1 /*
   2  * Copyright (c) 1997, 2016, 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 "oops/methodData.hpp"
  40 #include "oops/oop.inline.hpp"
  41 #include "prims/jvmtiRedefineClassesTrace.hpp"
  42 #include "prims/jvmtiImpl.hpp"
  43 #include "runtime/atomic.inline.hpp"
  44 #include "runtime/orderAccess.inline.hpp"
  45 #include "runtime/os.hpp"
  46 #include "runtime/sharedRuntime.hpp"
  47 #include "runtime/sweeper.hpp"
  48 #include "utilities/resourceHash.hpp"
  49 #include "utilities/dtrace.hpp"
  50 #include "utilities/events.hpp"
  51 #include "utilities/xmlstream.hpp"
  52 #include "logging/log.hpp"
  53 #ifdef TARGET_ARCH_x86
  54 # include "nativeInst_x86.hpp"
  55 #endif
  56 #ifdef TARGET_ARCH_sparc
  57 # include "nativeInst_sparc.hpp"
  58 #endif
  59 #ifdef TARGET_ARCH_zero
  60 # include "nativeInst_zero.hpp"
  61 #endif
  62 #ifdef TARGET_ARCH_arm
  63 # include "nativeInst_arm.hpp"
  64 #endif
  65 #ifdef TARGET_ARCH_ppc
  66 # include "nativeInst_ppc.hpp"
  67 #endif
  68 #ifdef SHARK
  69 #include "shark/sharkCompiler.hpp"
  70 #endif
  71 #if INCLUDE_JVMCI
  72 #include "jvmci/jvmciJavaClasses.hpp"
  73 #endif
  74 
  75 unsigned char nmethod::_global_unloading_clock = 0;
  76 
  77 #ifdef DTRACE_ENABLED
  78 
  79 // Only bother with this argument setup if dtrace is available
  80 
  81 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  82   {                                                                       \
  83     Method* m = (method);                                                 \
  84     if (m != NULL) {                                                      \
  85       Symbol* klass_name = m->klass_name();                               \
  86       Symbol* name = m->name();                                           \
  87       Symbol* signature = m->signature();                                 \
  88       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  89         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  90         (char *) name->bytes(), name->utf8_length(),                               \
  91         (char *) signature->bytes(), signature->utf8_length());                    \
  92     }                                                                     \
  93   }
  94 
  95 #else //  ndef DTRACE_ENABLED
  96 
  97 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  98 
  99 #endif
 100 
 101 bool nmethod::is_compiled_by_c1() const {
 102   if (compiler() == NULL) {
 103     return false;
 104   }
 105   return compiler()->is_c1();
 106 }
 107 bool nmethod::is_compiled_by_jvmci() const {
 108   if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
 109   if (is_native_method()) return false;
 110   return compiler()->is_jvmci();
 111 }
 112 bool nmethod::is_compiled_by_c2() const {
 113   if (compiler() == NULL) {
 114     return false;
 115   }
 116   return compiler()->is_c2();
 117 }
 118 bool nmethod::is_compiled_by_shark() const {
 119   if (compiler() == NULL) {
 120     return false;
 121   }
 122   return compiler()->is_shark();
 123 }
 124 
 125 
 126 
 127 //---------------------------------------------------------------------------------
 128 // NMethod statistics
 129 // They are printed under various flags, including:
 130 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
 131 // (In the latter two cases, they like other stats are printed to the log only.)
 132 
 133 #ifndef PRODUCT
 134 // These variables are put into one block to reduce relocations
 135 // and make it simpler to print from the debugger.
 136 struct java_nmethod_stats_struct {
 137   int nmethod_count;
 138   int total_size;
 139   int relocation_size;
 140   int consts_size;
 141   int insts_size;
 142   int stub_size;
 143   int scopes_data_size;
 144   int scopes_pcs_size;
 145   int dependencies_size;
 146   int handler_table_size;
 147   int nul_chk_table_size;
 148   int oops_size;
 149   int metadata_size;
 150 
 151   void note_nmethod(nmethod* nm) {
 152     nmethod_count += 1;
 153     total_size          += nm->size();
 154     relocation_size     += nm->relocation_size();
 155     consts_size         += nm->consts_size();
 156     insts_size          += nm->insts_size();
 157     stub_size           += nm->stub_size();
 158     oops_size           += nm->oops_size();
 159     metadata_size       += nm->metadata_size();
 160     scopes_data_size    += nm->scopes_data_size();
 161     scopes_pcs_size     += nm->scopes_pcs_size();
 162     dependencies_size   += nm->dependencies_size();
 163     handler_table_size  += nm->handler_table_size();
 164     nul_chk_table_size  += nm->nul_chk_table_size();
 165   }
 166   void print_nmethod_stats(const char* name) {
 167     if (nmethod_count == 0)  return;
 168     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 169     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 170     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 171     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 172     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 173     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 174     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 175     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 176     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 177     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 178     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 179     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 180     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 181     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 182   }
 183 };
 184 
 185 struct native_nmethod_stats_struct {
 186   int native_nmethod_count;
 187   int native_total_size;
 188   int native_relocation_size;
 189   int native_insts_size;
 190   int native_oops_size;
 191   int native_metadata_size;
 192   void note_native_nmethod(nmethod* nm) {
 193     native_nmethod_count += 1;
 194     native_total_size       += nm->size();
 195     native_relocation_size  += nm->relocation_size();
 196     native_insts_size       += nm->insts_size();
 197     native_oops_size        += nm->oops_size();
 198     native_metadata_size    += nm->metadata_size();
 199   }
 200   void print_native_nmethod_stats() {
 201     if (native_nmethod_count == 0)  return;
 202     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 203     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 204     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 205     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 206     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 207     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 208   }
 209 };
 210 
 211 struct pc_nmethod_stats_struct {
 212   int pc_desc_resets;   // number of resets (= number of caches)
 213   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 214   int pc_desc_approx;   // number of those which have approximate true
 215   int pc_desc_repeats;  // number of _pc_descs[0] hits
 216   int pc_desc_hits;     // number of LRU cache hits
 217   int pc_desc_tests;    // total number of PcDesc examinations
 218   int pc_desc_searches; // total number of quasi-binary search steps
 219   int pc_desc_adds;     // number of LUR cache insertions
 220 
 221   void print_pc_stats() {
 222     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 223                   pc_desc_queries,
 224                   (double)(pc_desc_tests + pc_desc_searches)
 225                   / pc_desc_queries);
 226     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 227                   pc_desc_resets,
 228                   pc_desc_queries, pc_desc_approx,
 229                   pc_desc_repeats, pc_desc_hits,
 230                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 231   }
 232 };
 233 
 234 #ifdef COMPILER1
 235 static java_nmethod_stats_struct c1_java_nmethod_stats;
 236 #endif
 237 #ifdef COMPILER2
 238 static java_nmethod_stats_struct c2_java_nmethod_stats;
 239 #endif
 240 #if INCLUDE_JVMCI
 241 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 242 #endif
 243 #ifdef SHARK
 244 static java_nmethod_stats_struct shark_java_nmethod_stats;
 245 #endif
 246 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 247 
 248 static native_nmethod_stats_struct native_nmethod_stats;
 249 static pc_nmethod_stats_struct pc_nmethod_stats;
 250 
 251 static void note_java_nmethod(nmethod* nm) {
 252 #ifdef COMPILER1
 253   if (nm->is_compiled_by_c1()) {
 254     c1_java_nmethod_stats.note_nmethod(nm);
 255   } else
 256 #endif
 257 #ifdef COMPILER2
 258   if (nm->is_compiled_by_c2()) {
 259     c2_java_nmethod_stats.note_nmethod(nm);
 260   } else
 261 #endif
 262 #if INCLUDE_JVMCI
 263   if (nm->is_compiled_by_jvmci()) {
 264     jvmci_java_nmethod_stats.note_nmethod(nm);
 265   } else
 266 #endif
 267 #ifdef SHARK
 268   if (nm->is_compiled_by_shark()) {
 269     shark_java_nmethod_stats.note_nmethod(nm);
 270   } else
 271 #endif
 272   {
 273     unknown_java_nmethod_stats.note_nmethod(nm);
 274   }
 275 }
 276 #endif // !PRODUCT
 277 
 278 //---------------------------------------------------------------------------------
 279 
 280 
 281 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 282   assert(pc != NULL, "Must be non null");
 283   assert(exception.not_null(), "Must be non null");
 284   assert(handler != NULL, "Must be non null");
 285 
 286   _count = 0;
 287   _exception_type = exception->klass();
 288   _next = NULL;
 289 
 290   add_address_and_handler(pc,handler);
 291 }
 292 
 293 
 294 address ExceptionCache::match(Handle exception, address pc) {
 295   assert(pc != NULL,"Must be non null");
 296   assert(exception.not_null(),"Must be non null");
 297   if (exception->klass() == exception_type()) {
 298     return (test_address(pc));
 299   }
 300 
 301   return NULL;
 302 }
 303 
 304 
 305 bool ExceptionCache::match_exception_with_space(Handle exception) {
 306   assert(exception.not_null(),"Must be non null");
 307   if (exception->klass() == exception_type() && count() < cache_size) {
 308     return true;
 309   }
 310   return false;
 311 }
 312 
 313 
 314 address ExceptionCache::test_address(address addr) {
 315   for (int i=0; i<count(); i++) {
 316     if (pc_at(i) == addr) {
 317       return handler_at(i);
 318     }
 319   }
 320   return NULL;
 321 }
 322 
 323 
 324 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 325   if (test_address(addr) == handler) return true;
 326 
 327   int index = count();
 328   if (index < cache_size) {
 329     set_pc_at(index, addr);
 330     set_handler_at(index, handler);
 331     OrderAccess::storestore();
 332     increment_count();
 333     return true;
 334   }
 335   return false;
 336 }
 337 
 338 
 339 // private method for handling exception cache
 340 // These methods are private, and used to manipulate the exception cache
 341 // directly.
 342 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 343   ExceptionCache* ec = exception_cache();
 344   while (ec != NULL) {
 345     if (ec->match_exception_with_space(exception)) {
 346       return ec;
 347     }
 348     ec = ec->next();
 349   }
 350   return NULL;
 351 }
 352 
 353 
 354 //-----------------------------------------------------------------------------
 355 
 356 
 357 // Helper used by both find_pc_desc methods.
 358 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 359   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 360   if (!approximate)
 361     return pc->pc_offset() == pc_offset;
 362   else
 363     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 364 }
 365 
 366 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 367   if (initial_pc_desc == NULL) {
 368     _pc_descs[0] = NULL; // native method; no PcDescs at all
 369     return;
 370   }
 371   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 372   // reset the cache by filling it with benign (non-null) values
 373   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 374   for (int i = 0; i < cache_size; i++)
 375     _pc_descs[i] = initial_pc_desc;
 376 }
 377 
 378 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 379   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 380   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 381 
 382   // Note: one might think that caching the most recently
 383   // read value separately would be a win, but one would be
 384   // wrong.  When many threads are updating it, the cache
 385   // line it's in would bounce between caches, negating
 386   // any benefit.
 387 
 388   // In order to prevent race conditions do not load cache elements
 389   // repeatedly, but use a local copy:
 390   PcDesc* res;
 391 
 392   // Step one:  Check the most recently added value.
