1 /*
   2  * Copyright (c) 1997, 2017, 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 "code/codeCache.hpp"
  27 #include "code/compiledIC.hpp"
  28 #include "code/dependencies.hpp"
  29 #include "code/nativeInst.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "code/scopeDesc.hpp"
  32 #include "compiler/abstractCompiler.hpp"
  33 #include "compiler/compileBroker.hpp"
  34 #include "compiler/compileLog.hpp"
  35 #include "compiler/compilerDirectives.hpp"
  36 #include "compiler/directivesParser.hpp"
  37 #include "compiler/disassembler.hpp"
  38 #include "interpreter/bytecode.hpp"
  39 #include "logging/log.hpp"
  40 #include "logging/logStream.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "oops/methodData.hpp"
  43 #include "oops/oop.inline.hpp"
  44 #include "prims/jvm.h"
  45 #include "prims/jvmtiImpl.hpp"
  46 #include "runtime/atomic.hpp"
  47 #include "runtime/orderAccess.inline.hpp"
  48 #include "runtime/os.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/sweeper.hpp"
  51 #include "utilities/align.hpp"
  52 #include "utilities/dtrace.hpp"
  53 #include "utilities/events.hpp"
  54 #include "utilities/resourceHash.hpp"
  55 #include "utilities/xmlstream.hpp"
  56 #ifdef SHARK
  57 #include "shark/sharkCompiler.hpp"
  58 #endif
  59 #if INCLUDE_JVMCI
  60 #include "jvmci/jvmciJavaClasses.hpp"
  61 #endif
  62 
  63 #ifdef DTRACE_ENABLED
  64 
  65 // Only bother with this argument setup if dtrace is available
  66 
  67 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  68   {                                                                       \
  69     Method* m = (method);                                                 \
  70     if (m != NULL) {                                                      \
  71       Symbol* klass_name = m->klass_name();                               \
  72       Symbol* name = m->name();                                           \
  73       Symbol* signature = m->signature();                                 \
  74       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  75         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  76         (char *) name->bytes(), name->utf8_length(),                               \
  77         (char *) signature->bytes(), signature->utf8_length());                    \
  78     }                                                                     \
  79   }
  80 
  81 #else //  ndef DTRACE_ENABLED
  82 
  83 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  84 
  85 #endif
  86 
  87 //---------------------------------------------------------------------------------
  88 // NMethod statistics
  89 // They are printed under various flags, including:
  90 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  91 // (In the latter two cases, they like other stats are printed to the log only.)
  92 
  93 #ifndef PRODUCT
  94 // These variables are put into one block to reduce relocations
  95 // and make it simpler to print from the debugger.
  96 struct java_nmethod_stats_struct {
  97   int nmethod_count;
  98   int total_size;
  99   int relocation_size;
 100   int consts_size;
 101   int insts_size;
 102   int stub_size;
 103   int scopes_data_size;
 104   int scopes_pcs_size;
 105   int dependencies_size;
 106   int handler_table_size;
 107   int nul_chk_table_size;
 108   int oops_size;
 109   int metadata_size;
 110 
 111   void note_nmethod(nmethod* nm) {
 112     nmethod_count += 1;
 113     total_size          += nm->size();
 114     relocation_size     += nm->relocation_size();
 115     consts_size         += nm->consts_size();
 116     insts_size          += nm->insts_size();
 117     stub_size           += nm->stub_size();
 118     oops_size           += nm->oops_size();
 119     metadata_size       += nm->metadata_size();
 120     scopes_data_size    += nm->scopes_data_size();
 121     scopes_pcs_size     += nm->scopes_pcs_size();
 122     dependencies_size   += nm->dependencies_size();
 123     handler_table_size  += nm->handler_table_size();
 124     nul_chk_table_size  += nm->nul_chk_table_size();
 125   }
 126   void print_nmethod_stats(const char* name) {
 127     if (nmethod_count == 0)  return;
 128     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 129     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 130     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 131     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 132     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 133     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 134     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 135     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 136     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 137     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 138     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 139     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 140     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 141     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 142   }
 143 };
 144 
 145 struct native_nmethod_stats_struct {
 146   int native_nmethod_count;
 147   int native_total_size;
 148   int native_relocation_size;
 149   int native_insts_size;
 150   int native_oops_size;
 151   int native_metadata_size;
 152   void note_native_nmethod(nmethod* nm) {
 153     native_nmethod_count += 1;
 154     native_total_size       += nm->size();
 155     native_relocation_size  += nm->relocation_size();
 156     native_insts_size       += nm->insts_size();
 157     native_oops_size        += nm->oops_size();
 158     native_metadata_size    += nm->metadata_size();
 159   }
 160   void print_native_nmethod_stats() {
 161     if (native_nmethod_count == 0)  return;
 162     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 163     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 164     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 165     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 166     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 167     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 168   }
 169 };
 170 
 171 struct pc_nmethod_stats_struct {
 172   int pc_desc_resets;   // number of resets (= number of caches)
 173   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 174   int pc_desc_approx;   // number of those which have approximate true
 175   int pc_desc_repeats;  // number of _pc_descs[0] hits
 176   int pc_desc_hits;     // number of LRU cache hits
 177   int pc_desc_tests;    // total number of PcDesc examinations
 178   int pc_desc_searches; // total number of quasi-binary search steps
 179   int pc_desc_adds;     // number of LUR cache insertions
 180 
 181   void print_pc_stats() {
 182     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 183                   pc_desc_queries,
 184                   (double)(pc_desc_tests + pc_desc_searches)
 185                   / pc_desc_queries);
 186     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 187                   pc_desc_resets,
 188                   pc_desc_queries, pc_desc_approx,
 189                   pc_desc_repeats, pc_desc_hits,
 190                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 191   }
 192 };
 193 
 194 #ifdef COMPILER1
 195 static java_nmethod_stats_struct c1_java_nmethod_stats;
 196 #endif
 197 #ifdef COMPILER2
 198 static java_nmethod_stats_struct c2_java_nmethod_stats;
 199 #endif
 200 #if INCLUDE_JVMCI
 201 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 202 #endif
 203 #ifdef SHARK
 204 static java_nmethod_stats_struct shark_java_nmethod_stats;
 205 #endif
 206 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 207 
 208 static native_nmethod_stats_struct native_nmethod_stats;
 209 static pc_nmethod_stats_struct pc_nmethod_stats;
 210 
 211 static void note_java_nmethod(nmethod* nm) {
 212 #ifdef COMPILER1
 213   if (nm->is_compiled_by_c1()) {
 214     c1_java_nmethod_stats.note_nmethod(nm);
 215   } else
 216 #endif
 217 #ifdef COMPILER2
 218   if (nm->is_compiled_by_c2()) {
 219     c2_java_nmethod_stats.note_nmethod(nm);
 220   } else
 221 #endif
 222 #if INCLUDE_JVMCI
 223   if (nm->is_compiled_by_jvmci()) {
 224     jvmci_java_nmethod_stats.note_nmethod(nm);
 225   } else
 226 #endif
 227 #ifdef SHARK
 228   if (nm->is_compiled_by_shark()) {
 229     shark_java_nmethod_stats.note_nmethod(nm);
 230   } else
 231 #endif
 232   {
 233     unknown_java_nmethod_stats.note_nmethod(nm);
 234   }
 235 }
 236 #endif // !PRODUCT
 237 
 238 //---------------------------------------------------------------------------------
 239 
 240 
 241 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 242   assert(pc != NULL, "Must be non null");
 243   assert(exception.not_null(), "Must be non null");
 244   assert(handler != NULL, "Must be non null");
 245 
 246   _count = 0;
 247   _exception_type = exception->klass();
 248   _next = NULL;
 249 
 250   add_address_and_handler(pc,handler);
 251 }
 252 
 253 
 254 address ExceptionCache::match(Handle exception, address pc) {
 255   assert(pc != NULL,"Must be non null");
 256   assert(exception.not_null(),"Must be non null");
 257   if (exception->klass() == exception_type()) {
 258     return (test_address(pc));
 259   }
 260 
 261   return NULL;
 262 }
 263 
 264 
 265 bool ExceptionCache::match_exception_with_space(Handle exception) {
 266   assert(exception.not_null(),"Must be non null");
 267   if (exception->klass() == exception_type() && count() < cache_size) {
 268     return true;
 269   }
 270   return false;
 271 }
 272 
 273 
 274 address ExceptionCache::test_address(address addr) {
 275   int limit = count();
 276   for (int i = 0; i < limit; i++) {
 277     if (pc_at(i) == addr) {
 278       return handler_at(i);
 279     }
 280   }
 281   return NULL;
 282 }
 283 
 284 
 285 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 286   if (test_address(addr) == handler) return true;
 287 
 288   int index = count();
 289   if (index < cache_size) {
 290     set_pc_at(index, addr);
 291     set_handler_at(index, handler);
 292     increment_count();
 293     return true;
 294   }
 295   return false;
 296 }
 297 
 298 //-----------------------------------------------------------------------------
 299 
 300 
 301 // Helper used by both find_pc_desc methods.
 302 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 303   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 304   if (!approximate)
 305     return pc->pc_offset() == pc_offset;
 306   else
 307     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 308 }
 309 
 310 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 311   if (initial_pc_desc == NULL) {
 312     _pc_descs[0] = NULL; // native method; no PcDescs at all
 313     return;
 314   }
 315   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 316   // reset the cache by filling it with benign (non-null) values
 317   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 318   for (int i = 0; i < cache_size; i++)
 319     _pc_descs[i] = initial_pc_desc;
 320 }
 321 
 322 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 323   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 324   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 325 
 326   // Note: one might think that caching the most recently
 327   // read value separately would be a win, but one would be
 328   // wrong.  When many threads are updating it, the cache
 329   // line it's in would bounce between caches, negating
 330   // any benefit.
 331 
 332   // In order to prevent race conditions do not load cache elements
 333   // repeatedly, but use a local copy:
 334   PcDesc* res;
 335 
 336   // Step one:  Check the most recently added value.
 337   res = _pc_descs[0];
 338   if (res == NULL) return NULL;  // native method; no PcDescs at all
 339   if (match_desc(res, pc_offset, approximate)) {
 340     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 341     return res;
 342   }
 343 
 344   // Step two:  Check the rest of the LRU cache.
 345   for (int i = 1; i < cache_size; ++i) {
 346     res = _pc_descs[i];
 347     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 348     if (match_desc(res, pc_offset, approximate)) {
 349       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 350       return res;
 351     }
 352   }
 353 
 354   // Report failure.
 355   return NULL;
 356 }
 357 
 358 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 359   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 360   // Update the LRU cache by shifting pc_desc forward.
