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 "memory/resourceArea.hpp"
  41 #include "oops/methodData.hpp"
  42 #include "oops/oop.inline.hpp"
  43 #include "prims/jvm.h"
  44 #include "prims/jvmtiImpl.hpp"
  45 #include "runtime/atomic.hpp"
  46 #include "runtime/orderAccess.inline.hpp"
  47 #include "runtime/os.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 #include "runtime/sweeper.hpp"
  50 #include "utilities/resourceHash.hpp"
  51 #include "utilities/dtrace.hpp"
  52 #include "utilities/events.hpp"
  53 #include "utilities/xmlstream.hpp"
  54 #include "logging/log.hpp"
  55 #ifdef SHARK
  56 #include "shark/sharkCompiler.hpp"
  57 #endif
  58 #if INCLUDE_JVMCI
  59 #include "jvmci/jvmciJavaClasses.hpp"
  60 #endif
  61 
  62 #ifdef DTRACE_ENABLED
  63 
  64 // Only bother with this argument setup if dtrace is available
  65 
  66 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  67   {                                                                       \
  68     Method* m = (method);                                                 \
  69     if (m != NULL) {                                                      \
  70       Symbol* klass_name = m->klass_name();                               \
  71       Symbol* name = m->name();                                           \
  72       Symbol* signature = m->signature();                                 \
  73       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  74         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  75         (char *) name->bytes(), name->utf8_length(),                               \
  76         (char *) signature->bytes(), signature->utf8_length());                    \
  77     }                                                                     \
  78   }
  79 
  80 #else //  ndef DTRACE_ENABLED
  81 
  82 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  83 
  84 #endif
  85 
  86 //---------------------------------------------------------------------------------
  87 // NMethod statistics
  88 // They are printed under various flags, including:
  89 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  90 // (In the latter two cases, they like other stats are printed to the log only.)
  91 
  92 #ifndef PRODUCT
  93 // These variables are put into one block to reduce relocations
  94 // and make it simpler to print from the debugger.
  95 struct java_nmethod_stats_struct {
  96   int nmethod_count;
  97   int total_size;
  98   int relocation_size;
  99   int consts_size;
 100   int insts_size;
 101   int stub_size;
 102   int scopes_data_size;
 103   int scopes_pcs_size;
 104   int dependencies_size;
 105   int handler_table_size;
 106   int nul_chk_table_size;
 107   int oops_size;
 108   int metadata_size;
 109 
 110   void note_nmethod(nmethod* nm) {
 111     nmethod_count += 1;
 112     total_size          += nm->size();
 113     relocation_size     += nm->relocation_size();
 114     consts_size         += nm->consts_size();
 115     insts_size          += nm->insts_size();
 116     stub_size           += nm->stub_size();
 117     oops_size           += nm->oops_size();
 118     metadata_size       += nm->metadata_size();
 119     scopes_data_size    += nm->scopes_data_size();
 120     scopes_pcs_size     += nm->scopes_pcs_size();
 121     dependencies_size   += nm->dependencies_size();
 122     handler_table_size  += nm->handler_table_size();
 123     nul_chk_table_size  += nm->nul_chk_table_size();
 124   }
 125   void print_nmethod_stats(const char* name) {
 126     if (nmethod_count == 0)  return;
 127     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 128     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 129     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 130     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 131     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 132     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 133     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 134     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 135     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 136     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 137     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 138     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 139     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 140     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 141   }
 142 };
 143 
 144 struct native_nmethod_stats_struct {
 145   int native_nmethod_count;
 146   int native_total_size;
 147   int native_relocation_size;
 148   int native_insts_size;
 149   int native_oops_size;
 150   int native_metadata_size;
 151   void note_native_nmethod(nmethod* nm) {
 152     native_nmethod_count += 1;
 153     native_total_size       += nm->size();
 154     native_relocation_size  += nm->relocation_size();
 155     native_insts_size       += nm->insts_size();
 156     native_oops_size        += nm->oops_size();
 157     native_metadata_size    += nm->metadata_size();
 158   }
 159   void print_native_nmethod_stats() {
 160     if (native_nmethod_count == 0)  return;
 161     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 162     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 163     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 164     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 165     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 166     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 167   }
 168 };
 169 
 170 struct pc_nmethod_stats_struct {
 171   int pc_desc_resets;   // number of resets (= number of caches)
 172   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 173   int pc_desc_approx;   // number of those which have approximate true
 174   int pc_desc_repeats;  // number of _pc_descs[0] hits
 175   int pc_desc_hits;     // number of LRU cache hits
 176   int pc_desc_tests;    // total number of PcDesc examinations
 177   int pc_desc_searches; // total number of quasi-binary search steps
 178   int pc_desc_adds;     // number of LUR cache insertions
 179 
 180   void print_pc_stats() {
 181     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 182                   pc_desc_queries,
 183                   (double)(pc_desc_tests + pc_desc_searches)
 184                   / pc_desc_queries);
 185     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 186                   pc_desc_resets,
 187                   pc_desc_queries, pc_desc_approx,
 188                   pc_desc_repeats, pc_desc_hits,
 189                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 190   }
 191 };
 192 
 193 #ifdef COMPILER1
 194 static java_nmethod_stats_struct c1_java_nmethod_stats;
 195 #endif
 196 #ifdef COMPILER2
 197 static java_nmethod_stats_struct c2_java_nmethod_stats;
 198 #endif
 199 #if INCLUDE_JVMCI
 200 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 201 #endif
 202 #ifdef SHARK
 203 static java_nmethod_stats_struct shark_java_nmethod_stats;
 204 #endif
 205 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 206 
 207 static native_nmethod_stats_struct native_nmethod_stats;
 208 static pc_nmethod_stats_struct pc_nmethod_stats;
 209 
 210 static void note_java_nmethod(nmethod* nm) {
 211 #ifdef COMPILER1
 212   if (nm->is_compiled_by_c1()) {
 213     c1_java_nmethod_stats.note_nmethod(nm);
 214   } else
 215 #endif
 216 #ifdef COMPILER2
 217   if (nm->is_compiled_by_c2()) {
 218     c2_java_nmethod_stats.note_nmethod(nm);
 219   } else
 220 #endif
 221 #if INCLUDE_JVMCI
 222   if (nm->is_compiled_by_jvmci()) {
 223     jvmci_java_nmethod_stats.note_nmethod(nm);
 224   } else
 225 #endif
 226 #ifdef SHARK
 227   if (nm->is_compiled_by_shark()) {
 228     shark_java_nmethod_stats.note_nmethod(nm);
 229   } else
 230 #endif
 231   {
 232     unknown_java_nmethod_stats.note_nmethod(nm);
 233   }
 234 }
 235 #endif // !PRODUCT
 236 
 237 //---------------------------------------------------------------------------------
 238 
 239 
 240 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 241   assert(pc != NULL, "Must be non null");
 242   assert(exception.not_null(), "Must be non null");
 243   assert(handler != NULL, "Must be non null");
 244 
 245   _count = 0;
 246   _exception_type = exception->klass();
 247   _next = NULL;
 248 
 249   add_address_and_handler(pc,handler);
 250 }
 251 
 252 
 253 address ExceptionCache::match(Handle exception, address pc) {
 254   assert(pc != NULL,"Must be non null");
 255   assert(exception.not_null(),"Must be non null");
 256   if (exception->klass() == exception_type()) {
 257     return (test_address(pc));
 258   }
 259 
 260   return NULL;
 261 }
 262 
 263 
 264 bool ExceptionCache::match_exception_with_space(Handle exception) {
 265   assert(exception.not_null(),"Must be non null");
 266   if (exception->klass() == exception_type() && count() < cache_size) {
 267     return true;
 268   }
 269   return false;
 270 }
 271 
 272 
 273 address ExceptionCache::test_address(address addr) {
 274   int limit = count();
 275   for (int i = 0; i < limit; i++) {
 276     if (pc_at(i) == addr) {
 277       return handler_at(i);
 278     }
 279   }
 280   return NULL;
 281 }
 282 
 283 
 284 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 285   if (test_address(addr) == handler) return true;
 286 
 287   int index = count();
 288   if (index < cache_size) {
 289     set_pc_at(index, addr);
 290     set_handler_at(index, handler);
 291     increment_count();
 292     return true;
 293   }
 294   return false;
 295 }
 296 
 297 //-----------------------------------------------------------------------------
 298 
 299 
 300 // Helper used by both find_pc_desc methods.
 301 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 302   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 303   if (!approximate)
 304     return pc->pc_offset() == pc_offset;
 305   else
 306     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 307 }
 308 
 309 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 310   if (initial_pc_desc == NULL) {
 311     _pc_descs[0] = NULL; // native method; no PcDescs at all
 312     return;
 313   }
 314   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 315   // reset the cache by filling it with benign (non-null) values
 316   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 317   for (int i = 0; i < cache_size; i++)
 318     _pc_descs[i] = initial_pc_desc;
 319 }
 320 
 321 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 322   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 323   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 324 
 325   // Note: one might think that caching the most recently
 326   // read value separately would be a win, but one would be
 327   // wrong.  When many threads are updating it, the cache
 328   // line it's in would bounce between caches, negating
 329   // any benefit.
 330 
 331   // In order to prevent race conditions do not load cache elements
 332   // repeatedly, but use a local copy:
 333   PcDesc* res;
 334 
 335   // Step one:  Check the most recently added value.
 336   res = _pc_descs[0];
 337   if (res == NULL) return NULL;  // native method; no PcDescs at all
 338   if (match_desc(res, pc_offset, approximate)) {
 339     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 340     return res;
 341   }
 342 
 343   // Step two:  Check the rest of the LRU cache.
 344   for (int i = 1; i < cache_size; ++i) {
 345     res = _pc_descs[i];
 346     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 347     if (match_desc(res, pc_offset, approximate)) {
 348       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 349       return res;
 350     }
 351   }
 352 
 353   // Report failure.
 354   return NULL;
 355 }
 356 
 357 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 358   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 359   // Update the LRU cache by shifting pc_desc forward.