 393   res = _pc_descs[0];
 394   if (res == NULL) return NULL;  // native method; no PcDescs at all
 395   if (match_desc(res, pc_offset, approximate)) {
 396     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 397     return res;
 398   }
 399 
 400   // Step two:  Check the rest of the LRU cache.
 401   for (int i = 1; i < cache_size; ++i) {
 402     res = _pc_descs[i];
 403     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 404     if (match_desc(res, pc_offset, approximate)) {
 405       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 406       return res;
 407     }
 408   }
 409 
 410   // Report failure.
 411   return NULL;
 412 }
 413 
 414 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 415   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 416   // Update the LRU cache by shifting pc_desc forward.
 417   for (int i = 0; i < cache_size; i++)  {
 418     PcDesc* next = _pc_descs[i];
 419     _pc_descs[i] = pc_desc;
 420     pc_desc = next;
 421   }
 422 }
 423 
 424 // adjust pcs_size so that it is a multiple of both oopSize and
 425 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 426 // of oopSize, then 2*sizeof(PcDesc) is)
 427 static int adjust_pcs_size(int pcs_size) {
 428   int nsize = round_to(pcs_size,   oopSize);
 429   if ((nsize % sizeof(PcDesc)) != 0) {
 430     nsize = pcs_size + sizeof(PcDesc);
 431   }
 432   assert((nsize % oopSize) == 0, "correct alignment");
 433   return nsize;
 434 }
 435 
 436 //-----------------------------------------------------------------------------
 437 
 438 
 439 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 440   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 441   assert(new_entry != NULL,"Must be non null");
 442   assert(new_entry->next() == NULL, "Must be null");
 443 
 444   if (exception_cache() != NULL) {
 445     new_entry->set_next(exception_cache());
 446   }
 447   set_exception_cache(new_entry);
 448 }
 449 
 450 void nmethod::clean_exception_cache(BoolObjectClosure* is_alive) {
 451   ExceptionCache* prev = NULL;
 452   ExceptionCache* curr = exception_cache();
 453 
 454   while (curr != NULL) {
 455     ExceptionCache* next = curr->next();
 456 
 457     Klass* ex_klass = curr->exception_type();
 458     if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
 459       if (prev == NULL) {
 460         set_exception_cache(next);
 461       } else {
 462         prev->set_next(next);
 463       }
 464       delete curr;
 465       // prev stays the same.
 466     } else {
 467       prev = curr;
 468     }
 469 
 470     curr = next;
 471   }
 472 }
 473 
 474 // public method for accessing the exception cache
 475 // These are the public access methods.
 476 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 477   // We never grab a lock to read the exception cache, so we may
 478   // have false negatives. This is okay, as it can only happen during
 479   // the first few exception lookups for a given nmethod.
 480   ExceptionCache* ec = exception_cache();
 481   while (ec != NULL) {
 482     address ret_val;
 483     if ((ret_val = ec->match(exception,pc)) != NULL) {
 484       return ret_val;
 485     }
 486     ec = ec->next();
 487   }
 488   return NULL;
 489 }
 490 
 491 
 492 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 493   // There are potential race conditions during exception cache updates, so we
 494   // must own the ExceptionCache_lock before doing ANY modifications. Because
 495   // we don't lock during reads, it is possible to have several threads attempt
 496   // to update the cache with the same data. We need to check for already inserted
 497   // copies of the current data before adding it.
 498 
 499   MutexLocker ml(ExceptionCache_lock);
 500   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 501 
 502   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
 503     target_entry = new ExceptionCache(exception,pc,handler);
 504     add_exception_cache_entry(target_entry);
 505   }
 506 }
 507 
 508 
 509 //-------------end of code for ExceptionCache--------------
 510 
 511 
 512 int nmethod::total_size() const {
 513   return
 514     consts_size()        +
 515     insts_size()         +
 516     stub_size()          +
 517     scopes_data_size()   +
 518     scopes_pcs_size()    +
 519     handler_table_size() +
 520     nul_chk_table_size();
 521 }
 522 
 523 const char* nmethod::compile_kind() const {
 524   if (is_osr_method())     return "osr";
 525   if (method() != NULL && is_native_method())  return "c2n";
 526   return NULL;
 527 }
 528 
 529 // Fill in default values for various flag fields
 530 void nmethod::init_defaults() {
 531   _state                      = in_use;
 532   _unloading_clock            = 0;
 533   _has_flushed_dependencies   = 0;
 534   _has_unsafe_access          = 0;
 535   _has_method_handle_invokes  = 0;
 536   _lazy_critical_native       = 0;
 537   _has_wide_vectors           = 0;
 538   _mark_for_deoptimization_status = not_marked;
 539   _lock_count                 = 0;
 540   _stack_traversal_mark       = 0;
 541   _unload_reported            = false; // jvmti state
 542 
 543 #ifdef ASSERT
 544   _oops_are_stale             = false;
 545 #endif
 546 
 547   _oops_do_mark_link       = NULL;
 548   _jmethod_id              = NULL;
 549   _osr_link                = NULL;
 550   if (UseG1GC) {
 551     _unloading_next        = NULL;
 552   } else {
 553     _scavenge_root_link    = NULL;
 554   }
 555   _scavenge_root_state     = 0;
 556   _compiler                = NULL;
 557 #if INCLUDE_RTM_OPT
 558   _rtm_state               = NoRTM;
 559 #endif
 560 #if INCLUDE_JVMCI
 561   _jvmci_installed_code   = NULL;
 562   _speculation_log        = NULL;
 563 #endif
 564 }
 565 
 566 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
 567   int compile_id,
 568   CodeBuffer *code_buffer,
 569   int vep_offset,
 570   int frame_complete,
 571   int frame_size,
 572   ByteSize basic_lock_owner_sp_offset,
 573   ByteSize basic_lock_sp_offset,
 574   OopMapSet* oop_maps) {
 575   code_buffer->finalize_oop_references(method);
 576   // create nmethod
 577   nmethod* nm = NULL;
 578   {
 579     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 580     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 581     CodeOffsets offsets;
 582     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 583     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 584     nm = new (native_nmethod_size, CompLevel_none) nmethod(method(), native_nmethod_size,
 585                                             compile_id, &offsets,
 586                                             code_buffer, frame_size,
 587                                             basic_lock_owner_sp_offset,
 588                                             basic_lock_sp_offset, oop_maps);
 589     NOT_PRODUCT(if (nm != NULL)  native_nmethod_stats.note_native_nmethod(nm));
 590   }
 591   // verify nmethod
 592   debug_only(if (nm) nm->verify();) // might block
 593 
 594   if (nm != NULL) {
 595     nm->log_new_nmethod();
 596   }
 597 
 598   return nm;
 599 }
 600 
 601 nmethod* nmethod::new_nmethod(const methodHandle& method,
 602   int compile_id,
 603   int entry_bci,
 604   CodeOffsets* offsets,
 605   int orig_pc_offset,
 606   DebugInformationRecorder* debug_info,
 607   Dependencies* dependencies,
 608   CodeBuffer* code_buffer, int frame_size,
 609   OopMapSet* oop_maps,
 610   ExceptionHandlerTable* handler_table,
 611   ImplicitExceptionTable* nul_chk_table,
 612   AbstractCompiler* compiler,
 613   int comp_level
 614 #if INCLUDE_JVMCI
 615   , Handle installed_code,
 616   Handle speculationLog
 617 #endif
 618 )
 619 {
 620   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 621   code_buffer->finalize_oop_references(method);
 622   // create nmethod
 623   nmethod* nm = NULL;
 624   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 625     int nmethod_size =
 626       allocation_size(code_buffer, sizeof(nmethod))
 627       + adjust_pcs_size(debug_info->pcs_size())
 628       + round_to(dependencies->size_in_bytes() , oopSize)
 629       + round_to(handler_table->size_in_bytes(), oopSize)
 630       + round_to(nul_chk_table->size_in_bytes(), oopSize)
 631       + round_to(debug_info->data_size()       , oopSize);
 632 
 633     nm = new (nmethod_size, comp_level)
 634     nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
 635             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 636             oop_maps,
 637             handler_table,
 638             nul_chk_table,
 639             compiler,
 640             comp_level
 641 #if INCLUDE_JVMCI
 642             , installed_code,
 643             speculationLog
 644 #endif
 645             );
 646 
 647     if (nm != NULL) {
 648       // To make dependency checking during class loading fast, record
 649       // the nmethod dependencies in the classes it is dependent on.
 650       // This allows the dependency checking code to simply walk the
 651       // class hierarchy above the loaded class, checking only nmethods
 652       // which are dependent on those classes.  The slow way is to
 653       // check every nmethod for dependencies which makes it linear in
 654       // the number of methods compiled.  For applications with a lot
 655       // classes the slow way is too slow.
 656       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 657         if (deps.type() == Dependencies::call_site_target_value) {
 658           // CallSite dependencies are managed on per-CallSite instance basis.
 659           oop call_site = deps.argument_oop(0);
 660           MethodHandles::add_dependent_nmethod(call_site, nm);
 661         } else {
 662           Klass* klass = deps.context_type();
 663           if (klass == NULL) {
 664             continue;  // ignore things like evol_method
 665           }
 666           // record this nmethod as dependent on this klass
 667           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 668         }
 669       }
 670       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 671     }
 672   }
 673   // Do verification and logging outside CodeCache_lock.
 674   if (nm != NULL) {
 675     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 676     DEBUG_ONLY(nm->verify();)
 677     nm->log_new_nmethod();
 678   }
 679   return nm;
 680 }
 681 
 682 // For native wrappers
 683 nmethod::nmethod(
 684   Method* method,
 685   int nmethod_size,
 686   int compile_id,
 687   CodeOffsets* offsets,
 688   CodeBuffer* code_buffer,
 689   int frame_size,
 690   ByteSize basic_lock_owner_sp_offset,
 691   ByteSize basic_lock_sp_offset,
 692   OopMapSet* oop_maps )
 693   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
 694              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 695   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 696   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 697 {
 698   {
 699     debug_only(NoSafepointVerifier nsv;)
 700     assert_locked_or_safepoint(CodeCache_lock);
 701 
 702     init_defaults();
 703     _method                  = method;
 704     _entry_bci               = InvocationEntryBci;
 705     // We have no exception handler or deopt handler make the
 706     // values something that will never match a pc like the nmethod vtable entry
 707     _exception_offset        = 0;
 708     _deoptimize_offset       = 0;
 709     _deoptimize_mh_offset    = 0;
 710     _orig_pc_offset          = 0;
 711 
 712     _consts_offset           = data_offset();
 713     _stub_offset             = data_offset();
 714     _oops_offset             = data_offset();
 715     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
 716     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
 717     _scopes_pcs_offset       = _scopes_data_offset;
 718     _dependencies_offset     = _scopes_pcs_offset;
 719     _handler_table_offset    = _dependencies_offset;
 720     _nul_chk_table_offset    = _handler_table_offset;
 721     _nmethod_end_offset      = _nul_chk_table_offset;
 722     _compile_id              = compile_id;
 723     _comp_level              = CompLevel_none;
 724     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 725     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 726     _osr_entry_point         = NULL;
 727     _exception_cache         = NULL;
 728     _pc_desc_cache.reset_to(NULL);
 729     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 730 
 731     code_buffer->copy_values_to(this);
 732     if (ScavengeRootsInCode) {
 733       if (detect_scavenge_root_oops()) {
 734         CodeCache::add_scavenge_root_nmethod(this);
 735       }
 736       Universe::heap()->register_nmethod(this);
 737     }
 738     debug_only(verify_scavenge_root_oops());
 739     CodeCache::commit(this);
 740   }
 741 
 742   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 743     ttyLocker ttyl;  // keep the following output all in one block
 744     // This output goes directly to the tty, not the compiler log.