 361   for (int i = 0; i < cache_size; i++)  {
 362     PcDesc* next = _pc_descs[i];
 363     _pc_descs[i] = pc_desc;
 364     pc_desc = next;
 365   }
 366 }
 367 
 368 // adjust pcs_size so that it is a multiple of both oopSize and
 369 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 370 // of oopSize, then 2*sizeof(PcDesc) is)
 371 static int adjust_pcs_size(int pcs_size) {
 372   int nsize = align_up(pcs_size,   oopSize);
 373   if ((nsize % sizeof(PcDesc)) != 0) {
 374     nsize = pcs_size + sizeof(PcDesc);
 375   }
 376   assert((nsize % oopSize) == 0, "correct alignment");
 377   return nsize;
 378 }
 379 
 380 
 381 int nmethod::total_size() const {
 382   return
 383     consts_size()        +
 384     insts_size()         +
 385     stub_size()          +
 386     scopes_data_size()   +
 387     scopes_pcs_size()    +
 388     handler_table_size() +
 389     nul_chk_table_size();
 390 }
 391 
 392 const char* nmethod::compile_kind() const {
 393   if (is_osr_method())     return "osr";
 394   if (method() != NULL && is_native_method())  return "c2n";
 395   return NULL;
 396 }
 397 
 398 // Fill in default values for various flag fields
 399 void nmethod::init_defaults() {
 400   _state                      = in_use;
 401   _has_flushed_dependencies   = 0;
 402   _lock_count                 = 0;
 403   _stack_traversal_mark       = 0;
 404   _unload_reported            = false; // jvmti state
 405   _is_far_code                = false; // nmethods are located in CodeCache
 406 
 407 #ifdef ASSERT
 408   _oops_are_stale             = false;
 409 #endif
 410 
 411   _oops_do_mark_link       = NULL;
 412   _jmethod_id              = NULL;
 413   _osr_link                = NULL;
 414   if (UseG1GC) {
 415     _unloading_next        = NULL;
 416   } else {
 417     _scavenge_root_link    = NULL;
 418   }
 419   _scavenge_root_state     = 0;
 420 #if INCLUDE_RTM_OPT
 421   _rtm_state               = NoRTM;
 422 #endif
 423 #if INCLUDE_JVMCI
 424   _jvmci_installed_code   = NULL;
 425   _speculation_log        = NULL;
 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   // verify nmethod
 455   debug_only(if (nm) nm->verify();) // might block
 456 
 457   if (nm != NULL) {
 458     nm->log_new_nmethod();
 459   }
 460 
 461   return nm;
 462 }
 463 
 464 nmethod* nmethod::new_nmethod(const methodHandle& method,
 465   int compile_id,
 466   int entry_bci,
 467   CodeOffsets* offsets,
 468   int orig_pc_offset,
 469   DebugInformationRecorder* debug_info,
 470   Dependencies* dependencies,
 471   CodeBuffer* code_buffer, int frame_size,
 472   OopMapSet* oop_maps,
 473   ExceptionHandlerTable* handler_table,
 474   ImplicitExceptionTable* nul_chk_table,
 475   AbstractCompiler* compiler,
 476   int comp_level
 477 #if INCLUDE_JVMCI
 478   , Handle installed_code,
 479   Handle speculationLog
 480 #endif
 481 )
 482 {
 483   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 484   code_buffer->finalize_oop_references(method);
 485   // create nmethod
 486   nmethod* nm = NULL;
 487   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 488     int nmethod_size =
 489       CodeBlob::allocation_size(code_buffer, sizeof(nmethod))
 490       + adjust_pcs_size(debug_info->pcs_size())
 491       + align_up((int)dependencies->size_in_bytes(), oopSize)
 492       + align_up(handler_table->size_in_bytes()    , oopSize)
 493       + align_up(nul_chk_table->size_in_bytes()    , oopSize)
 494       + align_up(debug_info->data_size()           , oopSize);
 495 
 496     nm = new (nmethod_size, comp_level)
 497     nmethod(method(), compiler->type(), nmethod_size, compile_id, entry_bci, offsets,
 498             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 499             oop_maps,
 500             handler_table,
 501             nul_chk_table,
 502             compiler,
 503             comp_level
 504 #if INCLUDE_JVMCI
 505             , installed_code,
 506             speculationLog
 507 #endif
 508             );
 509 
 510     if (nm != NULL) {
 511       // To make dependency checking during class loading fast, record
 512       // the nmethod dependencies in the classes it is dependent on.
 513       // This allows the dependency checking code to simply walk the
 514       // class hierarchy above the loaded class, checking only nmethods
 515       // which are dependent on those classes.  The slow way is to
 516       // check every nmethod for dependencies which makes it linear in
 517       // the number of methods compiled.  For applications with a lot
 518       // classes the slow way is too slow.
 519       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 520         if (deps.type() == Dependencies::call_site_target_value) {
 521           // CallSite dependencies are managed on per-CallSite instance basis.
 522           oop call_site = deps.argument_oop(0);
 523           MethodHandles::add_dependent_nmethod(call_site, nm);
 524         } else {
 525           Klass* klass = deps.context_type();
 526           if (klass == NULL) {
 527             continue;  // ignore things like evol_method
 528           }
 529           // record this nmethod as dependent on this klass
 530           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 531         }
 532       }
 533       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 534     }
 535   }
 536   // Do verification and logging outside CodeCache_lock.
 537   if (nm != NULL) {
 538     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 539     DEBUG_ONLY(nm->verify();)
 540     nm->log_new_nmethod();
 541   }
 542   return nm;
 543 }
 544 
 545 // For native wrappers
 546 nmethod::nmethod(
 547   Method* method,
 548   CompilerType type,
 549   int nmethod_size,
 550   int compile_id,
 551   CodeOffsets* offsets,
 552   CodeBuffer* code_buffer,
 553   int frame_size,
 554   ByteSize basic_lock_owner_sp_offset,
 555   ByteSize basic_lock_sp_offset,
 556   OopMapSet* oop_maps )
 557   : CompiledMethod(method, "native nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 558   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 559   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 560 {
 561   {
 562     int scopes_data_offset = 0;
 563     int deoptimize_offset       = 0;
 564     int deoptimize_mh_offset    = 0;
 565 
 566     debug_only(NoSafepointVerifier nsv;)
 567     assert_locked_or_safepoint(CodeCache_lock);
 568 
 569     init_defaults();
 570     _entry_bci               = InvocationEntryBci;
 571     // We have no exception handler or deopt handler make the
 572     // values something that will never match a pc like the nmethod vtable entry
 573     _exception_offset        = 0;
 574     _orig_pc_offset          = 0;
 575 
 576     _consts_offset           = data_offset();
 577     _stub_offset             = data_offset();
 578     _oops_offset             = data_offset();
 579     _metadata_offset         = _oops_offset         + align_up(code_buffer->total_oop_size(), oopSize);
 580     scopes_data_offset       = _metadata_offset     + align_up(code_buffer->total_metadata_size(), wordSize);
 581     _scopes_pcs_offset       = scopes_data_offset;
 582     _dependencies_offset     = _scopes_pcs_offset;
 583     _handler_table_offset    = _dependencies_offset;
 584     _nul_chk_table_offset    = _handler_table_offset;
 585     _nmethod_end_offset      = _nul_chk_table_offset;
 586     _compile_id              = compile_id;
 587     _comp_level              = CompLevel_none;
 588     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 589     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 590     _osr_entry_point         = NULL;
 591     _exception_cache         = NULL;
 592     _pc_desc_container.reset_to(NULL);
 593     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 594 
 595     _scopes_data_begin = (address) this + scopes_data_offset;
 596     _deopt_handler_begin = (address) this + deoptimize_offset;
 597     _deopt_mh_handler_begin = (address) this + deoptimize_mh_offset;
 598 
 599     code_buffer->copy_code_and_locs_to(this);
 600     code_buffer->copy_values_to(this);
 601     if (ScavengeRootsInCode) {
 602       if (detect_scavenge_root_oops()) {
 603         CodeCache::add_scavenge_root_nmethod(this);
 604       }
 605       Universe::heap()->register_nmethod(this);
 606     }
 607     debug_only(verify_scavenge_root_oops());
 608     CodeCache::commit(this);
 609   }
 610 
 611   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 612     ttyLocker ttyl;  // keep the following output all in one block
 613     // This output goes directly to the tty, not the compiler log.
 614     // To enable tools to match it up with the compilation activity,
 615     // be sure to tag this tty output with the compile ID.
 616     if (xtty != NULL) {
 617       xtty->begin_head("print_native_nmethod");
 618       xtty->method(_method);
 619       xtty->stamp();
 620       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 621     }
 622     // print the header part first
 623     print();
 624     // then print the requested information
 625     if (PrintNativeNMethods) {
 626       print_code();
 627       if (oop_maps != NULL) {
 628         oop_maps->print();
 629       }
 630     }
 631     if (PrintRelocations) {
 632       print_relocations();
 633     }
 634     if (xtty != NULL) {
 635       xtty->tail("print_native_nmethod");
 636     }
 637   }
 638 }
 639 
 640 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 641   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 642 }
 643 
 644 nmethod::nmethod(
 645   Method* method,
 646   CompilerType type,
 647   int nmethod_size,
 648   int compile_id,
 649   int entry_bci,
 650   CodeOffsets* offsets,
 651   int orig_pc_offset,
 652   DebugInformationRecorder* debug_info,
 653   Dependencies* dependencies,
 654   CodeBuffer *code_buffer,
 655   int frame_size,
 656   OopMapSet* oop_maps,
 657   ExceptionHandlerTable* handler_table,
 658   ImplicitExceptionTable* nul_chk_table,
 659   AbstractCompiler* compiler,
 660   int comp_level
 661 #if INCLUDE_JVMCI
 662   , Handle installed_code,
 663   Handle speculation_log
 664 #endif
 665   )
 666   : CompiledMethod(method, "nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 667   _native_receiver_sp_offset(in_ByteSize(-1)),
 668   _native_basic_lock_sp_offset(in_ByteSize(-1))
 669 {
 670   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 671   {
 672     debug_only(NoSafepointVerifier nsv;)
 673     assert_locked_or_safepoint(CodeCache_lock);
 674 
 675     _deopt_handler_begin = (address) this;
 676     _deopt_mh_handler_begin = (address) this;
 677 
 678     init_defaults();
 679     _entry_bci               = entry_bci;
 680     _compile_id              = compile_id;
 681     _comp_level              = comp_level;
 682     _orig_pc_offset          = orig_pc_offset;
 683     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 684 
 685     // Section offsets
 686     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 687     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 688     set_ctable_begin(header_begin() + _consts_offset);
 689 
 690 #if INCLUDE_JVMCI
 691     _jvmci_installed_code = installed_code();
 692     _speculation_log = (instanceOop)speculation_log();
 693 
 694     if (compiler->is_jvmci()) {
 695       // JVMCI might not produce any stub sections
 696       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 697         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 698       } else {
 699         _exception_offset = -1;
 700       }
 701       if (offsets->value(CodeOffsets::Deopt) != -1) {
 702         _deopt_handler_begin       = (address) this + code_offset()          + offsets->value(CodeOffsets::Deopt);
 703       } else {
 704         _deopt_handler_begin = NULL;
 705       }
 706       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 707         _deopt_mh_handler_begin  = (address) this + code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 708       } else {
 709         _deopt_mh_handler_begin = NULL;
 710       }
 711     } else {
 712 #endif
 713     // Exception handler and deopt handler are in the stub section
 714     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 715     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 716 
 717     _exception_offset       = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 718     _deopt_handler_begin    = (address) this + _stub_offset          + offsets->value(CodeOffsets::Deopt);
 719     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 720       _deopt_mh_handler_begin  = (address) this + _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 721     } else {
 722       _deopt_mh_handler_begin  = NULL;
 723 #if INCLUDE_JVMCI
 724     }
 725 #endif
 726     }
 727     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 728       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 729     } else {
 730       _unwind_handler_offset = -1;
 731     }
 732 
 733     _oops_offset             = data_offset();
 734     _metadata_offset         = _oops_offset          + align_up(code_buffer->total_oop_size(), oopSize);
 735     int scopes_data_offset   = _metadata_offset      + align_up(code_buffer->total_metadata_size(), wordSize);
 736 
 737     _scopes_pcs_offset       = scopes_data_offset    + align_up(debug_info->data_size       (), oopSize);
 738     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 739     _handler_table_offset    = _dependencies_offset  + align_up((int)dependencies->size_in_bytes (), oopSize);
 740     _nul_chk_table_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
 741     _nmethod_end_offset      = _nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize);
 742     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 743     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 744     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 745     _exception_cache         = NULL;
 746 
 747     _scopes_data_begin = (address) this + scopes_data_offset;
 748 
 749     _pc_desc_container.reset_to(scopes_pcs_begin());
 750 
 751     code_buffer->copy_code_and_locs_to(this);
 752     // Copy contents of ScopeDescRecorder to nmethod
 753     code_buffer->copy_values_to(this);
 754     debug_info->copy_to(this);
 755     dependencies->copy_to(this);
 756     if (ScavengeRootsInCode) {
 757       if (detect_scavenge_root_oops()) {
 758         CodeCache::add_scavenge_root_nmethod(this);
 759       }
 760       Universe::heap()->register_nmethod(this);
 761     }
 762     debug_only(verify_scavenge_root_oops());
 763 
 764     CodeCache::commit(this);
 765 
 766     // Copy contents of ExceptionHandlerTable to nmethod
 767     handler_table->copy_to(this);
 768     nul_chk_table->copy_to(this);
 769 
 770     // we use the information of entry points to find out if a method is
 771     // static or non static
 772     assert(compiler->is_c2() || compiler->is_jvmci() ||
 773            _method->is_static() == (entry_point() == _verified_entry_point),
 774            " entry points must be same for static methods and vice versa");
 775   }
 776 }
 777 
 778 // Print a short set of xml attributes to identify this nmethod.  The
 779 // output should be embedded in some other element.