 360   for (int i = 0; i < cache_size; i++)  {
 361     PcDesc* next = _pc_descs[i];
 362     _pc_descs[i] = pc_desc;
 363     pc_desc = next;
 364   }
 365 }
 366 
 367 // adjust pcs_size so that it is a multiple of both oopSize and
 368 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 369 // of oopSize, then 2*sizeof(PcDesc) is)
 370 static int adjust_pcs_size(int pcs_size) {
 371   int nsize = round_to(pcs_size,   oopSize);
 372   if ((nsize % sizeof(PcDesc)) != 0) {
 373     nsize = pcs_size + sizeof(PcDesc);
 374   }
 375   assert((nsize % oopSize) == 0, "correct alignment");
 376   return nsize;
 377 }
 378 
 379 
 380 int nmethod::total_size() const {
 381   return
 382     consts_size()        +
 383     insts_size()         +
 384     stub_size()          +
 385     scopes_data_size()   +
 386     scopes_pcs_size()    +
 387     handler_table_size() +
 388     nul_chk_table_size();
 389 }
 390 
 391 const char* nmethod::compile_kind() const {
 392   if (is_osr_method())     return "osr";
 393   if (method() != NULL && is_native_method())  return "c2n";
 394   return NULL;
 395 }
 396 
 397 // Fill in default values for various flag fields
 398 void nmethod::init_defaults() {
 399   _state                      = in_use;
 400   _has_flushed_dependencies   = 0;
 401   _lock_count                 = 0;
 402   _stack_traversal_mark       = 0;
 403   _unload_reported            = false; // jvmti state
 404   _is_far_code                = false; // nmethods are located in CodeCache
 405 
 406 #ifdef ASSERT
 407   _oops_are_stale             = false;
 408 #endif
 409 
 410   _oops_do_mark_link       = NULL;
 411   _jmethod_id              = NULL;
 412   _osr_link                = NULL;
 413   if (UseG1GC) {
 414     _unloading_next        = NULL;
 415   } else {
 416     _scavenge_root_link    = NULL;
 417   }
 418   _scavenge_root_state     = 0;
 419 #if INCLUDE_RTM_OPT
 420   _rtm_state               = NoRTM;
 421 #endif
 422 #if INCLUDE_JVMCI
 423   _jvmci_installed_code   = NULL;
 424   _speculation_log        = NULL;
 425 #endif
 426 }
 427 
 428 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
 429   int compile_id,
 430   CodeBuffer *code_buffer,
 431   int vep_offset,
 432   int frame_complete,
 433   int frame_size,
 434   ByteSize basic_lock_owner_sp_offset,
 435   ByteSize basic_lock_sp_offset,
 436   OopMapSet* oop_maps) {
 437   code_buffer->finalize_oop_references(method);
 438   // create nmethod
 439   nmethod* nm = NULL;
 440   {
 441     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 442     int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
 443     CodeOffsets offsets;
 444     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 445     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 446     nm = new (native_nmethod_size, CompLevel_none) nmethod(method(), compiler_none, native_nmethod_size,
 447                                             compile_id, &offsets,
 448                                             code_buffer, frame_size,
 449                                             basic_lock_owner_sp_offset,
 450                                             basic_lock_sp_offset, oop_maps);
 451     NOT_PRODUCT(if (nm != NULL)  native_nmethod_stats.note_native_nmethod(nm));
 452   }
 453   // verify nmethod
 454   debug_only(if (nm) nm->verify();) // might block
 455 
 456   if (nm != NULL) {
 457     nm->log_new_nmethod();
 458   }
 459 
 460   return nm;
 461 }
 462 
 463 nmethod* nmethod::new_nmethod(const methodHandle& method,
 464   int compile_id,
 465   int entry_bci,
 466   CodeOffsets* offsets,
 467   int orig_pc_offset,
 468   DebugInformationRecorder* debug_info,
 469   Dependencies* dependencies,
 470   CodeBuffer* code_buffer, int frame_size,
 471   OopMapSet* oop_maps,
 472   ExceptionHandlerTable* handler_table,
 473   ImplicitExceptionTable* nul_chk_table,
 474   AbstractCompiler* compiler,
 475   int comp_level
 476 #if INCLUDE_JVMCI
 477   , Handle installed_code,
 478   Handle speculationLog
 479 #endif
 480 )
 481 {
 482   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 483   code_buffer->finalize_oop_references(method);
 484   // create nmethod
 485   nmethod* nm = NULL;
 486   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 487     int nmethod_size =
 488       CodeBlob::allocation_size(code_buffer, sizeof(nmethod))
 489       + adjust_pcs_size(debug_info->pcs_size())
 490       + round_to(dependencies->size_in_bytes() , oopSize)
 491       + round_to(handler_table->size_in_bytes(), oopSize)
 492       + round_to(nul_chk_table->size_in_bytes(), oopSize)
 493       + round_to(debug_info->data_size()       , oopSize);
 494 
 495     nm = new (nmethod_size, comp_level)
 496     nmethod(method(), compiler->type(), nmethod_size, compile_id, entry_bci, offsets,
 497             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 498             oop_maps,
 499             handler_table,
 500             nul_chk_table,
 501             compiler,
 502             comp_level
 503 #if INCLUDE_JVMCI
 504             , installed_code,
 505             speculationLog
 506 #endif
 507             );
 508 
 509     if (nm != NULL) {
 510       // To make dependency checking during class loading fast, record
 511       // the nmethod dependencies in the classes it is dependent on.
 512       // This allows the dependency checking code to simply walk the
 513       // class hierarchy above the loaded class, checking only nmethods
 514       // which are dependent on those classes.  The slow way is to
 515       // check every nmethod for dependencies which makes it linear in
 516       // the number of methods compiled.  For applications with a lot
 517       // classes the slow way is too slow.
 518       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 519         if (deps.type() == Dependencies::call_site_target_value) {
 520           // CallSite dependencies are managed on per-CallSite instance basis.
 521           oop call_site = deps.argument_oop(0);
 522           MethodHandles::add_dependent_nmethod(call_site, nm);
 523         } else {
 524           Klass* klass = deps.context_type();
 525           if (klass == NULL) {
 526             continue;  // ignore things like evol_method
 527           }
 528           // record this nmethod as dependent on this klass
 529           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 530         }
 531       }
 532       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 533     }
 534   }
 535   // Do verification and logging outside CodeCache_lock.
 536   if (nm != NULL) {
 537     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 538     DEBUG_ONLY(nm->verify();)
 539     nm->log_new_nmethod();
 540   }
 541   return nm;
 542 }
 543 
 544 // For native wrappers
 545 nmethod::nmethod(
 546   Method* method,
 547   CompilerType type,
 548   int nmethod_size,
 549   int compile_id,
 550   CodeOffsets* offsets,
 551   CodeBuffer* code_buffer,
 552   int frame_size,
 553   ByteSize basic_lock_owner_sp_offset,
 554   ByteSize basic_lock_sp_offset,
 555   OopMapSet* oop_maps )
 556   : CompiledMethod(method, "native nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 557   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 558   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 559 {
 560   {
 561     int scopes_data_offset = 0;
 562     int deoptimize_offset       = 0;
 563     int deoptimize_mh_offset    = 0;
 564 
 565     debug_only(NoSafepointVerifier nsv;)
 566     assert_locked_or_safepoint(CodeCache_lock);
 567 
 568     init_defaults();
 569     _entry_bci               = InvocationEntryBci;
 570     // We have no exception handler or deopt handler make the
 571     // values something that will never match a pc like the nmethod vtable entry
 572     _exception_offset        = 0;
 573     _orig_pc_offset          = 0;
 574 
 575     _consts_offset           = data_offset();
 576     _stub_offset             = data_offset();
 577     _oops_offset             = data_offset();
 578     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
 579     scopes_data_offset       = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
 580     _scopes_pcs_offset       = scopes_data_offset;
 581     _dependencies_offset     = _scopes_pcs_offset;
 582     _handler_table_offset    = _dependencies_offset;
 583     _nul_chk_table_offset    = _handler_table_offset;
 584     _nmethod_end_offset      = _nul_chk_table_offset;
 585     _compile_id              = compile_id;
 586     _comp_level              = CompLevel_none;
 587     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 588     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 589     _osr_entry_point         = NULL;
 590     _exception_cache         = NULL;
 591     _pc_desc_container.reset_to(NULL);
 592     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 593 
 594     _scopes_data_begin = (address) this + scopes_data_offset;
 595     _deopt_handler_begin = (address) this + deoptimize_offset;
 596     _deopt_mh_handler_begin = (address) this + deoptimize_mh_offset;
 597 
 598     code_buffer->copy_code_and_locs_to(this);
 599     code_buffer->copy_values_to(this);
 600     if (ScavengeRootsInCode) {
 601       if (detect_scavenge_root_oops()) {
 602         CodeCache::add_scavenge_root_nmethod(this);
 603       }
 604       Universe::heap()->register_nmethod(this);
 605     }
 606     debug_only(verify_scavenge_root_oops());
 607     CodeCache::commit(this);
 608   }
 609 
 610   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 611     ttyLocker ttyl;  // keep the following output all in one block
 612     // This output goes directly to the tty, not the compiler log.
 613     // To enable tools to match it up with the compilation activity,
 614     // be sure to tag this tty output with the compile ID.
 615     if (xtty != NULL) {
 616       xtty->begin_head("print_native_nmethod");
 617       xtty->method(_method);
 618       xtty->stamp();
 619       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 620     }
 621     // print the header part first
 622     print();
 623     // then print the requested information
 624     if (PrintNativeNMethods) {
 625       print_code();
 626       if (oop_maps != NULL) {
 627         oop_maps->print();
 628       }
 629     }
 630     if (PrintRelocations) {
 631       print_relocations();
 632     }
 633     if (xtty != NULL) {
 634       xtty->tail("print_native_nmethod");
 635     }
 636   }
 637 }
 638 
 639 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 640   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 641 }
 642 
 643 nmethod::nmethod(
 644   Method* method,
 645   CompilerType type,
 646   int nmethod_size,
 647   int compile_id,
 648   int entry_bci,
 649   CodeOffsets* offsets,
 650   int orig_pc_offset,
 651   DebugInformationRecorder* debug_info,
 652   Dependencies* dependencies,
 653   CodeBuffer *code_buffer,
 654   int frame_size,
 655   OopMapSet* oop_maps,
 656   ExceptionHandlerTable* handler_table,
 657   ImplicitExceptionTable* nul_chk_table,
 658   AbstractCompiler* compiler,
 659   int comp_level
 660 #if INCLUDE_JVMCI
 661   , Handle installed_code,
 662   Handle speculation_log
 663 #endif
 664   )
 665   : CompiledMethod(method, "nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 666   _native_receiver_sp_offset(in_ByteSize(-1)),
 667   _native_basic_lock_sp_offset(in_ByteSize(-1))
 668 {
 669   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 670   {
 671     debug_only(NoSafepointVerifier nsv;)
 672     assert_locked_or_safepoint(CodeCache_lock);
 673 
 674     _deopt_handler_begin = (address) this;
 675     _deopt_mh_handler_begin = (address) this;
 676 
 677     init_defaults();
 678     _entry_bci               = entry_bci;
 679     _compile_id              = compile_id;
 680     _comp_level              = comp_level;
 681     _orig_pc_offset          = orig_pc_offset;
 682     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 683 
 684     // Section offsets
 685     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 686     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 687     set_ctable_begin(header_begin() + _consts_offset);
 688 
 689 #if INCLUDE_JVMCI
 690     _jvmci_installed_code = installed_code();
 691     _speculation_log = (instanceOop)speculation_log();
 692 
 693     if (compiler->is_jvmci()) {
 694       // JVMCI might not produce any stub sections
 695       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 696         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 697       } else {
 698         _exception_offset = -1;
 699       }
 700       if (offsets->value(CodeOffsets::Deopt) != -1) {
 701         _deopt_handler_begin       = (address) this + code_offset()          + offsets->value(CodeOffsets::Deopt);
 702       } else {
 703         _deopt_handler_begin = NULL;
 704       }
 705       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 706         _deopt_mh_handler_begin  = (address) this + code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 707       } else {
 708         _deopt_mh_handler_begin = NULL;
 709       }
 710     } else {
 711 #endif
 712     // Exception handler and deopt handler are in the stub section
 713     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 714     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 715 
 716     _exception_offset       = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 717     _deopt_handler_begin    = (address) this + _stub_offset          + offsets->value(CodeOffsets::Deopt);
 718     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 719       _deopt_mh_handler_begin  = (address) this + _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 720     } else {
 721       _deopt_mh_handler_begin  = NULL;
 722 #if INCLUDE_JVMCI
 723     }
 724 #endif
 725     }
 726     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 727       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 728     } else {
 729       _unwind_handler_offset = -1;
 730     }
 731 
 732     _oops_offset             = data_offset();
 733     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 734     int scopes_data_offset   = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
 735 
 736     _scopes_pcs_offset       = scopes_data_offset    + round_to(debug_info->data_size       (), oopSize);
 737     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 738     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
 739     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
 740     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
 741     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 742     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 743     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 744     _exception_cache         = NULL;
 745 
 746     _scopes_data_begin = (address) this + scopes_data_offset;
 747 
 748     _pc_desc_container.reset_to(scopes_pcs_begin());
 749 
 750     code_buffer->copy_code_and_locs_to(this);
 751     // Copy contents of ScopeDescRecorder to nmethod
 752     code_buffer->copy_values_to(this);
 753     debug_info->copy_to(this);
 754     dependencies->copy_to(this);
 755     if (ScavengeRootsInCode) {
 756       if (detect_scavenge_root_oops()) {
 757         CodeCache::add_scavenge_root_nmethod(this);
 758       }
 759       Universe::heap()->register_nmethod(this);
 760     }
 761     debug_only(verify_scavenge_root_oops());
 762 
 763     CodeCache::commit(this);
 764 
 765     // Copy contents of ExceptionHandlerTable to nmethod
 766     handler_table->copy_to(this);
 767     nul_chk_table->copy_to(this);
 768 
 769     // we use the information of entry points to find out if a method is
 770     // static or non static
 771     assert(compiler->is_c2() || compiler->is_jvmci() ||
 772            _method->is_static() == (entry_point() == _verified_entry_point),
 773            " entry points must be same for static methods and vice versa");
 774   }
 775 }
 776 
 777 // Print a short set of xml attributes to identify this nmethod.  The
 778 // output should be embedded in some other element.
