops_size;
 115   int metadata_size;
 116 
 117   void note_nmethod(nmethod* nm) {
 118     nmethod_count += 1;
 119     total_size          += nm->size();
 120     relocation_size     += nm->relocation_size();
 121     consts_size         += nm->consts_size();
 122     insts_size          += nm->insts_size();
 123     stub_size           += nm->stub_size();
 124     oops_size           += nm->oops_size();
 125     metadata_size       += nm->metadata_size();
 126     scopes_data_size    += nm->scopes_data_size();
 127     scopes_pcs_size     += nm->scopes_pcs_size();
 128     dependencies_size   += nm->dependencies_size();
 129     handler_table_size  += nm->handler_table_size();
 130     nul_chk_table_size  += nm->nul_chk_table_size();
 131   }
 132   void print_nmethod_stats(const char* name) {
 133     if (nmethod_count == 0)  return;
 134     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 135     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 136     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 137     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 138     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 139     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 140     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 141     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 142     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 143     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 144     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 145     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 146     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 147     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 148   }
 149 };
 150 
 151 struct native_nmethod_stats_struct {
 152   int native_nmethod_count;
 153   int native_total_size;
 154   int native_relocation_size;
 155   int native_insts_size;
 156   int native_oops_size;
 157   int native_metadata_size;
 158   void note_native_nmethod(nmethod* nm) {
 159     native_nmethod_count += 1;
 160     native_total_size       += nm->size();
 161     native_relocation_size  += nm->relocation_size();
 162     native_insts_size       += nm->insts_size();
 163     native_oops_size        += nm->oops_size();
 164     native_metadata_size    += nm->metadata_size();
 165   }
 166   void print_native_nmethod_stats() {
 167     if (native_nmethod_count == 0)  return;
 168     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 169     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 170     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 171     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 172     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 173     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 174   }
 175 };
 176 
 177 struct pc_nmethod_stats_struct {
 178   int pc_desc_resets;   // number of resets (= number of caches)
 179   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 180   int pc_desc_approx;   // number of those which have approximate true
 181   int pc_desc_repeats;  // number of _pc_descs[0] hits
 182   int pc_desc_hits;     // number of LRU cache hits
 183   int pc_desc_tests;    // total number of PcDesc examinations
 184   int pc_desc_searches; // total number of quasi-binary search steps
 185   int pc_desc_adds;     // number of LUR cache insertions
 186 
 187   void print_pc_stats() {
 188     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 189                   pc_desc_queries,
 190                   (double)(pc_desc_tests + pc_desc_searches)
 191                   / pc_desc_queries);
 192     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 193                   pc_desc_resets,
 194                   pc_desc_queries, pc_desc_approx,
 195                   pc_desc_repeats, pc_desc_hits,
 196                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 197   }
 198 };
 199 
 200 #ifdef COMPILER1
 201 static java_nmethod_stats_struct c1_java_nmethod_stats;
 202 #endif
 203 #ifdef COMPILER2
 204 static java_nmethod_stats_struct c2_java_nmethod_stats;
 205 #endif
 206 #if INCLUDE_JVMCI
 207 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 208 #endif
 209 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 210 
 211 static native_nmethod_stats_struct native_nmethod_stats;
 212 static pc_nmethod_stats_struct pc_nmethod_stats;
 213 
 214 static void note_java_nmethod(nmethod* nm) {
 215 #ifdef COMPILER1
 216   if (nm->is_compiled_by_c1()) {
 217     c1_java_nmethod_stats.note_nmethod(nm);
 218   } else
 219 #endif
 220 #ifdef COMPILER2
 221   if (nm->is_compiled_by_c2()) {
 222     c2_java_nmethod_stats.note_nmethod(nm);
 223   } else
 224 #endif
 225 #if INCLUDE_JVMCI
 226   if (nm->is_compiled_by_jvmci()) {
 227     jvmci_java_nmethod_stats.note_nmethod(nm);
 228   } else
 229 #endif
 230   {
 231     unknown_java_nmethod_stats.note_nmethod(nm);
 232   }
 233 }
 234 #endif // !PRODUCT
 235 
 236 //---------------------------------------------------------------------------------
 237 
 238 
 239 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 240   assert(pc != NULL, "Must be non null");
 241   assert(exception.not_null(), "Must be non null");
 242   assert(handler != NULL, "Must be non null");
 243 
 244   _count = 0;
 245   _exception_type = exception->klass();
 246   _next = NULL;
 247 
 248   add_address_and_handler(pc,handler);
 249 }
 250 
 251 
 252 address ExceptionCache::match(Handle exception, address pc) {
 253   assert(pc != NULL,"Must be non null");
 254   assert(exception.not_null(),"Must be non null");
 255   if (exception->klass() == exception_type()) {
 256     return (test_address(pc));
 257   }
 258 
 259   return NULL;
 260 }
 261 
 262 
 263 bool ExceptionCache::match_exception_with_space(Handle exception) {
 264   assert(exception.not_null(),"Must be non null");
 265   if (exception->klass() == exception_type() && count() < cache_size) {
 266     return true;
 267   }
 268   return false;
 269 }
 270 
 271 
 272 address ExceptionCache::test_address(address addr) {
 273   int limit = count();
 274   for (int i = 0; i < limit; i++) {
 275     if (pc_at(i) == addr) {
 276       return handler_at(i);
 277     }
 278   }
 279   return NULL;
 280 }
 281 
 282 
 283 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 284   if (test_address(addr) == handler) return true;
 285 
 286   int index = count();
 287   if (index < cache_size) {
 288     set_pc_at(index, addr);
 289     set_handler_at(index, handler);
 290     increment_count();
 291     return true;
 292   }
 293   return false;
 294 }
 295 
 296 //-----------------------------------------------------------------------------
 297 
 298 
 299 // Helper used by both find_pc_desc methods.
 300 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 301   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 302   if (!approximate)
 303     return pc->pc_offset() == pc_offset;
 304   else
 305     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 306 }
 307 
 308 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 309   if (initial_pc_desc == NULL) {
 310     _pc_descs[0] = NULL; // native method; no PcDescs at all
 311     return;
 312   }
 313   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 314   // reset the cache by filling it with benign (non-null) values
 315   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 316   for (int i = 0; i < cache_size; i++)
 317     _pc_descs[i] = initial_pc_desc;
 318 }
 319 
 320 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 321   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 322   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 323 
 324   // Note: one might think that caching the most recently
 325   // read value separately would be a win, but one would be
 326   // wrong.  When many threads are updating it, the cache
 327   // line it's in would bounce between caches, negating
 328   // any benefit.
 329 
 330   // In order to prevent race conditions do not load cache elements
 331   // repeatedly, but use a local copy:
 332   PcDesc* res;
 333 
 334   // Step one:  Check the most recently added value.
 335   res = _pc_descs[0];
 336   if (res == NULL) return NULL;  // native method; no PcDescs at all
 337   if (match_desc(res, pc_offset, approximate)) {
 338     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 339     return res;
 340   }
 341 
 342   // Step two:  Check the rest of the LRU cache.
 343   for (int i = 1; i < cache_size; ++i) {
 344     res = _pc_descs[i];
 345     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 346     if (match_desc(res, pc_offset, approximate)) {
 347       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 348       return res;
 349     }
 350   }
 351 
 352   // Report failure.
 353   return NULL;
 354 }
 355 
 356 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 357   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 358   // Update the LRU cache by shifting pc_desc forward.
 359   for (int i = 0; i < cache_size; i++)  {
 360     PcDesc* next = _pc_descs[i];
 361     _pc_descs[i] = pc_desc;
 362     pc_desc = next;
 363   }
 364 }
 365 
 366 // adjust pcs_size so that it is a multiple of both oopSize and
 367 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 368 // of oopSize, then 2*sizeof(PcDesc) is)
 369 static int adjust_pcs_size(int pcs_size) {
 370   int nsize = align_up(pcs_size,   oopSize);
 371   if ((nsize % sizeof(PcDesc)) != 0) {
 372     nsize = pcs_size + sizeof(PcDesc);
 373   }
 374   assert((nsize % oopSize) == 0, "correct alignment");
 375   return nsize;
 376 }
 377 
 378 
 379 int nmethod::total_size() const {
 380   return
 381     consts_size()        +
 382     insts_size()         +
 383     stub_size()          +
 384     scopes_data_size()   +
 385     scopes_pcs_size()    +
 386     handler_table_size() +
 387     nul_chk_table_size();
 388 }
 389 
 390 address* nmethod::orig_pc_addr(const frame* fr) {
 391   return (address*) ((address)fr->unextended_sp() + _orig_pc_offset);
 392 }
 393 
 394 const char* nmethod::compile_kind() const {
 395   if (is_osr_method())     return "osr";
 396   if (method() != NULL && is_native_method())  return "c2n";
 397   return NULL;
 398 }
 399 
 400 // Fill in default values for various flag fields
 401 void nmethod::init_defaults() {
 402   _state                      = not_installed;
 403   _has_flushed_dependencies   = 0;
 404   _lock_count                 = 0;
 405   _stack_traversal_mark       = 0;
 406   _unload_reported            = false; // jvmti state
 407   _is_far_code                = false; // nmethods are located in CodeCache
 408 
 409 #ifdef ASSERT
 410   _oops_are_stale             = false;
 411 #endif
 412 
 413   _oops_do_mark_link       = NULL;
 414   _jmethod_id              = NULL;
 415   _osr_link                = NULL;
 416   _unloading_next          = NULL;
 417   _scavenge_root_link      = NULL;
 418   _scavenge_root_state     = 0;
 419 #if INCLUDE_RTM_OPT
 420   _rtm_state               = NoRTM;
 421 #endif
 422 #if INCLUDE_JVMCI
 423   _jvmci_installed_code   = NULL;
 424   _speculation_log        = NULL;
 425   _jvmci_installed_code_triggers_unloading = false;
 426 #endif
 427 }
 428 
 429 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
 430   int compile_id,
 431   CodeBuffer *code_buffer,
 432   int vep_offset,
 433   int frame_complete,
 434   int frame_size,
 435   ByteSize basic_lock_owner_sp_offset,
 436   ByteSize basic_lock_sp_offset,
 437   OopMapSet* oop_maps) {
 438   code_buffer->finalize_oop_references(method);
 439   // create nmethod
 440   nmethod* nm = NULL;
 441   {
 442     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 443     int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
 444     CodeOffsets offsets;
 445     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 446     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 447     nm = new (native_nmethod_size, CompLevel_none) nmethod(method(), compiler_none, native_nmethod_size,
 448                                             compile_id, &offsets,
 449                                             code_buffer, frame_size,
 450                                             basic_lock_owner_sp_offset,
 451                                             basic_lock_sp_offset, oop_maps);
 452     NOT_PRODUCT(if (nm != NULL)  native_nmethod_stats.note_native_nmethod(nm));
 453   }
 454 
 455   if (nm != NULL) {
 456     // verify nmethod
 457     debug_only(nm->verify();) // might block
 458 
 459     nm->log_new_nmethod();
 460     nm->make_in_use();
 461   }
 462   return nm;
 463 }
 464 
 465 nmethod* nmethod::new_nmethod(const methodHandle& method,
 466   int compile_id,
 467   int entry_bci,
 468   CodeOffsets* offsets,
 469   int orig_pc_offset,
 470   DebugInformationRecorder* debug_info,
 471   Dependencies* dependencies,
 472   CodeBuffer* code_buffer, int frame_size,
 473   OopMapSet* oop_maps,
 474   ExceptionHandlerTable* handler_table,
 475   ImplicitExceptionTable* nul_chk_table,
 476   AbstractCompiler* compiler,
 477   int comp_level
 478 #if INCLUDE_JVMCI
 479   , jweak installed_code,
 480   jweak speculationLog
 481 #endif
 482 )
 483 {
 484   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 485   code_buffer->finalize_oop_references(method);
 486   // create nmethod
 487   nmethod* nm = NULL;
 488   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 489     int nmethod_size =
 490       CodeBlob::allocation_size(code_buffer, sizeof(nmethod))
 491       + adjust_pcs_size(debug_info->pcs_size())
 492       + align_up((int)dependencies->size_in_bytes(), oopSize)
 493       + align_up(handler_table->size_in_bytes()    , oopSize)
 494       + align_up(nul_chk_table->size_in_bytes()    , oopSize)
 495       + align_up(debug_info->data_size()           , oopSize);
 496 
 497     nm = new (nmethod_size, comp_level)
 498     nmethod(method(), compiler->type(), nmethod_size, compile_id, entry_bci, offsets,
 499             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 500             oop_maps,
 501             handler_table,
 502             nul_chk_table,
 503             compiler,
 504             comp_level
 505 #if INCLUDE_JVMCI
 506             , installed_code,
 507             speculationLog
 508 #endif
 509             );
 510 
 511     if (nm != NULL) {
 512       // To make dependency checking during class loading fast, record
 513       // the nmethod dependencies in the classes it is dependent on.