 780 void nmethod::log_identity(xmlStream* log) const {
 781   log->print(" compile_id='%d'", compile_id());
 782   const char* nm_kind = compile_kind();
 783   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 784   log->print(" compiler='%s'", compiler_name());
 785   if (TieredCompilation) {
 786     log->print(" level='%d'", comp_level());
 787   }
 788 }
 789 
 790 
 791 #define LOG_OFFSET(log, name)                    \
 792   if (p2i(name##_end()) - p2i(name##_begin())) \
 793     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 794                p2i(name##_begin()) - p2i(this))
 795 
 796 
 797 void nmethod::log_new_nmethod() const {
 798   if (LogCompilation && xtty != NULL) {
 799     ttyLocker ttyl;
 800     HandleMark hm;
 801     xtty->begin_elem("nmethod");
 802     log_identity(xtty);
 803     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 804     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 805 
 806     LOG_OFFSET(xtty, relocation);
 807     LOG_OFFSET(xtty, consts);
 808     LOG_OFFSET(xtty, insts);
 809     LOG_OFFSET(xtty, stub);
 810     LOG_OFFSET(xtty, scopes_data);
 811     LOG_OFFSET(xtty, scopes_pcs);
 812     LOG_OFFSET(xtty, dependencies);
 813     LOG_OFFSET(xtty, handler_table);
 814     LOG_OFFSET(xtty, nul_chk_table);
 815     LOG_OFFSET(xtty, oops);
 816     LOG_OFFSET(xtty, metadata);
 817 
 818     xtty->method(method());
 819     xtty->stamp();
 820     xtty->end_elem();
 821   }
 822 }
 823 
 824 #undef LOG_OFFSET
 825 
 826 
 827 // Print out more verbose output usually for a newly created nmethod.
 828 void nmethod::print_on(outputStream* st, const char* msg) const {
 829   if (st != NULL) {
 830     ttyLocker ttyl;
 831     if (WizardMode) {
 832       CompileTask::print(st, this, msg, /*short_form:*/ true);
 833       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 834     } else {
 835       CompileTask::print(st, this, msg, /*short_form:*/ false);
 836     }
 837   }
 838 }
 839 
 840 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 841   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 842   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 843     print_nmethod(printnmethods);
 844   }
 845 }
 846 
 847 void nmethod::print_nmethod(bool printmethod) {
 848   ttyLocker ttyl;  // keep the following output all in one block
 849   if (xtty != NULL) {
 850     xtty->begin_head("print_nmethod");
 851     xtty->stamp();
 852     xtty->end_head();
 853   }
 854   // print the header part first
 855   print();
 856   // then print the requested information
 857   if (printmethod) {
 858     print_code();
 859     print_pcs();
 860     if (oop_maps()) {
 861       oop_maps()->print();
 862     }
 863   }
 864   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 865     print_scopes();
 866   }
 867   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 868     print_relocations();
 869   }
 870   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 871     print_dependencies();
 872   }
 873   if (printmethod || PrintExceptionHandlers) {
 874     print_handler_table();
 875     print_nul_chk_table();
 876   }
 877   if (printmethod) {
 878     print_recorded_oops();
 879     print_recorded_metadata();
 880   }
 881   if (xtty != NULL) {
 882     xtty->tail("print_nmethod");
 883   }
 884 }
 885 
 886 
 887 // Promote one word from an assembly-time handle to a live embedded oop.
 888 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
 889   if (handle == NULL ||
 890       // As a special case, IC oops are initialized to 1 or -1.
 891       handle == (jobject) Universe::non_oop_word()) {
 892     (*dest) = (oop) handle;
 893   } else {
 894     (*dest) = JNIHandles::resolve_non_null(handle);
 895   }
 896 }
 897 
 898 
 899 // Have to have the same name because it's called by a template
 900 void nmethod::copy_values(GrowableArray<jobject>* array) {
 901   int length = array->length();
 902   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
 903   oop* dest = oops_begin();
 904   for (int index = 0 ; index < length; index++) {
 905     initialize_immediate_oop(&dest[index], array->at(index));
 906   }
 907 
 908   // Now we can fix up all the oops in the code.  We need to do this
 909   // in the code because the assembler uses jobjects as placeholders.
 910   // The code and relocations have already been initialized by the
 911   // CodeBlob constructor, so it is valid even at this early point to
 912   // iterate over relocations and patch the code.
 913   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 914 }
 915 
 916 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
 917   int length = array->length();
 918   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
 919   Metadata** dest = metadata_begin();
 920   for (int index = 0 ; index < length; index++) {
 921     dest[index] = array->at(index);
 922   }
 923 }
 924 
 925 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
 926   // re-patch all oop-bearing instructions, just in case some oops moved
 927   RelocIterator iter(this, begin, end);
 928   while (iter.next()) {
 929     if (iter.type() == relocInfo::oop_type) {
 930       oop_Relocation* reloc = iter.oop_reloc();
 931       if (initialize_immediates && reloc->oop_is_immediate()) {
 932         oop* dest = reloc->oop_addr();
 933         initialize_immediate_oop(dest, (jobject) *dest);
 934       }
 935       // Refresh the oop-related bits of this instruction.
 936       reloc->fix_oop_relocation();
 937     } else if (iter.type() == relocInfo::metadata_type) {
 938       metadata_Relocation* reloc = iter.metadata_reloc();
 939       reloc->fix_metadata_relocation();
 940     }
 941   }
 942 }
 943 
 944 
 945 void nmethod::verify_clean_inline_caches() {
 946   assert_locked_or_safepoint(CompiledIC_lock);
 947 
 948   // If the method is not entrant or zombie then a JMP is plastered over the
 949   // first few bytes.  If an oop in the old code was there, that oop
 950   // should not get GC'd.  Skip the first few bytes of oops on
 951   // not-entrant methods.
 952   address low_boundary = verified_entry_point();
 953   if (!is_in_use()) {
 954     low_boundary += NativeJump::instruction_size;
 955     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
 956     // This means that the low_boundary is going to be a little too high.
 957     // This shouldn't matter, since oops of non-entrant methods are never used.
 958     // In fact, why are we bothering to look at oops in a non-entrant method??
 959   }
 960 
 961   ResourceMark rm;
 962   RelocIterator iter(this, low_boundary);
 963   while(iter.next()) {
 964     switch(iter.type()) {
 965       case relocInfo::virtual_call_type:
 966       case relocInfo::opt_virtual_call_type: {
 967         CompiledIC *ic = CompiledIC_at(&iter);
 968         // Ok, to lookup references to zombies here
 969         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
 970         nmethod* nm = cb->as_nmethod_or_null();
 971         if( nm != NULL ) {
 972           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 973           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 974             assert(ic->is_clean(), "IC should be clean");
 975           }
 976         }
 977         break;
 978       }
 979       case relocInfo::static_call_type: {
 980         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
 981         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
 982         nmethod* nm = cb->as_nmethod_or_null();
 983         if( nm != NULL ) {
 984           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 985           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 986             assert(csc->is_clean(), "IC should be clean");
 987           }
 988         }
 989         break;
 990       }
 991       default:
 992         break;
 993     }
 994   }
 995 }
 996 
 997 // This is a private interface with the sweeper.
 998 void nmethod::mark_as_seen_on_stack() {
 999   assert(is_alive(), "Must be an alive method");
1000   // Set the traversal mark to ensure that the sweeper does 2
1001   // cleaning passes before moving to zombie.
1002   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1003 }
1004 
1005 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1006 // there are no activations on the stack, not in use by the VM,
1007 // and not in use by the ServiceThread)
1008 bool nmethod::can_convert_to_zombie() {
1009   assert(is_not_entrant(), "must be a non-entrant method");
1010 
1011   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1012   // count can be greater than the stack traversal count before it hits the
1013   // nmethod for the second time.
1014   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1015          !is_locked_by_vm();
1016 }
1017 
1018 void nmethod::inc_decompile_count() {
1019   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1020   // Could be gated by ProfileTraps, but do not bother...
1021   Method* m = method();
1022   if (m == NULL)  return;
1023   MethodData* mdo = m->method_data();
1024   if (mdo == NULL)  return;
1025   // There is a benign race here.  See comments in methodData.hpp.
1026   mdo->inc_decompile_count();
1027 }
1028 
1029 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1030 
1031   post_compiled_method_unload();
1032 
1033   // Since this nmethod is being unloaded, make sure that dependencies
1034   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1035   // indicate that this work is being done during a GC.
1036   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1037   assert(is_alive != NULL, "Should be non-NULL");
1038   // A non-NULL is_alive closure indicates that this is being called during GC.
1039   flush_dependencies(is_alive);
1040 
1041   // Break cycle between nmethod & method
1042   LogTarget(Trace, class, unload) lt;
1043   if (lt.is_enabled()) {
1044     LogStream ls(lt);
1045     ls.print_cr("making nmethod " INTPTR_FORMAT
1046                   " unloadable, Method*(" INTPTR_FORMAT
1047                   "), cause(" INTPTR_FORMAT ")",
1048                   p2i(this), p2i(_method), p2i(cause));
1049     if (!Universe::heap()->is_gc_active())
1050       cause->klass()->print_on(&ls);
1051   }
1052   // Unlink the osr method, so we do not look this up again
1053   if (is_osr_method()) {
1054     // Invalidate the osr nmethod only once
1055     if (is_in_use()) {
1056       invalidate_osr_method();
1057     }
1058 #ifdef ASSERT
1059     if (method() != NULL) {
1060       // Make sure osr nmethod is invalidated, i.e. not on the list
1061       bool found = method()->method_holder()->remove_osr_nmethod(this);
1062       assert(!found, "osr nmethod should have been invalidated");
1063     }
1064 #endif
1065   }
1066 
1067   // If _method is already NULL the Method* is about to be unloaded,
1068   // so we don't have to break the cycle. Note that it is possible to
1069   // have the Method* live here, in case we unload the nmethod because
1070   // it is pointing to some oop (other than the Method*) being unloaded.
1071   if (_method != NULL) {
1072     // OSR methods point to the Method*, but the Method* does not
1073     // point back!
1074     if (_method->code() == this) {
1075       _method->clear_code(); // Break a cycle
1076     }
1077     _method = NULL;            // Clear the method of this dead nmethod
1078   }
1079 
1080   // Make the class unloaded - i.e., change state and notify sweeper
1081   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1082   if (is_in_use()) {
1083     // Transitioning directly from live to unloaded -- so
1084     // we need to force a cache clean-up; remember this
1085     // for later on.
1086     CodeCache::set_needs_cache_clean(true);
1087   }
1088 
1089   // Unregister must be done before the state change
1090   Universe::heap()->unregister_nmethod(this);
1091 
1092   _state = unloaded;
1093 
1094   // Log the unloading.
1095   log_state_change();
1096 
1097 #if INCLUDE_JVMCI
1098   // The method can only be unloaded after the pointer to the installed code
1099   // Java wrapper is no longer alive. Here we need to clear out this weak
1100   // reference to the dead object. Nulling out the reference has to happen
1101   // after the method is unregistered since the original value may be still
1102   // tracked by the rset.
1103   maybe_invalidate_installed_code();
1104   // Clear these out after the nmethod has been unregistered and any
1105   // updates to the InstalledCode instance have been performed.
1106   _jvmci_installed_code = NULL;
1107   _speculation_log = NULL;
1108 #endif
1109 
1110   // The Method* is gone at this point
1111   assert(_method == NULL, "Tautology");
1112 
1113   set_osr_link(NULL);
1114   NMethodSweeper::report_state_change(this);
1115 }
1116 
1117 void nmethod::invalidate_osr_method() {
1118   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1119   // Remove from list of active nmethods
1120   if (method() != NULL) {
1121     method()->method_holder()->remove_osr_nmethod(this);
1122   }
1123 }
1124 
1125 void nmethod::log_state_change() const {
1126   if (LogCompilation) {
1127     if (xtty != NULL) {
1128       ttyLocker ttyl;  // keep the following output all in one block
1129       if (_state == unloaded) {
1130         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1131                          os::current_thread_id());
1132       } else {
1133         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1134                          os::current_thread_id(),
1135                          (_state == zombie ? " zombie='1'" : ""));
1136       }
1137       log_identity(xtty);
1138       xtty->stamp();
1139       xtty->end_elem();
1140     }
1141   }
1142 
1143   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1144   CompileTask::print_ul(this, state_msg);
1145   if (PrintCompilation && _state != unloaded) {
1146     print_on(tty, state_msg);
1147   }
1148 }
1149 
1150 /**
1151  * Common functionality for both make_not_entrant and make_zombie
1152  */
1153 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1154   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1155   assert(!is_zombie(), "should not already be a zombie");
1156 
1157   if (_state == state) {
1158     // Avoid taking the lock if already in required state.