 779 void nmethod::log_identity(xmlStream* log) const {
 780   log->print(" compile_id='%d'", compile_id());
 781   const char* nm_kind = compile_kind();
 782   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 783   log->print(" compiler='%s'", compiler_name());
 784   if (TieredCompilation) {
 785     log->print(" level='%d'", comp_level());
 786   }
 787 }
 788 
 789 
 790 #define LOG_OFFSET(log, name)                    \
 791   if (p2i(name##_end()) - p2i(name##_begin())) \
 792     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 793                p2i(name##_begin()) - p2i(this))
 794 
 795 
 796 void nmethod::log_new_nmethod() const {
 797   if (LogCompilation && xtty != NULL) {
 798     ttyLocker ttyl;
 799     HandleMark hm;
 800     xtty->begin_elem("nmethod");
 801     log_identity(xtty);
 802     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 803     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 804 
 805     LOG_OFFSET(xtty, relocation);
 806     LOG_OFFSET(xtty, consts);
 807     LOG_OFFSET(xtty, insts);
 808     LOG_OFFSET(xtty, stub);
 809     LOG_OFFSET(xtty, scopes_data);
 810     LOG_OFFSET(xtty, scopes_pcs);
 811     LOG_OFFSET(xtty, dependencies);
 812     LOG_OFFSET(xtty, handler_table);
 813     LOG_OFFSET(xtty, nul_chk_table);
 814     LOG_OFFSET(xtty, oops);
 815     LOG_OFFSET(xtty, metadata);
 816 
 817     xtty->method(method());
 818     xtty->stamp();
 819     xtty->end_elem();
 820   }
 821 }
 822 
 823 #undef LOG_OFFSET
 824 
 825 
 826 // Print out more verbose output usually for a newly created nmethod.
 827 void nmethod::print_on(outputStream* st, const char* msg) const {
 828   if (st != NULL) {
 829     ttyLocker ttyl;
 830     if (WizardMode) {
 831       CompileTask::print(st, this, msg, /*short_form:*/ true);
 832       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 833     } else {
 834       CompileTask::print(st, this, msg, /*short_form:*/ false);
 835     }
 836   }
 837 }
 838 
 839 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 840   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 841   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 842     print_nmethod(printnmethods);
 843   }
 844 }
 845 
 846 void nmethod::print_nmethod(bool printmethod) {
 847   ttyLocker ttyl;  // keep the following output all in one block
 848   if (xtty != NULL) {
 849     xtty->begin_head("print_nmethod");
 850     xtty->stamp();
 851     xtty->end_head();
 852   }
 853   // print the header part first
 854   print();
 855   // then print the requested information
 856   if (printmethod) {
 857     print_code();
 858     print_pcs();
 859     if (oop_maps()) {
 860       oop_maps()->print();
 861     }
 862   }
 863   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 864     print_scopes();
 865   }
 866   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 867     print_relocations();
 868   }
 869   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 870     print_dependencies();
 871   }
 872   if (printmethod || PrintExceptionHandlers) {
 873     print_handler_table();
 874     print_nul_chk_table();
 875   }
 876   if (printmethod) {
 877     print_recorded_oops();
 878     print_recorded_metadata();
 879   }
 880   if (xtty != NULL) {
 881     xtty->tail("print_nmethod");
 882   }
 883 }
 884 
 885 
 886 // Promote one word from an assembly-time handle to a live embedded oop.
 887 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
 888   if (handle == NULL ||
 889       // As a special case, IC oops are initialized to 1 or -1.
 890       handle == (jobject) Universe::non_oop_word()) {
 891     (*dest) = (oop) handle;
 892   } else {
 893     (*dest) = JNIHandles::resolve_non_null(handle);
 894   }
 895 }
 896 
 897 
 898 // Have to have the same name because it's called by a template
 899 void nmethod::copy_values(GrowableArray<jobject>* array) {
 900   int length = array->length();
 901   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
 902   oop* dest = oops_begin();
 903   for (int index = 0 ; index < length; index++) {
 904     initialize_immediate_oop(&dest[index], array->at(index));
 905   }
 906 
 907   // Now we can fix up all the oops in the code.  We need to do this
 908   // in the code because the assembler uses jobjects as placeholders.
 909   // The code and relocations have already been initialized by the
 910   // CodeBlob constructor, so it is valid even at this early point to
 911   // iterate over relocations and patch the code.
 912   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 913 }
 914 
 915 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
 916   int length = array->length();
 917   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
 918   Metadata** dest = metadata_begin();
 919   for (int index = 0 ; index < length; index++) {
 920     dest[index] = array->at(index);
 921   }
 922 }
 923 
 924 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
 925   // re-patch all oop-bearing instructions, just in case some oops moved
 926   RelocIterator iter(this, begin, end);
 927   while (iter.next()) {
 928     if (iter.type() == relocInfo::oop_type) {
 929       oop_Relocation* reloc = iter.oop_reloc();
 930       if (initialize_immediates && reloc->oop_is_immediate()) {
 931         oop* dest = reloc->oop_addr();
 932         initialize_immediate_oop(dest, (jobject) *dest);
 933       }
 934       // Refresh the oop-related bits of this instruction.
 935       reloc->fix_oop_relocation();
 936     } else if (iter.type() == relocInfo::metadata_type) {
 937       metadata_Relocation* reloc = iter.metadata_reloc();
 938       reloc->fix_metadata_relocation();
 939     }
 940   }
 941 }
 942 
 943 
 944 void nmethod::verify_clean_inline_caches() {
 945   assert_locked_or_safepoint(CompiledIC_lock);
 946 
 947   // If the method is not entrant or zombie then a JMP is plastered over the
 948   // first few bytes.  If an oop in the old code was there, that oop
 949   // should not get GC'd.  Skip the first few bytes of oops on
 950   // not-entrant methods.
 951   address low_boundary = verified_entry_point();
 952   if (!is_in_use()) {
 953     low_boundary += NativeJump::instruction_size;
 954     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
 955     // This means that the low_boundary is going to be a little too high.
 956     // This shouldn't matter, since oops of non-entrant methods are never used.
 957     // In fact, why are we bothering to look at oops in a non-entrant method??
 958   }
 959 
 960   ResourceMark rm;
 961   RelocIterator iter(this, low_boundary);
 962   while(iter.next()) {
 963     switch(iter.type()) {
 964       case relocInfo::virtual_call_type:
 965       case relocInfo::opt_virtual_call_type: {
 966         CompiledIC *ic = CompiledIC_at(&iter);
 967         // Ok, to lookup references to zombies here
 968         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
 969         nmethod* nm = cb->as_nmethod_or_null();
 970         if( nm != NULL ) {
 971           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 972           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 973             assert(ic->is_clean(), "IC should be clean");
 974           }
 975         }
 976         break;
 977       }
 978       case relocInfo::static_call_type: {
 979         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
 980         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
 981         nmethod* nm = cb->as_nmethod_or_null();
 982         if( nm != NULL ) {
 983           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 984           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 985             assert(csc->is_clean(), "IC should be clean");
 986           }
 987         }
 988         break;
 989       }
 990     }
 991   }
 992 }
 993 
 994 // This is a private interface with the sweeper.
 995 void nmethod::mark_as_seen_on_stack() {
 996   assert(is_alive(), "Must be an alive method");
 997   // Set the traversal mark to ensure that the sweeper does 2
 998   // cleaning passes before moving to zombie.
 999   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1000 }
1001 
1002 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1003 // there are no activations on the stack, not in use by the VM,
1004 // and not in use by the ServiceThread)
1005 bool nmethod::can_convert_to_zombie() {
1006   assert(is_not_entrant(), "must be a non-entrant method");
1007 
1008   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1009   // count can be greater than the stack traversal count before it hits the
1010   // nmethod for the second time.
1011   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1012          !is_locked_by_vm();
1013 }
1014 
1015 void nmethod::inc_decompile_count() {
1016   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1017   // Could be gated by ProfileTraps, but do not bother...
1018   Method* m = method();
1019   if (m == NULL)  return;
1020   MethodData* mdo = m->method_data();
1021   if (mdo == NULL)  return;
1022   // There is a benign race here.  See comments in methodData.hpp.
1023   mdo->inc_decompile_count();
1024 }
1025 
1026 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1027 
1028   post_compiled_method_unload();
1029 
1030   // Since this nmethod is being unloaded, make sure that dependencies
1031   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1032   // indicate that this work is being done during a GC.
1033   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1034   assert(is_alive != NULL, "Should be non-NULL");
1035   // A non-NULL is_alive closure indicates that this is being called during GC.
1036   flush_dependencies(is_alive);
1037 
1038   // Break cycle between nmethod & method
1039   if (log_is_enabled(Trace, class, unload)) {
1040     outputStream* log = Log(class, unload)::trace_stream();
1041     log->print_cr("making nmethod " INTPTR_FORMAT
1042                   " unloadable, Method*(" INTPTR_FORMAT
1043                   "), cause(" INTPTR_FORMAT ")",
1044                   p2i(this), p2i(_method), p2i(cause));
1045     if (!Universe::heap()->is_gc_active())
1046       cause->klass()->print_on(log);
1047   }
1048   // Unlink the osr method, so we do not look this up again
1049   if (is_osr_method()) {
1050     // Invalidate the osr nmethod only once
1051     if (is_in_use()) {
1052       invalidate_osr_method();
1053     }
1054 #ifdef ASSERT
1055     if (method() != NULL) {
1056       // Make sure osr nmethod is invalidated, i.e. not on the list
1057       bool found = method()->method_holder()->remove_osr_nmethod(this);
1058       assert(!found, "osr nmethod should have been invalidated");
1059     }
1060 #endif
1061   }
1062 
1063   // If _method is already NULL the Method* is about to be unloaded,
1064   // so we don't have to break the cycle. Note that it is possible to
1065   // have the Method* live here, in case we unload the nmethod because
1066   // it is pointing to some oop (other than the Method*) being unloaded.
1067   if (_method != NULL) {
1068     // OSR methods point to the Method*, but the Method* does not
1069     // point back!
1070     if (_method->code() == this) {
1071       _method->clear_code(); // Break a cycle
1072     }
1073     _method = NULL;            // Clear the method of this dead nmethod
1074   }
1075 
1076   // Make the class unloaded - i.e., change state and notify sweeper
1077   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1078   if (is_in_use()) {
1079     // Transitioning directly from live to unloaded -- so
1080     // we need to force a cache clean-up; remember this
1081     // for later on.
1082     CodeCache::set_needs_cache_clean(true);
1083   }
1084 
1085   // Unregister must be done before the state change
1086   Universe::heap()->unregister_nmethod(this);
1087 
1088   _state = unloaded;
1089 
1090   // Log the unloading.
1091   log_state_change();
1092 
1093 #if INCLUDE_JVMCI
1094   // The method can only be unloaded after the pointer to the installed code
1095   // Java wrapper is no longer alive. Here we need to clear out this weak
1096   // reference to the dead object. Nulling out the reference has to happen
1097   // after the method is unregistered since the original value may be still
1098   // tracked by the rset.
1099   maybe_invalidate_installed_code();
1100   // Clear these out after the nmethod has been unregistered and any
1101   // updates to the InstalledCode instance have been performed.
1102   _jvmci_installed_code = NULL;
1103   _speculation_log = NULL;
1104 #endif
1105 
1106   // The Method* is gone at this point
1107   assert(_method == NULL, "Tautology");
1108 
1109   set_osr_link(NULL);
1110   NMethodSweeper::report_state_change(this);
1111 }
1112 
1113 void nmethod::invalidate_osr_method() {
1114   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1115   // Remove from list of active nmethods
1116   if (method() != NULL) {
1117     method()->method_holder()->remove_osr_nmethod(this);
1118   }
1119 }
1120 
1121 void nmethod::log_state_change() const {
1122   if (LogCompilation) {
1123     if (xtty != NULL) {
1124       ttyLocker ttyl;  // keep the following output all in one block
1125       if (_state == unloaded) {
1126         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1127                          os::current_thread_id());
1128       } else {
1129         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1130                          os::current_thread_id(),
1131                          (_state == zombie ? " zombie='1'" : ""));
1132       }
1133       log_identity(xtty);
1134       xtty->stamp();
1135       xtty->end_elem();
1136     }
1137   }
1138 
1139   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1140   CompileTask::print_ul(this, state_msg);
1141   if (PrintCompilation && _state != unloaded) {
1142     print_on(tty, state_msg);
1143   }
1144 }
1145 
1146 /**
1147  * Common functionality for both make_not_entrant and make_zombie
1148  */
1149 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1150   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1151   assert(!is_zombie(), "should not already be a zombie");
1152 
1153   if (_state == state) {
1154     // Avoid taking the lock if already in required state.
