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       default:
 991         break;
 992     }
 993   }
 994 }
 995 
 996 // This is a private interface with the sweeper.
 997 void nmethod::mark_as_seen_on_stack() {
 998   assert(is_alive(), "Must be an alive method");
 999   // Set the traversal mark to ensure that the sweeper does 2
1000   // cleaning passes before moving to zombie.
1001   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1002 }
1003 
1004 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1005 // there are no activations on the stack, not in use by the VM,
1006 // and not in use by the ServiceThread)
1007 bool nmethod::can_convert_to_zombie() {
1008   assert(is_not_entrant(), "must be a non-entrant method");
1009 
1010   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1011   // count can be greater than the stack traversal count before it hits the
1012   // nmethod for the second time.
1013   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1014          !is_locked_by_vm();
1015 }
1016 
1017 void nmethod::inc_decompile_count() {
1018   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1019   // Could be gated by ProfileTraps, but do not bother...
1020   Method* m = method();
1021   if (m == NULL)  return;
1022   MethodData* mdo = m->method_data();
1023   if (mdo == NULL)  return;
1024   // There is a benign race here.  See comments in methodData.hpp.
1025   mdo->inc_decompile_count();
1026 }
1027 
1028 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1029 
1030   post_compiled_method_unload();
1031 
1032   // Since this nmethod is being unloaded, make sure that dependencies
1033   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1034   // indicate that this work is being done during a GC.
1035   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1036   assert(is_alive != NULL, "Should be non-NULL");
1037   // A non-NULL is_alive closure indicates that this is being called during GC.
1038   flush_dependencies(is_alive);
1039 
1040   // Break cycle between nmethod & method
1041   if (log_is_enabled(Trace, class, unload)) {
1042     outputStream* log = Log(class, unload)::trace_stream();
1043     log->print_cr("making nmethod " INTPTR_FORMAT
1044                   " unloadable, Method*(" INTPTR_FORMAT
1045                   "), cause(" INTPTR_FORMAT ")",
1046                   p2i(this), p2i(_method), p2i(cause));
1047     if (!Universe::heap()->is_gc_active())
1048       cause->klass()->print_on(log);
1049   }
1050   // Unlink the osr method, so we do not look this up again
1051   if (is_osr_method()) {
1052     // Invalidate the osr nmethod only once
1053     if (is_in_use()) {
1054       invalidate_osr_method();
1055     }
1056 #ifdef ASSERT
1057     if (method() != NULL) {
1058       // Make sure osr nmethod is invalidated, i.e. not on the list
1059       bool found = method()->method_holder()->remove_osr_nmethod(this);
1060       assert(!found, "osr nmethod should have been invalidated");
1061     }
1062 #endif
1063   }
1064 
1065   // If _method is already NULL the Method* is about to be unloaded,
1066   // so we don't have to break the cycle. Note that it is possible to
1067   // have the Method* live here, in case we unload the nmethod because
1068   // it is pointing to some oop (other than the Method*) being unloaded.
1069   if (_method != NULL) {
1070     // OSR methods point to the Method*, but the Method* does not
1071     // point back!
1072     if (_method->code() == this) {
1073       _method->clear_code(); // Break a cycle
1074     }
1075     _method = NULL;            // Clear the method of this dead nmethod
1076   }
1077 
1078   // Make the class unloaded - i.e., change state and notify sweeper
1079   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1080   if (is_in_use()) {
1081     // Transitioning directly from live to unloaded -- so
1082     // we need to force a cache clean-up; remember this
1083     // for later on.
1084     CodeCache::set_needs_cache_clean(true);
1085   }
1086 
1087   // Unregister must be done before the state change
1088   Universe::heap()->unregister_nmethod(this);
1089 
1090   _state = unloaded;
1091 
1092   // Log the unloading.
1093   log_state_change();
1094 
1095 #if INCLUDE_JVMCI
1096   // The method can only be unloaded after the pointer to the installed code
1097   // Java wrapper is no longer alive. Here we need to clear out this weak
1098   // reference to the dead object. Nulling out the reference has to happen
1099   // after the method is unregistered since the original value may be still
1100   // tracked by the rset.
1101   maybe_invalidate_installed_code();
1102   // Clear these out after the nmethod has been unregistered and any
1103   // updates to the InstalledCode instance have been performed.
1104   _jvmci_installed_code = NULL;
1105   _speculation_log = NULL;
1106 #endif
1107 
1108   // The Method* is gone at this point
1109   assert(_method == NULL, "Tautology");
1110 
1111   set_osr_link(NULL);
1112   NMethodSweeper::report_state_change(this);
1113 }
1114 
1115 void nmethod::invalidate_osr_method() {
1116   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1117   // Remove from list of active nmethods
1118   if (method() != NULL) {
1119     method()->method_holder()->remove_osr_nmethod(this);
1120   }
1121 }
1122 
1123 void nmethod::log_state_change() const {
1124   if (LogCompilation) {
1125     if (xtty != NULL) {
1126       ttyLocker ttyl;  // keep the following output all in one block
1127       if (_state == unloaded) {
1128         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1129                          os::current_thread_id());
1130       } else {
1131         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1132                          os::current_thread_id(),
1133                          (_state == zombie ? " zombie='1'" : ""));
1134       }
1135       log_identity(xtty);
1136       xtty->stamp();
1137       xtty->end_elem();
1138     }
1139   }
1140 
1141   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1142   CompileTask::print_ul(this, state_msg);
1143   if (PrintCompilation && _state != unloaded) {
1144     print_on(tty, state_msg);
1145   }
1146 }
1147 
1148 /**
1149  * Common functionality for both make_not_entrant and make_zombie
1150  */
1151 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1152   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1153   assert(!is_zombie(), "should not already be a zombie");
1154 
1155   if (_state == state) {
1156     // Avoid taking the lock if already in required state.
1157     // This is safe from races because the state is an end-state,
1158     // which the nmethod cannot back out of once entered.
1159     // No need for fencing either.
1160     return false;
1161   }
1162 
1163   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1164   nmethodLocker nml(this);
1165   methodHandle the_method(method());
1166   NoSafepointVerifier nsv;
1167 
1168   // during patching, depending on the nmethod state we must notify the GC that
1169   // code has been unloaded, unregistering it. We cannot do this right while
1170   // holding the Patching_lock because we need to use the CodeCache_lock. This
1171   // would be prone to deadlocks.
1172   // This flag is used to remember whether we need to later lock and unregister.
1173   bool nmethod_needs_unregister = false;
1174 
1175   {
1176     // invalidate osr nmethod before acquiring the patching lock since
1177     // they both acquire leaf locks and we don't want a deadlock.
1178     // This logic is equivalent to the logic below for patching the
1179     // verified entry point of regular methods. We check that the
1180     // nmethod is in use to ensure that it is invalidated only once.
1181     if (is_osr_method() && is_in_use()) {
1182       // this effectively makes the osr nmethod not entrant
1183       invalidate_osr_method();
1184     }
1185 
1186     // Enter critical section.  Does not block for safepoint.
1187     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1188 
1189     if (_state == state) {
1190       // another thread already performed this transition so nothing
1191       // to do, but return false to indicate this.
1192       return false;
1193     }
1194 
1195     // The caller can be calling the method statically or through an inline
1196     // cache call.
1197     if (!is_osr_method() && !is_not_entrant()) {
1198       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1199                   SharedRuntime::get_handle_wrong_method_stub());
1200     }
1201 
1202     if (is_in_use() && update_recompile_counts()) {
1203       // It's a true state change, so mark the method as decompiled.
1204       // Do it only for transition from alive.
1205       inc_decompile_count();
1206     }
1207 
1208     // If the state is becoming a zombie, signal to unregister the nmethod with
1209     // the heap.
1210     // This nmethod may have already been unloaded during a full GC.
1211     if ((state == zombie) && !is_unloaded()) {
1212       nmethod_needs_unregister = true;
1213     }
1214 
1215     // Must happen before state change. Otherwise we have a race condition in
1216     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1217     // transition its state from 'not_entrant' to 'zombie' without having to wait
1218     // for stack scanning.
1219     if (state == not_entrant) {
1220       mark_as_seen_on_stack();
1221       OrderAccess::storestore();
1222     }
1223 
1224     // Change state
1225     _state = state;
1226 
1227     // Log the transition once
1228     log_state_change();
1229 
1230     // Invalidate while holding the patching lock
1231     JVMCI_ONLY(maybe_invalidate_installed_code());
1232 
1233     // Remove nmethod from method.