1159     // This is safe from races because the state is an end-state,
1160     // which the nmethod cannot back out of once entered.
1161     // No need for fencing either.
1162     return false;
1163   }
1164 
1165   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1166   nmethodLocker nml(this);
1167   methodHandle the_method(method());
1168   NoSafepointVerifier nsv;
1169 
1170   // during patching, depending on the nmethod state we must notify the GC that
1171   // code has been unloaded, unregistering it. We cannot do this right while
1172   // holding the Patching_lock because we need to use the CodeCache_lock. This
1173   // would be prone to deadlocks.
1174   // This flag is used to remember whether we need to later lock and unregister.
1175   bool nmethod_needs_unregister = false;
1176 
1177   {
1178     // invalidate osr nmethod before acquiring the patching lock since
1179     // they both acquire leaf locks and we don't want a deadlock.
1180     // This logic is equivalent to the logic below for patching the
1181     // verified entry point of regular methods. We check that the
1182     // nmethod is in use to ensure that it is invalidated only once.
1183     if (is_osr_method() && is_in_use()) {
1184       // this effectively makes the osr nmethod not entrant
1185       invalidate_osr_method();
1186     }
1187 
1188     // Enter critical section.  Does not block for safepoint.
1189     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1190 
1191     if (_state == state) {
1192       // another thread already performed this transition so nothing
1193       // to do, but return false to indicate this.
1194       return false;
1195     }
1196 
1197     // The caller can be calling the method statically or through an inline
1198     // cache call.
1199     if (!is_osr_method() && !is_not_entrant()) {
1200       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1201                   SharedRuntime::get_handle_wrong_method_stub());
1202     }
1203 
1204     if (is_in_use() && update_recompile_counts()) {
1205       // It's a true state change, so mark the method as decompiled.
1206       // Do it only for transition from alive.
1207       inc_decompile_count();
1208     }
1209 
1210     // If the state is becoming a zombie, signal to unregister the nmethod with
1211     // the heap.
1212     // This nmethod may have already been unloaded during a full GC.
1213     if ((state == zombie) && !is_unloaded()) {
1214       nmethod_needs_unregister = true;
1215     }
1216 
1217     // Must happen before state change. Otherwise we have a race condition in
1218     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1219     // transition its state from 'not_entrant' to 'zombie' without having to wait
1220     // for stack scanning.
1221     if (state == not_entrant) {
1222       mark_as_seen_on_stack();
1223       OrderAccess::storestore();
1224     }
1225 
1226     // Change state
1227     _state = state;
1228 
1229     // Log the transition once
1230     log_state_change();
1231 
1232     // Invalidate while holding the patching lock
1233     JVMCI_ONLY(maybe_invalidate_installed_code());
1234 
1235     // Remove nmethod from method.
1236     // We need to check if both the _code and _from_compiled_code_entry_point
1237     // refer to this nmethod because there is a race in setting these two fields
1238     // in Method* as seen in bugid 4947125.
1239     // If the vep() points to the zombie nmethod, the memory for the nmethod
1240     // could be flushed and the compiler and vtable stubs could still call
1241     // through it.
1242     if (method() != NULL && (method()->code() == this ||
1243                              method()->from_compiled_entry() == verified_entry_point())) {
1244       HandleMark hm;
1245       method()->clear_code(false /* already owns Patching_lock */);
1246     }
1247   } // leave critical region under Patching_lock
1248 
1249 #ifdef ASSERT
1250   if (is_osr_method() && method() != NULL) {
1251     // Make sure osr nmethod is invalidated, i.e. not on the list
1252     bool found = method()->method_holder()->remove_osr_nmethod(this);
1253     assert(!found, "osr nmethod should have been invalidated");
1254   }
1255 #endif
1256 
1257   // When the nmethod becomes zombie it is no longer alive so the
1258   // dependencies must be flushed.  nmethods in the not_entrant
1259   // state will be flushed later when the transition to zombie
1260   // happens or they get unloaded.
1261   if (state == zombie) {
1262     {
1263       // Flushing dependencies must be done before any possible
1264       // safepoint can sneak in, otherwise the oops used by the
1265       // dependency logic could have become stale.
1266       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1267       if (nmethod_needs_unregister) {
1268         Universe::heap()->unregister_nmethod(this);
1269 #ifdef JVMCI
1270         _jvmci_installed_code = NULL;
1271         _speculation_log = NULL;
1272 #endif
1273       }
1274       flush_dependencies(NULL);
1275     }
1276 
1277     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1278     // event and it hasn't already been reported for this nmethod then
1279     // report it now. The event may have been reported earlier if the GC
1280     // marked it for unloading). JvmtiDeferredEventQueue support means
1281     // we no longer go to a safepoint here.
1282     post_compiled_method_unload();
1283 
1284 #ifdef ASSERT
1285     // It's no longer safe to access the oops section since zombie
1286     // nmethods aren't scanned for GC.
1287     _oops_are_stale = true;
1288 #endif
1289      // the Method may be reclaimed by class unloading now that the
1290      // nmethod is in zombie state
1291     set_method(NULL);
1292   } else {
1293     assert(state == not_entrant, "other cases may need to be handled differently");
1294   }
1295 
1296   if (TraceCreateZombies) {
1297     ResourceMark m;
1298     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");
1299   }
1300 
1301   NMethodSweeper::report_state_change(this);
1302   return true;
1303 }
1304 
1305 void nmethod::flush() {
1306   // Note that there are no valid oops in the nmethod anymore.
1307   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1308          "osr nmethod must be unloaded or zombie before flushing");
1309   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1310   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1311   assert_locked_or_safepoint(CodeCache_lock);
1312 
1313   // completely deallocate this method
1314   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1315   if (PrintMethodFlushing) {
1316     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1317                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1318                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1319                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1320   }
1321 
1322   // We need to deallocate any ExceptionCache data.
1323   // Note that we do not need to grab the nmethod lock for this, it
1324   // better be thread safe if we're disposing of it!
1325   ExceptionCache* ec = exception_cache();
1326   set_exception_cache(NULL);
1327   while(ec != NULL) {
1328     ExceptionCache* next = ec->next();
1329     delete ec;
1330     ec = next;
1331   }
1332 
1333   if (on_scavenge_root_list()) {
1334     CodeCache::drop_scavenge_root_nmethod(this);
1335   }
1336 
1337 #ifdef SHARK
1338   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1339 #endif // SHARK
1340 
1341   CodeBlob::flush();
1342   CodeCache::free(this);
1343 }
1344 
1345 //
1346 // Notify all classes this nmethod is dependent on that it is no
1347 // longer dependent. This should only be called in two situations.
1348 // First, when a nmethod transitions to a zombie all dependents need
1349 // to be clear.  Since zombification happens at a safepoint there's no
1350 // synchronization issues.  The second place is a little more tricky.
1351 // During phase 1 of mark sweep class unloading may happen and as a
1352 // result some nmethods may get unloaded.  In this case the flushing
1353 // of dependencies must happen during phase 1 since after GC any
1354 // dependencies in the unloaded nmethod won't be updated, so
1355 // traversing the dependency information in unsafe.  In that case this
1356 // function is called with a non-NULL argument and this function only
1357 // notifies instanceKlasses that are reachable
1358 
1359 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1360   assert_locked_or_safepoint(CodeCache_lock);
1361   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1362   "is_alive is non-NULL if and only if we are called during GC");
1363   if (!has_flushed_dependencies()) {
1364     set_has_flushed_dependencies();
1365     for (Dependencies::DepStream deps(this); deps.next(); ) {
1366       if (deps.type() == Dependencies::call_site_target_value) {
1367         // CallSite dependencies are managed on per-CallSite instance basis.
1368         oop call_site = deps.argument_oop(0);
1369         MethodHandles::remove_dependent_nmethod(call_site, this);
1370       } else {
1371         Klass* klass = deps.context_type();
1372         if (klass == NULL) {
1373           continue;  // ignore things like evol_method
1374         }
1375         // During GC the is_alive closure is non-NULL, and is used to
1376         // determine liveness of dependees that need to be updated.
1377         if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
1378           // The GC defers deletion of this entry, since there might be multiple threads
1379           // iterating over the _dependencies graph. Other call paths are single-threaded
1380           // and may delete it immediately.
1381           bool delete_immediately = is_alive == NULL;
1382           InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
1383         }
1384       }
1385     }
1386   }
1387 }
1388 
1389 
1390 // If this oop is not live, the nmethod can be unloaded.
1391 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
1392   assert(root != NULL, "just checking");
1393   oop obj = *root;
1394   if (obj == NULL || is_alive->do_object_b(obj)) {
1395       return false;
1396   }
1397 
1398   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1399   // simply because one of its constant oops has gone dead.
1400   // No actual classes need to be unloaded in order for this to occur.
1401   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1402   make_unloaded(is_alive, obj);
1403   return true;
1404 }
1405 
1406 // ------------------------------------------------------------------
1407 // post_compiled_method_load_event
1408 // new method for install_code() path
1409 // Transfer information from compilation to jvmti
1410 void nmethod::post_compiled_method_load_event() {
1411 
1412   Method* moop = method();
1413   HOTSPOT_COMPILED_METHOD_LOAD(
1414       (char *) moop->klass_name()->bytes(),
1415       moop->klass_name()->utf8_length(),
1416       (char *) moop->name()->bytes(),
1417       moop->name()->utf8_length(),
1418       (char *) moop->signature()->bytes(),
1419       moop->signature()->utf8_length(),
1420       insts_begin(), insts_size());
1421 
1422   if (JvmtiExport::should_post_compiled_method_load() ||
1423       JvmtiExport::should_post_compiled_method_unload()) {
1424     get_and_cache_jmethod_id();
1425   }
1426 
1427   if (JvmtiExport::should_post_compiled_method_load()) {
1428     // Let the Service thread (which is a real Java thread) post the event
1429     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1430     JvmtiDeferredEventQueue::enqueue(
1431       JvmtiDeferredEvent::compiled_method_load_event(this));
1432   }
1433 }
1434 
1435 jmethodID nmethod::get_and_cache_jmethod_id() {
1436   if (_jmethod_id == NULL) {
1437     // Cache the jmethod_id since it can no longer be looked up once the
1438     // method itself has been marked for unloading.
1439     _jmethod_id = method()->jmethod_id();
1440   }
1441   return _jmethod_id;
1442 }
1443 
1444 void nmethod::post_compiled_method_unload() {
1445   if (unload_reported()) {
1446     // During unloading we transition to unloaded and then to zombie
1447     // and the unloading is reported during the first transition.
1448     return;
1449   }
1450 
1451   assert(_method != NULL && !is_unloaded(), "just checking");
1452   DTRACE_METHOD_UNLOAD_PROBE(method());
1453 
1454   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1455   // post the event. Sometime later this nmethod will be made a zombie
1456   // by the sweeper but the Method* will not be valid at that point.
1457   // If the _jmethod_id is null then no load event was ever requested
1458   // so don't bother posting the unload.  The main reason for this is
1459   // that the jmethodID is a weak reference to the Method* so if
1460   // it's being unloaded there's no way to look it up since the weak
1461   // ref will have been cleared.
1462   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1463     assert(!unload_reported(), "already unloaded");
1464     JvmtiDeferredEvent event =
1465       JvmtiDeferredEvent::compiled_method_unload_event(this,
1466           _jmethod_id, insts_begin());
1467     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1468     JvmtiDeferredEventQueue::enqueue(event);
1469   }
1470 
1471   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1472   // any time. As the nmethod is being unloaded now we mark it has
1473   // having the unload event reported - this will ensure that we don't
1474   // attempt to report the event in the unlikely scenario where the
1475   // event is enabled at the time the nmethod is made a zombie.