1155     // This is safe from races because the state is an end-state,
1156     // which the nmethod cannot back out of once entered.
1157     // No need for fencing either.
1158     return false;
1159   }
1160 
1161   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1162   nmethodLocker nml(this);
1163   methodHandle the_method(method());
1164   NoSafepointVerifier nsv;
1165 
1166   // during patching, depending on the nmethod state we must notify the GC that
1167   // code has been unloaded, unregistering it. We cannot do this right while
1168   // holding the Patching_lock because we need to use the CodeCache_lock. This
1169   // would be prone to deadlocks.
1170   // This flag is used to remember whether we need to later lock and unregister.
1171   bool nmethod_needs_unregister = false;
1172 
1173   {
1174     // invalidate osr nmethod before acquiring the patching lock since
1175     // they both acquire leaf locks and we don't want a deadlock.
1176     // This logic is equivalent to the logic below for patching the
1177     // verified entry point of regular methods. We check that the
1178     // nmethod is in use to ensure that it is invalidated only once.
1179     if (is_osr_method() && is_in_use()) {
1180       // this effectively makes the osr nmethod not entrant
1181       invalidate_osr_method();
1182     }
1183 
1184     // Enter critical section.  Does not block for safepoint.
1185     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1186 
1187     if (_state == state) {
1188       // another thread already performed this transition so nothing
1189       // to do, but return false to indicate this.
1190       return false;
1191     }
1192 
1193     // The caller can be calling the method statically or through an inline
1194     // cache call.
1195     if (!is_osr_method() && !is_not_entrant()) {
1196       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1197                   SharedRuntime::get_handle_wrong_method_stub());
1198     }
1199 
1200     if (is_in_use() && update_recompile_counts()) {
1201       // It's a true state change, so mark the method as decompiled.
1202       // Do it only for transition from alive.
1203       inc_decompile_count();
1204     }
1205 
1206     // If the state is becoming a zombie, signal to unregister the nmethod with
1207     // the heap.
1208     // This nmethod may have already been unloaded during a full GC.
1209     if ((state == zombie) && !is_unloaded()) {
1210       nmethod_needs_unregister = true;
1211     }
1212 
1213     // Must happen before state change. Otherwise we have a race condition in
1214     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1215     // transition its state from 'not_entrant' to 'zombie' without having to wait
1216     // for stack scanning.
1217     if (state == not_entrant) {
1218       mark_as_seen_on_stack();
1219       OrderAccess::storestore();
1220     }
1221 
1222     // Change state
1223     _state = state;
1224 
1225     // Log the transition once
1226     log_state_change();
1227 
1228     // Invalidate while holding the patching lock
1229     JVMCI_ONLY(maybe_invalidate_installed_code());
1230 
1231     // Remove nmethod from method.
1232     // We need to check if both the _code and _from_compiled_code_entry_point
1233     // refer to this nmethod because there is a race in setting these two fields
1234     // in Method* as seen in bugid 4947125.
1235     // If the vep() points to the zombie nmethod, the memory for the nmethod
1236     // could be flushed and the compiler and vtable stubs could still call
1237     // through it.
1238     if (method() != NULL && (method()->code() == this ||
1239                              method()->from_compiled_entry() == verified_entry_point())) {
1240       HandleMark hm;
1241       method()->clear_code(false /* already owns Patching_lock */);
1242     }
1243   } // leave critical region under Patching_lock
1244 
1245 #ifdef ASSERT
1246   if (is_osr_method() && method() != NULL) {
1247     // Make sure osr nmethod is invalidated, i.e. not on the list
1248     bool found = method()->method_holder()->remove_osr_nmethod(this);
1249     assert(!found, "osr nmethod should have been invalidated");
1250   }
1251 #endif
1252 
1253   // When the nmethod becomes zombie it is no longer alive so the
1254   // dependencies must be flushed.  nmethods in the not_entrant
1255   // state will be flushed later when the transition to zombie
1256   // happens or they get unloaded.
1257   if (state == zombie) {
1258     {
1259       // Flushing dependencies must be done before any possible
1260       // safepoint can sneak in, otherwise the oops used by the
1261       // dependency logic could have become stale.
1262       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1263       if (nmethod_needs_unregister) {
1264         Universe::heap()->unregister_nmethod(this);
1265 #ifdef JVMCI
1266         _jvmci_installed_code = NULL;
1267         _speculation_log = NULL;
1268 #endif
1269       }
1270       flush_dependencies(NULL);
1271     }
1272 
1273     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1274     // event and it hasn't already been reported for this nmethod then
1275     // report it now. The event may have been reported earlier if the GC
1276     // marked it for unloading). JvmtiDeferredEventQueue support means
1277     // we no longer go to a safepoint here.
1278     post_compiled_method_unload();
1279 
1280 #ifdef ASSERT
1281     // It's no longer safe to access the oops section since zombie
1282     // nmethods aren't scanned for GC.
1283     _oops_are_stale = true;
1284 #endif
1285      // the Method may be reclaimed by class unloading now that the
1286      // nmethod is in zombie state
1287     set_method(NULL);
1288   } else {
1289     assert(state == not_entrant, "other cases may need to be handled differently");
1290   }
1291 
1292   if (TraceCreateZombies) {
1293     ResourceMark m;
1294     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");
1295   }
1296 
1297   NMethodSweeper::report_state_change(this);
1298   return true;
1299 }
1300 
1301 void nmethod::flush() {
1302   // Note that there are no valid oops in the nmethod anymore.
1303   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1304          "osr nmethod must be unloaded or zombie before flushing");
1305   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1306   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1307   assert_locked_or_safepoint(CodeCache_lock);
1308 
1309   // completely deallocate this method
1310   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1311   if (PrintMethodFlushing) {
1312     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1313                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1314                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1315                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1316   }
1317 
1318   // We need to deallocate any ExceptionCache data.
1319   // Note that we do not need to grab the nmethod lock for this, it
1320   // better be thread safe if we're disposing of it!
1321   ExceptionCache* ec = exception_cache();
1322   set_exception_cache(NULL);
1323   while(ec != NULL) {
1324     ExceptionCache* next = ec->next();
1325     delete ec;
1326     ec = next;
1327   }
1328 
1329   if (on_scavenge_root_list()) {
1330     CodeCache::drop_scavenge_root_nmethod(this);
1331   }
1332 
1333 #ifdef SHARK
1334   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1335 #endif // SHARK
1336 
1337   CodeBlob::flush();
1338   CodeCache::free(this);
1339 }
1340 
1341 //
1342 // Notify all classes this nmethod is dependent on that it is no
1343 // longer dependent. This should only be called in two situations.
1344 // First, when a nmethod transitions to a zombie all dependents need
1345 // to be clear.  Since zombification happens at a safepoint there's no
1346 // synchronization issues.  The second place is a little more tricky.
1347 // During phase 1 of mark sweep class unloading may happen and as a
1348 // result some nmethods may get unloaded.  In this case the flushing
1349 // of dependencies must happen during phase 1 since after GC any
1350 // dependencies in the unloaded nmethod won't be updated, so
1351 // traversing the dependency information in unsafe.  In that case this
1352 // function is called with a non-NULL argument and this function only
1353 // notifies instanceKlasses that are reachable
1354 
1355 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1356   assert_locked_or_safepoint(CodeCache_lock);
1357   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1358   "is_alive is non-NULL if and only if we are called during GC");
1359   if (!has_flushed_dependencies()) {
1360     set_has_flushed_dependencies();
1361     for (Dependencies::DepStream deps(this); deps.next(); ) {
1362       if (deps.type() == Dependencies::call_site_target_value) {
1363         // CallSite dependencies are managed on per-CallSite instance basis.
1364         oop call_site = deps.argument_oop(0);
1365         MethodHandles::remove_dependent_nmethod(call_site, this);
1366       } else {
1367         Klass* klass = deps.context_type();
1368         if (klass == NULL) {
1369           continue;  // ignore things like evol_method
1370         }
1371         // During GC the is_alive closure is non-NULL, and is used to
1372         // determine liveness of dependees that need to be updated.
1373         if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
1374           // The GC defers deletion of this entry, since there might be multiple threads
1375           // iterating over the _dependencies graph. Other call paths are single-threaded
1376           // and may delete it immediately.
1377           bool delete_immediately = is_alive == NULL;
1378           InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
1379         }
1380       }
1381     }
1382   }
1383 }
1384 
1385 
1386 // If this oop is not live, the nmethod can be unloaded.
1387 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
1388   assert(root != NULL, "just checking");
1389   oop obj = *root;
1390   if (obj == NULL || is_alive->do_object_b(obj)) {
1391       return false;
1392   }
1393 
1394   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1395   // simply because one of its constant oops has gone dead.
1396   // No actual classes need to be unloaded in order for this to occur.
1397   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1398   make_unloaded(is_alive, obj);
1399   return true;
1400 }
1401 
1402 // ------------------------------------------------------------------
1403 // post_compiled_method_load_event
1404 // new method for install_code() path
1405 // Transfer information from compilation to jvmti
1406 void nmethod::post_compiled_method_load_event() {
1407 
1408   Method* moop = method();
1409   HOTSPOT_COMPILED_METHOD_LOAD(
1410       (char *) moop->klass_name()->bytes(),
1411       moop->klass_name()->utf8_length(),
1412       (char *) moop->name()->bytes(),
1413       moop->name()->utf8_length(),
1414       (char *) moop->signature()->bytes(),
1415       moop->signature()->utf8_length(),
1416       insts_begin(), insts_size());
1417 
1418   if (JvmtiExport::should_post_compiled_method_load() ||
1419       JvmtiExport::should_post_compiled_method_unload()) {
1420     get_and_cache_jmethod_id();
1421   }
1422 
1423   if (JvmtiExport::should_post_compiled_method_load()) {
1424     // Let the Service thread (which is a real Java thread) post the event
1425     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1426     JvmtiDeferredEventQueue::enqueue(
1427       JvmtiDeferredEvent::compiled_method_load_event(this));
1428   }
1429 }
1430 
1431 jmethodID nmethod::get_and_cache_jmethod_id() {
1432   if (_jmethod_id == NULL) {
1433     // Cache the jmethod_id since it can no longer be looked up once the
1434     // method itself has been marked for unloading.
1435     _jmethod_id = method()->jmethod_id();
1436   }
1437   return _jmethod_id;
1438 }
1439 
1440 void nmethod::post_compiled_method_unload() {
1441   if (unload_reported()) {
1442     // During unloading we transition to unloaded and then to zombie
1443     // and the unloading is reported during the first transition.
1444     return;
1445   }
1446 
1447   assert(_method != NULL && !is_unloaded(), "just checking");
1448   DTRACE_METHOD_UNLOAD_PROBE(method());
1449 
1450   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1451   // post the event. Sometime later this nmethod will be made a zombie
1452   // by the sweeper but the Method* will not be valid at that point.
1453   // If the _jmethod_id is null then no load event was ever requested
1454   // so don't bother posting the unload.  The main reason for this is
1455   // that the jmethodID is a weak reference to the Method* so if
1456   // it's being unloaded there's no way to look it up since the weak
1457   // ref will have been cleared.
1458   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1459     assert(!unload_reported(), "already unloaded");
1460     JvmtiDeferredEvent event =
1461       JvmtiDeferredEvent::compiled_method_unload_event(this,
1462           _jmethod_id, insts_begin());
1463     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1464     JvmtiDeferredEventQueue::enqueue(event);
1465   }
1466 
1467   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1468   // any time. As the nmethod is being unloaded now we mark it has
1469   // having the unload event reported - this will ensure that we don't
1470   // attempt to report the event in the unlikely scenario where the
1471   // event is enabled at the time the nmethod is made a zombie.