1234     // We need to check if both the _code and _from_compiled_code_entry_point
1235     // refer to this nmethod because there is a race in setting these two fields
1236     // in Method* as seen in bugid 4947125.
1237     // If the vep() points to the zombie nmethod, the memory for the nmethod
1238     // could be flushed and the compiler and vtable stubs could still call
1239     // through it.
1240     if (method() != NULL && (method()->code() == this ||
1241                              method()->from_compiled_entry() == verified_entry_point())) {
1242       HandleMark hm;
1243       method()->clear_code(false /* already owns Patching_lock */);
1244     }
1245   } // leave critical region under Patching_lock
1246 
1247 #ifdef ASSERT
1248   if (is_osr_method() && method() != NULL) {
1249     // Make sure osr nmethod is invalidated, i.e. not on the list
1250     bool found = method()->method_holder()->remove_osr_nmethod(this);
1251     assert(!found, "osr nmethod should have been invalidated");
1252   }
1253 #endif
1254 
1255   // When the nmethod becomes zombie it is no longer alive so the
1256   // dependencies must be flushed.  nmethods in the not_entrant
1257   // state will be flushed later when the transition to zombie
1258   // happens or they get unloaded.
1259   if (state == zombie) {
1260     {
1261       // Flushing dependencies must be done before any possible
1262       // safepoint can sneak in, otherwise the oops used by the
1263       // dependency logic could have become stale.
1264       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1265       if (nmethod_needs_unregister) {
1266         Universe::heap()->unregister_nmethod(this);
1267 #ifdef JVMCI
1268         _jvmci_installed_code = NULL;
1269         _speculation_log = NULL;
1270 #endif
1271       }
1272       flush_dependencies(NULL);
1273     }
1274 
1275     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1276     // event and it hasn't already been reported for this nmethod then
1277     // report it now. The event may have been reported earlier if the GC
1278     // marked it for unloading). JvmtiDeferredEventQueue support means
1279     // we no longer go to a safepoint here.
1280     post_compiled_method_unload();
1281 
1282 #ifdef ASSERT
1283     // It's no longer safe to access the oops section since zombie
1284     // nmethods aren't scanned for GC.
1285     _oops_are_stale = true;
1286 #endif
1287      // the Method may be reclaimed by class unloading now that the
1288      // nmethod is in zombie state
1289     set_method(NULL);
1290   } else {
1291     assert(state == not_entrant, "other cases may need to be handled differently");
1292   }
1293 
1294   if (TraceCreateZombies) {
1295     ResourceMark m;
1296     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");
1297   }
1298 
1299   NMethodSweeper::report_state_change(this);
1300   return true;
1301 }
1302 
1303 void nmethod::flush() {
1304   // Note that there are no valid oops in the nmethod anymore.
1305   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1306          "osr nmethod must be unloaded or zombie before flushing");
1307   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1308   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1309   assert_locked_or_safepoint(CodeCache_lock);
1310 
1311   // completely deallocate this method
1312   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1313   if (PrintMethodFlushing) {
1314     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1315                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1316                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1317                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1318   }
1319 
1320   // We need to deallocate any ExceptionCache data.
1321   // Note that we do not need to grab the nmethod lock for this, it
1322   // better be thread safe if we're disposing of it!
1323   ExceptionCache* ec = exception_cache();
1324   set_exception_cache(NULL);
1325   while(ec != NULL) {
1326     ExceptionCache* next = ec->next();
1327     delete ec;
1328     ec = next;
1329   }
1330 
1331   if (on_scavenge_root_list()) {
1332     CodeCache::drop_scavenge_root_nmethod(this);
1333   }
1334 
1335 #ifdef SHARK
1336   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1337 #endif // SHARK
1338 
1339   CodeBlob::flush();
1340   CodeCache::free(this);
1341 }
1342 
1343 //
1344 // Notify all classes this nmethod is dependent on that it is no
1345 // longer dependent. This should only be called in two situations.
1346 // First, when a nmethod transitions to a zombie all dependents need
1347 // to be clear.  Since zombification happens at a safepoint there's no
1348 // synchronization issues.  The second place is a little more tricky.
1349 // During phase 1 of mark sweep class unloading may happen and as a
1350 // result some nmethods may get unloaded.  In this case the flushing
1351 // of dependencies must happen during phase 1 since after GC any
1352 // dependencies in the unloaded nmethod won't be updated, so
1353 // traversing the dependency information in unsafe.  In that case this
1354 // function is called with a non-NULL argument and this function only
1355 // notifies instanceKlasses that are reachable
1356 
1357 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1358   assert_locked_or_safepoint(CodeCache_lock);
1359   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1360   "is_alive is non-NULL if and only if we are called during GC");
1361   if (!has_flushed_dependencies()) {
1362     set_has_flushed_dependencies();
1363     for (Dependencies::DepStream deps(this); deps.next(); ) {
1364       if (deps.type() == Dependencies::call_site_target_value) {
1365         // CallSite dependencies are managed on per-CallSite instance basis.
1366         oop call_site = deps.argument_oop(0);
1367         MethodHandles::remove_dependent_nmethod(call_site, this);
1368       } else {
1369         Klass* klass = deps.context_type();
1370         if (klass == NULL) {
1371           continue;  // ignore things like evol_method
1372         }
1373         // During GC the is_alive closure is non-NULL, and is used to
1374         // determine liveness of dependees that need to be updated.
1375         if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
1376           // The GC defers deletion of this entry, since there might be multiple threads
1377           // iterating over the _dependencies graph. Other call paths are single-threaded
1378           // and may delete it immediately.
1379           bool delete_immediately = is_alive == NULL;
1380           InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
1381         }
1382       }
1383     }
1384   }
1385 }
1386 
1387 
1388 // If this oop is not live, the nmethod can be unloaded.
1389 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
1390   assert(root != NULL, "just checking");
1391   oop obj = *root;
1392   if (obj == NULL || is_alive->do_object_b(obj)) {
1393       return false;
1394   }
1395 
1396   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1397   // simply because one of its constant oops has gone dead.
1398   // No actual classes need to be unloaded in order for this to occur.
1399   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1400   make_unloaded(is_alive, obj);
1401   return true;
1402 }
1403 
1404 // ------------------------------------------------------------------
1405 // post_compiled_method_load_event
1406 // new method for install_code() path
1407 // Transfer information from compilation to jvmti
1408 void nmethod::post_compiled_method_load_event() {
1409 
1410   Method* moop = method();
1411   HOTSPOT_COMPILED_METHOD_LOAD(
1412       (char *) moop->klass_name()->bytes(),
1413       moop->klass_name()->utf8_length(),
1414       (char *) moop->name()->bytes(),
1415       moop->name()->utf8_length(),
1416       (char *) moop->signature()->bytes(),
1417       moop->signature()->utf8_length(),
1418       insts_begin(), insts_size());
1419 
1420   if (JvmtiExport::should_post_compiled_method_load() ||
1421       JvmtiExport::should_post_compiled_method_unload()) {
1422     get_and_cache_jmethod_id();
1423   }
1424 
1425   if (JvmtiExport::should_post_compiled_method_load()) {
1426     // Let the Service thread (which is a real Java thread) post the event
1427     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1428     JvmtiDeferredEventQueue::enqueue(
1429       JvmtiDeferredEvent::compiled_method_load_event(this));
1430   }
1431 }
1432 
1433 jmethodID nmethod::get_and_cache_jmethod_id() {
1434   if (_jmethod_id == NULL) {
1435     // Cache the jmethod_id since it can no longer be looked up once the
1436     // method itself has been marked for unloading.
1437     _jmethod_id = method()->jmethod_id();
1438   }
1439   return _jmethod_id;
1440 }
1441 
1442 void nmethod::post_compiled_method_unload() {
1443   if (unload_reported()) {
1444     // During unloading we transition to unloaded and then to zombie
1445     // and the unloading is reported during the first transition.
1446     return;
1447   }
1448 
1449   assert(_method != NULL && !is_unloaded(), "just checking");
1450   DTRACE_METHOD_UNLOAD_PROBE(method());
1451 
1452   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1453   // post the event. Sometime later this nmethod will be made a zombie
1454   // by the sweeper but the Method* will not be valid at that point.