 514       // This allows the dependency checking code to simply walk the
 515       // class hierarchy above the loaded class, checking only nmethods
 516       // which are dependent on those classes.  The slow way is to
 517       // check every nmethod for dependencies which makes it linear in
 518       // the number of methods compiled.  For applications with a lot
 519       // classes the slow way is too slow.
 520       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 521         if (deps.type() == Dependencies::call_site_target_value) {
 522           // CallSite dependencies are managed on per-CallSite instance basis.
 523           oop call_site = deps.argument_oop(0);
 524           MethodHandles::add_dependent_nmethod(call_site, nm);
 525         } else {
 526           Klass* klass = deps.context_type();
 527           if (klass == NULL) {
 528             continue;  // ignore things like evol_method
 529           }
 530           // record this nmethod as dependent on this klass
 531           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 532         }
 533       }
 534       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 535     }
 536   }
 537   // Do verification and logging outside CodeCache_lock.
 538   if (nm != NULL) {
 539     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 540     DEBUG_ONLY(nm->verify();)
 541     nm->log_new_nmethod();
 542   }
 543   return nm;
 544 }
 545 
 546 // For native wrappers
 547 nmethod::nmethod(
 548   Method* method,
 549   CompilerType type,
 550   int nmethod_size,
 551   int compile_id,
 552   CodeOffsets* offsets,
 553   CodeBuffer* code_buffer,
 554   int frame_size,
 555   ByteSize basic_lock_owner_sp_offset,
 556   ByteSize basic_lock_sp_offset,
 557   OopMapSet* oop_maps )
 558   : CompiledMethod(method, "native nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 559   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 560   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 561 {
 562   {
 563     int scopes_data_offset = 0;
 564     int deoptimize_offset       = 0;
 565     int deoptimize_mh_offset    = 0;
 566 
 567     debug_only(NoSafepointVerifier nsv;)
 568     assert_locked_or_safepoint(CodeCache_lock);
 569 
 570     init_defaults();
 571     _entry_bci               = InvocationEntryBci;
 572     // We have no exception handler or deopt handler make the
 573     // values something that will never match a pc like the nmethod vtable entry
 574     _exception_offset        = 0;
 575     _orig_pc_offset          = 0;
 576 
 577     _consts_offset           = data_offset();
 578     _stub_offset             = data_offset();
 579     _oops_offset             = data_offset();
 580     _metadata_offset         = _oops_offset         + align_up(code_buffer->total_oop_size(), oopSize);
 581     scopes_data_offset       = _metadata_offset     + align_up(code_buffer->total_metadata_size(), wordSize);
 582     _scopes_pcs_offset       = scopes_data_offset;
 583     _dependencies_offset     = _scopes_pcs_offset;
 584     _handler_table_offset    = _dependencies_offset;
 585     _nul_chk_table_offset    = _handler_table_offset;
 586     _nmethod_end_offset      = _nul_chk_table_offset;
 587     _compile_id              = compile_id;
 588     _comp_level              = CompLevel_none;
 589     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 590     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 591     _osr_entry_point         = NULL;
 592     _exception_cache         = NULL;
 593     _pc_desc_container.reset_to(NULL);
 594     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 595 
 596     _scopes_data_begin = (address) this + scopes_data_offset;
 597     _deopt_handler_begin = (address) this + deoptimize_offset;
 598     _deopt_mh_handler_begin = (address) this + deoptimize_mh_offset;
 599 
 600     code_buffer->copy_code_and_locs_to(this);
 601     code_buffer->copy_values_to(this);
 602     if (ScavengeRootsInCode) {
 603       Universe::heap()->register_nmethod(this);
 604     }
 605     debug_only(Universe::heap()->verify_nmethod(this));
 606     CodeCache::commit(this);
 607   }
 608 
 609   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 610     ttyLocker ttyl;  // keep the following output all in one block
 611     // This output goes directly to the tty, not the compiler log.
 612     // To enable tools to match it up with the compilation activity,
 613     // be sure to tag this tty output with the compile ID.
 614     if (xtty != NULL) {
 615       xtty->begin_head("print_native_nmethod");
 616       xtty->method(_method);
 617       xtty->stamp();
 618       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 619     }
 620     // print the header part first
 621     print();
 622     // then print the requested information
 623     if (PrintNativeNMethods) {
 624       print_code();
 625       if (oop_maps != NULL) {
 626         oop_maps->print();
 627       }
 628     }
 629     if (PrintRelocations) {
 630       print_relocations();
 631     }
 632     if (xtty != NULL) {
 633       xtty->tail("print_native_nmethod");
 634     }
 635   }
 636 }
 637 
 638 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 639   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 640 }
 641 
 642 nmethod::nmethod(
 643   Method* method,
 644   CompilerType type,
 645   int nmethod_size,
 646   int compile_id,
 647   int entry_bci,
 648   CodeOffsets* offsets,
 649   int orig_pc_offset,
 650   DebugInformationRecorder* debug_info,
 651   Dependencies* dependencies,
 652   CodeBuffer *code_buffer,
 653   int frame_size,
 654   OopMapSet* oop_maps,
 655   ExceptionHandlerTable* handler_table,
 656   ImplicitExceptionTable* nul_chk_table,
 657   AbstractCompiler* compiler,
 658   int comp_level
 659 #if INCLUDE_JVMCI
 660   , jweak installed_code,
 661   jweak speculation_log
 662 #endif
 663   )
 664   : CompiledMethod(method, "nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 665   _native_receiver_sp_offset(in_ByteSize(-1)),
 666   _native_basic_lock_sp_offset(in_ByteSize(-1))
 667 {
 668   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 669   {
 670     debug_only(NoSafepointVerifier nsv;)
 671     assert_locked_or_safepoint(CodeCache_lock);
 672 
 673     _deopt_handler_begin = (address) this;
 674     _deopt_mh_handler_begin = (address) this;
 675 
 676     init_defaults();
 677     _entry_bci               = entry_bci;
 678     _compile_id              = compile_id;
 679     _comp_level              = comp_level;
 680     _orig_pc_offset          = orig_pc_offset;
 681     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 682 
 683     // Section offsets
 684     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 685     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 686     set_ctable_begin(header_begin() + _consts_offset);
 687 
 688 #if INCLUDE_JVMCI
 689     _jvmci_installed_code = installed_code;
 690     _speculation_log = speculation_log;
 691     oop obj = JNIHandles::resolve(installed_code);
 692     if (obj == NULL || (obj->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(obj))) {
 693       _jvmci_installed_code_triggers_unloading = false;
 694     } else {
 695       _jvmci_installed_code_triggers_unloading = true;
 696     }
 697 
 698     if (compiler->is_jvmci()) {
 699       // JVMCI might not produce any stub sections
 700       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 701         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 702       } else {
 703         _exception_offset = -1;
 704       }
 705       if (offsets->value(CodeOffsets::Deopt) != -1) {
 706         _deopt_handler_begin       = (address) this + code_offset()          + offsets->value(CodeOffsets::Deopt);
 707       } else {
 708         _deopt_handler_begin = NULL;
 709       }
 710       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 711         _deopt_mh_handler_begin  = (address) this + code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 712       } else {
 713         _deopt_mh_handler_begin = NULL;
 714       }
 715     } else {
 716 #endif
 717     // Exception handler and deopt handler are in the stub section
 718     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 719     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 720 
 721     _exception_offset       = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 722     _deopt_handler_begin    = (address) this + _stub_offset          + offsets->value(CodeOffsets::Deopt);
 723     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 724       _deopt_mh_handler_begin  = (address) this + _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 725     } else {
 726       _deopt_mh_handler_begin  = NULL;
 727 #if INCLUDE_JVMCI
 728     }
 729 #endif
 730     }
 731     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 732       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 733     } else {
 734       _unwind_handler_offset = -1;
 735     }
 736 
 737     _oops_offset             = data_offset();
 738     _metadata_offset         = _oops_offset          + align_up(code_buffer->total_oop_size(), oopSize);
 739     int scopes_data_offset   = _metadata_offset      + align_up(code_buffer->total_metadata_size(), wordSize);
 740 
 741     _scopes_pcs_offset       = scopes_data_offset    + align_up(debug_info->data_size       (), oopSize);
 742     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 743     _handler_table_offset    = _dependencies_offset  + align_up((int)dependencies->size_in_bytes (), oopSize);
 744     _nul_chk_table_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
 745     _nmethod_end_offset      = _nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize);
 746     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 747     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 748     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 749     _exception_cache         = NULL;
 750 
 751     _scopes_data_begin = (address) this + scopes_data_offset;
 752 
 753     _pc_desc_container.reset_to(scopes_pcs_begin());
 754 
 755     code_buffer->copy_code_and_locs_to(this);
 756     // Copy contents of ScopeDescRecorder to nmethod
 757     code_buffer->copy_values_to(this);
 758     debug_info->copy_to(this);
 759     dependencies->copy_to(this);
 760     if (ScavengeRootsInCode) {
 761       Universe::heap()->register_nmethod(this);
 762     }
 763     debug_only(Universe::heap()->verify_nmethod(this));
 764 
 765     CodeCache::commit(this);
 766 
 767     // Copy contents of ExceptionHandlerTable to nmethod
 768     handler_table->copy_to(this);
 769     nul_chk_table->copy_to(this);
 770 
 771     // we use the information of entry points to find out if a method is
 772     // static or non static
 773     assert(compiler->is_c2() || compiler->is_jvmci() ||
 774            _method->is_static() == (entry_point() == _verified_entry_point),
 775            " entry points must be same for static methods and vice versa");
 776   }
 777 }
 778 
 779 // Print a short set of xml attributes to identify this nmethod.  The
 780 // output should be embedded in some other element.
 781 void nmethod::log_identity(xmlStream* log) const {
 782   log->print(" compile_id='%d'", compile_id());
 783   const char* nm_kind = compile_kind();
 784   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 785   log->print(" compiler='%s'", compiler_name());
 786   if (TieredCompilation) {
 787     log->print(" level='%d'", comp_level());
 788   }
 789 }
 790 
 791 
 792 #define LOG_OFFSET(log, name)                    \
 793   if (p2i(name##_end()) - p2i(name##_begin())) \
 794     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 795                p2i(name##_begin()) - p2i(this))
 796 
 797 
 798 void nmethod::log_new_nmethod() const {
 799   if (LogCompilation && xtty != NULL) {
 800     ttyLocker ttyl;
 801     HandleMark hm;
 802     xtty->begin_elem("nmethod");
 803     log_identity(xtty);
 804     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 805     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 806 
 807     LOG_OFFSET(xtty, relocation);
 808     LOG_OFFSET(xtty, consts);
 809     LOG_OFFSET(xtty, insts);
 810     LOG_OFFSET(xtty, stub);
 811     LOG_OFFSET(xtty, scopes_data);
 812     LOG_OFFSET(xtty, scopes_pcs);
 813     LOG_OFFSET(xtty, dependencies);
 814     LOG_OFFSET(xtty, handler_table);
 815     LOG_OFFSET(xtty, nul_chk_table);
 816     LOG_OFFSET(xtty, oops);
 817     LOG_OFFSET(xtty, metadata);
 818 
 819     xtty->method(method());
 820     xtty->stamp();
 821     xtty->end_elem();
 822   }
 823 }
 824 
 825 #undef LOG_OFFSET
 826 
 827 
 828 // Print out more verbose output usually for a newly created nmethod.