1476   set_unload_reported();
1477 }
1478 
1479 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
1480   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
1481 
1482   oop_Relocation* r = iter_at_oop->oop_reloc();
1483   // Traverse those oops directly embedded in the code.
1484   // Other oops (oop_index>0) are seen as part of scopes_oops.
1485   assert(1 == (r->oop_is_immediate()) +
1486          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1487          "oop must be found in exactly one place");
1488   if (r->oop_is_immediate() && r->oop_value() != NULL) {
1489     // Unload this nmethod if the oop is dead.
1490     if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1491       return true;;
1492     }
1493   }
1494 
1495   return false;
1496 }
1497 
1498 bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive, bool unloading_occurred) {
1499   // Scopes
1500   for (oop* p = oops_begin(); p < oops_end(); p++) {
1501     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1502     if (can_unload(is_alive, p, unloading_occurred)) {
1503       return true;
1504     }
1505   }
1506   return false;
1507 }
1508 
1509 bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {
1510   // Compiled code
1511   {
1512   RelocIterator iter(this, low_boundary);
1513   while (iter.next()) {
1514     if (iter.type() == relocInfo::oop_type) {
1515       if (unload_if_dead_at(&iter, is_alive, unloading_occurred)) {
1516         return true;
1517       }
1518     }
1519   }
1520   }
1521 
1522   return do_unloading_scopes(is_alive, unloading_occurred);
1523 }
1524 
1525 #if INCLUDE_JVMCI
1526 bool nmethod::do_unloading_jvmci(BoolObjectClosure* is_alive, bool unloading_occurred) {
1527   bool is_unloaded = false;
1528   // Follow JVMCI method
1529   BarrierSet* bs = Universe::heap()->barrier_set();
1530   if (_jvmci_installed_code != NULL) {
1531     if (_jvmci_installed_code->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(_jvmci_installed_code)) {
1532       if (!is_alive->do_object_b(_jvmci_installed_code)) {
1533         clear_jvmci_installed_code();
1534       }
1535     } else {
1536       if (can_unload(is_alive, (oop*)&_jvmci_installed_code, unloading_occurred)) {
1537         return true;
1538       }
1539     }
1540   }
1541 
1542   if (_speculation_log != NULL) {
1543     if (!is_alive->do_object_b(_speculation_log)) {
1544       bs->write_ref_nmethod_pre(&_speculation_log, this);
1545       _speculation_log = NULL;
1546       bs->write_ref_nmethod_post(&_speculation_log, this);
1547     }
1548   }
1549   return is_unloaded;
1550 }
1551 #endif
1552 
1553 // Iterate over metadata calling this function.   Used by RedefineClasses
1554 void nmethod::metadata_do(void f(Metadata*)) {
1555   address low_boundary = verified_entry_point();
1556   if (is_not_entrant()) {
1557     low_boundary += NativeJump::instruction_size;
1558     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1559     // (See comment above.)
1560   }
1561   {
1562     // Visit all immediate references that are embedded in the instruction stream.
1563     RelocIterator iter(this, low_boundary);
1564     while (iter.next()) {
1565       if (iter.type() == relocInfo::metadata_type ) {
1566         metadata_Relocation* r = iter.metadata_reloc();
1567         // In this metadata, we must only follow those metadatas directly embedded in
1568         // the code.  Other metadatas (oop_index>0) are seen as part of
1569         // the metadata section below.
1570         assert(1 == (r->metadata_is_immediate()) +
1571                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1572                "metadata must be found in exactly one place");
1573         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1574           Metadata* md = r->metadata_value();
1575           if (md != _method) f(md);
1576         }
1577       } else if (iter.type() == relocInfo::virtual_call_type) {
1578         // Check compiledIC holders associated with this nmethod
1579         CompiledIC *ic = CompiledIC_at(&iter);
1580         if (ic->is_icholder_call()) {
1581           CompiledICHolder* cichk = ic->cached_icholder();
1582           f(cichk->holder_method());
1583           f(cichk->holder_klass());
1584         } else {
1585           Metadata* ic_oop = ic->cached_metadata();
1586           if (ic_oop != NULL) {
1587             f(ic_oop);
1588           }
1589         }
1590       }
1591     }
1592   }
1593 
1594   // Visit the metadata section
1595   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1596     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1597     Metadata* md = *p;
1598     f(md);
1599   }
1600 
1601   // Visit metadata not embedded in the other places.
1602   if (_method != NULL) f(_method);
1603 }
1604 
1605 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1606   // make sure the oops ready to receive visitors
1607   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1608   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1609 
1610   // If the method is not entrant or zombie then a JMP is plastered over the
1611   // first few bytes.  If an oop in the old code was there, that oop
1612   // should not get GC'd.  Skip the first few bytes of oops on
1613   // not-entrant methods.
1614   address low_boundary = verified_entry_point();
1615   if (is_not_entrant()) {
1616     low_boundary += NativeJump::instruction_size;
1617     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1618     // (See comment above.)
1619   }
1620 
1621 #if INCLUDE_JVMCI
1622   if (_jvmci_installed_code != NULL) {
1623     f->do_oop((oop*) &_jvmci_installed_code);
1624   }
1625   if (_speculation_log != NULL) {
1626     f->do_oop((oop*) &_speculation_log);
1627   }
1628 #endif
1629 
1630   RelocIterator iter(this, low_boundary);
1631 
1632   while (iter.next()) {
1633     if (iter.type() == relocInfo::oop_type ) {
1634       oop_Relocation* r = iter.oop_reloc();
1635       // In this loop, we must only follow those oops directly embedded in
1636       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1637       assert(1 == (r->oop_is_immediate()) +
1638                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1639              "oop must be found in exactly one place");
1640       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1641         f->do_oop(r->oop_addr());
1642       }
1643     }
1644   }
1645 
1646   // Scopes
1647   // This includes oop constants not inlined in the code stream.
1648   for (oop* p = oops_begin(); p < oops_end(); p++) {
1649     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1650     f->do_oop(p);
1651   }
1652 }
1653 
1654 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1655 
1656 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1657 
1658 // An nmethod is "marked" if its _mark_link is set non-null.
1659 // Even if it is the end of the linked list, it will have a non-null link value,
1660 // as long as it is on the list.
1661 // This code must be MP safe, because it is used from parallel GC passes.
1662 bool nmethod::test_set_oops_do_mark() {
1663   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1664   nmethod* observed_mark_link = _oops_do_mark_link;
1665   if (observed_mark_link == NULL) {
1666     // Claim this nmethod for this thread to mark.
1667     observed_mark_link = (nmethod*)
1668       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1669     if (observed_mark_link == NULL) {
1670 
1671       // Atomically append this nmethod (now claimed) to the head of the list:
1672       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1673       for (;;) {
1674         nmethod* required_mark_nmethods = observed_mark_nmethods;
1675         _oops_do_mark_link = required_mark_nmethods;
1676         observed_mark_nmethods = (nmethod*)
1677           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1678         if (observed_mark_nmethods == required_mark_nmethods)
1679           break;
1680       }
1681       // Mark was clear when we first saw this guy.
1682       if (TraceScavenge) { print_on(tty, "oops_do, mark"); }
1683       return false;
1684     }
1685   }
1686   // On fall through, another racing thread marked this nmethod before we did.
1687   return true;
1688 }
1689 
1690 void nmethod::oops_do_marking_prologue() {
1691   if (TraceScavenge) { tty->print_cr("[oops_do_marking_prologue"); }
1692   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1693   // We use cmpxchg_ptr instead of regular assignment here because the user
1694   // may fork a bunch of threads, and we need them all to see the same state.
1695   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1696   guarantee(observed == NULL, "no races in this sequential code");
1697 }
1698 
1699 void nmethod::oops_do_marking_epilogue() {
1700   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1701   nmethod* cur = _oops_do_mark_nmethods;
1702   while (cur != NMETHOD_SENTINEL) {
1703     assert(cur != NULL, "not NULL-terminated");
1704     nmethod* next = cur->_oops_do_mark_link;
1705     cur->_oops_do_mark_link = NULL;
1706     DEBUG_ONLY(cur->verify_oop_relocations());
1707     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
1708     cur = next;
1709   }
1710   void* required = _oops_do_mark_nmethods;
1711   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1712   guarantee(observed == required, "no races in this sequential code");
1713   if (TraceScavenge) { tty->print_cr("oops_do_marking_epilogue]"); }
1714 }
1715 
1716 class DetectScavengeRoot: public OopClosure {
1717   bool     _detected_scavenge_root;
1718 public:
1719   DetectScavengeRoot() : _detected_scavenge_root(false)
1720   { NOT_PRODUCT(_print_nm = NULL); }
1721   bool detected_scavenge_root() { return _detected_scavenge_root; }
1722   virtual void do_oop(oop* p) {
1723     if ((*p) != NULL && (*p)->is_scavengable()) {
1724       NOT_PRODUCT(maybe_print(p));
1725       _detected_scavenge_root = true;
1726     }
1727   }
1728   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1729 
1730 #ifndef PRODUCT
1731   nmethod* _print_nm;
1732   void maybe_print(oop* p) {
1733     if (_print_nm == NULL)  return;
1734     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1735     tty->print_cr("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ")",
1736                   p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1737                   p2i(*p), p2i(p));
1738     (*p)->print();
1739   }
1740 #endif //PRODUCT
1741 };
1742 
1743 bool nmethod::detect_scavenge_root_oops() {
1744   DetectScavengeRoot detect_scavenge_root;
1745   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1746   oops_do(&detect_scavenge_root);
1747   return detect_scavenge_root.detected_scavenge_root();
1748 }
1749 
1750 inline bool includes(void* p, void* from, void* to) {
1751   return from <= p && p < to;
1752 }
1753 
1754 
1755 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1756   assert(count >= 2, "must be sentinel values, at least");
1757 
1758 #ifdef ASSERT
1759   // must be sorted and unique; we do a binary search in find_pc_desc()
1760   int prev_offset = pcs[0].pc_offset();
1761   assert(prev_offset == PcDesc::lower_offset_limit,
1762          "must start with a sentinel");
1763   for (int i = 1; i < count; i++) {
1764     int this_offset = pcs[i].pc_offset();
1765     assert(this_offset > prev_offset, "offsets must be sorted");
1766     prev_offset = this_offset;
1767   }
1768   assert(prev_offset == PcDesc::upper_offset_limit,
1769          "must end with a sentinel");
1770 #endif //ASSERT
1771 
1772   // Search for MethodHandle invokes and tag the nmethod.
1773   for (int i = 0; i < count; i++) {
1774     if (pcs[i].is_method_handle_invoke()) {
1775       set_has_method_handle_invokes(true);
1776       break;
1777     }
1778   }
1779   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1780 
1781   int size = count * sizeof(PcDesc);
1782   assert(scopes_pcs_size() >= size, "oob");
1783   memcpy(scopes_pcs_begin(), pcs, size);
1784 
1785   // Adjust the final sentinel downward.
1786   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1787   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1788   last_pc->set_pc_offset(content_size() + 1);
1789   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1790     // Fill any rounding gaps with copies of the last record.
1791     last_pc[1] = last_pc[0];
1792   }
1793   // The following assert could fail if sizeof(PcDesc) is not
1794   // an integral multiple of oopSize (the rounding term).
1795   // If it fails, change the logic to always allocate a multiple
1796   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1797   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1798 }
1799 
1800 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1801   assert(scopes_data_size() >= size, "oob");
1802   memcpy(scopes_data_begin(), buffer, size);
1803 }
1804 
1805 #ifdef ASSERT
1806 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1807   PcDesc* lower = search.scopes_pcs_begin();
1808   PcDesc* upper = search.scopes_pcs_end();
1809   lower += 1; // exclude initial sentinel
1810   PcDesc* res = NULL;
1811   for (PcDesc* p = lower; p < upper; p++) {
1812     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1813     if (match_desc(p, pc_offset, approximate)) {
1814       if (res == NULL)
1815         res = p;
1816       else
1817         res = (PcDesc*) badAddress;
1818     }
1819   }
1820   return res;
1821 }
1822 #endif
1823 
1824 
1825 // Finds a PcDesc with real-pc equal to "pc"
1826 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1827   address base_address = search.code_begin();
1828   if ((pc < base_address) ||
1829       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1830     return NULL;  // PC is wildly out of range
1831   }
1832   int pc_offset = (int) (pc - base_address);
1833 
1834   // Check the PcDesc cache if it contains the desired PcDesc
1835   // (This as an almost 100% hit rate.)