1455   // If the _jmethod_id is null then no load event was ever requested
1456   // so don't bother posting the unload.  The main reason for this is
1457   // that the jmethodID is a weak reference to the Method* so if
1458   // it's being unloaded there's no way to look it up since the weak
1459   // ref will have been cleared.
1460   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1461     assert(!unload_reported(), "already unloaded");
1462     JvmtiDeferredEvent event =
1463       JvmtiDeferredEvent::compiled_method_unload_event(this,
1464           _jmethod_id, insts_begin());
1465     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1466     JvmtiDeferredEventQueue::enqueue(event);
1467   }
1468 
1469   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1470   // any time. As the nmethod is being unloaded now we mark it has
1471   // having the unload event reported - this will ensure that we don't
1472   // attempt to report the event in the unlikely scenario where the
1473   // event is enabled at the time the nmethod is made a zombie.
1474   set_unload_reported();
1475 }
1476 
1477 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
1478   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
1479 
1480   oop_Relocation* r = iter_at_oop->oop_reloc();
1481   // Traverse those oops directly embedded in the code.
1482   // Other oops (oop_index>0) are seen as part of scopes_oops.
1483   assert(1 == (r->oop_is_immediate()) +
1484          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1485          "oop must be found in exactly one place");
1486   if (r->oop_is_immediate() && r->oop_value() != NULL) {
1487     // Unload this nmethod if the oop is dead.
1488     if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1489       return true;;
1490     }
1491   }
1492 
1493   return false;
1494 }
1495 
1496 bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive, bool unloading_occurred) {
1497   // Scopes
1498   for (oop* p = oops_begin(); p < oops_end(); p++) {
1499     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1500     if (can_unload(is_alive, p, unloading_occurred)) {
1501       return true;
1502     }
1503   }
1504   return false;
1505 }
1506 
1507 bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {
1508   // Compiled code
1509   {
1510   RelocIterator iter(this, low_boundary);
1511   while (iter.next()) {
1512     if (iter.type() == relocInfo::oop_type) {
1513       if (unload_if_dead_at(&iter, is_alive, unloading_occurred)) {
1514         return true;
1515       }
1516     }
1517   }
1518   }
1519 
1520   return do_unloading_scopes(is_alive, unloading_occurred);
1521 }
1522 
1523 #if INCLUDE_JVMCI
1524 bool nmethod::do_unloading_jvmci(BoolObjectClosure* is_alive, bool unloading_occurred) {
1525   bool is_unloaded = false;
1526   // Follow JVMCI method
1527   BarrierSet* bs = Universe::heap()->barrier_set();
1528   if (_jvmci_installed_code != NULL) {
1529     if (_jvmci_installed_code->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(_jvmci_installed_code)) {
1530       if (!is_alive->do_object_b(_jvmci_installed_code)) {
1531         clear_jvmci_installed_code();
1532       }
1533     } else {
1534       if (can_unload(is_alive, (oop*)&_jvmci_installed_code, unloading_occurred)) {
1535         return true;
1536       }
1537     }
1538   }
1539 
1540   if (_speculation_log != NULL) {
1541     if (!is_alive->do_object_b(_speculation_log)) {
1542       bs->write_ref_nmethod_pre(&_speculation_log, this);
1543       _speculation_log = NULL;
1544       bs->write_ref_nmethod_post(&_speculation_log, this);
1545     }
1546   }
1547   return is_unloaded;
1548 }
1549 #endif
1550 
1551 // Iterate over metadata calling this function.   Used by RedefineClasses
1552 void nmethod::metadata_do(void f(Metadata*)) {
1553   address low_boundary = verified_entry_point();
1554   if (is_not_entrant()) {
1555     low_boundary += NativeJump::instruction_size;
1556     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1557     // (See comment above.)
1558   }
1559   {
1560     // Visit all immediate references that are embedded in the instruction stream.
1561     RelocIterator iter(this, low_boundary);
1562     while (iter.next()) {
1563       if (iter.type() == relocInfo::metadata_type ) {
1564         metadata_Relocation* r = iter.metadata_reloc();
1565         // In this metadata, we must only follow those metadatas directly embedded in
1566         // the code.  Other metadatas (oop_index>0) are seen as part of
1567         // the metadata section below.
1568         assert(1 == (r->metadata_is_immediate()) +
1569                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1570                "metadata must be found in exactly one place");
1571         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1572           Metadata* md = r->metadata_value();
1573           if (md != _method) f(md);
1574         }
1575       } else if (iter.type() == relocInfo::virtual_call_type) {
1576         // Check compiledIC holders associated with this nmethod
1577         CompiledIC *ic = CompiledIC_at(&iter);
1578         if (ic->is_icholder_call()) {
1579           CompiledICHolder* cichk = ic->cached_icholder();
1580           f(cichk->holder_method());
1581           f(cichk->holder_klass());
1582         } else {
1583           Metadata* ic_oop = ic->cached_metadata();
1584           if (ic_oop != NULL) {
1585             f(ic_oop);
1586           }
1587         }
1588       }
1589     }
1590   }
1591 
1592   // Visit the metadata section
1593   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1594     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1595     Metadata* md = *p;
1596     f(md);
1597   }
1598 
1599   // Visit metadata not embedded in the other places.
1600   if (_method != NULL) f(_method);
1601 }
1602 
1603 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1604   // make sure the oops ready to receive visitors
1605   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1606   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1607 
1608   // If the method is not entrant or zombie then a JMP is plastered over the
1609   // first few bytes.  If an oop in the old code was there, that oop
1610   // should not get GC'd.  Skip the first few bytes of oops on
1611   // not-entrant methods.
1612   address low_boundary = verified_entry_point();
1613   if (is_not_entrant()) {
1614     low_boundary += NativeJump::instruction_size;
1615     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1616     // (See comment above.)
1617   }
1618 
1619 #if INCLUDE_JVMCI
1620   if (_jvmci_installed_code != NULL) {
1621     f->do_oop((oop*) &_jvmci_installed_code);
1622   }
1623   if (_speculation_log != NULL) {
1624     f->do_oop((oop*) &_speculation_log);
1625   }
1626 #endif
1627 
1628   RelocIterator iter(this, low_boundary);
1629 
1630   while (iter.next()) {
1631     if (iter.type() == relocInfo::oop_type ) {
1632       oop_Relocation* r = iter.oop_reloc();
1633       // In this loop, we must only follow those oops directly embedded in
1634       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1635       assert(1 == (r->oop_is_immediate()) +
1636                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1637              "oop must be found in exactly one place");
1638       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1639         f->do_oop(r->oop_addr());
1640       }
1641     }
1642   }
1643 
1644   // Scopes
1645   // This includes oop constants not inlined in the code stream.
1646   for (oop* p = oops_begin(); p < oops_end(); p++) {
1647     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1648     f->do_oop(p);
1649   }
1650 }
1651 
1652 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1653 
1654 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1655 
1656 // An nmethod is "marked" if its _mark_link is set non-null.
1657 // Even if it is the end of the linked list, it will have a non-null link value,
1658 // as long as it is on the list.
1659 // This code must be MP safe, because it is used from parallel GC passes.
1660 bool nmethod::test_set_oops_do_mark() {
1661   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1662   nmethod* observed_mark_link = _oops_do_mark_link;
1663   if (observed_mark_link == NULL) {
1664     // Claim this nmethod for this thread to mark.
1665     observed_mark_link = (nmethod*)
1666       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1667     if (observed_mark_link == NULL) {
1668 
1669       // Atomically append this nmethod (now claimed) to the head of the list:
1670       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1671       for (;;) {
1672         nmethod* required_mark_nmethods = observed_mark_nmethods;
1673         _oops_do_mark_link = required_mark_nmethods;
1674         observed_mark_nmethods = (nmethod*)
1675           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1676         if (observed_mark_nmethods == required_mark_nmethods)
1677           break;
1678       }
1679       // Mark was clear when we first saw this guy.
1680       if (TraceScavenge) { print_on(tty, "oops_do, mark"); }
1681       return false;
1682     }
1683   }
1684   // On fall through, another racing thread marked this nmethod before we did.
1685   return true;
1686 }
1687 
1688 void nmethod::oops_do_marking_prologue() {
1689   if (TraceScavenge) { tty->print_cr("[oops_do_marking_prologue"); }
1690   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1691   // We use cmpxchg_ptr instead of regular assignment here because the user
1692   // may fork a bunch of threads, and we need them all to see the same state.