 829 void nmethod::print_on(outputStream* st, const char* msg) const {
 830   if (st != NULL) {
 831     ttyLocker ttyl;
 832     if (WizardMode) {
 833       CompileTask::print(st, this, msg, /*short_form:*/ true);
 834       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 835     } else {
 836       CompileTask::print(st, this, msg, /*short_form:*/ false);
 837     }
 838   }
 839 }
 840 
 841 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 842   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 843   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 844     print_nmethod(printnmethods);
 845   }
 846 }
 847 
 848 void nmethod::print_nmethod(bool printmethod) {
 849   ttyLocker ttyl;  // keep the following output all in one block
 850   if (xtty != NULL) {
 851     xtty->begin_head("print_nmethod");
 852     xtty->stamp();
 853     xtty->end_head();
 854   }
 855   // print the header part first
 856   print();
 857   // then print the requested information
 858   if (printmethod) {
 859     print_code();
 860     print_pcs();
 861     if (oop_maps()) {
 862       oop_maps()->print();
 863     }
 864   }
 865   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 866     print_scopes();
 867   }
 868   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 869     print_relocations();
 870   }
 871   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 872     print_dependencies();
 873   }
 874   if (printmethod || PrintExceptionHandlers) {
 875     print_handler_table();
 876     print_nul_chk_table();
 877   }
 878   if (printmethod) {
 879     print_recorded_oops();
 880     print_recorded_metadata();
 881   }
 882   if (xtty != NULL) {
 883     xtty->tail("print_nmethod");
 884   }
 885 }
 886 
 887 
 888 // Promote one word from an assembly-time handle to a live embedded oop.
 889 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
 890   if (handle == NULL ||
 891       // As a special case, IC oops are initialized to 1 or -1.
 892       handle == (jobject) Universe::non_oop_word()) {
 893     (*dest) = (oop) handle;
 894   } else {
 895     (*dest) = JNIHandles::resolve_non_null(handle);
 896   }
 897 }
 898 
 899 
 900 // Have to have the same name because it's called by a template
 901 void nmethod::copy_values(GrowableArray<jobject>* array) {
 902   int length = array->length();
 903   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
 904   oop* dest = oops_begin();
 905   for (int index = 0 ; index < length; index++) {
 906     initialize_immediate_oop(&dest[index], array->at(index));
 907   }
 908 
 909   // Now we can fix up all the oops in the code.  We need to do this
 910   // in the code because the assembler uses jobjects as placeholders.
 911   // The code and relocations have already been initialized by the
 912   // CodeBlob constructor, so it is valid even at this early point to
 913   // iterate over relocations and patch the code.
 914   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 915 }
 916 
 917 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
 918   int length = array->length();
 919   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
 920   Metadata** dest = metadata_begin();
 921   for (int index = 0 ; index < length; index++) {
 922     dest[index] = array->at(index);
 923   }
 924 }
 925 
 926 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
 927   // re-patch all oop-bearing instructions, just in case some oops moved
 928   RelocIterator iter(this, begin, end);
 929   while (iter.next()) {
 930     if (iter.type() == relocInfo::oop_type) {
 931       oop_Relocation* reloc = iter.oop_reloc();
 932       if (initialize_immediates && reloc->oop_is_immediate()) {
 933         oop* dest = reloc->oop_addr();
 934         initialize_immediate_oop(dest, (jobject) *dest);
 935       }
 936       // Refresh the oop-related bits of this instruction.
 937       reloc->fix_oop_relocation();
 938     } else if (iter.type() == relocInfo::metadata_type) {
 939       metadata_Relocation* reloc = iter.metadata_reloc();
 940       reloc->fix_metadata_relocation();
 941     }
 942   }
 943 }
 944 
 945 
 946 void nmethod::verify_clean_inline_caches() {
 947   assert_locked_or_safepoint(CompiledIC_lock);
 948 
 949   ResourceMark rm;
 950   RelocIterator iter(this, oops_reloc_begin());
 951   while(iter.next()) {
 952     switch(iter.type()) {
 953       case relocInfo::virtual_call_type:
 954       case relocInfo::opt_virtual_call_type: {
 955         CompiledIC *ic = CompiledIC_at(&iter);
 956         // Ok, to lookup references to zombies here
 957         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
 958         assert(cb != NULL, "destination not in CodeBlob?");
 959         nmethod* nm = cb->as_nmethod_or_null();
 960         if( nm != NULL ) {
 961           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 962           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 963             assert(ic->is_clean(), "IC should be clean");
 964           }
 965         }
 966         break;
 967       }
 968       case relocInfo::static_call_type: {
 969         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
 970         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
 971         assert(cb != NULL, "destination not in CodeBlob?");
 972         nmethod* nm = cb->as_nmethod_or_null();
 973         if( nm != NULL ) {
 974           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 975           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 976             assert(csc->is_clean(), "IC should be clean");
 977           }
 978         }
 979         break;
 980       }
 981       default:
 982         break;
 983     }
 984   }
 985 }
 986 
 987 // This is a private interface with the sweeper.
 988 void nmethod::mark_as_seen_on_stack() {
 989   assert(is_alive(), "Must be an alive method");
 990   // Set the traversal mark to ensure that the sweeper does 2
 991   // cleaning passes before moving to zombie.
 992   set_stack_traversal_mark(NMethodSweeper::traversal_count());
 993 }
 994 
 995 // Tell if a non-entrant method can be converted to a zombie (i.e.,
 996 // there are no activations on the stack, not in use by the VM,
 997 // and not in use by the ServiceThread)
 998 bool nmethod::can_convert_to_zombie() {
 999   assert(is_not_entrant(), "must be a non-entrant method");
1000 
1001   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1002   // count can be greater than the stack traversal count before it hits the
1003   // nmethod for the second time.
1004   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1005          !is_locked_by_vm();
1006 }
1007 
1008 void nmethod::inc_decompile_count() {
1009   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1010   // Could be gated by ProfileTraps, but do not bother...
1011   Method* m = method();
1012   if (m == NULL)  return;
1013   MethodData* mdo = m->method_data();
1014   if (mdo == NULL)  return;
1015   // There is a benign race here.  See comments in methodData.hpp.
1016   mdo->inc_decompile_count();
1017 }
1018 
1019 void nmethod::make_unloaded(oop cause) {
1020 
1021   post_compiled_method_unload();
1022 
1023   // This nmethod is being unloaded, make sure that dependencies
1024   // recorded in instanceKlasses get flushed.
1025   // Since this work is being done during a GC, defer deleting dependencies from the
1026   // InstanceKlass.
1027   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1028   flush_dependencies(/*delete_immediately*/false);
1029 
1030   // Break cycle between nmethod & method
1031   LogTarget(Trace, class, unload, nmethod) lt;
1032   if (lt.is_enabled()) {
1033     LogStream ls(lt);
1034     ls.print("making nmethod " INTPTR_FORMAT
1035              " unloadable, Method*(" INTPTR_FORMAT
1036              "), cause(" INTPTR_FORMAT ") ",
1037              p2i(this), p2i(_method), p2i(cause));
1038      if (cause != NULL) {
1039        cause->print_value_on(&ls);
1040      }
1041      ls.cr();
1042   }
1043   // Unlink the osr method, so we do not look this up again
1044   if (is_osr_method()) {
1045     // Invalidate the osr nmethod only once
1046     if (is_in_use()) {
1047       invalidate_osr_method();
1048     }
1049 #ifdef ASSERT
1050     if (method() != NULL) {
1051       // Make sure osr nmethod is invalidated, i.e. not on the list
1052       bool found = method()->method_holder()->remove_osr_nmethod(this);
1053       assert(!found, "osr nmethod should have been invalidated");
1054     }
1055 #endif
1056   }
1057 
1058   // If _method is already NULL the Method* is about to be unloaded,
1059   // so we don't have to break the cycle. Note that it is possible to
1060   // have the Method* live here, in case we unload the nmethod because
1061   // it is pointing to some oop (other than the Method*) being unloaded.
1062   if (_method != NULL) {
1063     // OSR methods point to the Method*, but the Method* does not
1064     // point back!
1065     if (_method->code() == this) {
1066       _method->clear_code(); // Break a cycle
1067     }
1068     _method = NULL;            // Clear the method of this dead nmethod
1069   }
1070 
1071   // Make the class unloaded - i.e., change state and notify sweeper
1072   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1073   if (is_in_use()) {
1074     // Transitioning directly from live to unloaded -- so
1075     // we need to force a cache clean-up; remember this
1076     // for later on.
1077     CodeCache::set_needs_cache_clean(true);
1078   }
1079 
1080   // Unregister must be done before the state change
1081   Universe::heap()->unregister_nmethod(this);
1082 
1083   _state = unloaded;
1084 
1085   // Log the unloading.
1086   log_state_change();
1087 
1088 #if INCLUDE_JVMCI
1089   // The method can only be unloaded after the pointer to the installed code
1090   // Java wrapper is no longer alive. Here we need to clear out this weak
1091   // reference to the dead object.
1092   maybe_invalidate_installed_code();
1093 #endif
1094 
1095   // The Method* is gone at this point
1096   assert(_method == NULL, "Tautology");
1097 
1098   set_osr_link(NULL);
1099   NMethodSweeper::report_state_change(this);
1100 }
1101 
1102 void nmethod::invalidate_osr_method() {
1103   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1104   // Remove from list of active nmethods
1105   if (method() != NULL) {
1106     method()->method_holder()->remove_osr_nmethod(this);
1107   }
1108 }
1109 
1110 void nmethod::log_state_change() const {
1111   if (LogCompilation) {
1112     if (xtty != NULL) {
1113       ttyLocker ttyl;  // keep the following output all in one block
1114       if (_state == unloaded) {
1115         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1116                          os::current_thread_id());
1117       } else {
1118         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1119                          os::current_thread_id(),
1120                          (_state == zombie ? " zombie='1'" : ""));
1121       }
1122       log_identity(xtty);
1123       xtty->stamp();
1124       xtty->end_elem();
1125     }
1126   }
1127 
1128   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1129   CompileTask::print_ul(this, state_msg);
1130   if (PrintCompilation && _state != unloaded) {
1131     print_on(tty, state_msg);
1132   }
1133 }
1134 
1135 /**
1136  * Common functionality for both make_not_entrant and make_zombie
1137  */
1138 bool nmethod::make_not_entrant_or_zombie(int state) {
1139   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1140   assert(!is_zombie(), "should not already be a zombie");
1141 
1142   if (_state == state) {
1143     // Avoid taking the lock if already in required state.
1144     // This is safe from races because the state is an end-state,
1145     // which the nmethod cannot back out of once entered.
1146     // No need for fencing either.
1147     return false;
1148   }
1149 
1150   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1151   nmethodLocker nml(this);
1152   methodHandle the_method(method());
1153   NoSafepointVerifier nsv;
1154 
1155   // during patching, depending on the nmethod state we must notify the GC that
1156   // code has been unloaded, unregistering it. We cannot do this right while
1157   // holding the Patching_lock because we need to use the CodeCache_lock. This
1158   // would be prone to deadlocks.
1159   // This flag is used to remember whether we need to later lock and unregister.
1160   bool nmethod_needs_unregister = false;
1161 
1162   {
1163     // invalidate osr nmethod before acquiring the patching lock since
1164     // they both acquire leaf locks and we don't want a deadlock.
1165     // This logic is equivalent to the logic below for patching the
1166     // verified entry point of regular methods. We check that the
1167     // nmethod is in use to ensure that it is invalidated only once.
1168     if (is_osr_method() && is_in_use()) {
1169       // this effectively makes the osr nmethod not entrant
1170       invalidate_osr_method();
1171     }
1172 
1173     // Enter critical section.  Does not block for safepoint.