1472   set_unload_reported();
1473 }
1474 
1475 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
1476   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
1477 
1478   oop_Relocation* r = iter_at_oop->oop_reloc();
1479   // Traverse those oops directly embedded in the code.
1480   // Other oops (oop_index>0) are seen as part of scopes_oops.
1481   assert(1 == (r->oop_is_immediate()) +
1482          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1483          "oop must be found in exactly one place");
1484   if (r->oop_is_immediate() && r->oop_value() != NULL) {
1485     // Unload this nmethod if the oop is dead.
1486     if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1487       return true;;
1488     }
1489   }
1490 
1491   return false;
1492 }
1493 
1494 bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive, bool unloading_occurred) {
1495   // Scopes
1496   for (oop* p = oops_begin(); p < oops_end(); p++) {
1497     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1498     if (can_unload(is_alive, p, unloading_occurred)) {
1499       return true;
1500     }
1501   }
1502   return false;
1503 }
1504 
1505 bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {
1506   // Compiled code
1507   {
1508   RelocIterator iter(this, low_boundary);
1509   while (iter.next()) {
1510     if (iter.type() == relocInfo::oop_type) {
1511       if (unload_if_dead_at(&iter, is_alive, unloading_occurred)) {
1512         return true;
1513       }
1514     }
1515   }
1516   }
1517 
1518   return do_unloading_scopes(is_alive, unloading_occurred);
1519 }
1520 
1521 #if INCLUDE_JVMCI
1522 bool nmethod::do_unloading_jvmci(BoolObjectClosure* is_alive, bool unloading_occurred) {
1523   bool is_unloaded = false;
1524   // Follow JVMCI method
1525   BarrierSet* bs = Universe::heap()->barrier_set();
1526   if (_jvmci_installed_code != NULL) {
1527     if (_jvmci_installed_code->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(_jvmci_installed_code)) {
1528       if (!is_alive->do_object_b(_jvmci_installed_code)) {
1529         clear_jvmci_installed_code();
1530       }
1531     } else {
1532       if (can_unload(is_alive, (oop*)&_jvmci_installed_code, unloading_occurred)) {
1533         return true;
1534       }
1535     }
1536   }
1537 
1538   if (_speculation_log != NULL) {
1539     if (!is_alive->do_object_b(_speculation_log)) {
1540       bs->write_ref_nmethod_pre(&_speculation_log, this);
1541       _speculation_log = NULL;
1542       bs->write_ref_nmethod_post(&_speculation_log, this);
1543     }
1544   }
1545   return is_unloaded;
1546 }
1547 #endif
1548 
1549 // Iterate over metadata calling this function.   Used by RedefineClasses
1550 void nmethod::metadata_do(void f(Metadata*)) {
1551   address low_boundary = verified_entry_point();
1552   if (is_not_entrant()) {
1553     low_boundary += NativeJump::instruction_size;
1554     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1555     // (See comment above.)
1556   }
1557   {
1558     // Visit all immediate references that are embedded in the instruction stream.
1559     RelocIterator iter(this, low_boundary);
1560     while (iter.next()) {
1561       if (iter.type() == relocInfo::metadata_type ) {
1562         metadata_Relocation* r = iter.metadata_reloc();
1563         // In this metadata, we must only follow those metadatas directly embedded in
1564         // the code.  Other metadatas (oop_index>0) are seen as part of
1565         // the metadata section below.
1566         assert(1 == (r->metadata_is_immediate()) +
1567                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1568                "metadata must be found in exactly one place");
1569         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1570           Metadata* md = r->metadata_value();
1571           if (md != _method) f(md);
1572         }
1573       } else if (iter.type() == relocInfo::virtual_call_type) {
1574         // Check compiledIC holders associated with this nmethod
1575         CompiledIC *ic = CompiledIC_at(&iter);
1576         if (ic->is_icholder_call()) {
1577           CompiledICHolder* cichk = ic->cached_icholder();
1578           f(cichk->holder_method());
1579           f(cichk->holder_klass());
1580         } else {
1581           Metadata* ic_oop = ic->cached_metadata();
1582           if (ic_oop != NULL) {
1583             f(ic_oop);
1584           }
1585         }
1586       }
1587     }
1588   }
1589 
1590   // Visit the metadata section
1591   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1592     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1593     Metadata* md = *p;
1594     f(md);
1595   }
1596 
1597   // Visit metadata not embedded in the other places.
1598   if (_method != NULL) f(_method);
1599 }
1600 
1601 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1602   // make sure the oops ready to receive visitors
1603   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1604   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1605 
1606   // If the method is not entrant or zombie then a JMP is plastered over the
1607   // first few bytes.  If an oop in the old code was there, that oop
1608   // should not get GC'd.  Skip the first few bytes of oops on
1609   // not-entrant methods.
1610   address low_boundary = verified_entry_point();
1611   if (is_not_entrant()) {
1612     low_boundary += NativeJump::instruction_size;
1613     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1614     // (See comment above.)
1615   }
1616 
1617 #if INCLUDE_JVMCI
1618   if (_jvmci_installed_code != NULL) {
1619     f->do_oop((oop*) &_jvmci_installed_code);
1620   }
1621   if (_speculation_log != NULL) {
1622     f->do_oop((oop*) &_speculation_log);
1623   }
1624 #endif
1625 
1626   RelocIterator iter(this, low_boundary);
1627 
1628   while (iter.next()) {
1629     if (iter.type() == relocInfo::oop_type ) {
1630       oop_Relocation* r = iter.oop_reloc();
1631       // In this loop, we must only follow those oops directly embedded in
1632       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1633       assert(1 == (r->oop_is_immediate()) +
1634                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1635              "oop must be found in exactly one place");
1636       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1637         f->do_oop(r->oop_addr());
1638       }
1639     }
1640   }
1641 
1642   // Scopes
1643   // This includes oop constants not inlined in the code stream.
1644   for (oop* p = oops_begin(); p < oops_end(); p++) {
1645     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1646     f->do_oop(p);
1647   }
1648 }
1649 
1650 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1651 
1652 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1653 
1654 // An nmethod is "marked" if its _mark_link is set non-null.
1655 // Even if it is the end of the linked list, it will have a non-null link value,
1656 // as long as it is on the list.
1657 // This code must be MP safe, because it is used from parallel GC passes.
1658 bool nmethod::test_set_oops_do_mark() {
1659   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1660   nmethod* observed_mark_link = _oops_do_mark_link;
1661   if (observed_mark_link == NULL) {
1662     // Claim this nmethod for this thread to mark.
1663     observed_mark_link = (nmethod*)
1664       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1665     if (observed_mark_link == NULL) {
1666 
1667       // Atomically append this nmethod (now claimed) to the head of the list:
1668       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1669       for (;;) {
1670         nmethod* required_mark_nmethods = observed_mark_nmethods;
1671         _oops_do_mark_link = required_mark_nmethods;
1672         observed_mark_nmethods = (nmethod*)
1673           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1674         if (observed_mark_nmethods == required_mark_nmethods)
1675           break;
1676       }
1677       // Mark was clear when we first saw this guy.
1678       if (TraceScavenge) { print_on(tty, "oops_do, mark"); }
1679       return false;
1680     }
1681   }
1682   // On fall through, another racing thread marked this nmethod before we did.
1683   return true;
1684 }
1685 
1686 void nmethod::oops_do_marking_prologue() {
1687   if (TraceScavenge) { tty->print_cr("[oops_do_marking_prologue"); }
1688   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1689   // We use cmpxchg_ptr instead of regular assignment here because the user
1690   // may fork a bunch of threads, and we need them all to see the same state.
1691   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1692   guarantee(observed == NULL, "no races in this sequential code");
1693 }
1694 
1695 void nmethod::oops_do_marking_epilogue() {
1696   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1697   nmethod* cur = _oops_do_mark_nmethods;
1698   while (cur != NMETHOD_SENTINEL) {
1699     assert(cur != NULL, "not NULL-terminated");
1700     nmethod* next = cur->_oops_do_mark_link;
1701     cur->_oops_do_mark_link = NULL;
1702     DEBUG_ONLY(cur->verify_oop_relocations());
1703     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
1704     cur = next;
1705   }
1706   void* required = _oops_do_mark_nmethods;
1707   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1708   guarantee(observed == required, "no races in this sequential code");
1709   if (TraceScavenge) { tty->print_cr("oops_do_marking_epilogue]"); }
1710 }
1711 
1712 class DetectScavengeRoot: public OopClosure {
1713   bool     _detected_scavenge_root;
1714 public:
1715   DetectScavengeRoot() : _detected_scavenge_root(false)
1716   { NOT_PRODUCT(_print_nm = NULL); }
1717   bool detected_scavenge_root() { return _detected_scavenge_root; }
1718   virtual void do_oop(oop* p) {
1719     if ((*p) != NULL && (*p)->is_scavengable()) {
1720       NOT_PRODUCT(maybe_print(p));
1721       _detected_scavenge_root = true;
1722     }
1723   }
1724   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1725 
1726 #ifndef PRODUCT
1727   nmethod* _print_nm;
1728   void maybe_print(oop* p) {
1729     if (_print_nm == NULL)  return;
1730     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1731     tty->print_cr("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ")",
1732                   p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1733                   p2i(*p), p2i(p));
1734     (*p)->print();
1735   }
1736 #endif //PRODUCT
1737 };
1738 
1739 bool nmethod::detect_scavenge_root_oops() {
1740   DetectScavengeRoot detect_scavenge_root;
1741   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1742   oops_do(&detect_scavenge_root);
1743   return detect_scavenge_root.detected_scavenge_root();
1744 }
1745 
1746 inline bool includes(void* p, void* from, void* to) {
1747   return from <= p && p < to;
1748 }
1749 
1750 
1751 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1752   assert(count >= 2, "must be sentinel values, at least");
1753 
1754 #ifdef ASSERT
1755   // must be sorted and unique; we do a binary search in find_pc_desc()
1756   int prev_offset = pcs[0].pc_offset();
1757   assert(prev_offset == PcDesc::lower_offset_limit,
1758          "must start with a sentinel");
1759   for (int i = 1; i < count; i++) {
1760     int this_offset = pcs[i].pc_offset();
1761     assert(this_offset > prev_offset, "offsets must be sorted");
1762     prev_offset = this_offset;
1763   }
1764   assert(prev_offset == PcDesc::upper_offset_limit,
1765          "must end with a sentinel");
1766 #endif //ASSERT
1767 
1768   // Search for MethodHandle invokes and tag the nmethod.
1769   for (int i = 0; i < count; i++) {
1770     if (pcs[i].is_method_handle_invoke()) {
1771       set_has_method_handle_invokes(true);
1772       break;
1773     }
1774   }
1775   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1776 
1777   int size = count * sizeof(PcDesc);
1778   assert(scopes_pcs_size() >= size, "oob");
1779   memcpy(scopes_pcs_begin(), pcs, size);
1780 
1781   // Adjust the final sentinel downward.
1782   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1783   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1784   last_pc->set_pc_offset(content_size() + 1);
1785   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1786     // Fill any rounding gaps with copies of the last record.
1787     last_pc[1] = last_pc[0];
1788   }
1789   // The following assert could fail if sizeof(PcDesc) is not
1790   // an integral multiple of oopSize (the rounding term).
1791   // If it fails, change the logic to always allocate a multiple
1792   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1793   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1794 }
1795 
1796 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1797   assert(scopes_data_size() >= size, "oob");
1798   memcpy(scopes_data_begin(), buffer, size);
1799 }
1800 
1801 #ifdef ASSERT
1802 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1803   PcDesc* lower = search.scopes_pcs_begin();
1804   PcDesc* upper = search.scopes_pcs_end();
1805   lower += 1; // exclude initial sentinel
1806   PcDesc* res = NULL;
1807   for (PcDesc* p = lower; p < upper; p++) {
1808     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1809     if (match_desc(p, pc_offset, approximate)) {
1810       if (res == NULL)
1811         res = p;
1812       else
1813         res = (PcDesc*) badAddress;
1814     }
1815   }
1816   return res;
1817 }
1818 #endif
1819 
1820 
1821 // Finds a PcDesc with real-pc equal to "pc"
1822 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1823   address base_address = search.code_begin();
1824   if ((pc < base_address) ||
1825       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1826     return NULL;  // PC is wildly out of range
1827   }
1828   int pc_offset = (int) (pc - base_address);
1829 
1830   // Check the PcDesc cache if it contains the desired PcDesc
1831   // (This as an almost 100% hit rate.)