1836   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1837   if (res != NULL) {
1838     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1839     return res;
1840   }
1841 
1842   // Fallback algorithm: quasi-linear search for the PcDesc
1843   // Find the last pc_offset less than the given offset.
1844   // The successor must be the required match, if there is a match at all.
1845   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1846   PcDesc* lower = search.scopes_pcs_begin();
1847   PcDesc* upper = search.scopes_pcs_end();
1848   upper -= 1; // exclude final sentinel
1849   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1850 
1851 #define assert_LU_OK \
1852   /* invariant on lower..upper during the following search: */ \
1853   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1854   assert(upper->pc_offset() >= pc_offset, "sanity")
1855   assert_LU_OK;
1856 
1857   // Use the last successful return as a split point.
1858   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1859   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1860   if (mid->pc_offset() < pc_offset) {
1861     lower = mid;
1862   } else {
1863     upper = mid;
1864   }
1865 
1866   // Take giant steps at first (4096, then 256, then 16, then 1)
1867   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1868   const int RADIX = (1 << LOG2_RADIX);
1869   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1870     while ((mid = lower + step) < upper) {
1871       assert_LU_OK;
1872       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1873       if (mid->pc_offset() < pc_offset) {
1874         lower = mid;
1875       } else {
1876         upper = mid;
1877         break;
1878       }
1879     }
1880     assert_LU_OK;
1881   }
1882 
1883   // Sneak up on the value with a linear search of length ~16.
1884   while (true) {
1885     assert_LU_OK;
1886     mid = lower + 1;
1887     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1888     if (mid->pc_offset() < pc_offset) {
1889       lower = mid;
1890     } else {
1891       upper = mid;
1892       break;
1893     }
1894   }
1895 #undef assert_LU_OK
1896 
1897   if (match_desc(upper, pc_offset, approximate)) {
1898     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1899     _pc_desc_cache.add_pc_desc(upper);
1900     return upper;
1901   } else {
1902     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1903     return NULL;
1904   }
1905 }
1906 
1907 
1908 void nmethod::check_all_dependencies(DepChange& changes) {
1909   // Checked dependencies are allocated into this ResourceMark
1910   ResourceMark rm;
1911 
1912   // Turn off dependency tracing while actually testing dependencies.
1913   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1914 
1915   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1916                             &DependencySignature::equals, 11027> DepTable;
1917 
1918   DepTable* table = new DepTable();
1919 
1920   // Iterate over live nmethods and check dependencies of all nmethods that are not
1921   // marked for deoptimization. A particular dependency is only checked once.
1922   NMethodIterator iter;
1923   while(iter.next()) {
1924     nmethod* nm = iter.method();
1925     // Only notify for live nmethods
1926     if (nm->is_alive() && !nm->is_marked_for_deoptimization()) {
1927       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1928         // Construct abstraction of a dependency.
1929         DependencySignature* current_sig = new DependencySignature(deps);
1930 
1931         // Determine if dependency is already checked. table->put(...) returns
1932         // 'true' if the dependency is added (i.e., was not in the hashtable).
1933         if (table->put(*current_sig, 1)) {
1934           if (deps.check_dependency() != NULL) {
1935             // Dependency checking failed. Print out information about the failed
1936             // dependency and finally fail with an assert. We can fail here, since
1937             // dependency checking is never done in a product build.
1938             tty->print_cr("Failed dependency:");
1939             changes.print();
1940             nm->print();
1941             nm->print_dependencies();
1942             assert(false, "Should have been marked for deoptimization");
1943           }
1944         }
1945       }
1946     }
1947   }
1948 }
1949 
1950 bool nmethod::check_dependency_on(DepChange& changes) {
1951   // What has happened:
1952   // 1) a new class dependee has been added
1953   // 2) dependee and all its super classes have been marked
1954   bool found_check = false;  // set true if we are upset
1955   for (Dependencies::DepStream deps(this); deps.next(); ) {
1956     // Evaluate only relevant dependencies.
1957     if (deps.spot_check_dependency_at(changes) != NULL) {
1958       found_check = true;
1959       NOT_DEBUG(break);
1960     }
1961   }
1962   return found_check;
1963 }
1964 
1965 bool nmethod::is_evol_dependent_on(Klass* dependee) {
1966   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
1967   Array<Method*>* dependee_methods = dependee_ik->methods();
1968   for (Dependencies::DepStream deps(this); deps.next(); ) {
1969     if (deps.type() == Dependencies::evol_method) {
1970       Method* method = deps.method_argument(0);
1971       for (int j = 0; j < dependee_methods->length(); j++) {
1972         if (dependee_methods->at(j) == method) {
1973           if (log_is_enabled(Debug, redefine, class, nmethod)) {
1974             ResourceMark rm;
1975             log_debug(redefine, class, nmethod)
1976               ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
1977                _method->method_holder()->external_name(),
1978                _method->name()->as_C_string(),
1979                _method->signature()->as_C_string(),
1980                compile_id(),
1981                method->method_holder()->external_name(),
1982                method->name()->as_C_string(),
1983                method->signature()->as_C_string());
1984           }
1985           if (TraceDependencies || LogCompilation)
1986             deps.log_dependency(dependee);
1987           return true;
1988         }
1989       }
1990     }
1991   }
1992   return false;
1993 }
1994 
1995 // Called from mark_for_deoptimization, when dependee is invalidated.
1996 bool nmethod::is_dependent_on_method(Method* dependee) {
1997   for (Dependencies::DepStream deps(this); deps.next(); ) {
1998     if (deps.type() != Dependencies::evol_method)
1999       continue;
2000     Method* method = deps.method_argument(0);
2001     if (method == dependee) return true;
2002   }
2003   return false;
2004 }
2005 
2006 
2007 bool nmethod::is_patchable_at(address instr_addr) {
2008   assert(insts_contains(instr_addr), "wrong nmethod used");
2009   if (is_zombie()) {
2010     // a zombie may never be patched
2011     return false;
2012   }
2013   return true;
2014 }
2015 
2016 
2017 address nmethod::continuation_for_implicit_exception(address pc) {
2018   // Exception happened outside inline-cache check code => we are inside
2019   // an active nmethod => use cpc to determine a return address
2020   int exception_offset = pc - code_begin();
2021   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2022 #ifdef ASSERT
2023   if (cont_offset == 0) {
2024     Thread* thread = Thread::current();
2025     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2026     HandleMark hm(thread);
2027     ResourceMark rm(thread);
2028     CodeBlob* cb = CodeCache::find_blob(pc);
2029     assert(cb != NULL && cb == this, "");
2030     ttyLocker ttyl;
2031     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2032     print();
2033     method()->print_codes();
2034     print_code();
2035     print_pcs();
2036   }
2037 #endif
2038   if (cont_offset == 0) {
2039     // Let the normal error handling report the exception
2040     return NULL;
2041   }
2042   return code_begin() + cont_offset;
2043 }
2044 
2045 
2046 
2047 void nmethod_init() {
2048   // make sure you didn't forget to adjust the filler fields
2049   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2050 }
2051 
2052 
2053 //-------------------------------------------------------------------------------------------
2054 
2055 
2056 // QQQ might we make this work from a frame??
2057 nmethodLocker::nmethodLocker(address pc) {
2058   CodeBlob* cb = CodeCache::find_blob(pc);
2059   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2060   _nm = cb->as_compiled_method();
2061   lock_nmethod(_nm);
2062 }
2063 
2064 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2065 // should pass zombie_ok == true.
2066 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2067   if (cm == NULL)  return;
2068   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2069   nmethod* nm = cm->as_nmethod();
2070   Atomic::inc(&nm->_lock_count);
2071   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2072 }
2073 
2074 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2075   if (cm == NULL)  return;
2076   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2077   nmethod* nm = cm->as_nmethod();
2078   Atomic::dec(&nm->_lock_count);
2079   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2080 }
2081 
2082 
2083 // -----------------------------------------------------------------------------
2084 // Verification
2085 
2086 class VerifyOopsClosure: public OopClosure {
2087   nmethod* _nm;
2088   bool     _ok;
2089 public:
2090   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2091   bool ok() { return _ok; }
2092   virtual void do_oop(oop* p) {
2093     if (oopDesc::is_oop_or_null(*p)) return;
2094     if (_ok) {
2095       _nm->print_nmethod(true);
2096       _ok = false;
2097     }
2098     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2099                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2100   }
2101   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2102 };
2103 
2104 void nmethod::verify() {
2105 
2106   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2107   // seems odd.
2108 
2109   if (is_zombie() || is_not_entrant() || is_unloaded())
2110     return;
2111 
2112   // Make sure all the entry points are correctly aligned for patching.
2113   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2114 
2115   // assert(oopDesc::is_oop(method()), "must be valid");
2116 
2117   ResourceMark rm;
2118 
2119   if (!CodeCache::contains(this)) {
2120     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2121   }
2122 
2123   if(is_native_method() )
2124     return;
2125 
2126   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2127   if (nm != this) {
2128     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2129   }
2130 
2131   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2132     if (! p->verify(this)) {
2133       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2134     }
2135   }
2136 
2137   VerifyOopsClosure voc(this);
2138   oops_do(&voc);
2139   assert(voc.ok(), "embedded oops must be OK");
2140   verify_scavenge_root_oops();
2141 
2142   verify_scopes();
2143 }
2144 
2145 
2146 void nmethod::verify_interrupt_point(address call_site) {
2147   // Verify IC only when nmethod installation is finished.
2148   bool is_installed = (method()->code() == this) // nmethod is in state 'in_use' and installed
2149                       || !this->is_in_use();     // nmethod is installed, but not in 'in_use' state
2150   if (is_installed) {
2151     Thread *cur = Thread::current();
2152     if (CompiledIC_lock->owner() == cur ||
2153         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2154          SafepointSynchronize::is_at_safepoint())) {
2155       CompiledIC_at(this, call_site);
2156       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2157     } else {
2158       MutexLocker ml_verify (CompiledIC_lock);
2159       CompiledIC_at(this, call_site);
2160     }
2161   }
2162 
2163   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2164   assert(pd != NULL, "PcDesc must exist");
2165   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2166                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2167                                      pd->return_oop());
2168        !sd->is_top(); sd = sd->sender()) {
2169     sd->verify();
2170   }
2171 }
2172 
2173 void nmethod::verify_scopes() {
2174   if( !method() ) return;       // Runtime stubs have no scope
2175   if (method()->is_native()) return; // Ignore stub methods.
2176   // iterate through all interrupt point
2177   // and verify the debug information is valid.
2178   RelocIterator iter((nmethod*)this);
2179   while (iter.next()) {
2180     address stub = NULL;
2181     switch (iter.type()) {
2182       case relocInfo::virtual_call_type:
2183         verify_interrupt_point(iter.addr());
2184         break;
2185       case relocInfo::opt_virtual_call_type:
2186         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2187         verify_interrupt_point(iter.addr());
2188         break;
2189       case relocInfo::static_call_type:
2190         stub = iter.static_call_reloc()->static_stub(false);
2191         //verify_interrupt_point(iter.addr());
2192         break;
2193       case relocInfo::runtime_call_type:
2194       case relocInfo::runtime_call_w_cp_type: {
2195         address destination = iter.reloc()->value();
2196         // Right now there is no way to find out which entries support
2197         // an interrupt point.  It would be nice if we had this
2198         // information in a table.
2199         break;
2200       }
2201       default:
2202         break;
2203     }
2204     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2205   }
2206 }
2207 
2208 
2209 // -----------------------------------------------------------------------------
2210 // Non-product code
2211 #ifndef PRODUCT
2212 
2213 class DebugScavengeRoot: public OopClosure {
2214   nmethod* _nm;
2215   bool     _ok;
2216 public:
2217   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2218   bool ok() { return _ok; }
2219   virtual void do_oop(oop* p) {
2220     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2221     if (_ok) {
2222       _nm->print_nmethod(true);
2223       _ok = false;
2224     }
2225     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2226                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2227     (*p)->print();
2228   }
2229   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2230 };
2231 
2232 void nmethod::verify_scavenge_root_oops() {
2233   if (UseG1GC) {
2234     return;
2235   }
2236 
2237   if (!on_scavenge_root_list()) {
2238     // Actually look inside, to verify the claim that it's clean.