1693   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1694   guarantee(observed == NULL, "no races in this sequential code");
1695 }
1696 
1697 void nmethod::oops_do_marking_epilogue() {
1698   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1699   nmethod* cur = _oops_do_mark_nmethods;
1700   while (cur != NMETHOD_SENTINEL) {
1701     assert(cur != NULL, "not NULL-terminated");
1702     nmethod* next = cur->_oops_do_mark_link;
1703     cur->_oops_do_mark_link = NULL;
1704     DEBUG_ONLY(cur->verify_oop_relocations());
1705     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
1706     cur = next;
1707   }
1708   void* required = _oops_do_mark_nmethods;
1709   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1710   guarantee(observed == required, "no races in this sequential code");
1711   if (TraceScavenge) { tty->print_cr("oops_do_marking_epilogue]"); }
1712 }
1713 
1714 class DetectScavengeRoot: public OopClosure {
1715   bool     _detected_scavenge_root;
1716 public:
1717   DetectScavengeRoot() : _detected_scavenge_root(false)
1718   { NOT_PRODUCT(_print_nm = NULL); }
1719   bool detected_scavenge_root() { return _detected_scavenge_root; }
1720   virtual void do_oop(oop* p) {
1721     if ((*p) != NULL && (*p)->is_scavengable()) {
1722       NOT_PRODUCT(maybe_print(p));
1723       _detected_scavenge_root = true;
1724     }
1725   }
1726   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1727 
1728 #ifndef PRODUCT
1729   nmethod* _print_nm;
1730   void maybe_print(oop* p) {
1731     if (_print_nm == NULL)  return;
1732     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1733     tty->print_cr("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ")",
1734                   p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1735                   p2i(*p), p2i(p));
1736     (*p)->print();
1737   }
1738 #endif //PRODUCT
1739 };
1740 
1741 bool nmethod::detect_scavenge_root_oops() {
1742   DetectScavengeRoot detect_scavenge_root;
1743   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1744   oops_do(&detect_scavenge_root);
1745   return detect_scavenge_root.detected_scavenge_root();
1746 }
1747 
1748 inline bool includes(void* p, void* from, void* to) {
1749   return from <= p && p < to;
1750 }
1751 
1752 
1753 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1754   assert(count >= 2, "must be sentinel values, at least");
1755 
1756 #ifdef ASSERT
1757   // must be sorted and unique; we do a binary search in find_pc_desc()
1758   int prev_offset = pcs[0].pc_offset();
1759   assert(prev_offset == PcDesc::lower_offset_limit,
1760          "must start with a sentinel");
1761   for (int i = 1; i < count; i++) {
1762     int this_offset = pcs[i].pc_offset();
1763     assert(this_offset > prev_offset, "offsets must be sorted");
1764     prev_offset = this_offset;
1765   }
1766   assert(prev_offset == PcDesc::upper_offset_limit,
1767          "must end with a sentinel");
1768 #endif //ASSERT
1769 
1770   // Search for MethodHandle invokes and tag the nmethod.
1771   for (int i = 0; i < count; i++) {
1772     if (pcs[i].is_method_handle_invoke()) {
1773       set_has_method_handle_invokes(true);
1774       break;
1775     }
1776   }
1777   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1778 
1779   int size = count * sizeof(PcDesc);
1780   assert(scopes_pcs_size() >= size, "oob");
1781   memcpy(scopes_pcs_begin(), pcs, size);
1782 
1783   // Adjust the final sentinel downward.
1784   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1785   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1786   last_pc->set_pc_offset(content_size() + 1);
1787   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1788     // Fill any rounding gaps with copies of the last record.
1789     last_pc[1] = last_pc[0];
1790   }
1791   // The following assert could fail if sizeof(PcDesc) is not
1792   // an integral multiple of oopSize (the rounding term).
1793   // If it fails, change the logic to always allocate a multiple
1794   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1795   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1796 }
1797 
1798 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1799   assert(scopes_data_size() >= size, "oob");
1800   memcpy(scopes_data_begin(), buffer, size);
1801 }
1802 
1803 #ifdef ASSERT
1804 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1805   PcDesc* lower = search.scopes_pcs_begin();
1806   PcDesc* upper = search.scopes_pcs_end();
1807   lower += 1; // exclude initial sentinel
1808   PcDesc* res = NULL;
1809   for (PcDesc* p = lower; p < upper; p++) {
1810     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1811     if (match_desc(p, pc_offset, approximate)) {
1812       if (res == NULL)
1813         res = p;
1814       else
1815         res = (PcDesc*) badAddress;
1816     }
1817   }
1818   return res;
1819 }
1820 #endif
1821 
1822 
1823 // Finds a PcDesc with real-pc equal to "pc"
1824 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1825   address base_address = search.code_begin();
1826   if ((pc < base_address) ||
1827       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1828     return NULL;  // PC is wildly out of range
1829   }
1830   int pc_offset = (int) (pc - base_address);
1831 
1832   // Check the PcDesc cache if it contains the desired PcDesc
1833   // (This as an almost 100% hit rate.)
1834   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1835   if (res != NULL) {
1836     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1837     return res;
1838   }
1839 
1840   // Fallback algorithm: quasi-linear search for the PcDesc
1841   // Find the last pc_offset less than the given offset.
1842   // The successor must be the required match, if there is a match at all.
1843   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1844   PcDesc* lower = search.scopes_pcs_begin();
1845   PcDesc* upper = search.scopes_pcs_end();
1846   upper -= 1; // exclude final sentinel
1847   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1848 
1849 #define assert_LU_OK \
1850   /* invariant on lower..upper during the following search: */ \
1851   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1852   assert(upper->pc_offset() >= pc_offset, "sanity")
1853   assert_LU_OK;
1854 
1855   // Use the last successful return as a split point.
1856   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1857   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1858   if (mid->pc_offset() < pc_offset) {
1859     lower = mid;
1860   } else {
1861     upper = mid;
1862   }
1863 
1864   // Take giant steps at first (4096, then 256, then 16, then 1)
1865   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1866   const int RADIX = (1 << LOG2_RADIX);
1867   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1868     while ((mid = lower + step) < upper) {
1869       assert_LU_OK;
1870       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1871       if (mid->pc_offset() < pc_offset) {
1872         lower = mid;
1873       } else {
1874         upper = mid;
1875         break;
1876       }
1877     }
1878     assert_LU_OK;
1879   }
1880 
1881   // Sneak up on the value with a linear search of length ~16.
1882   while (true) {
1883     assert_LU_OK;
1884     mid = lower + 1;
1885     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1886     if (mid->pc_offset() < pc_offset) {
1887       lower = mid;
1888     } else {
1889       upper = mid;
1890       break;
1891     }
1892   }
1893 #undef assert_LU_OK
1894 
1895   if (match_desc(upper, pc_offset, approximate)) {
1896     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1897     _pc_desc_cache.add_pc_desc(upper);
1898     return upper;
1899   } else {
1900     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1901     return NULL;
1902   }
1903 }
1904 
1905 
1906 void nmethod::check_all_dependencies(DepChange& changes) {
1907   // Checked dependencies are allocated into this ResourceMark
1908   ResourceMark rm;
1909 
1910   // Turn off dependency tracing while actually testing dependencies.
1911   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1912 
1913   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1914                             &DependencySignature::equals, 11027> DepTable;
1915 
1916   DepTable* table = new DepTable();
1917 
1918   // Iterate over live nmethods and check dependencies of all nmethods that are not
1919   // marked for deoptimization. A particular dependency is only checked once.
1920   NMethodIterator iter;
1921   while(iter.next()) {
1922     nmethod* nm = iter.method();
1923     // Only notify for live nmethods
1924     if (nm->is_alive() && !nm->is_marked_for_deoptimization()) {
1925       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1926         // Construct abstraction of a dependency.
1927         DependencySignature* current_sig = new DependencySignature(deps);
1928 
1929         // Determine if dependency is already checked. table->put(...) returns
1930         // 'true' if the dependency is added (i.e., was not in the hashtable).
1931         if (table->put(*current_sig, 1)) {
1932           if (deps.check_dependency() != NULL) {
1933             // Dependency checking failed. Print out information about the failed
1934             // dependency and finally fail with an assert. We can fail here, since
1935             // dependency checking is never done in a product build.