1174     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1175 
1176     if (_state == state) {
1177       // another thread already performed this transition so nothing
1178       // to do, but return false to indicate this.
1179       return false;
1180     }
1181 
1182     // The caller can be calling the method statically or through an inline
1183     // cache call.
1184     if (!is_osr_method() && !is_not_entrant()) {
1185       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1186                   SharedRuntime::get_handle_wrong_method_stub());
1187     }
1188 
1189     if (is_in_use() && update_recompile_counts()) {
1190       // It's a true state change, so mark the method as decompiled.
1191       // Do it only for transition from alive.
1192       inc_decompile_count();
1193     }
1194 
1195     // If the state is becoming a zombie, signal to unregister the nmethod with
1196     // the heap.
1197     // This nmethod may have already been unloaded during a full GC.
1198     if ((state == zombie) && !is_unloaded()) {
1199       nmethod_needs_unregister = true;
1200     }
1201 
1202     // Must happen before state change. Otherwise we have a race condition in
1203     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1204     // transition its state from 'not_entrant' to 'zombie' without having to wait
1205     // for stack scanning.
1206     if (state == not_entrant) {
1207       mark_as_seen_on_stack();
1208       OrderAccess::storestore(); // _stack_traversal_mark and _state
1209     }
1210 
1211     // Change state
1212     _state = state;
1213 
1214     // Log the transition once
1215     log_state_change();
1216 
1217     // Invalidate while holding the patching lock
1218     JVMCI_ONLY(maybe_invalidate_installed_code());
1219 
1220     // Remove nmethod from method.
1221     // We need to check if both the _code and _from_compiled_code_entry_point
1222     // refer to this nmethod because there is a race in setting these two fields
1223     // in Method* as seen in bugid 4947125.
1224     // If the vep() points to the zombie nmethod, the memory for the nmethod
1225     // could be flushed and the compiler and vtable stubs could still call
1226     // through it.
1227     if (method() != NULL && (method()->code() == this ||
1228                              method()->from_compiled_entry() == verified_entry_point())) {
1229       HandleMark hm;
1230       method()->clear_code(false /* already owns Patching_lock */);
1231     }
1232   } // leave critical region under Patching_lock
1233 
1234 #ifdef ASSERT
1235   if (is_osr_method() && method() != NULL) {
1236     // Make sure osr nmethod is invalidated, i.e. not on the list
1237     bool found = method()->method_holder()->remove_osr_nmethod(this);
1238     assert(!found, "osr nmethod should have been invalidated");
1239   }
1240 #endif
1241 
1242   // When the nmethod becomes zombie it is no longer alive so the
1243   // dependencies must be flushed.  nmethods in the not_entrant
1244   // state will be flushed later when the transition to zombie
1245   // happens or they get unloaded.
1246   if (state == zombie) {
1247     {
1248       // Flushing dependencies must be done before any possible
1249       // safepoint can sneak in, otherwise the oops used by the
1250       // dependency logic could have become stale.
1251       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1252       if (nmethod_needs_unregister) {
1253         Universe::heap()->unregister_nmethod(this);
1254       }
1255       flush_dependencies(/*delete_immediately*/true);
1256     }
1257 
1258     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1259     // event and it hasn't already been reported for this nmethod then
1260     // report it now. The event may have been reported earlier if the GC
1261     // marked it for unloading). JvmtiDeferredEventQueue support means
1262     // we no longer go to a safepoint here.
1263     post_compiled_method_unload();
1264 
1265 #ifdef ASSERT
1266     // It's no longer safe to access the oops section since zombie
1267     // nmethods aren't scanned for GC.
1268     _oops_are_stale = true;
1269 #endif
1270      // the Method may be reclaimed by class unloading now that the
1271      // nmethod is in zombie state
1272     set_method(NULL);
1273   } else {
1274     assert(state == not_entrant, "other cases may need to be handled differently");
1275   }
1276 
1277   if (TraceCreateZombies) {
1278     ResourceMark m;
1279     tty->print_cr("nmethod <" INTPTR_FORMAT "> %s code made %s", p2i(this), this->method() ? this->method()->name_and_sig_as_C_string() : "null", (state == not_entrant) ? "not entrant" : "zombie");
1280   }
1281 
1282   NMethodSweeper::report_state_change(this);
1283   return true;
1284 }
1285 
1286 void nmethod::flush() {
1287   // Note that there are no valid oops in the nmethod anymore.
1288   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1289          "osr nmethod must be unloaded or zombie before flushing");
1290   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1291   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1292   assert_locked_or_safepoint(CodeCache_lock);
1293 
1294   // completely deallocate this method
1295   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1296   if (PrintMethodFlushing) {
1297     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1298                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1299                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1300                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1301   }
1302 
1303   // We need to deallocate any ExceptionCache data.
1304   // Note that we do not need to grab the nmethod lock for this, it
1305   // better be thread safe if we're disposing of it!
1306   ExceptionCache* ec = exception_cache();
1307   set_exception_cache(NULL);
1308   while(ec != NULL) {
1309     ExceptionCache* next = ec->next();
1310     delete ec;
1311     ec = next;
1312   }
1313 
1314   if (on_scavenge_root_list()) {
1315     CodeCache::drop_scavenge_root_nmethod(this);
1316   }
1317 
1318 #if INCLUDE_JVMCI
1319   assert(_jvmci_installed_code == NULL, "should have been nulled out when transitioned to zombie");
1320   assert(_speculation_log == NULL, "should have been nulled out when transitioned to zombie");
1321 #endif
1322 
1323   CodeBlob::flush();
1324   CodeCache::free(this);
1325 }
1326 
1327 //
1328 // Notify all classes this nmethod is dependent on that it is no
1329 // longer dependent. This should only be called in two situations.
1330 // First, when a nmethod transitions to a zombie all dependents need
1331 // to be clear.  Since zombification happens at a safepoint there's no
1332 // synchronization issues.  The second place is a little more tricky.
1333 // During phase 1 of mark sweep class unloading may happen and as a
1334 // result some nmethods may get unloaded.  In this case the flushing
1335 // of dependencies must happen during phase 1 since after GC any
1336 // dependencies in the unloaded nmethod won't be updated, so
1337 // traversing the dependency information in unsafe.  In that case this
1338 // function is called with a boolean argument and this function only
1339 // notifies instanceKlasses that are reachable
1340 
1341 void nmethod::flush_dependencies(bool delete_immediately) {
1342   assert_locked_or_safepoint(CodeCache_lock);
1343   assert(Universe::heap()->is_gc_active() != delete_immediately,
1344   "delete_immediately is false if and only if we are called during GC");
1345   if (!has_flushed_dependencies()) {
1346     set_has_flushed_dependencies();
1347     for (Dependencies::DepStream deps(this); deps.next(); ) {
1348       if (deps.type() == Dependencies::call_site_target_value) {
1349         // CallSite dependencies are managed on per-CallSite instance basis.
1350         oop call_site = deps.argument_oop(0);
1351         MethodHandles::remove_dependent_nmethod(call_site, this);
1352       } else {
1353         Klass* klass = deps.context_type();
1354         if (klass == NULL) {
1355           continue;  // ignore things like evol_method
1356         }
1357         // During GC delete_immediately is false, and liveness
1358         // of dependee determines class that needs to be updated.
1359         if (delete_immediately || klass->is_loader_alive()) {
1360           // The GC defers deletion of this entry, since there might be multiple threads
1361           // iterating over the _dependencies graph. Other call paths are single-threaded
1362           // and may delete it immediately.
1363           InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
1364         }
1365       }
1366     }
1367   }
1368 }
1369 
1370 
1371 // If this oop is not live, the nmethod can be unloaded.
1372 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root) {
1373   assert(root != NULL, "just checking");
1374   oop obj = *root;
1375   if (obj == NULL || is_alive->do_object_b(obj)) {
1376       return false;
1377   }
1378 
1379   // An nmethod might be unloaded simply because one of its constant oops has gone dead.
1380   // No actual classes need to be unloaded in order for this to occur.
1381   make_unloaded(obj);
1382   return true;
1383 }
1384 
1385 // ------------------------------------------------------------------
1386 // post_compiled_method_load_event
1387 // new method for install_code() path
1388 // Transfer information from compilation to jvmti
1389 void nmethod::post_compiled_method_load_event() {
1390 
1391   Method* moop = method();
1392   HOTSPOT_COMPILED_METHOD_LOAD(
1393       (char *) moop->klass_name()->bytes(),
1394       moop->klass_name()->utf8_length(),
1395       (char *) moop->name()->bytes(),
1396       moop->name()->utf8_length(),
1397       (char *) moop->signature()->bytes(),
1398       moop->signature()->utf8_length(),
1399       insts_begin(), insts_size());
1400 
1401   if (JvmtiExport::should_post_compiled_method_load() ||
1402       JvmtiExport::should_post_compiled_method_unload()) {
1403     get_and_cache_jmethod_id();
1404   }
1405 
1406   if (JvmtiExport::should_post_compiled_method_load()) {
1407     // Let the Service thread (which is a real Java thread) post the event
1408     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1409     JvmtiDeferredEventQueue::enqueue(
1410       JvmtiDeferredEvent::compiled_method_load_event(this));
1411   }
1412 }
1413 
1414 jmethodID nmethod::get_and_cache_jmethod_id() {
1415   if (_jmethod_id == NULL) {
1416     // Cache the jmethod_id since it can no longer be looked up once the
1417     // method itself has been marked for unloading.
1418     _jmethod_id = method()->jmethod_id();
1419   }
1420   return _jmethod_id;
1421 }
1422 
1423 void nmethod::post_compiled_method_unload() {
1424   if (unload_reported()) {
1425     // During unloading we transition to unloaded and then to zombie
1426     // and the unloading is reported during the first transition.
1427     return;
1428   }
1429 
1430   assert(_method != NULL && !is_unloaded(), "just checking");
1431   DTRACE_METHOD_UNLOAD_PROBE(method());
1432 
1433   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1434   // post the event. Sometime later this nmethod will be made a zombie
1435   // by the sweeper but the Method* will not be valid at that point.
1436   // If the _jmethod_id is null then no load event was ever requested
1437   // so don't bother posting the unload.  The main reason for this is
1438   // that the jmethodID is a weak reference to the Method* so if
1439   // it's being unloaded there's no way to look it up since the weak
1440   // ref will have been cleared.
1441   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1442     assert(!unload_reported(), "already unloaded");
1443     JvmtiDeferredEvent event =
1444       JvmtiDeferredEvent::compiled_method_unload_event(this,
1445           _jmethod_id, insts_begin());
1446     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1447     JvmtiDeferredEventQueue::enqueue(event);
1448   }
1449 
1450   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1451   // any time. As the nmethod is being unloaded now we mark it has
1452   // having the unload event reported - this will ensure that we don't
1453   // attempt to report the event in the unlikely scenario where the
1454   // event is enabled at the time the nmethod is made a zombie.
1455   set_unload_reported();
1456 }
1457 
1458 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive) {
1459   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
1460 
1461   oop_Relocation* r = iter_at_oop->oop_reloc();
1462   // Traverse those oops directly embedded in the code.
1463   // Other oops (oop_index>0) are seen as part of scopes_oops.
1464   assert(1 == (r->oop_is_immediate()) +
1465          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1466          "oop must be found in exactly one place");
1467   if (r->oop_is_immediate() && r->oop_value() != NULL) {
1468     // Unload this nmethod if the oop is dead.
1469     if (can_unload(is_alive, r->oop_addr())) {
1470       return true;;
1471     }
1472   }
1473 
1474   return false;
1475 }
1476 
1477 bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive) {
1478   // Scopes
1479   for (oop* p = oops_begin(); p < oops_end(); p++) {
1480     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1481     if (can_unload(is_alive, p)) {
1482       return true;
1483     }
1484   }
1485   return false;
1486 }
1487 
1488 bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive) {
1489   // Compiled code
1490 
1491   // Prevent extra code cache walk for platforms that don't have immediate oops.