1832   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1833   if (res != NULL) {
1834     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1835     return res;
1836   }
1837 
1838   // Fallback algorithm: quasi-linear search for the PcDesc
1839   // Find the last pc_offset less than the given offset.
1840   // The successor must be the required match, if there is a match at all.
1841   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1842   PcDesc* lower = search.scopes_pcs_begin();
1843   PcDesc* upper = search.scopes_pcs_end();
1844   upper -= 1; // exclude final sentinel
1845   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1846 
1847 #define assert_LU_OK \
1848   /* invariant on lower..upper during the following search: */ \
1849   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1850   assert(upper->pc_offset() >= pc_offset, "sanity")
1851   assert_LU_OK;
1852 
1853   // Use the last successful return as a split point.
1854   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1855   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1856   if (mid->pc_offset() < pc_offset) {
1857     lower = mid;
1858   } else {
1859     upper = mid;
1860   }
1861 
1862   // Take giant steps at first (4096, then 256, then 16, then 1)
1863   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1864   const int RADIX = (1 << LOG2_RADIX);
1865   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1866     while ((mid = lower + step) < upper) {
1867       assert_LU_OK;
1868       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1869       if (mid->pc_offset() < pc_offset) {
1870         lower = mid;
1871       } else {
1872         upper = mid;
1873         break;
1874       }
1875     }
1876     assert_LU_OK;
1877   }
1878 
1879   // Sneak up on the value with a linear search of length ~16.
1880   while (true) {
1881     assert_LU_OK;
1882     mid = lower + 1;
1883     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1884     if (mid->pc_offset() < pc_offset) {
1885       lower = mid;
1886     } else {
1887       upper = mid;
1888       break;
1889     }
1890   }
1891 #undef assert_LU_OK
1892 
1893   if (match_desc(upper, pc_offset, approximate)) {
1894     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1895     _pc_desc_cache.add_pc_desc(upper);
1896     return upper;
1897   } else {
1898     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1899     return NULL;
1900   }
1901 }
1902 
1903 
1904 void nmethod::check_all_dependencies(DepChange& changes) {
1905   // Checked dependencies are allocated into this ResourceMark
1906   ResourceMark rm;
1907 
1908   // Turn off dependency tracing while actually testing dependencies.
1909   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1910 
1911   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1912                             &DependencySignature::equals, 11027> DepTable;
1913 
1914   DepTable* table = new DepTable();
1915 
1916   // Iterate over live nmethods and check dependencies of all nmethods that are not
1917   // marked for deoptimization. A particular dependency is only checked once.
1918   NMethodIterator iter;
1919   while(iter.next()) {
1920     nmethod* nm = iter.method();
1921     // Only notify for live nmethods
1922     if (nm->is_alive() && !nm->is_marked_for_deoptimization()) {
1923       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1924         // Construct abstraction of a dependency.
1925         DependencySignature* current_sig = new DependencySignature(deps);
1926 
1927         // Determine if dependency is already checked. table->put(...) returns
1928         // 'true' if the dependency is added (i.e., was not in the hashtable).
1929         if (table->put(*current_sig, 1)) {
1930           if (deps.check_dependency() != NULL) {
1931             // Dependency checking failed. Print out information about the failed
1932             // dependency and finally fail with an assert. We can fail here, since
1933             // dependency checking is never done in a product build.
1934             tty->print_cr("Failed dependency:");
1935             changes.print();
1936             nm->print();
1937             nm->print_dependencies();
1938             assert(false, "Should have been marked for deoptimization");
1939           }
1940         }
1941       }
1942     }
1943   }
1944 }
1945 
1946 bool nmethod::check_dependency_on(DepChange& changes) {
1947   // What has happened:
1948   // 1) a new class dependee has been added
1949   // 2) dependee and all its super classes have been marked
1950   bool found_check = false;  // set true if we are upset
1951   for (Dependencies::DepStream deps(this); deps.next(); ) {
1952     // Evaluate only relevant dependencies.
1953     if (deps.spot_check_dependency_at(changes) != NULL) {
1954       found_check = true;
1955       NOT_DEBUG(break);
1956     }
1957   }
1958   return found_check;
1959 }
1960 
1961 bool nmethod::is_evol_dependent_on(Klass* dependee) {
1962   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
1963   Array<Method*>* dependee_methods = dependee_ik->methods();
1964   for (Dependencies::DepStream deps(this); deps.next(); ) {
1965     if (deps.type() == Dependencies::evol_method) {
1966       Method* method = deps.method_argument(0);
1967       for (int j = 0; j < dependee_methods->length(); j++) {
1968         if (dependee_methods->at(j) == method) {
1969           if (log_is_enabled(Debug, redefine, class, nmethod)) {
1970             ResourceMark rm;
1971             log_debug(redefine, class, nmethod)
1972               ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
1973                _method->method_holder()->external_name(),
1974                _method->name()->as_C_string(),
1975                _method->signature()->as_C_string(),
1976                compile_id(),
1977                method->method_holder()->external_name(),
1978                method->name()->as_C_string(),
1979                method->signature()->as_C_string());
1980           }
1981           if (TraceDependencies || LogCompilation)
1982             deps.log_dependency(dependee);
1983           return true;
1984         }
1985       }
1986     }
1987   }
1988   return false;
1989 }
1990 
1991 // Called from mark_for_deoptimization, when dependee is invalidated.
1992 bool nmethod::is_dependent_on_method(Method* dependee) {
1993   for (Dependencies::DepStream deps(this); deps.next(); ) {
1994     if (deps.type() != Dependencies::evol_method)
1995       continue;
1996     Method* method = deps.method_argument(0);
1997     if (method == dependee) return true;
1998   }
1999   return false;
2000 }
2001 
2002 
2003 bool nmethod::is_patchable_at(address instr_addr) {
2004   assert(insts_contains(instr_addr), "wrong nmethod used");
2005   if (is_zombie()) {
2006     // a zombie may never be patched
2007     return false;
2008   }
2009   return true;
2010 }
2011 
2012 
2013 address nmethod::continuation_for_implicit_exception(address pc) {
2014   // Exception happened outside inline-cache check code => we are inside
2015   // an active nmethod => use cpc to determine a return address
2016   int exception_offset = pc - code_begin();
2017   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2018 #ifdef ASSERT
2019   if (cont_offset == 0) {
2020     Thread* thread = Thread::current();
2021     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2022     HandleMark hm(thread);
2023     ResourceMark rm(thread);
2024     CodeBlob* cb = CodeCache::find_blob(pc);
2025     assert(cb != NULL && cb == this, "");
2026     ttyLocker ttyl;
2027     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2028     print();
2029     method()->print_codes();
2030     print_code();
2031     print_pcs();
2032   }
2033 #endif
2034   if (cont_offset == 0) {
2035     // Let the normal error handling report the exception
2036     return NULL;
2037   }
2038   return code_begin() + cont_offset;
2039 }
2040 
2041 
2042 
2043 void nmethod_init() {
2044   // make sure you didn't forget to adjust the filler fields
2045   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2046 }
2047 
2048 
2049 //-------------------------------------------------------------------------------------------
2050 
2051 
2052 // QQQ might we make this work from a frame??
2053 nmethodLocker::nmethodLocker(address pc) {
2054   CodeBlob* cb = CodeCache::find_blob(pc);
2055   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2056   _nm = cb->as_compiled_method();
2057   lock_nmethod(_nm);
2058 }
2059 
2060 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2061 // should pass zombie_ok == true.
2062 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2063   if (cm == NULL)  return;
2064   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2065   nmethod* nm = cm->as_nmethod();
2066   Atomic::inc(&nm->_lock_count);
2067   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2068 }
2069 
2070 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2071   if (cm == NULL)  return;
2072   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2073   nmethod* nm = cm->as_nmethod();
2074   Atomic::dec(&nm->_lock_count);
2075   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2076 }
2077 
2078 
2079 // -----------------------------------------------------------------------------
2080 // Verification
2081 
2082 class VerifyOopsClosure: public OopClosure {
2083   nmethod* _nm;
2084   bool     _ok;
2085 public:
2086   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2087   bool ok() { return _ok; }
2088   virtual void do_oop(oop* p) {
2089     if ((*p) == NULL || (*p)->is_oop())  return;
2090     if (_ok) {
2091       _nm->print_nmethod(true);
2092       _ok = false;
2093     }
2094     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2095                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2096   }
2097   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2098 };
2099 
2100 void nmethod::verify() {
2101 
2102   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2103   // seems odd.
2104 
2105   if (is_zombie() || is_not_entrant() || is_unloaded())
2106     return;
2107 
2108   // Make sure all the entry points are correctly aligned for patching.
2109   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2110 
2111   // assert(method()->is_oop(), "must be valid");
2112 
2113   ResourceMark rm;
2114 
2115   if (!CodeCache::contains(this)) {
2116     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2117   }
2118 
2119   if(is_native_method() )
2120     return;
2121 
2122   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2123   if (nm != this) {
2124     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2125   }
2126 
2127   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2128     if (! p->verify(this)) {
2129       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2130     }
2131   }
2132 
2133   VerifyOopsClosure voc(this);
2134   oops_do(&voc);
2135   assert(voc.ok(), "embedded oops must be OK");
2136   verify_scavenge_root_oops();
2137 
2138   verify_scopes();
2139 }
2140 
2141 
2142 void nmethod::verify_interrupt_point(address call_site) {
2143   // Verify IC only when nmethod installation is finished.
2144   bool is_installed = (method()->code() == this) // nmethod is in state 'in_use' and installed
2145                       || !this->is_in_use();     // nmethod is installed, but not in 'in_use' state
2146   if (is_installed) {
2147     Thread *cur = Thread::current();
2148     if (CompiledIC_lock->owner() == cur ||
2149         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2150          SafepointSynchronize::is_at_safepoint())) {
2151       CompiledIC_at(this, call_site);
2152       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2153     } else {
2154       MutexLocker ml_verify (CompiledIC_lock);
2155       CompiledIC_at(this, call_site);
2156     }
2157   }
2158 
2159   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2160   assert(pd != NULL, "PcDesc must exist");
2161   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2162                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2163                                      pd->return_oop());
2164        !sd->is_top(); sd = sd->sender()) {
2165     sd->verify();
2166   }
2167 }
2168 
2169 void nmethod::verify_scopes() {
2170   if( !method() ) return;       // Runtime stubs have no scope
2171   if (method()->is_native()) return; // Ignore stub methods.
2172   // iterate through all interrupt point
2173   // and verify the debug information is valid.
2174   RelocIterator iter((nmethod*)this);
2175   while (iter.next()) {
2176     address stub = NULL;
2177     switch (iter.type()) {
2178       case relocInfo::virtual_call_type:
2179         verify_interrupt_point(iter.addr());
2180         break;
2181       case relocInfo::opt_virtual_call_type:
2182         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2183         verify_interrupt_point(iter.addr());
2184         break;
2185       case relocInfo::static_call_type:
2186         stub = iter.static_call_reloc()->static_stub(false);
2187         //verify_interrupt_point(iter.addr());
2188         break;
2189       case relocInfo::runtime_call_type:
2190       case relocInfo::runtime_call_w_cp_type:
2191         address destination = iter.reloc()->value();
2192         // Right now there is no way to find out which entries support
2193         // an interrupt point.  It would be nice if we had this
2194         // information in a table.
2195         break;
2196     }
2197     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2198   }
2199 }
2200 
2201 
2202 // -----------------------------------------------------------------------------
2203 // Non-product code
2204 #ifndef PRODUCT
2205 
2206 class DebugScavengeRoot: public OopClosure {
2207   nmethod* _nm;
2208   bool     _ok;
2209 public:
2210   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2211   bool ok() { return _ok; }
2212   virtual void do_oop(oop* p) {
2213     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2214     if (_ok) {
2215       _nm->print_nmethod(true);
2216       _ok = false;
2217     }
2218     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2219                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2220     (*p)->print();
2221   }
2222   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2223 };
2224 
2225 void nmethod::verify_scavenge_root_oops() {
2226   if (UseG1GC) {
2227     return;
2228   }
2229 
2230   if (!on_scavenge_root_list()) {
2231     // Actually look inside, to verify the claim that it's clean.