1936             tty->print_cr("Failed dependency:");
1937             changes.print();
1938             nm->print();
1939             nm->print_dependencies();
1940             assert(false, "Should have been marked for deoptimization");
1941           }
1942         }
1943       }
1944     }
1945   }
1946 }
1947 
1948 bool nmethod::check_dependency_on(DepChange& changes) {
1949   // What has happened:
1950   // 1) a new class dependee has been added
1951   // 2) dependee and all its super classes have been marked
1952   bool found_check = false;  // set true if we are upset
1953   for (Dependencies::DepStream deps(this); deps.next(); ) {
1954     // Evaluate only relevant dependencies.
1955     if (deps.spot_check_dependency_at(changes) != NULL) {
1956       found_check = true;
1957       NOT_DEBUG(break);
1958     }
1959   }
1960   return found_check;
1961 }
1962 
1963 bool nmethod::is_evol_dependent_on(Klass* dependee) {
1964   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
1965   Array<Method*>* dependee_methods = dependee_ik->methods();
1966   for (Dependencies::DepStream deps(this); deps.next(); ) {
1967     if (deps.type() == Dependencies::evol_method) {
1968       Method* method = deps.method_argument(0);
1969       for (int j = 0; j < dependee_methods->length(); j++) {
1970         if (dependee_methods->at(j) == method) {
1971           if (log_is_enabled(Debug, redefine, class, nmethod)) {
1972             ResourceMark rm;
1973             log_debug(redefine, class, nmethod)
1974               ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
1975                _method->method_holder()->external_name(),
1976                _method->name()->as_C_string(),
1977                _method->signature()->as_C_string(),
1978                compile_id(),
1979                method->method_holder()->external_name(),
1980                method->name()->as_C_string(),
1981                method->signature()->as_C_string());
1982           }
1983           if (TraceDependencies || LogCompilation)
1984             deps.log_dependency(dependee);
1985           return true;
1986         }
1987       }
1988     }
1989   }
1990   return false;
1991 }
1992 
1993 // Called from mark_for_deoptimization, when dependee is invalidated.
1994 bool nmethod::is_dependent_on_method(Method* dependee) {
1995   for (Dependencies::DepStream deps(this); deps.next(); ) {
1996     if (deps.type() != Dependencies::evol_method)
1997       continue;
1998     Method* method = deps.method_argument(0);
1999     if (method == dependee) return true;
2000   }
2001   return false;
2002 }
2003 
2004 
2005 bool nmethod::is_patchable_at(address instr_addr) {
2006   assert(insts_contains(instr_addr), "wrong nmethod used");
2007   if (is_zombie()) {
2008     // a zombie may never be patched
2009     return false;
2010   }
2011   return true;
2012 }
2013 
2014 
2015 address nmethod::continuation_for_implicit_exception(address pc) {
2016   // Exception happened outside inline-cache check code => we are inside
2017   // an active nmethod => use cpc to determine a return address
2018   int exception_offset = pc - code_begin();
2019   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2020 #ifdef ASSERT
2021   if (cont_offset == 0) {
2022     Thread* thread = Thread::current();
2023     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2024     HandleMark hm(thread);
2025     ResourceMark rm(thread);
2026     CodeBlob* cb = CodeCache::find_blob(pc);
2027     assert(cb != NULL && cb == this, "");
2028     ttyLocker ttyl;
2029     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2030     print();
2031     method()->print_codes();
2032     print_code();
2033     print_pcs();
2034   }
2035 #endif
2036   if (cont_offset == 0) {
2037     // Let the normal error handling report the exception
2038     return NULL;
2039   }
2040   return code_begin() + cont_offset;
2041 }
2042 
2043 
2044 
2045 void nmethod_init() {
2046   // make sure you didn't forget to adjust the filler fields
2047   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2048 }
2049 
2050 
2051 //-------------------------------------------------------------------------------------------
2052 
2053 
2054 // QQQ might we make this work from a frame??
2055 nmethodLocker::nmethodLocker(address pc) {
2056   CodeBlob* cb = CodeCache::find_blob(pc);
2057   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2058   _nm = cb->as_compiled_method();
2059   lock_nmethod(_nm);
2060 }
2061 
2062 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2063 // should pass zombie_ok == true.
2064 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2065   if (cm == NULL)  return;
2066   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2067   nmethod* nm = cm->as_nmethod();
2068   Atomic::inc(&nm->_lock_count);
2069   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2070 }
2071 
2072 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2073   if (cm == NULL)  return;
2074   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2075   nmethod* nm = cm->as_nmethod();
2076   Atomic::dec(&nm->_lock_count);
2077   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2078 }
2079 
2080 
2081 // -----------------------------------------------------------------------------
2082 // Verification
2083 
2084 class VerifyOopsClosure: public OopClosure {
2085   nmethod* _nm;
2086   bool     _ok;
2087 public:
2088   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2089   bool ok() { return _ok; }
2090   virtual void do_oop(oop* p) {
2091     if ((*p) == NULL || (*p)->is_oop())  return;
2092     if (_ok) {
2093       _nm->print_nmethod(true);
2094       _ok = false;
2095     }
2096     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2097                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2098   }
2099   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2100 };
2101 
2102 void nmethod::verify() {
2103 
2104   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2105   // seems odd.
2106 
2107   if (is_zombie() || is_not_entrant() || is_unloaded())
2108     return;
2109 
2110   // Make sure all the entry points are correctly aligned for patching.
2111   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2112 
2113   // assert(method()->is_oop(), "must be valid");
2114 
2115   ResourceMark rm;
2116 
2117   if (!CodeCache::contains(this)) {
2118     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2119   }
2120 
2121   if(is_native_method() )
2122     return;
2123 
2124   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2125   if (nm != this) {
2126     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2127   }
2128 
2129   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2130     if (! p->verify(this)) {
2131       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2132     }
2133   }
2134 
2135   VerifyOopsClosure voc(this);
2136   oops_do(&voc);
2137   assert(voc.ok(), "embedded oops must be OK");
2138   verify_scavenge_root_oops();
2139 
2140   verify_scopes();
2141 }
2142 
2143 
2144 void nmethod::verify_interrupt_point(address call_site) {
2145   // Verify IC only when nmethod installation is finished.
2146   bool is_installed = (method()->code() == this) // nmethod is in state 'in_use' and installed
2147                       || !this->is_in_use();     // nmethod is installed, but not in 'in_use' state
2148   if (is_installed) {
2149     Thread *cur = Thread::current();
2150     if (CompiledIC_lock->owner() == cur ||
2151         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2152          SafepointSynchronize::is_at_safepoint())) {
2153       CompiledIC_at(this, call_site);
2154       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2155     } else {
2156       MutexLocker ml_verify (CompiledIC_lock);
2157       CompiledIC_at(this, call_site);
2158     }
2159   }
2160 
2161   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2162   assert(pd != NULL, "PcDesc must exist");
2163   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2164                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2165                                      pd->return_oop());
2166        !sd->is_top(); sd = sd->sender()) {
2167     sd->verify();
2168   }
2169 }
2170 
2171 void nmethod::verify_scopes() {
2172   if( !method() ) return;       // Runtime stubs have no scope
2173   if (method()->is_native()) return; // Ignore stub methods.
2174   // iterate through all interrupt point
2175   // and verify the debug information is valid.
2176   RelocIterator iter((nmethod*)this);
2177   while (iter.next()) {
2178     address stub = NULL;
2179     switch (iter.type()) {
2180       case relocInfo::virtual_call_type:
2181         verify_interrupt_point(iter.addr());
2182         break;
2183       case relocInfo::opt_virtual_call_type:
2184         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2185         verify_interrupt_point(iter.addr());
2186         break;
2187       case relocInfo::static_call_type:
2188         stub = iter.static_call_reloc()->static_stub(false);
2189         //verify_interrupt_point(iter.addr());
2190         break;
2191       case relocInfo::runtime_call_type:
2192       case relocInfo::runtime_call_w_cp_type: {
2193         address destination = iter.reloc()->value();
2194         // Right now there is no way to find out which entries support
2195         // an interrupt point.  It would be nice if we had this
2196         // information in a table.