1492   if (relocInfo::mustIterateImmediateOopsInCode()) {
1493     RelocIterator iter(this, low_boundary);
1494     while (iter.next()) {
1495       if (iter.type() == relocInfo::oop_type) {
1496         if (unload_if_dead_at(&iter, is_alive)) {
1497           return true;
1498         }
1499       }
1500     }
1501   }
1502 
1503   return do_unloading_scopes(is_alive);
1504 }
1505 
1506 #if INCLUDE_JVMCI
1507 bool nmethod::do_unloading_jvmci() {
1508   if (_jvmci_installed_code != NULL) {
1509     if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
1510       if (_jvmci_installed_code_triggers_unloading) {
1511         // jweak reference processing has already cleared the referent
1512         make_unloaded(NULL);
1513         return true;
1514       } else {
1515         clear_jvmci_installed_code();
1516       }
1517     }
1518   }
1519   return false;
1520 }
1521 #endif
1522 
1523 // Iterate over metadata calling this function.   Used by RedefineClasses
1524 void nmethod::metadata_do(void f(Metadata*)) {
1525   {
1526     // Visit all immediate references that are embedded in the instruction stream.
1527     RelocIterator iter(this, oops_reloc_begin());
1528     while (iter.next()) {
1529       if (iter.type() == relocInfo::metadata_type ) {
1530         metadata_Relocation* r = iter.metadata_reloc();
1531         // In this metadata, we must only follow those metadatas directly embedded in
1532         // the code.  Other metadatas (oop_index>0) are seen as part of
1533         // the metadata section below.
1534         assert(1 == (r->metadata_is_immediate()) +
1535                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1536                "metadata must be found in exactly one place");
1537         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1538           Metadata* md = r->metadata_value();
1539           if (md != _method) f(md);
1540         }
1541       } else if (iter.type() == relocInfo::virtual_call_type) {
1542         // Check compiledIC holders associated with this nmethod
1543         CompiledIC *ic = CompiledIC_at(&iter);
1544         if (ic->is_icholder_call()) {
1545           CompiledICHolder* cichk = ic->cached_icholder();
1546           f(cichk->holder_metadata());
1547           f(cichk->holder_klass());
1548         } else {
1549           Metadata* ic_oop = ic->cached_metadata();
1550           if (ic_oop != NULL) {
1551             f(ic_oop);
1552           }
1553         }
1554       }
1555     }
1556   }
1557 
1558   // Visit the metadata section
1559   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1560     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1561     Metadata* md = *p;
1562     f(md);
1563   }
1564 
1565   // Visit metadata not embedded in the other places.
1566   if (_method != NULL) f(_method);
1567 }
1568 
1569 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1570   // make sure the oops ready to receive visitors
1571   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1572   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1573 
1574   // Prevent extra code cache walk for platforms that don't have immediate oops.
1575   if (relocInfo::mustIterateImmediateOopsInCode()) {
1576     RelocIterator iter(this, oops_reloc_begin());
1577 
1578     while (iter.next()) {
1579       if (iter.type() == relocInfo::oop_type ) {
1580         oop_Relocation* r = iter.oop_reloc();
1581         // In this loop, we must only follow those oops directly embedded in
1582         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1583         assert(1 == (r->oop_is_immediate()) +
1584                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1585                "oop must be found in exactly one place");
1586         if (r->oop_is_immediate() && r->oop_value() != NULL) {
1587           f->do_oop(r->oop_addr());
1588         }
1589       }
1590     }
1591   }
1592 
1593   // Scopes
1594   // This includes oop constants not inlined in the code stream.
1595   for (oop* p = oops_begin(); p < oops_end(); p++) {
1596     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1597     f->do_oop(p);
1598   }
1599 }
1600 
1601 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1602 
1603 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1604 
1605 // An nmethod is "marked" if its _mark_link is set non-null.
1606 // Even if it is the end of the linked list, it will have a non-null link value,
1607 // as long as it is on the list.
1608 // This code must be MP safe, because it is used from parallel GC passes.
1609 bool nmethod::test_set_oops_do_mark() {
1610   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1611   if (_oops_do_mark_link == NULL) {
1612     // Claim this nmethod for this thread to mark.
1613     if (Atomic::replace_if_null(NMETHOD_SENTINEL, &_oops_do_mark_link)) {
1614       // Atomically append this nmethod (now claimed) to the head of the list:
1615       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1616       for (;;) {
1617         nmethod* required_mark_nmethods = observed_mark_nmethods;
1618         _oops_do_mark_link = required_mark_nmethods;
1619         observed_mark_nmethods =
1620           Atomic::cmpxchg(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1621         if (observed_mark_nmethods == required_mark_nmethods)
1622           break;
1623       }
1624       // Mark was clear when we first saw this guy.
1625       LogTarget(Trace, gc, nmethod) lt;
1626       if (lt.is_enabled()) {
1627         LogStream ls(lt);
1628         CompileTask::print(&ls, this, "oops_do, mark", /*short_form:*/ true);
1629       }
1630       return false;
1631     }
1632   }
1633   // On fall through, another racing thread marked this nmethod before we did.
1634   return true;
1635 }
1636 
1637 void nmethod::oops_do_marking_prologue() {
1638   log_trace(gc, nmethod)("oops_do_marking_prologue");
1639   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1640   // We use cmpxchg instead of regular assignment here because the user
1641   // may fork a bunch of threads, and we need them all to see the same state.
1642   nmethod* observed = Atomic::cmpxchg(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, (nmethod*)NULL);
1643   guarantee(observed == NULL, "no races in this sequential code");
1644 }
1645 
1646 void nmethod::oops_do_marking_epilogue() {
1647   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1648   nmethod* cur = _oops_do_mark_nmethods;
1649   while (cur != NMETHOD_SENTINEL) {
1650     assert(cur != NULL, "not NULL-terminated");
1651     nmethod* next = cur->_oops_do_mark_link;
1652     cur->_oops_do_mark_link = NULL;
1653     DEBUG_ONLY(cur->verify_oop_relocations());
1654 
1655     LogTarget(Trace, gc, nmethod) lt;
1656     if (lt.is_enabled()) {
1657       LogStream ls(lt);
1658       CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
1659     }
1660     cur = next;
1661   }
1662   nmethod* required = _oops_do_mark_nmethods;
1663   nmethod* observed = Atomic::cmpxchg((nmethod*)NULL, &_oops_do_mark_nmethods, required);
1664   guarantee(observed == required, "no races in this sequential code");
1665   log_trace(gc, nmethod)("oops_do_marking_epilogue");
1666 }
1667 
1668 class DetectScavengeRoot: public OopClosure {
1669   bool     _detected_scavenge_root;
1670   nmethod* _print_nm;
1671 public:
1672   DetectScavengeRoot(nmethod* nm) : _detected_scavenge_root(false), _print_nm(nm) {}
1673 
1674   bool detected_scavenge_root() { return _detected_scavenge_root; }
1675   virtual void do_oop(oop* p) {
1676     if ((*p) != NULL && Universe::heap()->is_scavengable(*p)) {
1677       NOT_PRODUCT(maybe_print(p));
1678       _detected_scavenge_root = true;
1679     }
1680   }
1681   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1682 
1683 #ifndef PRODUCT
1684   void maybe_print(oop* p) {
1685     LogTarget(Trace, gc, nmethod) lt;
1686     if (lt.is_enabled()) {
1687       LogStream ls(lt);
1688       if (!_detected_scavenge_root) {
1689         CompileTask::print(&ls, _print_nm, "new scavenge root", /*short_form:*/ true);
1690       }
1691       ls.print("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ") ",
1692                p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1693                p2i(*p), p2i(p));
1694       ls.cr();
1695     }
1696   }
1697 #endif //PRODUCT
1698 };
1699 
1700 bool nmethod::detect_scavenge_root_oops() {
1701   DetectScavengeRoot detect_scavenge_root(this);
1702   oops_do(&detect_scavenge_root);
1703   return detect_scavenge_root.detected_scavenge_root();
1704 }
1705 
1706 inline bool includes(void* p, void* from, void* to) {
1707   return from <= p && p < to;
1708 }
1709 
1710 
1711 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1712   assert(count >= 2, "must be sentinel values, at least");
1713 
1714 #ifdef ASSERT
1715   // must be sorted and unique; we do a binary search in find_pc_desc()
1716   int prev_offset = pcs[0].pc_offset();
1717   assert(prev_offset == PcDesc::lower_offset_limit,
1718          "must start with a sentinel");
1719   for (int i = 1; i < count; i++) {
1720     int this_offset = pcs[i].pc_offset();
1721     assert(this_offset > prev_offset, "offsets must be sorted");
1722     prev_offset = this_offset;
1723   }
1724   assert(prev_offset == PcDesc::upper_offset_limit,
1725          "must end with a sentinel");
1726 #endif //ASSERT
1727 
1728   // Search for MethodHandle invokes and tag the nmethod.
1729   for (int i = 0; i < count; i++) {
1730     if (pcs[i].is_method_handle_invoke()) {
1731       set_has_method_handle_invokes(true);
1732       break;
1733     }
1734   }
1735   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1736 
1737   int size = count * sizeof(PcDesc);
1738   assert(scopes_pcs_size() >= size, "oob");
1739   memcpy(scopes_pcs_begin(), pcs, size);
1740 
1741   // Adjust the final sentinel downward.
1742   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1743   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1744   last_pc->set_pc_offset(content_size() + 1);
1745   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1746     // Fill any rounding gaps with copies of the last record.
1747     last_pc[1] = last_pc[0];
1748   }
1749   // The following assert could fail if sizeof(PcDesc) is not
1750   // an integral multiple of oopSize (the rounding term).
1751   // If it fails, change the logic to always allocate a multiple
1752   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1753   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1754 }
1755 
1756 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1757   assert(scopes_data_size() >= size, "oob");
1758   memcpy(scopes_data_begin(), buffer, size);
1759 }
1760 
1761 #ifdef ASSERT
1762 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1763   PcDesc* lower = search.scopes_pcs_begin();
1764   PcDesc* upper = search.scopes_pcs_end();
1765   lower += 1; // exclude initial sentinel
1766   PcDesc* res = NULL;
1767   for (PcDesc* p = lower; p < upper; p++) {
1768     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1769     if (match_desc(p, pc_offset, approximate)) {
1770       if (res == NULL)
1771         res = p;
1772       else
1773         res = (PcDesc*) badAddress;
1774     }
1775   }
1776   return res;
1777 }
1778 #endif
1779 
1780 
1781 // Finds a PcDesc with real-pc equal to "pc"
1782 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1783   address base_address = search.code_begin();
1784   if ((pc < base_address) ||
1785       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1786     return NULL;  // PC is wildly out of range
1787   }
1788   int pc_offset = (int) (pc - base_address);
1789 
1790   // Check the PcDesc cache if it contains the desired PcDesc
1791   // (This as an almost 100% hit rate.)
1792   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1793   if (res != NULL) {
1794     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1795     return res;
1796   }
1797 
1798   // Fallback algorithm: quasi-linear search for the PcDesc
1799   // Find the last pc_offset less than the given offset.
1800   // The successor must be the required match, if there is a match at all.
1801   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1802   PcDesc* lower = search.scopes_pcs_begin();
1803   PcDesc* upper = search.scopes_pcs_end();
1804   upper -= 1; // exclude final sentinel
1805   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1806 
1807 #define assert_LU_OK \
1808   /* invariant on lower..upper during the following search: */ \
1809   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1810   assert(upper->pc_offset() >= pc_offset, "sanity")
1811   assert_LU_OK;
1812 
1813   // Use the last successful return as a split point.
1814   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1815   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1816   if (mid->pc_offset() < pc_offset) {
1817     lower = mid;
1818   } else {
1819     upper = mid;
1820   }
1821 
1822   // Take giant steps at first (4096, then 256, then 16, then 1)
1823   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1824   const int RADIX = (1 << LOG2_RADIX);
1825   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1826     while ((mid = lower + step) < upper) {
1827       assert_LU_OK;
1828       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1829       if (mid->pc_offset() < pc_offset) {
1830         lower = mid;
1831       } else {
1832         upper = mid;
1833         break;
1834       }
1835     }
1836     assert_LU_OK;
1837   }
1838 
1839   // Sneak up on the value with a linear search of length ~16.