2239     DebugScavengeRoot debug_scavenge_root(this);
2240     oops_do(&debug_scavenge_root);
2241     if (!debug_scavenge_root.ok())
2242       fatal("found an unadvertised bad scavengable oop in the code cache");
2243   }
2244   assert(scavenge_root_not_marked(), "");
2245 }
2246 
2247 #endif // PRODUCT
2248 
2249 // Printing operations
2250 
2251 void nmethod::print() const {
2252   ResourceMark rm;
2253   ttyLocker ttyl;   // keep the following output all in one block
2254 
2255   tty->print("Compiled method ");
2256 
2257   if (is_compiled_by_c1()) {
2258     tty->print("(c1) ");
2259   } else if (is_compiled_by_c2()) {
2260     tty->print("(c2) ");
2261   } else if (is_compiled_by_shark()) {
2262     tty->print("(shark) ");
2263   } else if (is_compiled_by_jvmci()) {
2264     tty->print("(JVMCI) ");
2265   } else {
2266     tty->print("(nm) ");
2267   }
2268 
2269   print_on(tty, NULL);
2270 
2271   if (WizardMode) {
2272     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2273     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2274     tty->print(" { ");
2275     tty->print_cr("%s ", state());
2276     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2277     tty->print_cr("}:");
2278   }
2279   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2280                                               p2i(this),
2281                                               p2i(this) + size(),
2282                                               size());
2283   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2284                                               p2i(relocation_begin()),
2285                                               p2i(relocation_end()),
2286                                               relocation_size());
2287   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2288                                               p2i(consts_begin()),
2289                                               p2i(consts_end()),
2290                                               consts_size());
2291   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2292                                               p2i(insts_begin()),
2293                                               p2i(insts_end()),
2294                                               insts_size());
2295   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2296                                               p2i(stub_begin()),
2297                                               p2i(stub_end()),
2298                                               stub_size());
2299   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2300                                               p2i(oops_begin()),
2301                                               p2i(oops_end()),
2302                                               oops_size());
2303   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2304                                               p2i(metadata_begin()),
2305                                               p2i(metadata_end()),
2306                                               metadata_size());
2307   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2308                                               p2i(scopes_data_begin()),
2309                                               p2i(scopes_data_end()),
2310                                               scopes_data_size());
2311   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2312                                               p2i(scopes_pcs_begin()),
2313                                               p2i(scopes_pcs_end()),
2314                                               scopes_pcs_size());
2315   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2316                                               p2i(dependencies_begin()),
2317                                               p2i(dependencies_end()),
2318                                               dependencies_size());
2319   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2320                                               p2i(handler_table_begin()),
2321                                               p2i(handler_table_end()),
2322                                               handler_table_size());
2323   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2324                                               p2i(nul_chk_table_begin()),
2325                                               p2i(nul_chk_table_end()),
2326                                               nul_chk_table_size());
2327 }
2328 
2329 #ifndef PRODUCT
2330 
2331 void nmethod::print_scopes() {
2332   // Find the first pc desc for all scopes in the code and print it.
2333   ResourceMark rm;
2334   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2335     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2336       continue;
2337 
2338     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2339     while (sd != NULL) {
2340       sd->print_on(tty, p);
2341       sd = sd->sender();
2342     }
2343   }
2344 }
2345 
2346 void nmethod::print_dependencies() {
2347   ResourceMark rm;
2348   ttyLocker ttyl;   // keep the following output all in one block
2349   tty->print_cr("Dependencies:");
2350   for (Dependencies::DepStream deps(this); deps.next(); ) {
2351     deps.print_dependency();
2352     Klass* ctxk = deps.context_type();
2353     if (ctxk != NULL) {
2354       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2355         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2356       }
2357     }
2358     deps.log_dependency();  // put it into the xml log also
2359   }
2360 }
2361 
2362 
2363 void nmethod::print_relocations() {
2364   ResourceMark m;       // in case methods get printed via the debugger
2365   tty->print_cr("relocations:");
2366   RelocIterator iter(this);
2367   iter.print();
2368 }
2369 
2370 
2371 void nmethod::print_pcs() {
2372   ResourceMark m;       // in case methods get printed via debugger
2373   tty->print_cr("pc-bytecode offsets:");
2374   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2375     p->print(this);
2376   }
2377 }
2378 
2379 void nmethod::print_recorded_oops() {
2380   tty->print_cr("Recorded oops:");
2381   for (int i = 0; i < oops_count(); i++) {
2382     oop o = oop_at(i);
2383     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2384     if (o == (oop)Universe::non_oop_word()) {
2385       tty->print("non-oop word");
2386     } else {
2387       o->print_value();
2388     }
2389     tty->cr();
2390   }
2391 }
2392 
2393 void nmethod::print_recorded_metadata() {
2394   tty->print_cr("Recorded metadata:");
2395   for (int i = 0; i < metadata_count(); i++) {
2396     Metadata* m = metadata_at(i);
2397     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2398     if (m == (Metadata*)Universe::non_oop_word()) {
2399       tty->print("non-metadata word");
2400     } else {
2401       m->print_value_on_maybe_null(tty);
2402     }
2403     tty->cr();
2404   }
2405 }
2406 
2407 #endif // PRODUCT
2408 
2409 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2410   RelocIterator iter(this, begin, end);
2411   bool have_one = false;
2412   while (iter.next()) {
2413     have_one = true;
2414     switch (iter.type()) {
2415         case relocInfo::none:                  return "no_reloc";
2416         case relocInfo::oop_type: {
2417           stringStream st;
2418           oop_Relocation* r = iter.oop_reloc();
2419           oop obj = r->oop_value();
2420           st.print("oop(");
2421           if (obj == NULL) st.print("NULL");
2422           else obj->print_value_on(&st);
2423           st.print(")");
2424           return st.as_string();
2425         }
2426         case relocInfo::metadata_type: {
2427           stringStream st;
2428           metadata_Relocation* r = iter.metadata_reloc();
2429           Metadata* obj = r->metadata_value();
2430           st.print("metadata(");
2431           if (obj == NULL) st.print("NULL");
2432           else obj->print_value_on(&st);
2433           st.print(")");
2434           return st.as_string();
2435         }
2436         case relocInfo::runtime_call_type:
2437         case relocInfo::runtime_call_w_cp_type: {
2438           stringStream st;
2439           st.print("runtime_call");
2440           CallRelocation* r = (CallRelocation*)iter.reloc();
2441           address dest = r->destination();
2442           CodeBlob* cb = CodeCache::find_blob(dest);
2443           if (cb != NULL) {
2444             st.print(" %s", cb->name());
2445           } else {
2446             ResourceMark rm;
2447             const int buflen = 1024;
2448             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2449             int offset;
2450             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2451               st.print(" %s", buf);
2452               if (offset != 0) {
2453                 st.print("+%d", offset);
2454               }
2455             }
2456           }
2457           return st.as_string();
2458         }
2459         case relocInfo::virtual_call_type: {
2460           stringStream st;
2461           st.print_raw("virtual_call");
2462           virtual_call_Relocation* r = iter.virtual_call_reloc();
2463           Method* m = r->method_value();
2464           if (m != NULL) {
2465             assert(m->is_method(), "");
2466             m->print_short_name(&st);
2467           }
2468           return st.as_string();
2469         }
2470         case relocInfo::opt_virtual_call_type: {
2471           stringStream st;
2472           st.print_raw("optimized virtual_call");
2473           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2474           Method* m = r->method_value();
2475           if (m != NULL) {
2476             assert(m->is_method(), "");
2477             m->print_short_name(&st);
2478           }
2479           return st.as_string();
2480         }
2481         case relocInfo::static_call_type: {
2482           stringStream st;
2483           st.print_raw("static_call");
2484           static_call_Relocation* r = iter.static_call_reloc();
2485           Method* m = r->method_value();
2486           if (m != NULL) {
2487             assert(m->is_method(), "");
2488             m->print_short_name(&st);
2489           }
2490           return st.as_string();
2491         }
2492         case relocInfo::static_stub_type:      return "static_stub";
2493         case relocInfo::external_word_type:    return "external_word";
2494         case relocInfo::internal_word_type:    return "internal_word";
2495         case relocInfo::section_word_type:     return "section_word";
2496         case relocInfo::poll_type:             return "poll";
2497         case relocInfo::poll_return_type:      return "poll_return";
2498         case relocInfo::type_mask:             return "type_bit_mask";
2499 
2500         default:
2501           break;
2502     }
2503   }
2504   return have_one ? "other" : NULL;
2505 }
2506 
2507 // Return a the last scope in (begin..end]
2508 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2509   PcDesc* p = pc_desc_near(begin+1);
2510   if (p != NULL && p->real_pc(this) <= end) {
2511     return new ScopeDesc(this, p->scope_decode_offset(),
2512                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2513                          p->return_oop());
2514   }
2515   return NULL;
2516 }
2517 
2518 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2519   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2520   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2521   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2522   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2523   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2524 
2525   if (has_method_handle_invokes())
2526     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2527 
2528   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2529 
2530   if (block_begin == entry_point()) {
2531     methodHandle m = method();
2532     if (m.not_null()) {
2533       stream->print("  # ");
2534       m->print_value_on(stream);
2535       stream->cr();
2536     }
2537     if (m.not_null() && !is_osr_method()) {
2538       ResourceMark rm;
2539       int sizeargs = m->size_of_parameters();
2540       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2541       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2542       {
2543         int sig_index = 0;
2544         if (!m->is_static())
2545           sig_bt[sig_index++] = T_OBJECT; // 'this'
2546         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2547           BasicType t = ss.type();
2548           sig_bt[sig_index++] = t;
2549           if (type2size[t] == 2) {
2550             sig_bt[sig_index++] = T_VOID;
2551           } else {
2552             assert(type2size[t] == 1, "size is 1 or 2");
2553           }
2554         }
2555         assert(sig_index == sizeargs, "");
2556       }
2557       const char* spname = "sp"; // make arch-specific?
2558       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2559       int stack_slot_offset = this->frame_size() * wordSize;
2560       int tab1 = 14, tab2 = 24;
2561       int sig_index = 0;
2562       int arg_index = (m->is_static() ? 0 : -1);
2563       bool did_old_sp = false;
2564       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2565         bool at_this = (arg_index == -1);
2566         bool at_old_sp = false;
2567         BasicType t = (at_this ? T_OBJECT : ss.type());
2568         assert(t == sig_bt[sig_index], "sigs in sync");
2569         if (at_this)
2570           stream->print("  # this: ");
2571         else
2572           stream->print("  # parm%d: ", arg_index);
2573         stream->move_to(tab1);
2574         VMReg fst = regs[sig_index].first();
2575         VMReg snd = regs[sig_index].second();
2576         if (fst->is_reg()) {
2577           stream->print("%s", fst->name());
2578           if (snd->is_valid())  {
2579             stream->print(":%s", snd->name());
2580           }
2581         } else if (fst->is_stack()) {
2582           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2583           if (offset == stack_slot_offset)  at_old_sp = true;
2584           stream->print("[%s+0x%x]", spname, offset);
2585         } else {
2586           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2587         }
2588         stream->print(" ");
2589         stream->move_to(tab2);
2590         stream->print("= ");
2591         if (at_this) {
2592           m->method_holder()->print_value_on(stream);
2593         } else {
2594           bool did_name = false;
2595           if (!at_this && ss.is_object()) {
2596             Symbol* name = ss.as_symbol_or_null();
2597             if (name != NULL) {
2598               name->print_value_on(stream);
2599               did_name = true;
2600             }
2601           }
2602           if (!did_name)
2603             stream->print("%s", type2name(t));
2604         }
2605         if (at_old_sp) {
2606           stream->print("  (%s of caller)", spname);
2607           did_old_sp = true;
2608         }
2609         stream->cr();
2610         sig_index += type2size[t];
2611         arg_index += 1;
2612         if (!at_this)  ss.next();
2613       }
2614       if (!did_old_sp) {
2615         stream->print("  # ");
2616         stream->move_to(tab1);
2617         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2618         stream->print("  (%s of caller)", spname);
2619         stream->cr();
2620       }
2621     }
2622   }
2623 }
2624 
2625 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2626   // First, find an oopmap in (begin, end].