 745     // To enable tools to match it up with the compilation activity,
 746     // be sure to tag this tty output with the compile ID.
 747     if (xtty != NULL) {
 748       xtty->begin_head("print_native_nmethod");
 749       xtty->method(_method);
 750       xtty->stamp();
 751       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 752     }
 753     // print the header part first
 754     print();
 755     // then print the requested information
 756     if (PrintNativeNMethods) {
 757       print_code();
 758       if (oop_maps != NULL) {
 759         oop_maps->print();
 760       }
 761     }
 762     if (PrintRelocations) {
 763       print_relocations();
 764     }
 765     if (xtty != NULL) {
 766       xtty->tail("print_native_nmethod");
 767     }
 768   }
 769 }
 770 
 771 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 772   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 773 }
 774 
 775 nmethod::nmethod(
 776   Method* method,
 777   int nmethod_size,
 778   int compile_id,
 779   int entry_bci,
 780   CodeOffsets* offsets,
 781   int orig_pc_offset,
 782   DebugInformationRecorder* debug_info,
 783   Dependencies* dependencies,
 784   CodeBuffer *code_buffer,
 785   int frame_size,
 786   OopMapSet* oop_maps,
 787   ExceptionHandlerTable* handler_table,
 788   ImplicitExceptionTable* nul_chk_table,
 789   AbstractCompiler* compiler,
 790   int comp_level
 791 #if INCLUDE_JVMCI
 792   , Handle installed_code,
 793   Handle speculation_log
 794 #endif
 795   )
 796   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
 797              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 798   _native_receiver_sp_offset(in_ByteSize(-1)),
 799   _native_basic_lock_sp_offset(in_ByteSize(-1))
 800 {
 801   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 802   {
 803     debug_only(NoSafepointVerifier nsv;)
 804     assert_locked_or_safepoint(CodeCache_lock);
 805 
 806     init_defaults();
 807     _method                  = method;
 808     _entry_bci               = entry_bci;
 809     _compile_id              = compile_id;
 810     _comp_level              = comp_level;
 811     _compiler                = compiler;
 812     _orig_pc_offset          = orig_pc_offset;
 813     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 814 
 815     // Section offsets
 816     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 817     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 818 
 819 #if INCLUDE_JVMCI
 820     _jvmci_installed_code = installed_code();
 821     _speculation_log = (instanceOop)speculation_log();
 822 
 823     if (compiler->is_jvmci()) {
 824       // JVMCI might not produce any stub sections
 825       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 826         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 827       } else {
 828         _exception_offset = -1;
 829       }
 830       if (offsets->value(CodeOffsets::Deopt) != -1) {
 831         _deoptimize_offset       = code_offset()          + offsets->value(CodeOffsets::Deopt);
 832       } else {
 833         _deoptimize_offset = -1;
 834       }
 835       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 836         _deoptimize_mh_offset  = code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 837       } else {
 838         _deoptimize_mh_offset  = -1;
 839       }
 840     } else {
 841 #endif
 842     // Exception handler and deopt handler are in the stub section
 843     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 844     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 845 
 846     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 847     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
 848     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 849       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 850     } else {
 851       _deoptimize_mh_offset  = -1;
 852 #if INCLUDE_JVMCI
 853     }
 854 #endif
 855     }
 856     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 857       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 858     } else {
 859       _unwind_handler_offset = -1;
 860     }
 861 
 862     _oops_offset             = data_offset();
 863     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 864     _scopes_data_offset      = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
 865 
 866     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
 867     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 868     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
 869     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
 870     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
 871 
 872     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 873     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 874     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 875     _exception_cache         = NULL;
 876     _pc_desc_cache.reset_to(scopes_pcs_begin());
 877 
 878     // Copy contents of ScopeDescRecorder to nmethod
 879     code_buffer->copy_values_to(this);
 880     debug_info->copy_to(this);
 881     dependencies->copy_to(this);
 882     if (ScavengeRootsInCode) {
 883       if (detect_scavenge_root_oops()) {
 884         CodeCache::add_scavenge_root_nmethod(this);
 885       }
 886       Universe::heap()->register_nmethod(this);
 887     }
 888     debug_only(verify_scavenge_root_oops());
 889 
 890     CodeCache::commit(this);
 891 
 892     // Copy contents of ExceptionHandlerTable to nmethod
 893     handler_table->copy_to(this);
 894     nul_chk_table->copy_to(this);
 895 
 896     // we use the information of entry points to find out if a method is
 897     // static or non static
 898     assert(compiler->is_c2() || compiler->is_jvmci() ||
 899            _method->is_static() == (entry_point() == _verified_entry_point),
 900            " entry points must be same for static methods and vice versa");
 901   }
 902 }
 903 
 904 // Print a short set of xml attributes to identify this nmethod.  The
 905 // output should be embedded in some other element.
 906 void nmethod::log_identity(xmlStream* log) const {
 907   log->print(" compile_id='%d'", compile_id());
 908   const char* nm_kind = compile_kind();
 909   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 910   if (compiler() != NULL) {
 911     log->print(" compiler='%s'", compiler()->name());
 912   }
 913   if (TieredCompilation) {
 914     log->print(" level='%d'", comp_level());
 915   }
 916 }
 917 
 918 
 919 #define LOG_OFFSET(log, name)                    \
 920   if (p2i(name##_end()) - p2i(name##_begin())) \
 921     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 922                p2i(name##_begin()) - p2i(this))
 923 
 924 
 925 void nmethod::log_new_nmethod() const {
 926   if (LogCompilation && xtty != NULL) {
 927     ttyLocker ttyl;
 928     HandleMark hm;
 929     xtty->begin_elem("nmethod");
 930     log_identity(xtty);
 931     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 932     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 933 
 934     LOG_OFFSET(xtty, relocation);
 935     LOG_OFFSET(xtty, consts);
 936     LOG_OFFSET(xtty, insts);
 937     LOG_OFFSET(xtty, stub);
 938     LOG_OFFSET(xtty, scopes_data);
 939     LOG_OFFSET(xtty, scopes_pcs);
 940     LOG_OFFSET(xtty, dependencies);
 941     LOG_OFFSET(xtty, handler_table);
 942     LOG_OFFSET(xtty, nul_chk_table);
 943     LOG_OFFSET(xtty, oops);
 944     LOG_OFFSET(xtty, metadata);
 945 
 946     xtty->method(method());
 947     xtty->stamp();
 948     xtty->end_elem();
 949   }
 950 }
 951 
 952 #undef LOG_OFFSET
 953 
 954 
 955 // Print out more verbose output usually for a newly created nmethod.
 956 void nmethod::print_on(outputStream* st, const char* msg) const {
 957   if (st != NULL) {
 958     ttyLocker ttyl;
 959     if (WizardMode) {
 960       CompileTask::print(st, this, msg, /*short_form:*/ true);
 961       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 962     } else {
 963       CompileTask::print(st, this, msg, /*short_form:*/ false);
 964     }
 965   }
 966 }
 967 
 968 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 969   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 970   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 971     print_nmethod(printnmethods);
 972   }
 973 }
 974 
 975 void nmethod::print_nmethod(bool printmethod) {
 976   ttyLocker ttyl;  // keep the following output all in one block
 977   if (xtty != NULL) {
 978     xtty->begin_head("print_nmethod");
 979     xtty->stamp();
 980     xtty->end_head();
 981   }
 982   // print the header part first
 983   print();
 984   // then print the requested information
 985   if (printmethod) {
 986     print_code();
 987     print_pcs();
 988     if (oop_maps()) {
 989       oop_maps()->print();
 990     }
 991   }
 992   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 993     print_scopes();
 994   }
 995   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 996     print_relocations();
 997   }
 998   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 999     print_dependencies();
1000   }
1001   if (printmethod || PrintExceptionHandlers) {
1002     print_handler_table();
1003     print_nul_chk_table();
1004   }
1005   if (printmethod) {
1006     print_recorded_oops();
1007     print_recorded_metadata();
1008   }
1009   if (xtty != NULL) {
1010     xtty->tail("print_nmethod");
1011   }
1012 }
1013 
1014 
1015 // Promote one word from an assembly-time handle to a live embedded oop.
1016 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1017   if (handle == NULL ||
1018       // As a special case, IC oops are initialized to 1 or -1.
1019       handle == (jobject) Universe::non_oop_word()) {
1020     (*dest) = (oop) handle;
1021   } else {
1022     (*dest) = JNIHandles::resolve_non_null(handle);
1023   }
1024 }
1025 
1026 
1027 // Have to have the same name because it's called by a template
1028 void nmethod::copy_values(GrowableArray<jobject>* array) {
1029   int length = array->length();
1030   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
1031   oop* dest = oops_begin();
1032   for (int index = 0 ; index < length; index++) {
1033     initialize_immediate_oop(&dest[index], array->at(index));
1034   }
1035 
1036   // Now we can fix up all the oops in the code.  We need to do this
1037   // in the code because the assembler uses jobjects as placeholders.
1038   // The code and relocations have already been initialized by the
1039   // CodeBlob constructor, so it is valid even at this early point to
1040   // iterate over relocations and patch the code.
1041   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
1042 }
1043 
1044 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
1045   int length = array->length();
1046   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
1047   Metadata** dest = metadata_begin();
1048   for (int index = 0 ; index < length; index++) {
1049     dest[index] = array->at(index);
1050   }
1051 }
1052 
1053 bool nmethod::is_at_poll_return(address pc) {
1054   RelocIterator iter(this, pc, pc+1);
1055   while (iter.next()) {
1056     if (iter.type() == relocInfo::poll_return_type)
1057       return true;
1058   }
1059   return false;
1060 }
1061 
1062 
1063 bool nmethod::is_at_poll_or_poll_return(address pc) {
1064   RelocIterator iter(this, pc, pc+1);
1065   while (iter.next()) {
1066     relocInfo::relocType t = iter.type();
1067     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
1068       return true;
1069   }
1070   return false;
1071 }
1072 
1073 
1074 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1075   // re-patch all oop-bearing instructions, just in case some oops moved
1076   RelocIterator iter(this, begin, end);
1077   while (iter.next()) {
1078     if (iter.type() == relocInfo::oop_type) {
1079       oop_Relocation* reloc = iter.oop_reloc();
1080       if (initialize_immediates && reloc->oop_is_immediate()) {
1081         oop* dest = reloc->oop_addr();
1082         initialize_immediate_oop(dest, (jobject) *dest);
1083       }
1084       // Refresh the oop-related bits of this instruction.