2232     DebugScavengeRoot debug_scavenge_root(this);
2233     oops_do(&debug_scavenge_root);
2234     if (!debug_scavenge_root.ok())
2235       fatal("found an unadvertised bad scavengable oop in the code cache");
2236   }
2237   assert(scavenge_root_not_marked(), "");
2238 }
2239 
2240 #endif // PRODUCT
2241 
2242 // Printing operations
2243 
2244 void nmethod::print() const {
2245   ResourceMark rm;
2246   ttyLocker ttyl;   // keep the following output all in one block
2247 
2248   tty->print("Compiled method ");
2249 
2250   if (is_compiled_by_c1()) {
2251     tty->print("(c1) ");
2252   } else if (is_compiled_by_c2()) {
2253     tty->print("(c2) ");
2254   } else if (is_compiled_by_shark()) {
2255     tty->print("(shark) ");
2256   } else if (is_compiled_by_jvmci()) {
2257     tty->print("(JVMCI) ");
2258   } else {
2259     tty->print("(nm) ");
2260   }
2261 
2262   print_on(tty, NULL);
2263 
2264   if (WizardMode) {
2265     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2266     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2267     tty->print(" { ");
2268     tty->print_cr("%s ", state());
2269     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2270     tty->print_cr("}:");
2271   }
2272   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2273                                               p2i(this),
2274                                               p2i(this) + size(),
2275                                               size());
2276   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2277                                               p2i(relocation_begin()),
2278                                               p2i(relocation_end()),
2279                                               relocation_size());
2280   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2281                                               p2i(consts_begin()),
2282                                               p2i(consts_end()),
2283                                               consts_size());
2284   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2285                                               p2i(insts_begin()),
2286                                               p2i(insts_end()),
2287                                               insts_size());
2288   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2289                                               p2i(stub_begin()),
2290                                               p2i(stub_end()),
2291                                               stub_size());
2292   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2293                                               p2i(oops_begin()),
2294                                               p2i(oops_end()),
2295                                               oops_size());
2296   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2297                                               p2i(metadata_begin()),
2298                                               p2i(metadata_end()),
2299                                               metadata_size());
2300   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2301                                               p2i(scopes_data_begin()),
2302                                               p2i(scopes_data_end()),
2303                                               scopes_data_size());
2304   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2305                                               p2i(scopes_pcs_begin()),
2306                                               p2i(scopes_pcs_end()),
2307                                               scopes_pcs_size());
2308   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2309                                               p2i(dependencies_begin()),
2310                                               p2i(dependencies_end()),
2311                                               dependencies_size());
2312   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2313                                               p2i(handler_table_begin()),
2314                                               p2i(handler_table_end()),
2315                                               handler_table_size());
2316   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2317                                               p2i(nul_chk_table_begin()),
2318                                               p2i(nul_chk_table_end()),
2319                                               nul_chk_table_size());
2320 }
2321 
2322 #ifndef PRODUCT
2323 
2324 void nmethod::print_scopes() {
2325   // Find the first pc desc for all scopes in the code and print it.
2326   ResourceMark rm;
2327   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2328     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2329       continue;
2330 
2331     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2332     while (sd != NULL) {
2333       sd->print_on(tty, p);
2334       sd = sd->sender();
2335     }
2336   }
2337 }
2338 
2339 void nmethod::print_dependencies() {
2340   ResourceMark rm;
2341   ttyLocker ttyl;   // keep the following output all in one block
2342   tty->print_cr("Dependencies:");
2343   for (Dependencies::DepStream deps(this); deps.next(); ) {
2344     deps.print_dependency();
2345     Klass* ctxk = deps.context_type();
2346     if (ctxk != NULL) {
2347       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2348         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2349       }
2350     }
2351     deps.log_dependency();  // put it into the xml log also
2352   }
2353 }
2354 
2355 
2356 void nmethod::print_relocations() {
2357   ResourceMark m;       // in case methods get printed via the debugger
2358   tty->print_cr("relocations:");
2359   RelocIterator iter(this);
2360   iter.print();
2361 }
2362 
2363 
2364 void nmethod::print_pcs() {
2365   ResourceMark m;       // in case methods get printed via debugger
2366   tty->print_cr("pc-bytecode offsets:");
2367   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2368     p->print(this);
2369   }
2370 }
2371 
2372 void nmethod::print_recorded_oops() {
2373   tty->print_cr("Recorded oops:");
2374   for (int i = 0; i < oops_count(); i++) {
2375     oop o = oop_at(i);
2376     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2377     if (o == (oop)Universe::non_oop_word()) {
2378       tty->print("non-oop word");
2379     } else {
2380       o->print_value();
2381     }
2382     tty->cr();
2383   }
2384 }
2385 
2386 void nmethod::print_recorded_metadata() {
2387   tty->print_cr("Recorded metadata:");
2388   for (int i = 0; i < metadata_count(); i++) {
2389     Metadata* m = metadata_at(i);
2390     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2391     if (m == (Metadata*)Universe::non_oop_word()) {
2392       tty->print("non-metadata word");
2393     } else {
2394       m->print_value_on_maybe_null(tty);
2395     }
2396     tty->cr();
2397   }
2398 }
2399 
2400 #endif // PRODUCT
2401 
2402 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2403   RelocIterator iter(this, begin, end);
2404   bool have_one = false;
2405   while (iter.next()) {
2406     have_one = true;
2407     switch (iter.type()) {
2408         case relocInfo::none:                  return "no_reloc";
2409         case relocInfo::oop_type: {
2410           stringStream st;
2411           oop_Relocation* r = iter.oop_reloc();
2412           oop obj = r->oop_value();
2413           st.print("oop(");
2414           if (obj == NULL) st.print("NULL");
2415           else obj->print_value_on(&st);
2416           st.print(")");
2417           return st.as_string();
2418         }
2419         case relocInfo::metadata_type: {
2420           stringStream st;
2421           metadata_Relocation* r = iter.metadata_reloc();
2422           Metadata* obj = r->metadata_value();
2423           st.print("metadata(");
2424           if (obj == NULL) st.print("NULL");
2425           else obj->print_value_on(&st);
2426           st.print(")");
2427           return st.as_string();
2428         }
2429         case relocInfo::runtime_call_type:
2430         case relocInfo::runtime_call_w_cp_type: {
2431           stringStream st;
2432           st.print("runtime_call");
2433           CallRelocation* r = (CallRelocation*)iter.reloc();
2434           address dest = r->destination();
2435           CodeBlob* cb = CodeCache::find_blob(dest);
2436           if (cb != NULL) {
2437             st.print(" %s", cb->name());
2438           } else {
2439             ResourceMark rm;
2440             const int buflen = 1024;
2441             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2442             int offset;
2443             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2444               st.print(" %s", buf);
2445               if (offset != 0) {
2446                 st.print("+%d", offset);
2447               }
2448             }
2449           }
2450           return st.as_string();
2451         }
2452         case relocInfo::virtual_call_type: {
2453           stringStream st;
2454           st.print_raw("virtual_call");
2455           virtual_call_Relocation* r = iter.virtual_call_reloc();
2456           Method* m = r->method_value();
2457           if (m != NULL) {
2458             assert(m->is_method(), "");
2459             m->print_short_name(&st);
2460           }
2461           return st.as_string();
2462         }
2463         case relocInfo::opt_virtual_call_type: {
2464           stringStream st;
2465           st.print_raw("optimized virtual_call");
2466           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2467           Method* m = r->method_value();
2468           if (m != NULL) {
2469             assert(m->is_method(), "");
2470             m->print_short_name(&st);
2471           }
2472           return st.as_string();
2473         }
2474         case relocInfo::static_call_type: {
2475           stringStream st;
2476           st.print_raw("static_call");
2477           static_call_Relocation* r = iter.static_call_reloc();
2478           Method* m = r->method_value();
2479           if (m != NULL) {
2480             assert(m->is_method(), "");
2481             m->print_short_name(&st);
2482           }
2483           return st.as_string();
2484         }
2485         case relocInfo::static_stub_type:      return "static_stub";
2486         case relocInfo::external_word_type:    return "external_word";
2487         case relocInfo::internal_word_type:    return "internal_word";
2488         case relocInfo::section_word_type:     return "section_word";
2489         case relocInfo::poll_type:             return "poll";
2490         case relocInfo::poll_return_type:      return "poll_return";
2491         case relocInfo::type_mask:             return "type_bit_mask";
2492     }
2493   }
2494   return have_one ? "other" : NULL;
2495 }
2496 
2497 // Return a the last scope in (begin..end]
2498 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2499   PcDesc* p = pc_desc_near(begin+1);
2500   if (p != NULL && p->real_pc(this) <= end) {
2501     return new ScopeDesc(this, p->scope_decode_offset(),
2502                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2503                          p->return_oop());
2504   }
2505   return NULL;
2506 }
2507 
2508 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2509   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2510   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2511   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2512   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2513   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2514 
2515   if (has_method_handle_invokes())
2516     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2517 
2518   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2519 
2520   if (block_begin == entry_point()) {
2521     methodHandle m = method();
2522     if (m.not_null()) {
2523       stream->print("  # ");
2524       m->print_value_on(stream);
2525       stream->cr();
2526     }
2527     if (m.not_null() && !is_osr_method()) {
2528       ResourceMark rm;
2529       int sizeargs = m->size_of_parameters();
2530       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2531       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2532       {
2533         int sig_index = 0;
2534         if (!m->is_static())
2535           sig_bt[sig_index++] = T_OBJECT; // 'this'
2536         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2537           BasicType t = ss.type();
2538           sig_bt[sig_index++] = t;
2539           if (type2size[t] == 2) {
2540             sig_bt[sig_index++] = T_VOID;
2541           } else {
2542             assert(type2size[t] == 1, "size is 1 or 2");
2543           }
2544         }
2545         assert(sig_index == sizeargs, "");
2546       }
2547       const char* spname = "sp"; // make arch-specific?
2548       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2549       int stack_slot_offset = this->frame_size() * wordSize;
2550       int tab1 = 14, tab2 = 24;
2551       int sig_index = 0;
2552       int arg_index = (m->is_static() ? 0 : -1);
2553       bool did_old_sp = false;
2554       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2555         bool at_this = (arg_index == -1);
2556         bool at_old_sp = false;
2557         BasicType t = (at_this ? T_OBJECT : ss.type());
2558         assert(t == sig_bt[sig_index], "sigs in sync");
2559         if (at_this)
2560           stream->print("  # this: ");
2561         else
2562           stream->print("  # parm%d: ", arg_index);
2563         stream->move_to(tab1);
2564         VMReg fst = regs[sig_index].first();
2565         VMReg snd = regs[sig_index].second();
2566         if (fst->is_reg()) {
2567           stream->print("%s", fst->name());
2568           if (snd->is_valid())  {
2569             stream->print(":%s", snd->name());
2570           }
2571         } else if (fst->is_stack()) {
2572           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2573           if (offset == stack_slot_offset)  at_old_sp = true;
2574           stream->print("[%s+0x%x]", spname, offset);
2575         } else {
2576           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2577         }
2578         stream->print(" ");
2579         stream->move_to(tab2);
2580         stream->print("= ");
2581         if (at_this) {
2582           m->method_holder()->print_value_on(stream);
2583         } else {
2584           bool did_name = false;
2585           if (!at_this && ss.is_object()) {
2586             Symbol* name = ss.as_symbol_or_null();
2587             if (name != NULL) {
2588               name->print_value_on(stream);
2589               did_name = true;
2590             }
2591           }
2592           if (!did_name)
2593             stream->print("%s", type2name(t));
2594         }
2595         if (at_old_sp) {
2596           stream->print("  (%s of caller)", spname);
2597           did_old_sp = true;
2598         }
2599         stream->cr();
2600         sig_index += type2size[t];
2601         arg_index += 1;
2602         if (!at_this)  ss.next();
2603       }
2604       if (!did_old_sp) {
2605         stream->print("  # ");
2606         stream->move_to(tab1);
2607         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2608         stream->print("  (%s of caller)", spname);
2609         stream->cr();
2610       }
2611     }
2612   }
2613 }
2614 
2615 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2616   // First, find an oopmap in (begin, end].