2197         break;
2198       }
2199       default:
2200         break;
2201     }
2202     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2203   }
2204 }
2205 
2206 
2207 // -----------------------------------------------------------------------------
2208 // Non-product code
2209 #ifndef PRODUCT
2210 
2211 class DebugScavengeRoot: public OopClosure {
2212   nmethod* _nm;
2213   bool     _ok;
2214 public:
2215   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2216   bool ok() { return _ok; }
2217   virtual void do_oop(oop* p) {
2218     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2219     if (_ok) {
2220       _nm->print_nmethod(true);
2221       _ok = false;
2222     }
2223     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2224                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2225     (*p)->print();
2226   }
2227   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2228 };
2229 
2230 void nmethod::verify_scavenge_root_oops() {
2231   if (UseG1GC) {
2232     return;
2233   }
2234 
2235   if (!on_scavenge_root_list()) {
2236     // Actually look inside, to verify the claim that it's clean.
2237     DebugScavengeRoot debug_scavenge_root(this);
2238     oops_do(&debug_scavenge_root);
2239     if (!debug_scavenge_root.ok())
2240       fatal("found an unadvertised bad scavengable oop in the code cache");
2241   }
2242   assert(scavenge_root_not_marked(), "");
2243 }
2244 
2245 #endif // PRODUCT
2246 
2247 // Printing operations
2248 
2249 void nmethod::print() const {
2250   ResourceMark rm;
2251   ttyLocker ttyl;   // keep the following output all in one block
2252 
2253   tty->print("Compiled method ");
2254 
2255   if (is_compiled_by_c1()) {
2256     tty->print("(c1) ");
2257   } else if (is_compiled_by_c2()) {
2258     tty->print("(c2) ");
2259   } else if (is_compiled_by_shark()) {
2260     tty->print("(shark) ");
2261   } else if (is_compiled_by_jvmci()) {
2262     tty->print("(JVMCI) ");
2263   } else {
2264     tty->print("(nm) ");
2265   }
2266 
2267   print_on(tty, NULL);
2268 
2269   if (WizardMode) {
2270     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2271     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2272     tty->print(" { ");
2273     tty->print_cr("%s ", state());
2274     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2275     tty->print_cr("}:");
2276   }
2277   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2278                                               p2i(this),
2279                                               p2i(this) + size(),
2280                                               size());
2281   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2282                                               p2i(relocation_begin()),
2283                                               p2i(relocation_end()),
2284                                               relocation_size());
2285   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2286                                               p2i(consts_begin()),
2287                                               p2i(consts_end()),
2288                                               consts_size());
2289   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2290                                               p2i(insts_begin()),
2291                                               p2i(insts_end()),
2292                                               insts_size());
2293   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2294                                               p2i(stub_begin()),
2295                                               p2i(stub_end()),
2296                                               stub_size());
2297   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2298                                               p2i(oops_begin()),
2299                                               p2i(oops_end()),
2300                                               oops_size());
2301   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2302                                               p2i(metadata_begin()),
2303                                               p2i(metadata_end()),
2304                                               metadata_size());
2305   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2306                                               p2i(scopes_data_begin()),
2307                                               p2i(scopes_data_end()),
2308                                               scopes_data_size());
2309   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2310                                               p2i(scopes_pcs_begin()),
2311                                               p2i(scopes_pcs_end()),
2312                                               scopes_pcs_size());
2313   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2314                                               p2i(dependencies_begin()),
2315                                               p2i(dependencies_end()),
2316                                               dependencies_size());
2317   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2318                                               p2i(handler_table_begin()),
2319                                               p2i(handler_table_end()),
2320                                               handler_table_size());
2321   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2322                                               p2i(nul_chk_table_begin()),
2323                                               p2i(nul_chk_table_end()),
2324                                               nul_chk_table_size());
2325 }
2326 
2327 #ifndef PRODUCT
2328 
2329 void nmethod::print_scopes() {
2330   // Find the first pc desc for all scopes in the code and print it.
2331   ResourceMark rm;
2332   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2333     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2334       continue;
2335 
2336     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2337     while (sd != NULL) {
2338       sd->print_on(tty, p);
2339       sd = sd->sender();
2340     }
2341   }
2342 }
2343 
2344 void nmethod::print_dependencies() {
2345   ResourceMark rm;
2346   ttyLocker ttyl;   // keep the following output all in one block
2347   tty->print_cr("Dependencies:");
2348   for (Dependencies::DepStream deps(this); deps.next(); ) {
2349     deps.print_dependency();
2350     Klass* ctxk = deps.context_type();
2351     if (ctxk != NULL) {
2352       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2353         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2354       }
2355     }
2356     deps.log_dependency();  // put it into the xml log also
2357   }
2358 }
2359 
2360 
2361 void nmethod::print_relocations() {
2362   ResourceMark m;       // in case methods get printed via the debugger
2363   tty->print_cr("relocations:");
2364   RelocIterator iter(this);
2365   iter.print();
2366 }
2367 
2368 
2369 void nmethod::print_pcs() {
2370   ResourceMark m;       // in case methods get printed via debugger
2371   tty->print_cr("pc-bytecode offsets:");
2372   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2373     p->print(this);
2374   }
2375 }
2376 
2377 void nmethod::print_recorded_oops() {
2378   tty->print_cr("Recorded oops:");
2379   for (int i = 0; i < oops_count(); i++) {
2380     oop o = oop_at(i);
2381     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2382     if (o == (oop)Universe::non_oop_word()) {
2383       tty->print("non-oop word");
2384     } else {
2385       o->print_value();
2386     }
2387     tty->cr();
2388   }
2389 }
2390 
2391 void nmethod::print_recorded_metadata() {
2392   tty->print_cr("Recorded metadata:");
2393   for (int i = 0; i < metadata_count(); i++) {
2394     Metadata* m = metadata_at(i);
2395     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2396     if (m == (Metadata*)Universe::non_oop_word()) {
2397       tty->print("non-metadata word");
2398     } else {
2399       m->print_value_on_maybe_null(tty);
2400     }
2401     tty->cr();
2402   }
2403 }
2404 
2405 #endif // PRODUCT
2406 
2407 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2408   RelocIterator iter(this, begin, end);
2409   bool have_one = false;
2410   while (iter.next()) {
2411     have_one = true;
2412     switch (iter.type()) {
2413         case relocInfo::none:                  return "no_reloc";
2414         case relocInfo::oop_type: {
2415           stringStream st;
2416           oop_Relocation* r = iter.oop_reloc();
2417           oop obj = r->oop_value();
2418           st.print("oop(");
2419           if (obj == NULL) st.print("NULL");
2420           else obj->print_value_on(&st);
2421           st.print(")");
2422           return st.as_string();
2423         }
2424         case relocInfo::metadata_type: {
2425           stringStream st;
2426           metadata_Relocation* r = iter.metadata_reloc();
2427           Metadata* obj = r->metadata_value();
2428           st.print("metadata(");
2429           if (obj == NULL) st.print("NULL");
2430           else obj->print_value_on(&st);
2431           st.print(")");
2432           return st.as_string();
2433         }
2434         case relocInfo::runtime_call_type:
2435         case relocInfo::runtime_call_w_cp_type: {
2436           stringStream st;
2437           st.print("runtime_call");
2438           CallRelocation* r = (CallRelocation*)iter.reloc();
2439           address dest = r->destination();
2440           CodeBlob* cb = CodeCache::find_blob(dest);
2441           if (cb != NULL) {
2442             st.print(" %s", cb->name());
2443           } else {
2444             ResourceMark rm;
2445             const int buflen = 1024;
2446             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2447             int offset;
2448             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2449               st.print(" %s", buf);
2450               if (offset != 0) {
2451                 st.print("+%d", offset);
2452               }
2453             }
2454           }
2455           return st.as_string();
2456         }
2457         case relocInfo::virtual_call_type: {
2458           stringStream st;
2459           st.print_raw("virtual_call");
2460           virtual_call_Relocation* r = iter.virtual_call_reloc();
2461           Method* m = r->method_value();
2462           if (m != NULL) {
2463             assert(m->is_method(), "");
2464             m->print_short_name(&st);
2465           }
2466           return st.as_string();
2467         }
2468         case relocInfo::opt_virtual_call_type: {
2469           stringStream st;
2470           st.print_raw("optimized virtual_call");
2471           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2472           Method* m = r->method_value();
2473           if (m != NULL) {
2474             assert(m->is_method(), "");
2475             m->print_short_name(&st);
2476           }
2477           return st.as_string();
2478         }
2479         case relocInfo::static_call_type: {
2480           stringStream st;
2481           st.print_raw("static_call");
2482           static_call_Relocation* r = iter.static_call_reloc();
2483           Method* m = r->method_value();
2484           if (m != NULL) {
2485             assert(m->is_method(), "");
2486             m->print_short_name(&st);
2487           }
2488           return st.as_string();
2489         }
2490         case relocInfo::static_stub_type:      return "static_stub";
2491         case relocInfo::external_word_type:    return "external_word";
2492         case relocInfo::internal_word_type:    return "internal_word";
2493         case relocInfo::section_word_type:     return "section_word";
2494         case relocInfo::poll_type:             return "poll";
2495         case relocInfo::poll_return_type:      return "poll_return";
2496         case relocInfo::type_mask:             return "type_bit_mask";
2497 
2498         default:
2499           break;
2500     }
2501   }
2502   return have_one ? "other" : NULL;
2503 }
2504 
2505 // Return a the last scope in (begin..end]
2506 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2507   PcDesc* p = pc_desc_near(begin+1);
2508   if (p != NULL && p->real_pc(this) <= end) {
2509     return new ScopeDesc(this, p->scope_decode_offset(),
2510                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2511                          p->return_oop());
2512   }
2513   return NULL;
2514 }
2515 
2516 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2517   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2518   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2519   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2520   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2521   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2522 
2523   if (has_method_handle_invokes())
2524     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2525 
2526   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2527 
2528   if (block_begin == entry_point()) {
2529     methodHandle m = method();
2530     if (m.not_null()) {
2531       stream->print("  # ");
2532       m->print_value_on(stream);
2533       stream->cr();
2534     }
2535     if (m.not_null() && !is_osr_method()) {
2536       ResourceMark rm;
2537       int sizeargs = m->size_of_parameters();
2538       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2539       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2540       {
2541         int sig_index = 0;
2542         if (!m->is_static())
2543           sig_bt[sig_index++] = T_OBJECT; // 'this'
2544         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2545           BasicType t = ss.type();
2546           sig_bt[sig_index++] = t;
2547           if (type2size[t] == 2) {
2548             sig_bt[sig_index++] = T_VOID;
2549           } else {
2550             assert(type2size[t] == 1, "size is 1 or 2");
2551           }
2552         }
2553         assert(sig_index == sizeargs, "");
2554       }
2555       const char* spname = "sp"; // make arch-specific?