1085       reloc->fix_oop_relocation();
1086     } else if (iter.type() == relocInfo::metadata_type) {
1087       metadata_Relocation* reloc = iter.metadata_reloc();
1088       reloc->fix_metadata_relocation();
1089     }
1090   }
1091 }
1092 
1093 
1094 void nmethod::verify_oop_relocations() {
1095   // Ensure sure that the code matches the current oop values
1096   RelocIterator iter(this, NULL, NULL);
1097   while (iter.next()) {
1098     if (iter.type() == relocInfo::oop_type) {
1099       oop_Relocation* reloc = iter.oop_reloc();
1100       if (!reloc->oop_is_immediate()) {
1101         reloc->verify_oop_relocation();
1102       }
1103     }
1104   }
1105 }
1106 
1107 
1108 ScopeDesc* nmethod::scope_desc_at(address pc) {
1109   PcDesc* pd = pc_desc_at(pc);
1110   guarantee(pd != NULL, "scope must be present");
1111   return new ScopeDesc(this, pd->scope_decode_offset(),
1112                        pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
1113                        pd->return_oop());
1114 }
1115 
1116 
1117 void nmethod::clear_inline_caches() {
1118   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
1119   if (is_zombie()) {
1120     return;
1121   }
1122 
1123   RelocIterator iter(this);
1124   while (iter.next()) {
1125     iter.reloc()->clear_inline_cache();
1126   }
1127 }
1128 
1129 // Clear ICStubs of all compiled ICs
1130 void nmethod::clear_ic_stubs() {
1131   assert_locked_or_safepoint(CompiledIC_lock);
1132   RelocIterator iter(this);
1133   while(iter.next()) {
1134     if (iter.type() == relocInfo::virtual_call_type) {
1135       CompiledIC* ic = CompiledIC_at(&iter);
1136       ic->clear_ic_stub();
1137     }
1138   }
1139 }
1140 
1141 
1142 void nmethod::cleanup_inline_caches() {
1143   assert_locked_or_safepoint(CompiledIC_lock);
1144 
1145   // If the method is not entrant or zombie then a JMP is plastered over the
1146   // first few bytes.  If an oop in the old code was there, that oop
1147   // should not get GC'd.  Skip the first few bytes of oops on
1148   // not-entrant methods.
1149   address low_boundary = verified_entry_point();
1150   if (!is_in_use()) {
1151     low_boundary += NativeJump::instruction_size;
1152     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1153     // This means that the low_boundary is going to be a little too high.
1154     // This shouldn't matter, since oops of non-entrant methods are never used.
1155     // In fact, why are we bothering to look at oops in a non-entrant method??
1156   }
1157 
1158   // Find all calls in an nmethod and clear the ones that point to non-entrant,
1159   // zombie and unloaded nmethods.
1160   ResourceMark rm;
1161   RelocIterator iter(this, low_boundary);
1162   while(iter.next()) {
1163     switch(iter.type()) {
1164       case relocInfo::virtual_call_type:
1165       case relocInfo::opt_virtual_call_type: {
1166         CompiledIC *ic = CompiledIC_at(&iter);
1167         // Ok, to lookup references to zombies here
1168         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1169         if( cb != NULL && cb->is_nmethod() ) {
1170           nmethod* nm = (nmethod*)cb;
1171           // Clean inline caches pointing to zombie, non-entrant and unloaded methods
1172           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive());
1173         }
1174         break;
1175       }
1176       case relocInfo::static_call_type: {
1177         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1178         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1179         if( cb != NULL && cb->is_nmethod() ) {
1180           nmethod* nm = (nmethod*)cb;
1181           // Clean inline caches pointing to zombie, non-entrant and unloaded methods
1182           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
1183         }
1184         break;
1185       }
1186     }
1187   }
1188 }
1189 
1190 void nmethod::verify_clean_inline_caches() {
1191   assert_locked_or_safepoint(CompiledIC_lock);
1192 
1193   // If the method is not entrant or zombie then a JMP is plastered over the
1194   // first few bytes.  If an oop in the old code was there, that oop
1195   // should not get GC'd.  Skip the first few bytes of oops on
1196   // not-entrant methods.
1197   address low_boundary = verified_entry_point();
1198   if (!is_in_use()) {
1199     low_boundary += NativeJump::instruction_size;
1200     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1201     // This means that the low_boundary is going to be a little too high.
1202     // This shouldn't matter, since oops of non-entrant methods are never used.
1203     // In fact, why are we bothering to look at oops in a non-entrant method??
1204   }
1205 
1206   ResourceMark rm;
1207   RelocIterator iter(this, low_boundary);
1208   while(iter.next()) {
1209     switch(iter.type()) {
1210       case relocInfo::virtual_call_type:
1211       case relocInfo::opt_virtual_call_type: {
1212         CompiledIC *ic = CompiledIC_at(&iter);
1213         // Ok, to lookup references to zombies here
1214         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1215         if( cb != NULL && cb->is_nmethod() ) {
1216           nmethod* nm = (nmethod*)cb;
1217           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
1218           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
1219             assert(ic->is_clean(), "IC should be clean");
1220           }
1221         }
1222         break;
1223       }
1224       case relocInfo::static_call_type: {
1225         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1226         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1227         if( cb != NULL && cb->is_nmethod() ) {
1228           nmethod* nm = (nmethod*)cb;
1229           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
1230           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
1231             assert(csc->is_clean(), "IC should be clean");
1232           }
1233         }
1234         break;
1235       }
1236     }
1237   }
1238 }
1239 
1240 int nmethod::verify_icholder_relocations() {
1241   int count = 0;
1242 
1243   RelocIterator iter(this);
1244   while(iter.next()) {
1245     if (iter.type() == relocInfo::virtual_call_type) {
1246       if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc())) {
1247         CompiledIC *ic = CompiledIC_at(&iter);
1248         if (TraceCompiledIC) {
1249           tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
1250           ic->print();
1251         }
1252         assert(ic->cached_icholder() != NULL, "must be non-NULL");
1253         count++;
1254       }
1255     }
1256   }
1257 
1258   return count;
1259 }
1260 
1261 // This is a private interface with the sweeper.
1262 void nmethod::mark_as_seen_on_stack() {
1263   assert(is_alive(), "Must be an alive method");
1264   // Set the traversal mark to ensure that the sweeper does 2
1265   // cleaning passes before moving to zombie.
1266   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1267 }
1268 
1269 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1270 // there are no activations on the stack, not in use by the VM,
1271 // and not in use by the ServiceThread)
1272 bool nmethod::can_convert_to_zombie() {
1273   assert(is_not_entrant(), "must be a non-entrant method");
1274 
1275   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1276   // count can be greater than the stack traversal count before it hits the
1277   // nmethod for the second time.
1278   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1279          !is_locked_by_vm();
1280 }
1281 
1282 void nmethod::inc_decompile_count() {
1283   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1284   // Could be gated by ProfileTraps, but do not bother...
1285   Method* m = method();
1286   if (m == NULL)  return;
1287   MethodData* mdo = m->method_data();
1288   if (mdo == NULL)  return;
1289   // There is a benign race here.  See comments in methodData.hpp.
1290   mdo->inc_decompile_count();
1291 }
1292 
1293 void nmethod::increase_unloading_clock() {
1294   _global_unloading_clock++;
1295   if (_global_unloading_clock == 0) {
1296     // _nmethods are allocated with _unloading_clock == 0,
1297     // so 0 is never used as a clock value.
1298     _global_unloading_clock = 1;
1299   }
1300 }
1301 
1302 void nmethod::set_unloading_clock(unsigned char unloading_clock) {
1303   OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock);
1304 }
1305 
1306 unsigned char nmethod::unloading_clock() {
1307   return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock);
1308 }
1309 
1310 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1311 
1312   post_compiled_method_unload();
1313 
1314   // Since this nmethod is being unloaded, make sure that dependencies
1315   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1316   // indicate that this work is being done during a GC.
1317   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1318   assert(is_alive != NULL, "Should be non-NULL");
1319   // A non-NULL is_alive closure indicates that this is being called during GC.
1320   flush_dependencies(is_alive);
1321 
1322   // Break cycle between nmethod & method
1323   if (log_is_enabled(Trace, classunload)) {
1324     outputStream* log = LogHandle(classunload)::trace_stream();
1325     log->print_cr("making nmethod " INTPTR_FORMAT
1326                   " unloadable, Method*(" INTPTR_FORMAT
1327                   "), cause(" INTPTR_FORMAT ")",
1328                   p2i(this), p2i(_method), p2i(cause));
1329     if (!Universe::heap()->is_gc_active())
1330       cause->klass()->print_on(log);
1331   }
1332   // Unlink the osr method, so we do not look this up again
1333   if (is_osr_method()) {
1334     // Invalidate the osr nmethod only once
1335     if (is_in_use()) {
1336       invalidate_osr_method();
1337     }
1338 #ifdef ASSERT
1339     if (method() != NULL) {
1340       // Make sure osr nmethod is invalidated, i.e. not on the list
1341       bool found = method()->method_holder()->remove_osr_nmethod(this);
1342       assert(!found, "osr nmethod should have been invalidated");
1343     }
1344 #endif
1345   }
1346 
1347   // If _method is already NULL the Method* is about to be unloaded,
1348   // so we don't have to break the cycle. Note that it is possible to
1349   // have the Method* live here, in case we unload the nmethod because
1350   // it is pointing to some oop (other than the Method*) being unloaded.
1351   if (_method != NULL) {
1352     // OSR methods point to the Method*, but the Method* does not
1353     // point back!
1354     if (_method->code() == this) {
1355       _method->clear_code(); // Break a cycle
1356     }
1357     _method = NULL;            // Clear the method of this dead nmethod
1358   }
1359 
1360   // Make the class unloaded - i.e., change state and notify sweeper
1361   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1362   if (is_in_use()) {
1363     // Transitioning directly from live to unloaded -- so
1364     // we need to force a cache clean-up; remember this
1365     // for later on.
1366     CodeCache::set_needs_cache_clean(true);
1367   }
1368 
1369   // Unregister must be done before the state change
1370   Universe::heap()->unregister_nmethod(this);
1371 
1372   _state = unloaded;
1373 
1374   // Log the unloading.
1375   log_state_change();
1376 
1377 #if INCLUDE_JVMCI
1378   // The method can only be unloaded after the pointer to the installed code
1379   // Java wrapper is no longer alive. Here we need to clear out this weak
1380   // reference to the dead object. Nulling out the reference has to happen
1381   // after the method is unregistered since the original value may be still
1382   // tracked by the rset.
1383   maybe_invalidate_installed_code();
1384   // Clear these out after the nmethod has been unregistered and any
1385   // updates to the InstalledCode instance have been performed.
1386   _jvmci_installed_code = NULL;
1387   _speculation_log = NULL;
1388 #endif
1389 
1390   // The Method* is gone at this point
1391   assert(_method == NULL, "Tautology");
1392 
1393   set_osr_link(NULL);
1394   NMethodSweeper::report_state_change(this);
1395 }
1396 
1397 void nmethod::invalidate_osr_method() {
1398   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1399   // Remove from list of active nmethods
1400   if (method() != NULL) {
1401     method()->method_holder()->remove_osr_nmethod(this);
1402   }
1403 }
1404 
1405 void nmethod::log_state_change() const {
1406   if (LogCompilation) {
1407     if (xtty != NULL) {
1408       ttyLocker ttyl;  // keep the following output all in one block
1409       if (_state == unloaded) {
1410         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1411                          os::current_thread_id());
1412       } else {
1413         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1414                          os::current_thread_id(),
1415                          (_state == zombie ? " zombie='1'" : ""));
1416       }
1417       log_identity(xtty);
1418       xtty->stamp();
1419       xtty->end_elem();
1420     }
1421   }
1422   if (PrintCompilation && _state != unloaded) {
1423     print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
1424   }
1425 }
1426 
1427 /**
1428  * Common functionality for both make_not_entrant and make_zombie
1429  */
1430 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1431   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1432   assert(!is_zombie(), "should not already be a zombie");
1433 
1434   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1435   nmethodLocker nml(this);
1436   methodHandle the_method(method());
1437   NoSafepointVerifier nsv;
1438 
1439   // during patching, depending on the nmethod state we must notify the GC that
1440   // code has been unloaded, unregistering it. We cannot do this right while
1441   // holding the Patching_lock because we need to use the CodeCache_lock. This
1442   // would be prone to deadlocks.