1840   while (true) {
1841     assert_LU_OK;
1842     mid = lower + 1;
1843     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1844     if (mid->pc_offset() < pc_offset) {
1845       lower = mid;
1846     } else {
1847       upper = mid;
1848       break;
1849     }
1850   }
1851 #undef assert_LU_OK
1852 
1853   if (match_desc(upper, pc_offset, approximate)) {
1854     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1855     _pc_desc_cache.add_pc_desc(upper);
1856     return upper;
1857   } else {
1858     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1859     return NULL;
1860   }
1861 }
1862 
1863 
1864 void nmethod::check_all_dependencies(DepChange& changes) {
1865   // Checked dependencies are allocated into this ResourceMark
1866   ResourceMark rm;
1867 
1868   // Turn off dependency tracing while actually testing dependencies.
1869   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1870 
1871   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1872                             &DependencySignature::equals, 11027> DepTable;
1873 
1874   DepTable* table = new DepTable();
1875 
1876   // Iterate over live nmethods and check dependencies of all nmethods that are not
1877   // marked for deoptimization. A particular dependency is only checked once.
1878   NMethodIterator iter;
1879   while(iter.next()) {
1880     nmethod* nm = iter.method();
1881     // Only notify for live nmethods
1882     if (nm->is_alive() && !nm->is_marked_for_deoptimization()) {
1883       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1884         // Construct abstraction of a dependency.
1885         DependencySignature* current_sig = new DependencySignature(deps);
1886 
1887         // Determine if dependency is already checked. table->put(...) returns
1888         // 'true' if the dependency is added (i.e., was not in the hashtable).
1889         if (table->put(*current_sig, 1)) {
1890           if (deps.check_dependency() != NULL) {
1891             // Dependency checking failed. Print out information about the failed
1892             // dependency and finally fail with an assert. We can fail here, since
1893             // dependency checking is never done in a product build.
1894             tty->print_cr("Failed dependency:");
1895             changes.print();
1896             nm->print();
1897             nm->print_dependencies();
1898             assert(false, "Should have been marked for deoptimization");
1899           }
1900         }
1901       }
1902     }
1903   }
1904 }
1905 
1906 bool nmethod::check_dependency_on(DepChange& changes) {
1907   // What has happened:
1908   // 1) a new class dependee has been added
1909   // 2) dependee and all its super classes have been marked
1910   bool found_check = false;  // set true if we are upset
1911   for (Dependencies::DepStream deps(this); deps.next(); ) {
1912     // Evaluate only relevant dependencies.
1913     if (deps.spot_check_dependency_at(changes) != NULL) {
1914       found_check = true;
1915       NOT_DEBUG(break);
1916     }
1917   }
1918   return found_check;
1919 }
1920 
1921 bool nmethod::is_evol_dependent_on(Klass* dependee) {
1922   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
1923   Array<Method*>* dependee_methods = dependee_ik->methods();
1924   for (Dependencies::DepStream deps(this); deps.next(); ) {
1925     if (deps.type() == Dependencies::evol_method) {
1926       Method* method = deps.method_argument(0);
1927       for (int j = 0; j < dependee_methods->length(); j++) {
1928         if (dependee_methods->at(j) == method) {
1929           if (log_is_enabled(Debug, redefine, class, nmethod)) {
1930             ResourceMark rm;
1931             log_debug(redefine, class, nmethod)
1932               ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
1933                _method->method_holder()->external_name(),
1934                _method->name()->as_C_string(),
1935                _method->signature()->as_C_string(),
1936                compile_id(),
1937                method->method_holder()->external_name(),
1938                method->name()->as_C_string(),
1939                method->signature()->as_C_string());
1940           }
1941           if (TraceDependencies || LogCompilation)
1942             deps.log_dependency(dependee);
1943           return true;
1944         }
1945       }
1946     }
1947   }
1948   return false;
1949 }
1950 
1951 // Called from mark_for_deoptimization, when dependee is invalidated.
1952 bool nmethod::is_dependent_on_method(Method* dependee) {
1953   for (Dependencies::DepStream deps(this); deps.next(); ) {
1954     if (deps.type() != Dependencies::evol_method)
1955       continue;
1956     Method* method = deps.method_argument(0);
1957     if (method == dependee) return true;
1958   }
1959   return false;
1960 }
1961 
1962 
1963 bool nmethod::is_patchable_at(address instr_addr) {
1964   assert(insts_contains(instr_addr), "wrong nmethod used");
1965   if (is_zombie()) {
1966     // a zombie may never be patched
1967     return false;
1968   }
1969   return true;
1970 }
1971 
1972 
1973 address nmethod::continuation_for_implicit_exception(address pc) {
1974   // Exception happened outside inline-cache check code => we are inside
1975   // an active nmethod => use cpc to determine a return address
1976   int exception_offset = pc - code_begin();
1977   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
1978 #ifdef ASSERT
1979   if (cont_offset == 0) {
1980     Thread* thread = Thread::current();
1981     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
1982     HandleMark hm(thread);
1983     ResourceMark rm(thread);
1984     CodeBlob* cb = CodeCache::find_blob(pc);
1985     assert(cb != NULL && cb == this, "");
1986     ttyLocker ttyl;
1987     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
1988     print();
1989     method()->print_codes();
1990     print_code();
1991     print_pcs();
1992   }
1993 #endif
1994   if (cont_offset == 0) {
1995     // Let the normal error handling report the exception
1996     return NULL;
1997   }
1998   return code_begin() + cont_offset;
1999 }
2000 
2001 
2002 
2003 void nmethod_init() {
2004   // make sure you didn't forget to adjust the filler fields
2005   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2006 }
2007 
2008 
2009 //-------------------------------------------------------------------------------------------
2010 
2011 
2012 // QQQ might we make this work from a frame??
2013 nmethodLocker::nmethodLocker(address pc) {
2014   CodeBlob* cb = CodeCache::find_blob(pc);
2015   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2016   _nm = cb->as_compiled_method();
2017   lock_nmethod(_nm);
2018 }
2019 
2020 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2021 // should pass zombie_ok == true.
2022 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2023   if (cm == NULL)  return;
2024   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2025   nmethod* nm = cm->as_nmethod();
2026   Atomic::inc(&nm->_lock_count);
2027   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2028 }
2029 
2030 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2031   if (cm == NULL)  return;
2032   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2033   nmethod* nm = cm->as_nmethod();
2034   Atomic::dec(&nm->_lock_count);
2035   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2036 }
2037 
2038 
2039 // -----------------------------------------------------------------------------
2040 // Verification
2041 
2042 class VerifyOopsClosure: public OopClosure {
2043   nmethod* _nm;
2044   bool     _ok;
2045 public:
2046   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2047   bool ok() { return _ok; }
2048   virtual void do_oop(oop* p) {
2049     if (oopDesc::is_oop_or_null(*p)) return;
2050     if (_ok) {
2051       _nm->print_nmethod(true);
2052       _ok = false;
2053     }
2054     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2055                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2056   }
2057   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2058 };
2059 
2060 void nmethod::verify() {
2061 
2062   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2063   // seems odd.
2064 
2065   if (is_zombie() || is_not_entrant() || is_unloaded())
2066     return;
2067 
2068   // Make sure all the entry points are correctly aligned for patching.
2069   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2070 
2071   // assert(oopDesc::is_oop(method()), "must be valid");
2072 
2073   ResourceMark rm;
2074 
2075   if (!CodeCache::contains(this)) {
2076     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2077   }
2078 
2079   if(is_native_method() )
2080     return;
2081 
2082   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2083   if (nm != this) {
2084     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2085   }
2086 
2087   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2088     if (! p->verify(this)) {
2089       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2090     }
2091   }
2092 
2093   VerifyOopsClosure voc(this);
2094   oops_do(&voc);
2095   assert(voc.ok(), "embedded oops must be OK");
2096   Universe::heap()->verify_nmethod(this);
2097 
2098   verify_scopes();
2099 }
2100 
2101 
2102 void nmethod::verify_interrupt_point(address call_site) {
2103   // Verify IC only when nmethod installation is finished.
2104   if (!is_not_installed()) {
2105     Thread *cur = Thread::current();
2106     if (CompiledIC_lock->owner() == cur ||
2107         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2108          SafepointSynchronize::is_at_safepoint())) {
2109       CompiledIC_at(this, call_site);
2110       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2111     } else {
2112       MutexLocker ml_verify (CompiledIC_lock);
2113       CompiledIC_at(this, call_site);
2114     }
2115   }
2116 
2117   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2118   assert(pd != NULL, "PcDesc must exist");
2119   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2120                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2121                                      pd->return_oop());
2122        !sd->is_top(); sd = sd->sender()) {
2123     sd->verify();
2124   }
2125 }
2126 
2127 void nmethod::verify_scopes() {
2128   if( !method() ) return;       // Runtime stubs have no scope
2129   if (method()->is_native()) return; // Ignore stub methods.
2130   // iterate through all interrupt point
2131   // and verify the debug information is valid.
2132   RelocIterator iter((nmethod*)this);
2133   while (iter.next()) {
2134     address stub = NULL;
2135     switch (iter.type()) {
2136       case relocInfo::virtual_call_type:
2137         verify_interrupt_point(iter.addr());
2138         break;
2139       case relocInfo::opt_virtual_call_type:
2140         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2141         verify_interrupt_point(iter.addr());
2142         break;
2143       case relocInfo::static_call_type:
2144         stub = iter.static_call_reloc()->static_stub(false);
2145         //verify_interrupt_point(iter.addr());
2146         break;
2147       case relocInfo::runtime_call_type:
2148       case relocInfo::runtime_call_w_cp_type: {
2149         address destination = iter.reloc()->value();
2150         // Right now there is no way to find out which entries support
2151         // an interrupt point.  It would be nice if we had this
2152         // information in a table.
2153         break;
2154       }
2155       default:
2156         break;
2157     }
2158     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2159   }
2160 }
2161 
2162 
2163 // -----------------------------------------------------------------------------
2164 // Non-product code
2165 #ifndef PRODUCT
2166 
2167 class DebugScavengeRoot: public OopClosure {
2168   nmethod* _nm;
2169   bool     _ok;
2170 public:
2171   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2172   bool ok() { return _ok; }
2173   virtual void do_oop(oop* p) {
2174     if ((*p) == NULL || !Universe::heap()->is_scavengable(*p))  return;
2175     if (_ok) {
2176       _nm->print_nmethod(true);
2177       _ok = false;
2178     }
2179     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2180                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2181     (*p)->print();
2182   }
2183   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2184 };
2185 
2186 void nmethod::verify_scavenge_root_oops() {
2187   if (!on_scavenge_root_list()) {
2188     // Actually look inside, to verify the claim that it's clean.