2556       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2557       int stack_slot_offset = this->frame_size() * wordSize;
2558       int tab1 = 14, tab2 = 24;
2559       int sig_index = 0;
2560       int arg_index = (m->is_static() ? 0 : -1);
2561       bool did_old_sp = false;
2562       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2563         bool at_this = (arg_index == -1);
2564         bool at_old_sp = false;
2565         BasicType t = (at_this ? T_OBJECT : ss.type());
2566         assert(t == sig_bt[sig_index], "sigs in sync");
2567         if (at_this)
2568           stream->print("  # this: ");
2569         else
2570           stream->print("  # parm%d: ", arg_index);
2571         stream->move_to(tab1);
2572         VMReg fst = regs[sig_index].first();
2573         VMReg snd = regs[sig_index].second();
2574         if (fst->is_reg()) {
2575           stream->print("%s", fst->name());
2576           if (snd->is_valid())  {
2577             stream->print(":%s", snd->name());
2578           }
2579         } else if (fst->is_stack()) {
2580           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2581           if (offset == stack_slot_offset)  at_old_sp = true;
2582           stream->print("[%s+0x%x]", spname, offset);
2583         } else {
2584           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2585         }
2586         stream->print(" ");
2587         stream->move_to(tab2);
2588         stream->print("= ");
2589         if (at_this) {
2590           m->method_holder()->print_value_on(stream);
2591         } else {
2592           bool did_name = false;
2593           if (!at_this && ss.is_object()) {
2594             Symbol* name = ss.as_symbol_or_null();
2595             if (name != NULL) {
2596               name->print_value_on(stream);
2597               did_name = true;
2598             }
2599           }
2600           if (!did_name)
2601             stream->print("%s", type2name(t));
2602         }
2603         if (at_old_sp) {
2604           stream->print("  (%s of caller)", spname);
2605           did_old_sp = true;
2606         }
2607         stream->cr();
2608         sig_index += type2size[t];
2609         arg_index += 1;
2610         if (!at_this)  ss.next();
2611       }
2612       if (!did_old_sp) {
2613         stream->print("  # ");
2614         stream->move_to(tab1);
2615         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2616         stream->print("  (%s of caller)", spname);
2617         stream->cr();
2618       }
2619     }
2620   }
2621 }
2622 
2623 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2624   // First, find an oopmap in (begin, end].
2625   // We use the odd half-closed interval so that oop maps and scope descs
2626   // which are tied to the byte after a call are printed with the call itself.
2627   address base = code_begin();
2628   ImmutableOopMapSet* oms = oop_maps();
2629   if (oms != NULL) {
2630     for (int i = 0, imax = oms->count(); i < imax; i++) {
2631       const ImmutableOopMapPair* pair = oms->pair_at(i);
2632       const ImmutableOopMap* om = pair->get_from(oms);
2633       address pc = base + pair->pc_offset();
2634       if (pc > begin) {
2635         if (pc <= end) {
2636           st->move_to(column);
2637           st->print("; ");
2638           om->print_on(st);
2639         }
2640         break;
2641       }
2642     }
2643   }
2644 
2645   // Print any debug info present at this pc.
2646   ScopeDesc* sd  = scope_desc_in(begin, end);
2647   if (sd != NULL) {
2648     st->move_to(column);
2649     if (sd->bci() == SynchronizationEntryBCI) {
2650       st->print(";*synchronization entry");
2651     } else {
2652       if (sd->method() == NULL) {
2653         st->print("method is NULL");
2654       } else if (sd->method()->is_native()) {
2655         st->print("method is native");
2656       } else {
2657         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2658         st->print(";*%s", Bytecodes::name(bc));
2659         switch (bc) {
2660         case Bytecodes::_invokevirtual:
2661         case Bytecodes::_invokespecial:
2662         case Bytecodes::_invokestatic:
2663         case Bytecodes::_invokeinterface:
2664           {
2665             Bytecode_invoke invoke(sd->method(), sd->bci());
2666             st->print(" ");
2667             if (invoke.name() != NULL)
2668               invoke.name()->print_symbol_on(st);
2669             else
2670               st->print("<UNKNOWN>");
2671             break;
2672           }
2673         case Bytecodes::_getfield:
2674         case Bytecodes::_putfield:
2675         case Bytecodes::_getstatic:
2676         case Bytecodes::_putstatic:
2677           {
2678             Bytecode_field field(sd->method(), sd->bci());
2679             st->print(" ");
2680             if (field.name() != NULL)
2681               field.name()->print_symbol_on(st);
2682             else
2683               st->print("<UNKNOWN>");
2684           }
2685         default:
2686           break;
2687         }
2688       }
2689       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2690     }
2691 
2692     // Print all scopes
2693     for (;sd != NULL; sd = sd->sender()) {
2694       st->move_to(column);
2695       st->print("; -");
2696       if (sd->method() == NULL) {
2697         st->print("method is NULL");
2698       } else {
2699         sd->method()->print_short_name(st);
2700       }
2701       int lineno = sd->method()->line_number_from_bci(sd->bci());
2702       if (lineno != -1) {
2703         st->print("@%d (line %d)", sd->bci(), lineno);
2704       } else {
2705         st->print("@%d", sd->bci());
2706       }
2707       st->cr();
2708     }
2709   }
2710 
2711   // Print relocation information
2712   const char* str = reloc_string_for(begin, end);
2713   if (str != NULL) {
2714     if (sd != NULL) st->cr();
2715     st->move_to(column);
2716     st->print(";   {%s}", str);
2717   }
2718   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2719   if (cont_offset != 0) {
2720     st->move_to(column);
2721     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2722   }
2723 
2724 }
2725 
2726 class DirectNativeCallWrapper: public NativeCallWrapper {
2727 private:
2728   NativeCall* _call;
2729 
2730 public:
2731   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2732 
2733   virtual address destination() const { return _call->destination(); }
2734   virtual address instruction_address() const { return _call->instruction_address(); }
2735   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2736   virtual address return_address() const { return _call->return_address(); }
2737 
2738   virtual address get_resolve_call_stub(bool is_optimized) const {
2739     if (is_optimized) {
2740       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2741     }
2742     return SharedRuntime::get_resolve_virtual_call_stub();
2743   }
2744 
2745   virtual void set_destination_mt_safe(address dest) {
2746 #if INCLUDE_AOT
2747     if (UseAOT) {
2748       CodeBlob* callee = CodeCache::find_blob(dest);
2749       CompiledMethod* cm = callee->as_compiled_method_or_null();
2750       if (cm != NULL && cm->is_far_code()) {
2751         // Temporary fix, see JDK-8143106
2752         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2753         csc->set_to_far(methodHandle(cm->method()), dest);
2754         return;
2755       }
2756     }
2757 #endif
2758     _call->set_destination_mt_safe(dest);
2759   }
2760 
2761   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2762     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2763 #if INCLUDE_AOT
2764     if (info.to_aot()) {
2765       csc->set_to_far(method, info.entry());
2766     } else
2767 #endif
2768     {
2769       csc->set_to_interpreted(method, info.entry());
2770     }
2771   }
2772 
2773   virtual void verify() const {