1443   // This flag is used to remember whether we need to later lock and unregister.
1444   bool nmethod_needs_unregister = false;
1445 
1446   {
1447     // invalidate osr nmethod before acquiring the patching lock since
1448     // they both acquire leaf locks and we don't want a deadlock.
1449     // This logic is equivalent to the logic below for patching the
1450     // verified entry point of regular methods. We check that the
1451     // nmethod is in use to ensure that it is invalidated only once.
1452     if (is_osr_method() && is_in_use()) {
1453       // this effectively makes the osr nmethod not entrant
1454       invalidate_osr_method();
1455     }
1456 
1457     // Enter critical section.  Does not block for safepoint.
1458     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1459 
1460     if (_state == state) {
1461       // another thread already performed this transition so nothing
1462       // to do, but return false to indicate this.
1463       return false;
1464     }
1465 
1466     // The caller can be calling the method statically or through an inline
1467     // cache call.
1468     if (!is_osr_method() && !is_not_entrant()) {
1469       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1470                   SharedRuntime::get_handle_wrong_method_stub());
1471     }
1472 
1473     if (is_in_use() && update_recompile_counts()) {
1474       // It's a true state change, so mark the method as decompiled.
1475       // Do it only for transition from alive.
1476       inc_decompile_count();
1477     }
1478 
1479     // If the state is becoming a zombie, signal to unregister the nmethod with
1480     // the heap.
1481     // This nmethod may have already been unloaded during a full GC.
1482     if ((state == zombie) && !is_unloaded()) {
1483       nmethod_needs_unregister = true;
1484     }
1485 
1486     // Must happen before state change. Otherwise we have a race condition in
1487     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1488     // transition its state from 'not_entrant' to 'zombie' without having to wait
1489     // for stack scanning.
1490     if (state == not_entrant) {
1491       mark_as_seen_on_stack();
1492       OrderAccess::storestore();
1493     }
1494 
1495     // Change state
1496     _state = state;
1497 
1498     // Log the transition once
1499     log_state_change();
1500 
1501     // Invalidate while holding the patching lock
1502     JVMCI_ONLY(maybe_invalidate_installed_code());
1503 
1504     // Remove nmethod from method.
1505     // We need to check if both the _code and _from_compiled_code_entry_point
1506     // refer to this nmethod because there is a race in setting these two fields
1507     // in Method* as seen in bugid 4947125.
1508     // If the vep() points to the zombie nmethod, the memory for the nmethod
1509     // could be flushed and the compiler and vtable stubs could still call
1510     // through it.
1511     if (method() != NULL && (method()->code() == this ||
1512                              method()->from_compiled_entry() == verified_entry_point())) {
1513       HandleMark hm;
1514       method()->clear_code();
1515     }
1516   } // leave critical region under Patching_lock
1517 
1518 #ifdef ASSERT
1519   if (is_osr_method() && method() != NULL) {
1520     // Make sure osr nmethod is invalidated, i.e. not on the list
1521     bool found = method()->method_holder()->remove_osr_nmethod(this);
1522     assert(!found, "osr nmethod should have been invalidated");
1523   }
1524 #endif
1525 
1526   // When the nmethod becomes zombie it is no longer alive so the
1527   // dependencies must be flushed.  nmethods in the not_entrant
1528   // state will be flushed later when the transition to zombie
1529   // happens or they get unloaded.
1530   if (state == zombie) {
1531     {
1532       // Flushing dependencies must be done before any possible
1533       // safepoint can sneak in, otherwise the oops used by the
1534       // dependency logic could have become stale.
1535       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1536       if (nmethod_needs_unregister) {
1537         Universe::heap()->unregister_nmethod(this);
1538 #ifdef JVMCI
1539         _jvmci_installed_code = NULL;
1540         _speculation_log = NULL;
1541 #endif
1542       }
1543       flush_dependencies(NULL);
1544     }
1545 
1546     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1547     // event and it hasn't already been reported for this nmethod then
1548     // report it now. The event may have been reported earlier if the GC
1549     // marked it for unloading). JvmtiDeferredEventQueue support means
1550     // we no longer go to a safepoint here.
1551     post_compiled_method_unload();
1552 
1553 #ifdef ASSERT
1554     // It's no longer safe to access the oops section since zombie
1555     // nmethods aren't scanned for GC.
1556     _oops_are_stale = true;
1557 #endif
1558      // the Method may be reclaimed by class unloading now that the
1559      // nmethod is in zombie state
1560     set_method(NULL);
1561   } else {
1562     assert(state == not_entrant, "other cases may need to be handled differently");
1563   }
1564 
1565   if (TraceCreateZombies) {
1566     ResourceMark m;
1567     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");
1568   }
1569 
1570   NMethodSweeper::report_state_change(this);
1571   return true;
1572 }
1573 
1574 void nmethod::flush() {
1575   // Note that there are no valid oops in the nmethod anymore.
1576   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1577          "osr nmethod must be unloaded or zombie before flushing");
1578   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1579   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1580   assert_locked_or_safepoint(CodeCache_lock);
1581 
1582   // completely deallocate this method
1583   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1584   if (PrintMethodFlushing) {
1585     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1586                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1587                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1588                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1589   }
1590 
1591   // We need to deallocate any ExceptionCache data.
1592   // Note that we do not need to grab the nmethod lock for this, it
1593   // better be thread safe if we're disposing of it!
1594   ExceptionCache* ec = exception_cache();
1595   set_exception_cache(NULL);
1596   while(ec != NULL) {
1597     ExceptionCache* next = ec->next();
1598     delete ec;
1599     ec = next;
1600   }
1601 
1602   if (on_scavenge_root_list()) {
1603     CodeCache::drop_scavenge_root_nmethod(this);
1604   }
1605 
1606 #ifdef SHARK
1607   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1608 #endif // SHARK
1609 
1610   ((CodeBlob*)(this))->flush();
1611 
1612   CodeCache::free(this);
1613 }
1614 
1615 //
1616 // Notify all classes this nmethod is dependent on that it is no
1617 // longer dependent. This should only be called in two situations.
1618 // First, when a nmethod transitions to a zombie all dependents need
1619 // to be clear.  Since zombification happens at a safepoint there's no
1620 // synchronization issues.  The second place is a little more tricky.
1621 // During phase 1 of mark sweep class unloading may happen and as a
1622 // result some nmethods may get unloaded.  In this case the flushing
1623 // of dependencies must happen during phase 1 since after GC any
1624 // dependencies in the unloaded nmethod won't be updated, so
1625 // traversing the dependency information in unsafe.  In that case this
1626 // function is called with a non-NULL argument and this function only
1627 // notifies instanceKlasses that are reachable
1628 
1629 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1630   assert_locked_or_safepoint(CodeCache_lock);
1631   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1632   "is_alive is non-NULL if and only if we are called during GC");
1633   if (!has_flushed_dependencies()) {
1634     set_has_flushed_dependencies();
1635     for (Dependencies::DepStream deps(this); deps.next(); ) {
1636       if (deps.type() == Dependencies::call_site_target_value) {
1637         // CallSite dependencies are managed on per-CallSite instance basis.
1638         oop call_site = deps.argument_oop(0);
1639         MethodHandles::remove_dependent_nmethod(call_site, this);
1640       } else {
1641         Klass* klass = deps.context_type();
1642         if (klass == NULL) {
1643           continue;  // ignore things like evol_method
1644         }
1645         // During GC the is_alive closure is non-NULL, and is used to
1646         // determine liveness of dependees that need to be updated.
1647         if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
1648           // The GC defers deletion of this entry, since there might be multiple threads
1649           // iterating over the _dependencies graph. Other call paths are single-threaded
1650           // and may delete it immediately.
1651           bool delete_immediately = is_alive == NULL;
1652           InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
1653         }
1654       }
1655     }
1656   }
1657 }
1658 
1659 
1660 // If this oop is not live, the nmethod can be unloaded.
1661 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
1662   assert(root != NULL, "just checking");
1663   oop obj = *root;
1664   if (obj == NULL || is_alive->do_object_b(obj)) {
1665       return false;
1666   }
1667 
1668   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1669   // simply because one of its constant oops has gone dead.
1670   // No actual classes need to be unloaded in order for this to occur.
1671   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1672   make_unloaded(is_alive, obj);
1673   return true;
1674 }
1675 
1676 // ------------------------------------------------------------------
1677 // post_compiled_method_load_event
1678 // new method for install_code() path
1679 // Transfer information from compilation to jvmti
1680 void nmethod::post_compiled_method_load_event() {
1681 
1682   Method* moop = method();
1683   HOTSPOT_COMPILED_METHOD_LOAD(
1684       (char *) moop->klass_name()->bytes(),
1685       moop->klass_name()->utf8_length(),
1686       (char *) moop->name()->bytes(),
1687       moop->name()->utf8_length(),
1688       (char *) moop->signature()->bytes(),
1689       moop->signature()->utf8_length(),
1690       insts_begin(), insts_size());
1691 
1692   if (JvmtiExport::should_post_compiled_method_load() ||
1693       JvmtiExport::should_post_compiled_method_unload()) {
1694     get_and_cache_jmethod_id();
1695   }
1696 
1697   if (JvmtiExport::should_post_compiled_method_load()) {
1698     // Let the Service thread (which is a real Java thread) post the event
1699     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1700     JvmtiDeferredEventQueue::enqueue(
1701       JvmtiDeferredEvent::compiled_method_load_event(this));
1702   }
1703 }
1704 
1705 jmethodID nmethod::get_and_cache_jmethod_id() {
1706   if (_jmethod_id == NULL) {
1707     // Cache the jmethod_id since it can no longer be looked up once the
1708     // method itself has been marked for unloading.
1709     _jmethod_id = method()->jmethod_id();
1710   }
1711   return _jmethod_id;
1712 }
1713 
1714 void nmethod::post_compiled_method_unload() {
1715   if (unload_reported()) {
1716     // During unloading we transition to unloaded and then to zombie
1717     // and the unloading is reported during the first transition.
1718     return;
1719   }
1720 
1721   assert(_method != NULL && !is_unloaded(), "just checking");
1722   DTRACE_METHOD_UNLOAD_PROBE(method());
1723 
1724   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1725   // post the event. Sometime later this nmethod will be made a zombie
1726   // by the sweeper but the Method* will not be valid at that point.
1727   // If the _jmethod_id is null then no load event was ever requested
1728   // so don't bother posting the unload.  The main reason for this is
1729   // that the jmethodID is a weak reference to the Method* so if
1730   // it's being unloaded there's no way to look it up since the weak
1731   // ref will have been cleared.