2189     DebugScavengeRoot debug_scavenge_root(this);
2190     oops_do(&debug_scavenge_root);
2191     if (!debug_scavenge_root.ok())
2192       fatal("found an unadvertised bad scavengable oop in the code cache");
2193   }
2194   assert(scavenge_root_not_marked(), "");
2195 }
2196 
2197 #endif // PRODUCT
2198 
2199 // Printing operations
2200 
2201 void nmethod::print() const {
2202   ResourceMark rm;
2203   ttyLocker ttyl;   // keep the following output all in one block
2204 
2205   tty->print("Compiled method ");
2206 
2207   if (is_compiled_by_c1()) {
2208     tty->print("(c1) ");
2209   } else if (is_compiled_by_c2()) {
2210     tty->print("(c2) ");
2211   } else if (is_compiled_by_jvmci()) {
2212     tty->print("(JVMCI) ");
2213   } else {
2214     tty->print("(nm) ");
2215   }
2216 
2217   print_on(tty, NULL);
2218 
2219   if (WizardMode) {
2220     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2221     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2222     tty->print(" { ");
2223     tty->print_cr("%s ", state());
2224     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2225     tty->print_cr("}:");
2226   }
2227   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2228                                               p2i(this),
2229                                               p2i(this) + size(),
2230                                               size());
2231   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2232                                               p2i(relocation_begin()),
2233                                               p2i(relocation_end()),
2234                                               relocation_size());
2235   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2236                                               p2i(consts_begin()),
2237                                               p2i(consts_end()),
2238                                               consts_size());
2239   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2240                                               p2i(insts_begin()),
2241                                               p2i(insts_end()),
2242                                               insts_size());
2243   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2244                                               p2i(stub_begin()),
2245                                               p2i(stub_end()),
2246                                               stub_size());
2247   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2248                                               p2i(oops_begin()),
2249                                               p2i(oops_end()),
2250                                               oops_size());
2251   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2252                                               p2i(metadata_begin()),
2253                                               p2i(metadata_end()),
2254                                               metadata_size());
2255   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2256                                               p2i(scopes_data_begin()),
2257                                               p2i(scopes_data_end()),
2258                                               scopes_data_size());
2259   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2260                                               p2i(scopes_pcs_begin()),
2261                                               p2i(scopes_pcs_end()),
2262                                               scopes_pcs_size());
2263   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2264                                               p2i(dependencies_begin()),
2265                                               p2i(dependencies_end()),
2266                                               dependencies_size());
2267   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2268                                               p2i(handler_table_begin()),
2269                                               p2i(handler_table_end()),
2270                                               handler_table_size());
2271   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2272                                               p2i(nul_chk_table_begin()),
2273                                               p2i(nul_chk_table_end()),
2274                                               nul_chk_table_size());
2275 }
2276 
2277 #ifndef PRODUCT
2278 
2279 void nmethod::print_scopes() {
2280   // Find the first pc desc for all scopes in the code and print it.
2281   ResourceMark rm;
2282   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2283     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2284       continue;
2285 
2286     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2287     while (sd != NULL) {
2288       sd->print_on(tty, p);
2289       sd = sd->sender();
2290     }
2291   }
2292 }
2293 
2294 void nmethod::print_dependencies() {
2295   ResourceMark rm;
2296   ttyLocker ttyl;   // keep the following output all in one block
2297   tty->print_cr("Dependencies:");
2298   for (Dependencies::DepStream deps(this); deps.next(); ) {
2299     deps.print_dependency();
2300     Klass* ctxk = deps.context_type();
2301     if (ctxk != NULL) {
2302       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2303         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2304       }
2305     }
2306     deps.log_dependency();  // put it into the xml log also
2307   }
2308 }
2309 
2310 
2311 void nmethod::print_relocations() {
2312   ResourceMark m;       // in case methods get printed via the debugger
2313   tty->print_cr("relocations:");
2314   RelocIterator iter(this);
2315   iter.print();
2316 }
2317 
2318 
2319 void nmethod::print_pcs() {
2320   ResourceMark m;       // in case methods get printed via debugger
2321   tty->print_cr("pc-bytecode offsets:");
2322   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2323     p->print(this);
2324   }
2325 }
2326 
2327 void nmethod::print_recorded_oops() {
2328   tty->print_cr("Recorded oops:");
2329   for (int i = 0; i < oops_count(); i++) {
2330     oop o = oop_at(i);
2331     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2332     if (o == (oop)Universe::non_oop_word()) {
2333       tty->print("non-oop word");
2334     } else {
2335       if (o != NULL) {
2336         o->print_value();
2337       } else {
2338         tty->print_cr("NULL");
2339       }
2340     }
2341     tty->cr();
2342   }
2343 }
2344 
2345 void nmethod::print_recorded_metadata() {
2346   tty->print_cr("Recorded metadata:");
2347   for (int i = 0; i < metadata_count(); i++) {
2348     Metadata* m = metadata_at(i);
2349     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2350     if (m == (Metadata*)Universe::non_oop_word()) {
2351       tty->print("non-metadata word");
2352     } else {
2353       Metadata::print_value_on_maybe_null(tty, m);
2354     }
2355     tty->cr();
2356   }
2357 }
2358 
2359 #endif // PRODUCT
2360 
2361 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2362   RelocIterator iter(this, begin, end);
2363   bool have_one = false;
2364   while (iter.next()) {
2365     have_one = true;
2366     switch (iter.type()) {
2367         case relocInfo::none:                  return "no_reloc";
2368         case relocInfo::oop_type: {
2369           stringStream st;
2370           oop_Relocation* r = iter.oop_reloc();
2371           oop obj = r->oop_value();
2372           st.print("oop(");
2373           if (obj == NULL) st.print("NULL");
2374           else obj->print_value_on(&st);
2375           st.print(")");
2376           return st.as_string();
2377         }
2378         case relocInfo::metadata_type: {
2379           stringStream st;
2380           metadata_Relocation* r = iter.metadata_reloc();
2381           Metadata* obj = r->metadata_value();
2382           st.print("metadata(");
2383           if (obj == NULL) st.print("NULL");
2384           else obj->print_value_on(&st);
2385           st.print(")");
2386           return st.as_string();
2387         }
2388         case relocInfo::runtime_call_type:
2389         case relocInfo::runtime_call_w_cp_type: {
2390           stringStream st;
2391           st.print("runtime_call");
2392           CallRelocation* r = (CallRelocation*)iter.reloc();
2393           address dest = r->destination();
2394           CodeBlob* cb = CodeCache::find_blob(dest);
2395           if (cb != NULL) {
2396             st.print(" %s", cb->name());
2397           } else {
2398             ResourceMark rm;
2399             const int buflen = 1024;
2400             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2401             int offset;
2402             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2403               st.print(" %s", buf);
2404               if (offset != 0) {
2405                 st.print("+%d", offset);
2406               }
2407             }
2408           }
2409           return st.as_string();
2410         }
2411         case relocInfo::virtual_call_type: {
2412           stringStream st;
2413           st.print_raw("virtual_call");
2414           virtual_call_Relocation* r = iter.virtual_call_reloc();
2415           Method* m = r->method_value();
2416           if (m != NULL) {
2417             assert(m->is_method(), "");
2418             m->print_short_name(&st);
2419           }
2420           return st.as_string();
2421         }
2422         case relocInfo::opt_virtual_call_type: {
2423           stringStream st;
2424           st.print_raw("optimized virtual_call");
2425           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2426           Method* m = r->method_value();
2427           if (m != NULL) {
2428             assert(m->is_method(), "");
2429             m->print_short_name(&st);
2430           }
2431           return st.as_string();
2432         }
2433         case relocInfo::static_call_type: {
2434           stringStream st;
2435           st.print_raw("static_call");
2436           static_call_Relocation* r = iter.static_call_reloc();
2437           Method* m = r->method_value();
2438           if (m != NULL) {
2439             assert(m->is_method(), "");
2440             m->print_short_name(&st);
2441           }
2442           return st.as_string();
2443         }
2444         case relocInfo::static_stub_type:      return "static_stub";
2445         case relocInfo::external_word_type:    return "external_word";
2446         case relocInfo::internal_word_type:    return "internal_word";
2447         case relocInfo::section_word_type:     return "section_word";
2448         case relocInfo::poll_type:             return "poll";
2449         case relocInfo::poll_return_type:      return "poll_return";
2450         case relocInfo::type_mask:             return "type_bit_mask";
2451 
2452         default:
2453           break;
2454     }
2455   }
2456   return have_one ? "other" : NULL;
2457 }
2458 
2459 // Return a the last scope in (begin..end]
2460 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2461   PcDesc* p = pc_desc_near(begin+1);
2462   if (p != NULL && p->real_pc(this) <= end) {
2463     return new ScopeDesc(this, p->scope_decode_offset(),
2464                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2465                          p->return_oop());
2466   }
2467   return NULL;
2468 }
2469 
2470 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2471   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2472   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2473   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2474   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2475   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2476 
2477   if (has_method_handle_invokes())
2478     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2479 
2480   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2481 
2482   if (block_begin == entry_point()) {
2483     methodHandle m = method();
2484     if (m.not_null()) {
2485       stream->print("  # ");
2486       m->print_value_on(stream);
2487       stream->cr();
2488     }
2489     if (m.not_null() && !is_osr_method()) {
2490       ResourceMark rm;
2491       int sizeargs = m->size_of_parameters();
2492       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2493       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2494       {
2495         int sig_index = 0;
2496         if (!m->is_static())
2497           sig_bt[sig_index++] = T_OBJECT; // 'this'
2498         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2499           BasicType t = ss.type();
2500           sig_bt[sig_index++] = t;
2501           if (type2size[t] == 2) {
2502             sig_bt[sig_index++] = T_VOID;
2503           } else {
2504             assert(type2size[t] == 1, "size is 1 or 2");
2505           }
2506         }
2507         assert(sig_index == sizeargs, "");
2508       }
2509       const char* spname = "sp"; // make arch-specific?
2510       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2511       int stack_slot_offset = this->frame_size() * wordSize;
2512       int tab1 = 14, tab2 = 24;
2513       int sig_index = 0;
2514       int arg_index = (m->is_static() ? 0 : -1);
2515       bool did_old_sp = false;
2516       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2517         bool at_this = (arg_index == -1);
2518         bool at_old_sp = false;
2519         BasicType t = (at_this ? T_OBJECT : ss.type());
2520         assert(t == sig_bt[sig_index], "sigs in sync");
2521         if (at_this)
2522           stream->print("  # this: ");
2523         else
2524           stream->print("  # parm%d: ", arg_index);
2525         stream->move_to(tab1);
2526         VMReg fst = regs[sig_index].first();
2527         VMReg snd = regs[sig_index].second();
2528         if (fst->is_reg()) {
2529           stream->print("%s", fst->name());
2530           if (snd->is_valid())  {
2531             stream->print(":%s", snd->name());
2532           }
2533         } else if (fst->is_stack()) {
2534           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2535           if (offset == stack_slot_offset)  at_old_sp = true;
2536           stream->print("[%s+0x%x]", spname, offset);
2537         } else {
2538           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2539         }
2540         stream->print(" ");
2541         stream->move_to(tab2);
2542         stream->print("= ");
2543         if (at_this) {
2544           m->method_holder()->print_value_on(stream);
2545         } else {
2546           bool did_name = false;
2547           if (!at_this && ss.is_object()) {
2548             Symbol* name = ss.as_symbol_or_null();
2549             if (name != NULL) {
2550               name->print_value_on(stream);
2551               did_name = true;
2552             }
2553           }
2554           if (!did_name)
2555             stream->print("%s", type2name(t));
2556         }
2557         if (at_old_sp) {
2558           stream->print("  (%s of caller)", spname);
2559           did_old_sp = true;
2560         }
2561         stream->cr();
2562         sig_index += type2size[t];
2563         arg_index += 1;
2564         if (!at_this)  ss.next();
2565       }
2566       if (!did_old_sp) {
2567         stream->print("  # ");
2568         stream->move_to(tab1);
2569         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2570         stream->print("  (%s of caller)", spname);
2571         stream->cr();
2572       }
2573     }
2574   }
2575 }
2576 
2577 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2578   // First, find an oopmap in (begin, end].
2579   // We use the odd half-closed interval so that oop maps and scope descs
2580   // which are tied to the byte after a call are printed with the call itself.
2581   address base = code_begin();
2582   ImmutableOopMapSet* oms = oop_maps();
2583   if (oms != NULL) {
2584     for (int i = 0, imax = oms->count(); i < imax; i++) {
2585       const ImmutableOopMapPair* pair = oms->pair_at(i);
2586       const ImmutableOopMap* om = pair->get_from(oms);
2587       address pc = base + pair->pc_offset();
2588       if (pc > begin) {
2589         if (pc <= end) {
2590           st->move_to(column);
2591           st->print("; ");
2592           om->print_on(st);
2593         }
2594         break;
2595       }
2596     }
2597   }
2598 
2599   // Print any debug info present at this pc.