2627   // We use the odd half-closed interval so that oop maps and scope descs
2628   // which are tied to the byte after a call are printed with the call itself.
2629   address base = code_begin();
2630   ImmutableOopMapSet* oms = oop_maps();
2631   if (oms != NULL) {
2632     for (int i = 0, imax = oms->count(); i < imax; i++) {
2633       const ImmutableOopMapPair* pair = oms->pair_at(i);
2634       const ImmutableOopMap* om = pair->get_from(oms);
2635       address pc = base + pair->pc_offset();
2636       if (pc > begin) {
2637         if (pc <= end) {
2638           st->move_to(column);
2639           st->print("; ");
2640           om->print_on(st);
2641         }
2642         break;
2643       }
2644     }
2645   }
2646 
2647   // Print any debug info present at this pc.
2648   ScopeDesc* sd  = scope_desc_in(begin, end);
2649   if (sd != NULL) {
2650     st->move_to(column);
2651     if (sd->bci() == SynchronizationEntryBCI) {
2652       st->print(";*synchronization entry");
2653     } else {
2654       if (sd->method() == NULL) {
2655         st->print("method is NULL");
2656       } else if (sd->method()->is_native()) {
2657         st->print("method is native");
2658       } else {
2659         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2660         st->print(";*%s", Bytecodes::name(bc));
2661         switch (bc) {
2662         case Bytecodes::_invokevirtual:
2663         case Bytecodes::_invokespecial:
2664         case Bytecodes::_invokestatic:
2665         case Bytecodes::_invokeinterface:
2666           {
2667             Bytecode_invoke invoke(sd->method(), sd->bci());
2668             st->print(" ");
2669             if (invoke.name() != NULL)
2670               invoke.name()->print_symbol_on(st);
2671             else
2672               st->print("<UNKNOWN>");
2673             break;
2674           }
2675         case Bytecodes::_getfield:
2676         case Bytecodes::_putfield:
2677         case Bytecodes::_getstatic:
2678         case Bytecodes::_putstatic:
2679           {
2680             Bytecode_field field(sd->method(), sd->bci());
2681             st->print(" ");
2682             if (field.name() != NULL)
2683               field.name()->print_symbol_on(st);
2684             else
2685               st->print("<UNKNOWN>");
2686           }
2687         default:
2688           break;
2689         }
2690       }
2691       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2692     }
2693 
2694     // Print all scopes
2695     for (;sd != NULL; sd = sd->sender()) {
2696       st->move_to(column);
2697       st->print("; -");
2698       if (sd->method() == NULL) {
2699         st->print("method is NULL");
2700       } else {
2701         sd->method()->print_short_name(st);
2702       }
2703       int lineno = sd->method()->line_number_from_bci(sd->bci());
2704       if (lineno != -1) {
2705         st->print("@%d (line %d)", sd->bci(), lineno);
2706       } else {
2707         st->print("@%d", sd->bci());
2708       }
2709       st->cr();
2710     }
2711   }
2712 
2713   // Print relocation information
2714   const char* str = reloc_string_for(begin, end);
2715   if (str != NULL) {
2716     if (sd != NULL) st->cr();
2717     st->move_to(column);
2718     st->print(";   {%s}", str);
2719   }
2720   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2721   if (cont_offset != 0) {
2722     st->move_to(column);
2723     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2724   }
2725 
2726 }
2727 
2728 class DirectNativeCallWrapper: public NativeCallWrapper {
2729 private:
2730   NativeCall* _call;
2731 
2732 public:
2733   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2734 
2735   virtual address destination() const { return _call->destination(); }
2736   virtual address instruction_address() const { return _call->instruction_address(); }
2737   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2738   virtual address return_address() const { return _call->return_address(); }
2739 
2740   virtual address get_resolve_call_stub(bool is_optimized) const {
2741     if (is_optimized) {
2742       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2743     }
2744     return SharedRuntime::get_resolve_virtual_call_stub();
2745   }
2746 
2747   virtual void set_destination_mt_safe(address dest) {
2748 #if INCLUDE_AOT
2749     if (UseAOT) {
2750       CodeBlob* callee = CodeCache::find_blob(dest);
2751       CompiledMethod* cm = callee->as_compiled_method_or_null();
2752       if (cm != NULL && cm->is_far_code()) {
2753         // Temporary fix, see JDK-8143106
2754         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2755         csc->set_to_far(methodHandle(cm->method()), dest);
2756         return;
2757       }
2758     }
2759 #endif
2760     _call->set_destination_mt_safe(dest);
2761   }
2762 
2763   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2764     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2765 #if INCLUDE_AOT
2766     if (info.to_aot()) {
2767       csc->set_to_far(method, info.entry());
2768     } else
2769 #endif
2770     {
2771       csc->set_to_interpreted(method, info.entry());
2772     }
2773   }
2774 
2775   virtual void verify() const {
2776     // make sure code pattern is actually a call imm32 instruction
2777     _call->verify();
2778     if (os::is_MP()) {
2779       _call->verify_alignment();
2780     }
2781   }
2782 
2783   virtual void verify_resolve_call(address dest) const {
2784     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2785     assert(!db->is_adapter_blob(), "must use stub!");
2786   }
2787 
2788   virtual bool is_call_to_interpreted(address dest) const {
2789     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2790     return cb->contains(dest);
2791   }
2792 
2793   virtual bool is_safe_for_patching() const { return false; }
2794 
2795   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2796     return nativeMovConstReg_at(r->cached_value());
2797   }
2798 
2799   virtual void *get_data(NativeInstruction* instruction) const {
2800     return (void*)((NativeMovConstReg*) instruction)->data();
2801   }
2802 
2803   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2804     ((NativeMovConstReg*) instruction)->set_data(data);
2805   }
2806 };
2807 
2808 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2809   return new DirectNativeCallWrapper((NativeCall*) call);
2810 }
2811 
2812 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2813   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2814 }
2815 
2816 address nmethod::call_instruction_address(address pc) const {
2817   if (NativeCall::is_call_before(pc)) {
2818     NativeCall *ncall = nativeCall_before(pc);
2819     return ncall->instruction_address();
2820   }
2821   return NULL;
2822 }
2823 
2824 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2825   return CompiledDirectStaticCall::at(call_site);
2826 }
2827 
2828 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2829   return CompiledDirectStaticCall::at(call_site);
2830 }
2831 
2832 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2833   return CompiledDirectStaticCall::before(return_addr);
2834 }
2835 
2836 #ifndef PRODUCT
2837 
2838 void nmethod::print_value_on(outputStream* st) const {
2839   st->print("nmethod");
2840   print_on(st, NULL);
2841 }
2842 
2843 void nmethod::print_calls(outputStream* st) {
2844   RelocIterator iter(this);
2845   while (iter.next()) {
2846     switch (iter.type()) {
2847     case relocInfo::virtual_call_type:
2848     case relocInfo::opt_virtual_call_type: {
2849       VerifyMutexLocker mc(CompiledIC_lock);
2850       CompiledIC_at(&iter)->print();
2851       break;
2852     }
2853     case relocInfo::static_call_type:
2854       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2855       CompiledDirectStaticCall::at(iter.reloc())->print();
2856       break;
2857     default:
2858       break;
2859     }
2860   }
2861 }
2862 
2863 void nmethod::print_handler_table() {
2864   ExceptionHandlerTable(this).print();
2865 }
2866 
2867 void nmethod::print_nul_chk_table() {
2868   ImplicitExceptionTable(this).print(code_begin());
2869 }
2870 
2871 void nmethod::print_statistics() {
2872   ttyLocker ttyl;
2873   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2874   native_nmethod_stats.print_native_nmethod_stats();
2875 #ifdef COMPILER1
2876   c1_java_nmethod_stats.print_nmethod_stats("C1");
2877 #endif
2878 #ifdef COMPILER2
2879   c2_java_nmethod_stats.print_nmethod_stats("C2");
2880 #endif
2881 #if INCLUDE_JVMCI
2882   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2883 #endif
2884 #ifdef SHARK
2885   shark_java_nmethod_stats.print_nmethod_stats("Shark");
2886 #endif
2887   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2888   DebugInformationRecorder::print_statistics();
2889 #ifndef PRODUCT
2890   pc_nmethod_stats.print_pc_stats();
2891 #endif
2892   Dependencies::print_statistics();
2893   if (xtty != NULL)  xtty->tail("statistics");
2894 }
2895 
2896 #endif // !PRODUCT
2897 
2898 #if INCLUDE_JVMCI
2899 void nmethod::clear_jvmci_installed_code() {
2900   // write_ref_method_pre/post can only be safely called at a
2901   // safepoint or while holding the CodeCache_lock
2902   assert(CodeCache_lock->is_locked() ||
2903          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2904   if (_jvmci_installed_code != NULL) {
2905     // This must be done carefully to maintain nmethod remembered sets properly
2906     BarrierSet* bs = Universe::heap()->barrier_set();
2907     bs->write_ref_nmethod_pre(&_jvmci_installed_code, this);
2908     _jvmci_installed_code = NULL;
2909     bs->write_ref_nmethod_post(&_jvmci_installed_code, this);
2910   }
2911 }
2912 
2913 void nmethod::maybe_invalidate_installed_code() {
2914   assert(Patching_lock->is_locked() ||
2915          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2916   oop installed_code = jvmci_installed_code();
2917   if (installed_code != NULL) {
2918     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2919     if (nm == NULL || nm != this) {
2920       // The link has been broken or the InstalledCode instance is
2921       // associated with another nmethod so do nothing.
2922       return;
2923     }
2924     if (!is_alive()) {
2925       // Break the link between nmethod and InstalledCode such that the nmethod
2926       // can subsequently be flushed safely.  The link must be maintained while
2927       // the method could have live activations since invalidateInstalledCode
2928       // might want to invalidate all existing activations.
2929       InstalledCode::set_address(installed_code, 0);
2930       InstalledCode::set_entryPoint(installed_code, 0);
2931     } else if (is_not_entrant()) {
2932       // Remove the entry point so any invocation will fail but keep
2933       // the address link around that so that existing activations can
2934       // be invalidated.
2935       InstalledCode::set_entryPoint(installed_code, 0);
2936     }
2937   }
2938 }
2939 
2940 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
2941   if (installedCode() == NULL) {
2942     THROW(vmSymbols::java_lang_NullPointerException());
2943   }
2944   jlong nativeMethod = InstalledCode::address(installedCode);
2945   nmethod* nm = (nmethod*)nativeMethod;
2946   if (nm == NULL) {
2947     // Nothing to do
2948     return;
2949   }
2950 
2951   nmethodLocker nml(nm);
2952 #ifdef ASSERT
2953   {
2954     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2955     // This relationship can only be checked safely under a lock
2956     assert(nm == NULL || !nm->is_alive() || nm->jvmci_installed_code() == installedCode(), "sanity check");
2957   }
2958 #endif
2959 
2960   if (nm->is_alive()) {
2961     // The nmethod state machinery maintains the link between the
2962     // HotSpotInstalledCode and nmethod* so as long as the nmethod appears to be
2963     // alive assume there is work to do and deoptimize the nmethod.
2964     nm->mark_for_deoptimization();
2965     VM_Deoptimize op;
2966     VMThread::execute(&op);
2967   }
2968 
2969   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2970   // Check that it's still associated with the same nmethod and break
2971   // the link if it is.
2972   if (InstalledCode::address(installedCode) == nativeMethod) {
2973     InstalledCode::set_address(installedCode, 0);
2974   }
2975 }
2976 
2977 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) {
2978   if (!this->is_compiled_by_jvmci()) {
2979     return NULL;
2980   }
2981   oop installedCode = this->jvmci_installed_code();
2982   if (installedCode != NULL) {
2983     oop installedCodeName = NULL;
2984     if (installedCode->is_a(InstalledCode::klass())) {
2985       installedCodeName = InstalledCode::name(installedCode);
2986     }
2987     if (installedCodeName != NULL) {
2988       return java_lang_String::as_utf8_string(installedCodeName, buf, (int)buflen);
2989     } else {
2990       jio_snprintf(buf, buflen, "null");
2991       return buf;
2992     }
2993   }
2994   jio_snprintf(buf, buflen, "noInstalledCode");
2995   return buf;
2996 }
2997 #endif