1732   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1733     assert(!unload_reported(), "already unloaded");
1734     JvmtiDeferredEvent event =
1735       JvmtiDeferredEvent::compiled_method_unload_event(this,
1736           _jmethod_id, insts_begin());
1737     if (SafepointSynchronize::is_at_safepoint()) {
1738       // Don't want to take the queueing lock. Add it as pending and
1739       // it will get enqueued later.
1740       JvmtiDeferredEventQueue::add_pending_event(event);
1741     } else {
1742       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1743       JvmtiDeferredEventQueue::enqueue(event);
1744     }
1745   }
1746 
1747   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1748   // any time. As the nmethod is being unloaded now we mark it has
1749   // having the unload event reported - this will ensure that we don't
1750   // attempt to report the event in the unlikely scenario where the
1751   // event is enabled at the time the nmethod is made a zombie.
1752   set_unload_reported();
1753 }
1754 
1755 void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
1756   if (ic->is_icholder_call()) {
1757     // The only exception is compiledICHolder oops which may
1758     // yet be marked below. (We check this further below).
1759     CompiledICHolder* cichk_oop = ic->cached_icholder();
1760 
1761     if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
1762         cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
1763       return;
1764     }
1765   } else {
1766     Metadata* ic_oop = ic->cached_metadata();
1767     if (ic_oop != NULL) {
1768       if (ic_oop->is_klass()) {
1769         if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
1770           return;
1771         }
1772       } else if (ic_oop->is_method()) {
1773         if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
1774           return;
1775         }
1776       } else {
1777         ShouldNotReachHere();
1778       }
1779     }
1780   }
1781 
1782   ic->set_to_clean();
1783 }
1784 
1785 // This is called at the end of the strong tracing/marking phase of a
1786 // GC to unload an nmethod if it contains otherwise unreachable
1787 // oops.
1788 
1789 void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
1790   // Make sure the oop's ready to receive visitors
1791   assert(!is_zombie() && !is_unloaded(),
1792          "should not call follow on zombie or unloaded nmethod");
1793 
1794   // If the method is not entrant then a JMP is plastered over the
1795   // first few bytes.  If an oop in the old code was there, that oop
1796   // should not get GC'd.  Skip the first few bytes of oops on
1797   // not-entrant methods.
1798   address low_boundary = verified_entry_point();
1799   if (is_not_entrant()) {
1800     low_boundary += NativeJump::instruction_size;
1801     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1802     // (See comment above.)
1803   }
1804 
1805   // The RedefineClasses() API can cause the class unloading invariant
1806   // to no longer be true. See jvmtiExport.hpp for details.
1807   // Also, leave a debugging breadcrumb in local flag.
1808   if (JvmtiExport::has_redefined_a_class()) {
1809     // This set of the unloading_occurred flag is done before the
1810     // call to post_compiled_method_unload() so that the unloading
1811     // of this nmethod is reported.
1812     unloading_occurred = true;
1813   }
1814 
1815   // Exception cache
1816   clean_exception_cache(is_alive);
1817 
1818   // If class unloading occurred we first iterate over all inline caches and
1819   // clear ICs where the cached oop is referring to an unloaded klass or method.
1820   // The remaining live cached oops will be traversed in the relocInfo::oop_type
1821   // iteration below.
1822   if (unloading_occurred) {
1823     RelocIterator iter(this, low_boundary);
1824     while(iter.next()) {
1825       if (iter.type() == relocInfo::virtual_call_type) {
1826         CompiledIC *ic = CompiledIC_at(&iter);
1827         clean_ic_if_metadata_is_dead(ic, is_alive);
1828       }
1829     }
1830   }
1831 
1832   // Compiled code
1833   {
1834   RelocIterator iter(this, low_boundary);
1835   while (iter.next()) {
1836     if (iter.type() == relocInfo::oop_type) {
1837       oop_Relocation* r = iter.oop_reloc();
1838       // In this loop, we must only traverse those oops directly embedded in
1839       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1840       assert(1 == (r->oop_is_immediate()) +
1841                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1842              "oop must be found in exactly one place");
1843       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1844         if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1845           return;
1846         }
1847       }
1848     }
1849   }
1850   }
1851 
1852 
1853   // Scopes
1854   for (oop* p = oops_begin(); p < oops_end(); p++) {
1855     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1856     if (can_unload(is_alive, p, unloading_occurred)) {
1857       return;
1858     }
1859   }
1860 
1861 #if INCLUDE_JVMCI
1862   // Follow JVMCI method
1863   BarrierSet* bs = Universe::heap()->barrier_set();
1864   if (_jvmci_installed_code != NULL) {
1865     if (_jvmci_installed_code->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(_jvmci_installed_code)) {
1866       if (!is_alive->do_object_b(_jvmci_installed_code)) {
1867         clear_jvmci_installed_code();
1868       }
1869     } else {
1870       if (can_unload(is_alive, (oop*)&_jvmci_installed_code, unloading_occurred)) {
1871         return;
1872       }
1873     }
1874   }
1875 
1876   if (_speculation_log != NULL) {
1877     if (!is_alive->do_object_b(_speculation_log)) {
1878       bs->write_ref_nmethod_pre(&_speculation_log, this);
1879       _speculation_log = NULL;
1880       bs->write_ref_nmethod_post(&_speculation_log, this);
1881     }
1882   }
1883 #endif
1884 
1885 
1886   // Ensure that all metadata is still alive
1887   verify_metadata_loaders(low_boundary, is_alive);
1888 }
1889 
1890 template <class CompiledICorStaticCall>
1891 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, nmethod* from) {
1892   // Ok, to lookup references to zombies here
1893   CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
1894   if (cb != NULL && cb->is_nmethod()) {
1895     nmethod* nm = (nmethod*)cb;
1896 
1897     if (nm->unloading_clock() != nmethod::global_unloading_clock()) {
1898       // The nmethod has not been processed yet.
1899       return true;
1900     }
1901 
1902     // Clean inline caches pointing to both zombie and not_entrant methods
1903     if (!nm->is_in_use() || (nm->method()->code() != nm)) {
1904       ic->set_to_clean();
1905       assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string());
1906     }
1907   }
1908 
1909   return false;
1910 }
1911 
1912 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, nmethod* from) {
1913   return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
1914 }
1915 
1916 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, nmethod* from) {
1917   return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
1918 }
1919 
1920 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
1921   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
1922 
1923   oop_Relocation* r = iter_at_oop->oop_reloc();
1924   // Traverse those oops directly embedded in the code.
1925   // Other oops (oop_index>0) are seen as part of scopes_oops.
1926   assert(1 == (r->oop_is_immediate()) +
1927          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1928          "oop must be found in exactly one place");
1929   if (r->oop_is_immediate() && r->oop_value() != NULL) {
1930     // Unload this nmethod if the oop is dead.
1931     if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1932       return true;;
1933     }
1934   }
1935 
1936   return false;
1937 }
1938 
1939 
1940 bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
1941   ResourceMark rm;
1942 
1943   // Make sure the oop's ready to receive visitors
1944   assert(!is_zombie() && !is_unloaded(),
1945          "should not call follow on zombie or unloaded nmethod");
1946 
1947   // If the method is not entrant then a JMP is plastered over the
1948   // first few bytes.  If an oop in the old code was there, that oop
1949   // should not get GC'd.  Skip the first few bytes of oops on
1950   // not-entrant methods.
1951   address low_boundary = verified_entry_point();
1952   if (is_not_entrant()) {
1953     low_boundary += NativeJump::instruction_size;
1954     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1955     // (See comment above.)
1956   }
1957 
1958   // The RedefineClasses() API can cause the class unloading invariant
1959   // to no longer be true. See jvmtiExport.hpp for details.
1960   // Also, leave a debugging breadcrumb in local flag.
1961   if (JvmtiExport::has_redefined_a_class()) {
1962     // This set of the unloading_occurred flag is done before the
1963     // call to post_compiled_method_unload() so that the unloading
1964     // of this nmethod is reported.
1965     unloading_occurred = true;
1966   }
1967 
1968   // Exception cache
1969   clean_exception_cache(is_alive);
1970 
1971   bool is_unloaded = false;
1972   bool postponed = false;
1973 
1974   RelocIterator iter(this, low_boundary);
1975   while(iter.next()) {
1976 
1977     switch (iter.type()) {
1978 
1979     case relocInfo::virtual_call_type:
1980       if (unloading_occurred) {
1981         // If class unloading occurred we first iterate over all inline caches and
1982         // clear ICs where the cached oop is referring to an unloaded klass or method.
1983         clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
1984       }
1985 
1986       postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
1987       break;
1988 
1989     case relocInfo::opt_virtual_call_type:
1990       postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
1991       break;
1992 
1993     case relocInfo::static_call_type:
1994       postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
1995       break;
1996 
1997     case relocInfo::oop_type:
1998       if (!is_unloaded) {
1999         is_unloaded = unload_if_dead_at(&iter, is_alive, unloading_occurred);
2000       }
2001       break;
2002 
2003     case relocInfo::metadata_type:
2004       break; // nothing to do.
2005     }
2006   }
2007 
2008   if (is_unloaded) {
2009     return postponed;
2010   }
2011 
2012   // Scopes
2013   for (oop* p = oops_begin(); p < oops_end(); p++) {
2014     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
2015     if (can_unload(is_alive, p, unloading_occurred)) {
2016       is_unloaded = true;
2017       break;
2018     }
2019   }
2020 
2021   if (is_unloaded) {
2022     return postponed;
2023   }
2024 
2025 #if INCLUDE_JVMCI
2026   // Follow JVMCI method
2027   BarrierSet* bs = Universe::heap()->barrier_set();
2028   if (_jvmci_installed_code != NULL) {
2029     if (_jvmci_installed_code->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(_jvmci_installed_code)) {
2030       if (!is_alive->do_object_b(_jvmci_installed_code)) {
2031         clear_jvmci_installed_code();
2032       }
2033     } else {
2034       if (can_unload(is_alive, (oop*)&_jvmci_installed_code, unloading_occurred)) {
2035         is_unloaded = true;
2036       }
2037     }
2038   }
2039 
2040   if (_speculation_log != NULL) {
2041     if (!is_alive->do_object_b(_speculation_log)) {
2042       bs->write_ref_nmethod_pre(&_speculation_log, this);
2043       _speculation_log = NULL;
2044       bs->write_ref_nmethod_post(&_speculation_log, this);
2045     }
2046   }
2047 #endif
2048 
2049   // Ensure that all metadata is still alive
2050   verify_metadata_loaders(low_boundary, is_alive);
2051 
2052   return postponed;
2053 }
2054 
2055 void nmethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
2056   ResourceMark rm;
2057 
2058   // Make sure the oop's ready to receive visitors
2059   assert(!is_zombie(),
2060          "should not call follow on zombie nmethod");
2061 
2062   // If the method is not entrant then a JMP is plastered over the
2063   // first few bytes.  If an oop in the old code was there, that oop
2064   // should not get GC'd.  Skip the first few bytes of oops on
2065   // not-entrant methods.
2066   address low_boundary = verified_entry_point();
2067   if (is_not_entrant()) {
2068     low_boundary += NativeJump::instruction_size;
2069     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
2070     // (See comment above.)