2600   ScopeDesc* sd  = scope_desc_in(begin, end);
2601   if (sd != NULL) {
2602     st->move_to(column);
2603     if (sd->bci() == SynchronizationEntryBCI) {
2604       st->print(";*synchronization entry");
2605     } else if (sd->bci() == AfterBci) {
2606       st->print(";* method exit (unlocked if synchronized)");
2607     } else if (sd->bci() == UnwindBci) {
2608       st->print(";* unwind (locked if synchronized)");
2609     } else if (sd->bci() == AfterExceptionBci) {
2610       st->print(";* unwind (unlocked if synchronized)");
2611     } else if (sd->bci() == UnknownBci) {
2612       st->print(";* unknown");
2613     } else if (sd->bci() == InvalidFrameStateBci) {
2614       st->print(";* invalid frame state");
2615     } else {
2616       if (sd->method() == NULL) {
2617         st->print("method is NULL");
2618       } else if (sd->method()->is_native()) {
2619         st->print("method is native");
2620       } else {
2621         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2622         st->print(";*%s", Bytecodes::name(bc));
2623         switch (bc) {
2624         case Bytecodes::_invokevirtual:
2625         case Bytecodes::_invokespecial:
2626         case Bytecodes::_invokestatic:
2627         case Bytecodes::_invokeinterface:
2628           {
2629             Bytecode_invoke invoke(sd->method(), sd->bci());
2630             st->print(" ");
2631             if (invoke.name() != NULL)
2632               invoke.name()->print_symbol_on(st);
2633             else
2634               st->print("<UNKNOWN>");
2635             break;
2636           }
2637         case Bytecodes::_getfield:
2638         case Bytecodes::_putfield:
2639         case Bytecodes::_getstatic:
2640         case Bytecodes::_putstatic:
2641           {
2642             Bytecode_field field(sd->method(), sd->bci());
2643             st->print(" ");
2644             if (field.name() != NULL)
2645               field.name()->print_symbol_on(st);
2646             else
2647               st->print("<UNKNOWN>");
2648           }
2649         default:
2650           break;
2651         }
2652       }
2653       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2654     }
2655 
2656     // Print all scopes
2657     for (;sd != NULL; sd = sd->sender()) {
2658       st->move_to(column);
2659       st->print("; -");
2660       if (sd->method() == NULL) {
2661         st->print("method is NULL");
2662       } else {
2663         sd->method()->print_short_name(st);
2664       }
2665       int lineno = sd->method()->line_number_from_bci(sd->bci());
2666       if (lineno != -1) {
2667         st->print("@%d (line %d)", sd->bci(), lineno);
2668       } else {
2669         st->print("@%d", sd->bci());
2670       }
2671       st->cr();
2672     }
2673   }
2674 
2675   // Print relocation information
2676   const char* str = reloc_string_for(begin, end);
2677   if (str != NULL) {
2678     if (sd != NULL) st->cr();
2679     st->move_to(column);
2680     st->print(";   {%s}", str);
2681   }
2682   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2683   if (cont_offset != 0) {
2684     st->move_to(column);
2685     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2686   }
2687 
2688 }
2689 
2690 class DirectNativeCallWrapper: public NativeCallWrapper {
2691 private:
2692   NativeCall* _call;
2693 
2694 public:
2695   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2696 
2697   virtual address destination() const { return _call->destination(); }
2698   virtual address instruction_address() const { return _call->instruction_address(); }
2699   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2700   virtual address return_address() const { return _call->return_address(); }
2701 
2702   virtual address get_resolve_call_stub(bool is_optimized) const {
2703     if (is_optimized) {
2704       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2705     }
2706     return SharedRuntime::get_resolve_virtual_call_stub();
2707   }
2708 
2709   virtual void set_destination_mt_safe(address dest) {
2710 #if INCLUDE_AOT
2711     if (UseAOT) {
2712       CodeBlob* callee = CodeCache::find_blob(dest);
2713       CompiledMethod* cm = callee->as_compiled_method_or_null();
2714       if (cm != NULL && cm->is_far_code()) {
2715         // Temporary fix, see JDK-8143106
2716         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2717         csc->set_to_far(methodHandle(cm->method()), dest);
2718         return;
2719       }
2720     }
2721 #endif
2722     _call->set_destination_mt_safe(dest);
2723   }
2724 
2725   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2726     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2727 #if INCLUDE_AOT
2728     if (info.to_aot()) {
2729       csc->set_to_far(method, info.entry());
2730     } else
2731 #endif
2732     {
2733       csc->set_to_interpreted(method, info.entry());
2734     }
2735   }
2736 
2737   virtual void verify() const {
2738     // make sure code pattern is actually a call imm32 instruction
2739     _call->verify();
2740     if (os::is_MP()) {
2741       _call->verify_alignment();
2742     }
2743   }
2744 
2745   virtual void verify_resolve_call(address dest) const {
2746     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2747     assert(db != NULL && !db->is_adapter_blob(), "must use stub!");
2748   }
2749 
2750   virtual bool is_call_to_interpreted(address dest) const {
2751     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2752     return cb->contains(dest);
2753   }
2754 
2755   virtual bool is_safe_for_patching() const { return false; }
2756 
2757   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2758     return nativeMovConstReg_at(r->cached_value());
2759   }
2760 
2761   virtual void *get_data(NativeInstruction* instruction) const {
2762     return (void*)((NativeMovConstReg*) instruction)->data();
2763   }
2764 
2765   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2766     ((NativeMovConstReg*) instruction)->set_data(data);
2767   }
2768 };
2769 
2770 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2771   return new DirectNativeCallWrapper((NativeCall*) call);
2772 }
2773 
2774 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2775   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2776 }
2777 
2778 address nmethod::call_instruction_address(address pc) const {
2779   if (NativeCall::is_call_before(pc)) {
2780     NativeCall *ncall = nativeCall_before(pc);
2781     return ncall->instruction_address();
2782   }
2783   return NULL;
2784 }
2785 
2786 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2787   return CompiledDirectStaticCall::at(call_site);
2788 }
2789 
2790 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2791   return CompiledDirectStaticCall::at(call_site);
2792 }
2793 
2794 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2795   return CompiledDirectStaticCall::before(return_addr);
2796 }
2797 
2798 #ifndef PRODUCT
2799 
2800 void nmethod::print_value_on(outputStream* st) const {
2801   st->print("nmethod");
2802   print_on(st, NULL);
2803 }
2804 
2805 void nmethod::print_calls(outputStream* st) {
2806   RelocIterator iter(this);
2807   while (iter.next()) {
2808     switch (iter.type()) {
2809     case relocInfo::virtual_call_type:
2810     case relocInfo::opt_virtual_call_type: {
2811       VerifyMutexLocker mc(CompiledIC_lock);
2812       CompiledIC_at(&iter)->print();
2813       break;
2814     }
2815     case relocInfo::static_call_type:
2816       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2817       CompiledDirectStaticCall::at(iter.reloc())->print();
2818       break;
2819     default:
2820       break;
2821     }
2822   }
2823 }
2824 
2825 void nmethod::print_handler_table() {
2826   ExceptionHandlerTable(this).print();
2827 }
2828 
2829 void nmethod::print_nul_chk_table() {
2830   ImplicitExceptionTable(this).print(code_begin());
2831 }
2832 
2833 void nmethod::print_statistics() {
2834   ttyLocker ttyl;
2835   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2836   native_nmethod_stats.print_native_nmethod_stats();
2837 #ifdef COMPILER1
2838   c1_java_nmethod_stats.print_nmethod_stats("C1");
2839 #endif
2840 #ifdef COMPILER2
2841   c2_java_nmethod_stats.print_nmethod_stats("C2");
2842 #endif
2843 #if INCLUDE_JVMCI
2844   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2845 #endif
2846   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2847   DebugInformationRecorder::print_statistics();
2848 #ifndef PRODUCT
2849   pc_nmethod_stats.print_pc_stats();
2850 #endif
2851   Dependencies::print_statistics();
2852   if (xtty != NULL)  xtty->tail("statistics");
2853 }
2854 
2855 #endif // !PRODUCT
2856 
2857 #if INCLUDE_JVMCI
2858 void nmethod::clear_jvmci_installed_code() {
2859   assert_locked_or_safepoint(Patching_lock);
2860   if (_jvmci_installed_code != NULL) {
2861     JNIHandles::destroy_weak_global(_jvmci_installed_code);
2862     _jvmci_installed_code = NULL;
2863   }
2864 }
2865 
2866 void nmethod::clear_speculation_log() {
2867   assert_locked_or_safepoint(Patching_lock);
2868   if (_speculation_log != NULL) {
2869     JNIHandles::destroy_weak_global(_speculation_log);
2870     _speculation_log = NULL;
2871   }
2872 }
2873 
2874 void nmethod::maybe_invalidate_installed_code() {
2875   assert(Patching_lock->is_locked() ||
2876          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2877   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
2878   if (installed_code != NULL) {
2879     // Update the values in the InstalledCode instance if it still refers to this nmethod
2880     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2881     if (nm == this) {
2882       if (!is_alive()) {
2883         // Break the link between nmethod and InstalledCode such that the nmethod
2884         // can subsequently be flushed safely.  The link must be maintained while
2885         // the method could have live activations since invalidateInstalledCode
2886         // might want to invalidate all existing activations.
2887         InstalledCode::set_address(installed_code, 0);
2888         InstalledCode::set_entryPoint(installed_code, 0);
2889       } else if (is_not_entrant()) {
2890         // Remove the entry point so any invocation will fail but keep
2891         // the address link around that so that existing activations can
2892         // be invalidated.
2893         InstalledCode::set_entryPoint(installed_code, 0);
2894       }
2895     }
2896   }
2897   if (!is_alive()) {
2898     // Clear these out after the nmethod has been unregistered and any
2899     // updates to the InstalledCode instance have been performed.
2900     clear_jvmci_installed_code();
2901     clear_speculation_log();
2902   }
2903 }
2904 
2905 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
2906   if (installedCode() == NULL) {
2907     THROW(vmSymbols::java_lang_NullPointerException());
2908   }
2909   jlong nativeMethod = InstalledCode::address(installedCode);
2910   nmethod* nm = (nmethod*)nativeMethod;
2911   if (nm == NULL) {
2912     // Nothing to do
2913     return;
2914   }
2915 
2916   nmethodLocker nml(nm);
2917 #ifdef ASSERT
2918   {
2919     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2920     // This relationship can only be checked safely under a lock
2921     assert(!nm->is_alive() || nm->jvmci_installed_code() == installedCode(), "sanity check");
2922   }
2923 #endif
2924 
2925   if (nm->is_alive()) {
2926     // Invalidating the InstalledCode means we want the nmethod
2927     // to be deoptimized.
2928     nm->mark_for_deoptimization();
2929     VM_Deoptimize op;
2930     VMThread::execute(&op);
2931   }
2932 
2933   // Multiple threads could reach this point so we now need to
2934   // lock and re-check the link to the nmethod so that only one
2935   // thread clears it.
2936   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2937   if (InstalledCode::address(installedCode) == nativeMethod) {
2938       InstalledCode::set_address(installedCode, 0);
2939   }
2940 }
2941 
2942 oop nmethod::jvmci_installed_code() {
2943   return JNIHandles::resolve(_jvmci_installed_code);
2944 }
2945 
2946 oop nmethod::speculation_log() {
2947   return JNIHandles::resolve(_speculation_log);
2948 }
2949 
2950 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) {
2951   if (!this->is_compiled_by_jvmci()) {
2952     return NULL;
2953   }
2954   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
2955   if (installed_code != NULL) {
2956     oop installed_code_name = NULL;
2957     if (installed_code->is_a(InstalledCode::klass())) {
2958       installed_code_name = InstalledCode::name(installed_code);
2959     }
2960     if (installed_code_name != NULL) {
2961       return java_lang_String::as_utf8_string(installed_code_name, buf, (int)buflen);
2962     }
2963   }
2964   return NULL;
2965 }
2966 #endif