2774     // make sure code pattern is actually a call imm32 instruction
2775     _call->verify();
2776     if (os::is_MP()) {
2777       _call->verify_alignment();
2778     }
2779   }
2780 
2781   virtual void verify_resolve_call(address dest) const {
2782     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2783     assert(!db->is_adapter_blob(), "must use stub!");
2784   }
2785 
2786   virtual bool is_call_to_interpreted(address dest) const {
2787     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2788     return cb->contains(dest);
2789   }
2790 
2791   virtual bool is_safe_for_patching() const { return false; }
2792 
2793   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2794     return nativeMovConstReg_at(r->cached_value());
2795   }
2796 
2797   virtual void *get_data(NativeInstruction* instruction) const {
2798     return (void*)((NativeMovConstReg*) instruction)->data();
2799   }
2800 
2801   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2802     ((NativeMovConstReg*) instruction)->set_data(data);
2803   }
2804 };
2805 
2806 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2807   return new DirectNativeCallWrapper((NativeCall*) call);
2808 }
2809 
2810 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2811   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2812 }
2813 
2814 address nmethod::call_instruction_address(address pc) const {
2815   if (NativeCall::is_call_before(pc)) {
2816     NativeCall *ncall = nativeCall_before(pc);
2817     return ncall->instruction_address();
2818   }
2819   return NULL;
2820 }
2821 
2822 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2823   return CompiledDirectStaticCall::at(call_site);
2824 }
2825 
2826 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2827   return CompiledDirectStaticCall::at(call_site);
2828 }
2829 
2830 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2831   return CompiledDirectStaticCall::before(return_addr);
2832 }
2833 
2834 #ifndef PRODUCT
2835 
2836 void nmethod::print_value_on(outputStream* st) const {
2837   st->print("nmethod");
2838   print_on(st, NULL);
2839 }
2840 
2841 void nmethod::print_calls(outputStream* st) {
2842   RelocIterator iter(this);
2843   while (iter.next()) {
2844     switch (iter.type()) {
2845     case relocInfo::virtual_call_type:
2846     case relocInfo::opt_virtual_call_type: {
2847       VerifyMutexLocker mc(CompiledIC_lock);
2848       CompiledIC_at(&iter)->print();
2849       break;
2850     }
2851     case relocInfo::static_call_type:
2852       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2853       CompiledDirectStaticCall::at(iter.reloc())->print();
2854       break;
2855     }
2856   }
2857 }
2858 
2859 void nmethod::print_handler_table() {
2860   ExceptionHandlerTable(this).print();
2861 }
2862 
2863 void nmethod::print_nul_chk_table() {
2864   ImplicitExceptionTable(this).print(code_begin());
2865 }
2866 
2867 void nmethod::print_statistics() {
2868   ttyLocker ttyl;
2869   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2870   native_nmethod_stats.print_native_nmethod_stats();
2871 #ifdef COMPILER1
2872   c1_java_nmethod_stats.print_nmethod_stats("C1");
2873 #endif
2874 #ifdef COMPILER2
2875   c2_java_nmethod_stats.print_nmethod_stats("C2");
2876 #endif
2877 #if INCLUDE_JVMCI
2878   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2879 #endif
2880 #ifdef SHARK
2881   shark_java_nmethod_stats.print_nmethod_stats("Shark");
2882 #endif
2883   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2884   DebugInformationRecorder::print_statistics();
2885 #ifndef PRODUCT
2886   pc_nmethod_stats.print_pc_stats();
2887 #endif
2888   Dependencies::print_statistics();
2889   if (xtty != NULL)  xtty->tail("statistics");
2890 }
2891 
2892 #endif // !PRODUCT
2893 
2894 #if INCLUDE_JVMCI
2895 void nmethod::clear_jvmci_installed_code() {
2896   // write_ref_method_pre/post can only be safely called at a
2897   // safepoint or while holding the CodeCache_lock
2898   assert(CodeCache_lock->is_locked() ||
2899          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2900   if (_jvmci_installed_code != NULL) {
2901     // This must be done carefully to maintain nmethod remembered sets properly
2902     BarrierSet* bs = Universe::heap()->barrier_set();
2903     bs->write_ref_nmethod_pre(&_jvmci_installed_code, this);
2904     _jvmci_installed_code = NULL;
2905     bs->write_ref_nmethod_post(&_jvmci_installed_code, this);
2906   }
2907 }
2908 
2909 void nmethod::maybe_invalidate_installed_code() {
2910   assert(Patching_lock->is_locked() ||
2911          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2912   oop installed_code = jvmci_installed_code();
2913   if (installed_code != NULL) {
2914     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2915     if (nm == NULL || nm != this) {
2916       // The link has been broken or the InstalledCode instance is
2917       // associated with another nmethod so do nothing.
2918       return;
2919     }
2920     if (!is_alive()) {
2921       // Break the link between nmethod and InstalledCode such that the nmethod
2922       // can subsequently be flushed safely.  The link must be maintained while
2923       // the method could have live activations since invalidateInstalledCode
2924       // might want to invalidate all existing activations.
2925       InstalledCode::set_address(installed_code, 0);
2926       InstalledCode::set_entryPoint(installed_code, 0);
2927     } else if (is_not_entrant()) {
2928       // Remove the entry point so any invocation will fail but keep
2929       // the address link around that so that existing activations can
2930       // be invalidated.
2931       InstalledCode::set_entryPoint(installed_code, 0);
2932     }
2933   }
2934 }
2935 
2936 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
2937   if (installedCode() == NULL) {
2938     THROW(vmSymbols::java_lang_NullPointerException());
2939   }
2940   jlong nativeMethod = InstalledCode::address(installedCode);
2941   nmethod* nm = (nmethod*)nativeMethod;
2942   if (nm == NULL) {
2943     // Nothing to do
2944     return;
2945   }
2946 
2947   nmethodLocker nml(nm);
2948 #ifdef ASSERT
2949   {
2950     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2951     // This relationship can only be checked safely under a lock
2952     assert(nm == NULL || !nm->is_alive() || nm->jvmci_installed_code() == installedCode(), "sanity check");
2953   }
2954 #endif
2955 
2956   if (nm->is_alive()) {
2957     // The nmethod state machinery maintains the link between the
2958     // HotSpotInstalledCode and nmethod* so as long as the nmethod appears to be
2959     // alive assume there is work to do and deoptimize the nmethod.
2960     nm->mark_for_deoptimization();
2961     VM_Deoptimize op;
2962     VMThread::execute(&op);
2963   }
2964 
2965   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
2966   // Check that it's still associated with the same nmethod and break
2967   // the link if it is.
2968   if (InstalledCode::address(installedCode) == nativeMethod) {
2969     InstalledCode::set_address(installedCode, 0);
2970   }
2971 }
2972 
2973 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) {
2974   if (!this->is_compiled_by_jvmci()) {
2975     return NULL;
2976   }
2977   oop installedCode = this->jvmci_installed_code();
2978   if (installedCode != NULL) {
2979     oop installedCodeName = NULL;
2980     if (installedCode->is_a(InstalledCode::klass())) {
2981       installedCodeName = InstalledCode::name(installedCode);
2982     }
2983     if (installedCodeName != NULL) {
2984       return java_lang_String::as_utf8_string(installedCodeName, buf, (int)buflen);
2985     } else {
2986       jio_snprintf(buf, buflen, "null");
2987       return buf;
2988     }
2989   }
2990   jio_snprintf(buf, buflen, "noInstalledCode");
2991   return buf;
2992 }
2993 #endif