2071   }
2072 
2073   RelocIterator iter(this, low_boundary);
2074   while(iter.next()) {
2075 
2076     switch (iter.type()) {
2077 
2078     case relocInfo::virtual_call_type:
2079       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
2080       break;
2081 
2082     case relocInfo::opt_virtual_call_type:
2083       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
2084       break;
2085 
2086     case relocInfo::static_call_type:
2087       clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
2088       break;
2089     }
2090   }
2091 }
2092 
2093 #ifdef ASSERT
2094 
2095 class CheckClass : AllStatic {
2096   static BoolObjectClosure* _is_alive;
2097 
2098   // Check class_loader is alive for this bit of metadata.
2099   static void check_class(Metadata* md) {
2100     Klass* klass = NULL;
2101     if (md->is_klass()) {
2102       klass = ((Klass*)md);
2103     } else if (md->is_method()) {
2104       klass = ((Method*)md)->method_holder();
2105     } else if (md->is_methodData()) {
2106       klass = ((MethodData*)md)->method()->method_holder();
2107     } else {
2108       md->print();
2109       ShouldNotReachHere();
2110     }
2111     assert(klass->is_loader_alive(_is_alive), "must be alive");
2112   }
2113  public:
2114   static void do_check_class(BoolObjectClosure* is_alive, nmethod* nm) {
2115     assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
2116     _is_alive = is_alive;
2117     nm->metadata_do(check_class);
2118   }
2119 };
2120 
2121 // This is called during a safepoint so can use static data
2122 BoolObjectClosure* CheckClass::_is_alive = NULL;
2123 #endif // ASSERT
2124 
2125 
2126 // Processing of oop references should have been sufficient to keep
2127 // all strong references alive.  Any weak references should have been
2128 // cleared as well.  Visit all the metadata and ensure that it's
2129 // really alive.
2130 void nmethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
2131 #ifdef ASSERT
2132     RelocIterator iter(this, low_boundary);
2133     while (iter.next()) {
2134     // static_stub_Relocations may have dangling references to
2135     // Method*s so trim them out here.  Otherwise it looks like
2136     // compiled code is maintaining a link to dead metadata.
2137     address static_call_addr = NULL;
2138     if (iter.type() == relocInfo::opt_virtual_call_type) {
2139       CompiledIC* cic = CompiledIC_at(&iter);
2140       if (!cic->is_call_to_interpreted()) {
2141         static_call_addr = iter.addr();
2142       }
2143     } else if (iter.type() == relocInfo::static_call_type) {
2144       CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
2145       if (!csc->is_call_to_interpreted()) {
2146         static_call_addr = iter.addr();
2147       }
2148     }
2149     if (static_call_addr != NULL) {
2150       RelocIterator sciter(this, low_boundary);
2151       while (sciter.next()) {
2152         if (sciter.type() == relocInfo::static_stub_type &&
2153             sciter.static_stub_reloc()->static_call() == static_call_addr) {
2154           sciter.static_stub_reloc()->clear_inline_cache();
2155         }
2156       }
2157     }
2158   }
2159   // Check that the metadata embedded in the nmethod is alive
2160   CheckClass::do_check_class(is_alive, this);
2161 #endif
2162 }
2163 
2164 
2165 // Iterate over metadata calling this function.   Used by RedefineClasses
2166 void nmethod::metadata_do(void f(Metadata*)) {
2167   address low_boundary = verified_entry_point();
2168   if (is_not_entrant()) {
2169     low_boundary += NativeJump::instruction_size;
2170     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
2171     // (See comment above.)
2172   }
2173   {
2174     // Visit all immediate references that are embedded in the instruction stream.
2175     RelocIterator iter(this, low_boundary);
2176     while (iter.next()) {
2177       if (iter.type() == relocInfo::metadata_type ) {
2178         metadata_Relocation* r = iter.metadata_reloc();
2179         // In this metadata, we must only follow those metadatas directly embedded in
2180         // the code.  Other metadatas (oop_index>0) are seen as part of
2181         // the metadata section below.
2182         assert(1 == (r->metadata_is_immediate()) +
2183                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
2184                "metadata must be found in exactly one place");
2185         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
2186           Metadata* md = r->metadata_value();
2187           if (md != _method) f(md);
2188         }
2189       } else if (iter.type() == relocInfo::virtual_call_type) {
2190         // Check compiledIC holders associated with this nmethod
2191         CompiledIC *ic = CompiledIC_at(&iter);
2192         if (ic->is_icholder_call()) {
2193           CompiledICHolder* cichk = ic->cached_icholder();
2194           f(cichk->holder_method());
2195           f(cichk->holder_klass());
2196         } else {
2197           Metadata* ic_oop = ic->cached_metadata();
2198           if (ic_oop != NULL) {
2199             f(ic_oop);
2200           }
2201         }
2202       }
2203     }
2204   }
2205 
2206   // Visit the metadata section
2207   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
2208     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
2209     Metadata* md = *p;
2210     f(md);
2211   }
2212 
2213   // Visit metadata not embedded in the other places.
2214   if (_method != NULL) f(_method);
2215 }
2216 
2217 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
2218   // make sure the oops ready to receive visitors
2219   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
2220   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
2221 
2222   // If the method is not entrant or zombie then a JMP is plastered over the
2223   // first few bytes.  If an oop in the old code was there, that oop
2224   // should not get GC'd.  Skip the first few bytes of oops on
2225   // not-entrant methods.
2226   address low_boundary = verified_entry_point();
2227   if (is_not_entrant()) {
2228     low_boundary += NativeJump::instruction_size;
2229     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
2230     // (See comment above.)
2231   }
2232 
2233 #if INCLUDE_JVMCI
2234   if (_jvmci_installed_code != NULL) {
2235     f->do_oop((oop*) &_jvmci_installed_code);
2236   }
2237   if (_speculation_log != NULL) {
2238     f->do_oop((oop*) &_speculation_log);
2239   }
2240 #endif
2241 
2242   RelocIterator iter(this, low_boundary);
2243 
2244   while (iter.next()) {
2245     if (iter.type() == relocInfo::oop_type ) {
2246       oop_Relocation* r = iter.oop_reloc();
2247       // In this loop, we must only follow those oops directly embedded in
2248       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
2249       assert(1 == (r->oop_is_immediate()) +
2250                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
2251              "oop must be found in exactly one place");
2252       if (r->oop_is_immediate() && r->oop_value() != NULL) {
2253         f->do_oop(r->oop_addr());
2254       }
2255     }
2256   }
2257 
2258   // Scopes
2259   // This includes oop constants not inlined in the code stream.
2260   for (oop* p = oops_begin(); p < oops_end(); p++) {
2261     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
2262     f->do_oop(p);
2263   }
2264 }
2265 
2266 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
2267 
2268 nmethod* volatile nmethod::_oops_do_mark_nmethods;
2269 
2270 // An nmethod is "marked" if its _mark_link is set non-null.
2271 // Even if it is the end of the linked list, it will have a non-null link value,
2272 // as long as it is on the list.
2273 // This code must be MP safe, because it is used from parallel GC passes.
2274 bool nmethod::test_set_oops_do_mark() {
2275   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
2276   nmethod* observed_mark_link = _oops_do_mark_link;
2277   if (observed_mark_link == NULL) {
2278     // Claim this nmethod for this thread to mark.
2279     observed_mark_link = (nmethod*)
2280       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
2281     if (observed_mark_link == NULL) {
2282 
2283       // Atomically append this nmethod (now claimed) to the head of the list:
2284       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
2285       for (;;) {
2286         nmethod* required_mark_nmethods = observed_mark_nmethods;
2287         _oops_do_mark_link = required_mark_nmethods;
2288         observed_mark_nmethods = (nmethod*)
2289           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
2290         if (observed_mark_nmethods == required_mark_nmethods)
2291           break;
2292       }
2293       // Mark was clear when we first saw this guy.
2294       if (TraceScavenge) { print_on(tty, "oops_do, mark"); }
2295       return false;
2296     }
2297   }
2298   // On fall through, another racing thread marked this nmethod before we did.
2299   return true;
2300 }
2301 
2302 void nmethod::oops_do_marking_prologue() {
2303   if (TraceScavenge) { tty->print_cr("[oops_do_marking_prologue"); }
2304   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
2305   // We use cmpxchg_ptr instead of regular assignment here because the user
2306   // may fork a bunch of threads, and we need them all to see the same state.
2307   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
2308   guarantee(observed == NULL, "no races in this sequential code");
2309 }
2310 
2311 void nmethod::oops_do_marking_epilogue() {
2312   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
2313   nmethod* cur = _oops_do_mark_nmethods;
2314   while (cur != NMETHOD_SENTINEL) {
2315     assert(cur != NULL, "not NULL-terminated");
2316     nmethod* next = cur->_oops_do_mark_link;
2317     cur->_oops_do_mark_link = NULL;
2318     DEBUG_ONLY(cur->verify_oop_relocations());
2319     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
2320     cur = next;
2321   }
2322   void* required = _oops_do_mark_nmethods;
2323   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
2324   guarantee(observed == required, "no races in this sequential code");
2325   if (TraceScavenge) { tty->print_cr("oops_do_marking_epilogue]"); }
2326 }
2327 
2328 class DetectScavengeRoot: public OopClosure {
2329   bool     _detected_scavenge_root;
2330 public:
2331   DetectScavengeRoot() : _detected_scavenge_root(false)
2332   { NOT_PRODUCT(_print_nm = NULL); }
2333   bool detected_scavenge_root() { return _detected_scavenge_root; }
2334   virtual void do_oop(oop* p) {
2335     if ((*p) != NULL && (*p)->is_scavengable()) {
2336       NOT_PRODUCT(maybe_print(p));
2337       _detected_scavenge_root = true;
2338     }
2339   }
2340   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2341 
2342 #ifndef PRODUCT
2343   nmethod* _print_nm;
2344   void maybe_print(oop* p) {
2345     if (_print_nm == NULL)  return;
2346     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
2347     tty->print_cr("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ")",
2348                   p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
2349                   p2i(*p), p2i(p));
2350     (*p)->print();
2351   }
2352 #endif //PRODUCT
2353 };
2354 
2355 bool nmethod::detect_scavenge_root_oops() {
2356   DetectScavengeRoot detect_scavenge_root;
2357   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
2358   oops_do(&detect_scavenge_root);
2359   return detect_scavenge_root.detected_scavenge_root();
2360 }
2361 
2362 // Method that knows how to preserve outgoing arguments at call. This method must be
2363 // called with a frame corresponding to a Java invoke
2364 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
2365 #ifndef SHARK
2366   if (method() != NULL && !method()->is_native()) {
2367     address pc = fr.pc();
2368     SimpleScopeDesc ssd(this, pc);
2369     Bytecode_invoke call(ssd.method(), ssd.bci());
2370     bool has_receiver = call.has_receiver();
2371     bool has_appendix = call.has_appendix();
2372     Symbol* signature = call.signature();
2373 
2374     // The method attached by JIT-compilers should be used, if present.
2375     // Bytecode can be inaccurate in such case.