2617   // We use the odd half-closed interval so that oop maps and scope descs
2618   // which are tied to the byte after a call are printed with the call itself.
2619   address base = code_begin();
2620   ImmutableOopMapSet* oms = oop_maps();
2621   if (oms != NULL) {
2622     for (int i = 0, imax = oms->count(); i < imax; i++) {
2623       const ImmutableOopMapPair* pair = oms->pair_at(i);
2624       const ImmutableOopMap* om = pair->get_from(oms);
2625       address pc = base + pair->pc_offset();
2626       if (pc > begin) {
2627         if (pc <= end) {
2628           st->move_to(column);
2629           st->print("; ");
2630           om->print_on(st);
2631         }
2632         break;
2633       }
2634     }
2635   }
2636 
2637   // Print any debug info present at this pc.
2638   ScopeDesc* sd  = scope_desc_in(begin, end);
2639   if (sd != NULL) {
2640     st->move_to(column);
2641     if (sd->bci() == SynchronizationEntryBCI) {
2642       st->print(";*synchronization entry");
2643     } else {
2644       if (sd->method() == NULL) {
2645         st->print("method is NULL");
2646       } else if (sd->method()->is_native()) {
2647         st->print("method is native");
2648       } else {
2649         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2650         st->print(";*%s", Bytecodes::name(bc));
2651         switch (bc) {
2652         case Bytecodes::_invokevirtual:
2653         case Bytecodes::_invokespecial:
2654         case Bytecodes::_invokestatic:
2655         case Bytecodes::_invokeinterface:
2656           {
2657             Bytecode_invoke invoke(sd->method(), sd->bci());
2658             st->print(" ");
2659             if (invoke.name() != NULL)
2660               invoke.name()->print_symbol_on(st);
2661             else
2662               st->print("<UNKNOWN>");
2663             break;
2664           }
2665         case Bytecodes::_getfield:
2666         case Bytecodes::_putfield:
2667         case Bytecodes::_getstatic:
2668         case Bytecodes::_putstatic:
2669           {
2670             Bytecode_field field(sd->method(), sd->bci());
2671             st->print(" ");
2672             if (field.name() != NULL)
2673               field.name()->print_symbol_on(st);
2674             else
2675               st->print("<UNKNOWN>");
2676           }
2677         }
2678       }
2679       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2680     }
2681 
2682     // Print all scopes
2683     for (;sd != NULL; sd = sd->sender()) {
2684       st->move_to(column);
2685       st->print("; -");
2686       if (sd->method() == NULL) {
2687         st->print("method is NULL");
2688       } else {
2689         sd->method()->print_short_name(st);
2690       }
2691       int lineno = sd->method()->line_number_from_bci(sd->bci());
2692       if (lineno != -1) {
2693         st->print("@%d (line %d)", sd->bci(), lineno);
2694       } else {
2695         st->print("@%d", sd->bci());
2696       }
2697       st->cr();
2698     }
2699   }
2700 
2701   // Print relocation information
2702   const char* str = reloc_string_for(begin, end);
2703   if (str != NULL) {
2704     if (sd != NULL) st->cr();
2705     st->move_to(column);
2706     st->print(";   {%s}", str);
2707   }
2708   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2709   if (cont_offset != 0) {
2710     st->move_to(column);
2711     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2712   }
2713 
2714 }
2715 
2716 class DirectNativeCallWrapper: public NativeCallWrapper {
2717 private:
2718   NativeCall* _call;
2719 
2720 public:
2721   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2722 
2723   virtual address destination() const { return _call->destination(); }
2724   virtual address instruction_address() const { return _call->instruction_address(); }
2725   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2726   virtual address return_address() const { return _call->return_address(); }
2727 
2728   virtual address get_resolve_call_stub(bool is_optimized) const {
2729     if (is_optimized) {
2730       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2731     }
2732     return SharedRuntime::get_resolve_virtual_call_stub();
2733   }
2734 
2735   virtual void set_destination_mt_safe(address dest) {
2736 #if INCLUDE_AOT
2737     if (UseAOT) {
2738       CodeBlob* callee = CodeCache::find_blob(dest);
2739       CompiledMethod* cm = callee->as_compiled_method_or_null();
2740       if (cm != NULL && cm->is_far_code()) {
2741         // Temporary fix, see JDK-8143106
2742         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2743         csc->set_to_far(methodHandle(cm->method()), dest);
2744         return;
2745       }
2746     }
2747 #endif
2748     _call->set_destination_mt_safe(dest);
2749   }
2750 
2751   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2752     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2753 #if INCLUDE_AOT
2754     if (info.to_aot()) {
2755       csc->set_to_far(method, info.entry());
2756     } else
2757 #endif
2758     {
2759       csc->set_to_interpreted(method, info.entry());
2760     }
2761   }
2762 
2763   virtual void verify() const {
2764     // make sure code pattern is actually a call imm32 instruction
2765     _call->verify();
2766     if (os::is_MP()) {
2767       _call->verify_alignment();
2768     }
2769   }
2770 
2771   virtual void verify_resolve_call(address dest) const {
2772     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2773     assert(!db->is_adapter_blob(), "must use stub!");
2774   }
2775 
2776   virtual bool is_call_to_interpreted(address dest) const {
2777     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2778     return cb->contains(dest);
2779   }
2780 
2781   virtual bool is_safe_for_patching() const { return false; }
2782 
2783   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2784     return nativeMovConstReg_at(r->cached_value());
2785   }
2786 
2787   virtual void *get_data(NativeInstruction* instruction) const {
2788     return (void*)((NativeMovConstReg*) instruction)->data();
2789   }
2790 
2791   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2792     ((NativeMovConstReg*) instruction)->set_data(data);
2793   }
2794 };
2795 
2796 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2797   return new DirectNativeCallWrapper((NativeCall*) call);
2798 }
2799 
2800 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2801   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2802 }
2803 
2804 address nmethod::call_instruction_address(address pc) const {
2805   if (NativeCall::is_call_before(pc)) {
2806     NativeCall *ncall = nativeCall_before(pc);
2807     return ncall->instruction_address();
2808   }
2809   return NULL;
2810 }
2811 
2812 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2813   return CompiledDirectStaticCall::at(call_site);
2814 }
2815 
2816 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2817   return CompiledDirectStaticCall::at(call_site);
2818 }
2819 
2820 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2821   return CompiledDirectStaticCall::before(return_addr);
2822 }
2823 
2824 #ifndef PRODUCT
2825 
2826 void nmethod::print_value_on(outputStream* st) const {
2827   st->print("nmethod");
2828   print_on(st, NULL);
2829 }
2830 
2831 void nmethod::print_calls(outputStream* st) {
2832   RelocIterator iter(this);
2833   while (iter.next()) {
2834     switch (iter.type()) {
2835     case relocInfo::virtual_call_type:
2836     case relocInfo::opt_virtual_call_type: {
2837       VerifyMutexLocker mc(CompiledIC_lock);
2838       CompiledIC_at(&iter)->print();
2839       break;
2840     }
2841     case relocInfo::static_call_type:
2842       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2843       CompiledDirectStaticCall::at(iter.reloc())->print();
2844       break;
2845     }
2846   }
2847 }
2848 
2849 void nmethod::print_handler_table() {
2850   ExceptionHandlerTable(this).print();
2851 }
2852 
2853 void nmethod::print_nul_chk_table() {
2854   ImplicitExceptionTable(this).print(code_begin());
2855 }
2856 
2857 void nmethod::print_statistics() {
2858   ttyLocker ttyl;
2859   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2860   native_nmethod_stats.print_native_nmethod_stats();
2861 #ifdef COMPILER1
2862   c1_java_nmethod_stats.print_nmethod_stats("C1");
2863 #endif
2864 #ifdef COMPILER2
2865   c2_java_nmethod_stats.print_nmethod_stats("C2");
2866 #endif
2867 #if INCLUDE_JVMCI
2868   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2869 #endif
2870 #ifdef SHARK
2871   shark_java_nmethod_stats.print_nmethod_stats("Shark");
2872 #endif
2873   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2874   DebugInformationRecorder::print_statistics();
2875 #ifndef PRODUCT
2876   pc_nmethod_stats.print_pc_stats();
2877 #endif
2878   Dependencies::print_statistics();
2879   if (xtty != NULL)  xtty->tail("statistics");
2880 }
2881 
2882 #endif // !PRODUCT
2883 
2884 #if INCLUDE_JVMCI
2885 void nmethod::clear_jvmci_installed_code() {
2886   // write_ref_method_pre/post can only be safely called at a
2887   // safepoint or while holding the CodeCache_lock
2888   assert(CodeCache_lock->is_locked() ||
2889          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2890   if (_jvmci_installed_code != NULL) {
2891     // This must be done carefully to maintain nmethod remembered sets properly
2892     BarrierSet* bs = Universe::heap()->barrier_set();
2893     bs->write_ref_nmethod_pre(&_jvmci_installed_code, this);
2894     _jvmci_installed_code = NULL;
2895     bs->write_ref_nmethod_post(&_jvmci_installed_code, this);
2896   }
2897 }
2898 
2899 void nmethod::maybe_invalidate_installed_code() {
2900   assert(Patching_lock->is_locked() ||
2901          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2902   oop installed_code = jvmci_installed_code();
2903   if (installed_code != NULL) {
2904     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2905     if (nm == NULL || nm != this) {
2906       // The link has been broken or the InstalledCode instance is
2907       // associated with another nmethod so do nothing.
2908       return;
2909     }
2910     if (!is_alive()) {
2911       // Break the link between nmethod and InstalledCode such that the nmethod
2912       // can subsequently be flushed safely.  The link must be maintained while
2913       // the method could have live activations since invalidateInstalledCode
2914       // might want to invalidate all existing activations.
2915       InstalledCode::set_address(installed_code, 0);
2916       InstalledCode::set_entryPoint(installed_code, 0);
2917     } else if (is_not_entrant()) {
2918       // Remove the entry point so any invocation will fail but keep
2919       // the address link around that so that existing activations can
2920       // be invalidated.
2921       InstalledCode::set_entryPoint(installed_code, 0);
2922     }
2923   }
2924 }
2925 
2926 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
2927   if (installedCode() == NULL) {
2928     THROW(vmSymbols::java_lang_NullPointerException());
2929   }
2930   jlong nativeMethod = InstalledCode::address(installedCode);
2931   nmethod* nm = (nmethod*)nativeMethod;
2932   if (nm == NULL) {
2933     // Nothing to do
2934     return;
2935   }
2936 
2937   nmethodLocker nml(nm);
2938 #ifdef ASSERT
2939   {
2940     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2941     // This relationship can only be checked safely under a lock
2942     assert(nm == NULL || !nm->is_alive() || nm->jvmci_installed_code() == installedCode(), "sanity check");
2943   }
2944 #endif
2945 
2946   if (nm->is_alive()) {
2947     // The nmethod state machinery maintains the link between the
2948     // HotSpotInstalledCode and nmethod* so as long as the nmethod appears to be
2949     // alive assume there is work to do and deoptimize the nmethod.
2950     nm->mark_for_deoptimization();
2951     VM_Deoptimize op;
2952     VMThread::execute(&op);
2953   }
2954 
2955   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2956   // Check that it's still associated with the same nmethod and break
2957   // the link if it is.
2958   if (InstalledCode::address(installedCode) == nativeMethod) {
2959     InstalledCode::set_address(installedCode, 0);
2960   }
2961 }
2962 
2963 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) {
2964   if (!this->is_compiled_by_jvmci()) {
2965     return NULL;
2966   }
2967   oop installedCode = this->jvmci_installed_code();
2968   if (installedCode != NULL) {
2969     oop installedCodeName = NULL;
2970     if (installedCode->is_a(InstalledCode::klass())) {
2971       installedCodeName = InstalledCode::name(installedCode);
2972     }
2973     if (installedCodeName != NULL) {
2974       return java_lang_String::as_utf8_string(installedCodeName, buf, (int)buflen);
2975     } else {
2976       jio_snprintf(buf, buflen, "null");
2977       return buf;
2978     }
2979   }
2980   jio_snprintf(buf, buflen, "noInstalledCode");
2981   return buf;
2982 }
2983 #endif
2984