2376     Method* callee = attached_method_before_pc(pc);
2377     if (callee != NULL) {
2378       has_receiver = !(callee->access_flags().is_static());
2379       has_appendix = false;
2380       signature = callee->signature();
2381     }
2382 
2383     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
2384   }
2385 #endif // !SHARK
2386 }
2387 
2388 inline bool includes(void* p, void* from, void* to) {
2389   return from <= p && p < to;
2390 }
2391 
2392 
2393 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
2394   assert(count >= 2, "must be sentinel values, at least");
2395 
2396 #ifdef ASSERT
2397   // must be sorted and unique; we do a binary search in find_pc_desc()
2398   int prev_offset = pcs[0].pc_offset();
2399   assert(prev_offset == PcDesc::lower_offset_limit,
2400          "must start with a sentinel");
2401   for (int i = 1; i < count; i++) {
2402     int this_offset = pcs[i].pc_offset();
2403     assert(this_offset > prev_offset, "offsets must be sorted");
2404     prev_offset = this_offset;
2405   }
2406   assert(prev_offset == PcDesc::upper_offset_limit,
2407          "must end with a sentinel");
2408 #endif //ASSERT
2409 
2410   // Search for MethodHandle invokes and tag the nmethod.
2411   for (int i = 0; i < count; i++) {
2412     if (pcs[i].is_method_handle_invoke()) {
2413       set_has_method_handle_invokes(true);
2414       break;
2415     }
2416   }
2417   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
2418 
2419   int size = count * sizeof(PcDesc);
2420   assert(scopes_pcs_size() >= size, "oob");
2421   memcpy(scopes_pcs_begin(), pcs, size);
2422 
2423   // Adjust the final sentinel downward.
2424   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
2425   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
2426   last_pc->set_pc_offset(content_size() + 1);
2427   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
2428     // Fill any rounding gaps with copies of the last record.
2429     last_pc[1] = last_pc[0];
2430   }
2431   // The following assert could fail if sizeof(PcDesc) is not
2432   // an integral multiple of oopSize (the rounding term).
2433   // If it fails, change the logic to always allocate a multiple
2434   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
2435   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
2436 }
2437 
2438 void nmethod::copy_scopes_data(u_char* buffer, int size) {
2439   assert(scopes_data_size() >= size, "oob");
2440   memcpy(scopes_data_begin(), buffer, size);
2441 }
2442 
2443 // When using JVMCI the address might be off by the size of a call instruction.
2444 bool nmethod::is_deopt_entry(address pc) {
2445   return pc == deopt_handler_begin()
2446 #if INCLUDE_JVMCI
2447     || pc == (deopt_handler_begin() + NativeCall::instruction_size)
2448 #endif
2449     ;
2450 }
2451 
2452 #ifdef ASSERT
2453 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
2454   PcDesc* lower = nm->scopes_pcs_begin();
2455   PcDesc* upper = nm->scopes_pcs_end();
2456   lower += 1; // exclude initial sentinel
2457   PcDesc* res = NULL;
2458   for (PcDesc* p = lower; p < upper; p++) {
2459     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
2460     if (match_desc(p, pc_offset, approximate)) {
2461       if (res == NULL)
2462         res = p;
2463       else
2464         res = (PcDesc*) badAddress;
2465     }
2466   }
2467   return res;
2468 }
2469 #endif
2470 
2471 
2472 // Finds a PcDesc with real-pc equal to "pc"
2473 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
2474   address base_address = code_begin();
2475   if ((pc < base_address) ||
2476       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
2477     return NULL;  // PC is wildly out of range
2478   }
2479   int pc_offset = (int) (pc - base_address);
2480 
2481   // Check the PcDesc cache if it contains the desired PcDesc
2482   // (This as an almost 100% hit rate.)
2483   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
2484   if (res != NULL) {
2485     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
2486     return res;
2487   }
2488 
2489   // Fallback algorithm: quasi-linear search for the PcDesc
2490   // Find the last pc_offset less than the given offset.
2491   // The successor must be the required match, if there is a match at all.
2492   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
2493   PcDesc* lower = scopes_pcs_begin();
2494   PcDesc* upper = scopes_pcs_end();
2495   upper -= 1; // exclude final sentinel
2496   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
2497 
2498 #define assert_LU_OK \
2499   /* invariant on lower..upper during the following search: */ \
2500   assert(lower->pc_offset() <  pc_offset, "sanity"); \
2501   assert(upper->pc_offset() >= pc_offset, "sanity")
2502   assert_LU_OK;
2503 
2504   // Use the last successful return as a split point.
2505   PcDesc* mid = _pc_desc_cache.last_pc_desc();
2506   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2507   if (mid->pc_offset() < pc_offset) {
2508     lower = mid;
2509   } else {
2510     upper = mid;
2511   }
2512 
2513   // Take giant steps at first (4096, then 256, then 16, then 1)
2514   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
2515   const int RADIX = (1 << LOG2_RADIX);
2516   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
2517     while ((mid = lower + step) < upper) {
2518       assert_LU_OK;
2519       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2520       if (mid->pc_offset() < pc_offset) {
2521         lower = mid;
2522       } else {
2523         upper = mid;
2524         break;
2525       }
2526     }
2527     assert_LU_OK;
2528   }
2529 
2530   // Sneak up on the value with a linear search of length ~16.
2531   while (true) {
2532     assert_LU_OK;
2533     mid = lower + 1;
2534     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2535     if (mid->pc_offset() < pc_offset) {
2536       lower = mid;
2537     } else {
2538       upper = mid;
2539       break;
2540     }
2541   }
2542 #undef assert_LU_OK
2543 
2544   if (match_desc(upper, pc_offset, approximate)) {
2545     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
2546     _pc_desc_cache.add_pc_desc(upper);
2547     return upper;
2548   } else {
2549     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
2550     return NULL;
2551   }
2552 }
2553 
2554 
2555 void nmethod::check_all_dependencies(DepChange& changes) {
2556   // Checked dependencies are allocated into this ResourceMark
2557   ResourceMark rm;
2558 
2559   // Turn off dependency tracing while actually testing dependencies.
2560   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
2561 
2562   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
2563                             &DependencySignature::equals, 11027> DepTable;
2564 
2565   DepTable* table = new DepTable();
2566 
2567   // Iterate over live nmethods and check dependencies of all nmethods that are not
2568   // marked for deoptimization. A particular dependency is only checked once.
2569   NMethodIterator iter;
2570   while(iter.next()) {
2571     nmethod* nm = iter.method();
2572     // Only notify for live nmethods
2573     if (nm->is_alive() && !nm->is_marked_for_deoptimization()) {
2574       for (Dependencies::DepStream deps(nm); deps.next(); ) {
2575         // Construct abstraction of a dependency.
2576         DependencySignature* current_sig = new DependencySignature(deps);
2577 
2578         // Determine if dependency is already checked. table->put(...) returns
2579         // 'true' if the dependency is added (i.e., was not in the hashtable).
2580         if (table->put(*current_sig, 1)) {
2581           if (deps.check_dependency() != NULL) {
2582             // Dependency checking failed. Print out information about the failed
2583             // dependency and finally fail with an assert. We can fail here, since
2584             // dependency checking is never done in a product build.
2585             tty->print_cr("Failed dependency:");
2586             changes.print();
2587             nm->print();
2588             nm->print_dependencies();
2589             assert(false, "Should have been marked for deoptimization");
2590           }
2591         }
2592       }
2593     }
2594   }
2595 }
2596 
2597 bool nmethod::check_dependency_on(DepChange& changes) {
2598   // What has happened:
2599   // 1) a new class dependee has been added
2600   // 2) dependee and all its super classes have been marked
2601   bool found_check = false;  // set true if we are upset
2602   for (Dependencies::DepStream deps(this); deps.next(); ) {
2603     // Evaluate only relevant dependencies.
2604     if (deps.spot_check_dependency_at(changes) != NULL) {
2605       found_check = true;
2606       NOT_DEBUG(break);
2607     }
2608   }
2609   return found_check;
2610 }
2611 
2612 bool nmethod::is_evol_dependent_on(Klass* dependee) {
2613   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
2614   Array<Method*>* dependee_methods = dependee_ik->methods();
2615   for (Dependencies::DepStream deps(this); deps.next(); ) {
2616     if (deps.type() == Dependencies::evol_method) {
2617       Method* method = deps.method_argument(0);
2618       for (int j = 0; j < dependee_methods->length(); j++) {
2619         if (dependee_methods->at(j) == method) {
2620           // RC_TRACE macro has an embedded ResourceMark
2621           RC_TRACE(0x01000000,
2622             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2623             _method->method_holder()->external_name(),
2624             _method->name()->as_C_string(),
2625             _method->signature()->as_C_string(), compile_id(),
2626             method->method_holder()->external_name(),
2627             method->name()->as_C_string(),
2628             method->signature()->as_C_string()));
2629           if (TraceDependencies || LogCompilation)
2630             deps.log_dependency(dependee);
2631           return true;
2632         }
2633       }
2634     }
2635   }
2636   return false;
2637 }
2638 
2639 // Called from mark_for_deoptimization, when dependee is invalidated.
2640 bool nmethod::is_dependent_on_method(Method* dependee) {
2641   for (Dependencies::DepStream deps(this); deps.next(); ) {
2642     if (deps.type() != Dependencies::evol_method)
2643       continue;
2644     Method* method = deps.method_argument(0);
2645     if (method == dependee) return true;
2646   }
2647   return false;
2648 }
2649 
2650 
2651 bool nmethod::is_patchable_at(address instr_addr) {
2652   assert(insts_contains(instr_addr), "wrong nmethod used");
2653   if (is_zombie()) {
2654     // a zombie may never be patched
2655     return false;
2656   }
2657   return true;
2658 }
2659 
2660 
2661 address nmethod::continuation_for_implicit_exception(address pc) {
2662   // Exception happened outside inline-cache check code => we are inside
2663   // an active nmethod => use cpc to determine a return address
2664   int exception_offset = pc - code_begin();
2665   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2666 #ifdef ASSERT
2667   if (cont_offset == 0) {
2668     Thread* thread = Thread::current();
2669     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2670     HandleMark hm(thread);
2671     ResourceMark rm(thread);
2672     CodeBlob* cb = CodeCache::find_blob(pc);
2673     assert(cb != NULL && cb == this, "");
2674     ttyLocker ttyl;
2675     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2676     print();
2677     method()->print_codes();
2678     print_code();
2679     print_pcs();
2680   }
2681 #endif
2682   if (cont_offset == 0) {
2683     // Let the normal error handling report the exception
2684     return NULL;
2685   }
2686   return code_begin() + cont_offset;
2687 }
2688 
2689 
2690 
2691 void nmethod_init() {
2692   // make sure you didn't forget to adjust the filler fields
2693   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2694 }
2695 
2696 
2697 //-------------------------------------------------------------------------------------------
2698 
2699 
2700 // QQQ might we make this work from a frame??
2701 nmethodLocker::nmethodLocker(address pc) {
2702   CodeBlob* cb = CodeCache::find_blob(pc);
2703   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
2704   _nm = (nmethod*)cb;
2705   lock_nmethod(_nm);
2706 }
2707 
2708 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2709 // should pass zombie_ok == true.
2710 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
2711   if (nm == NULL)  return;
2712   Atomic::inc(&nm->_lock_count);
2713   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2714 }
2715 
2716 void nmethodLocker::unlock_nmethod(nmethod* nm) {
2717   if (nm == NULL)  return;
2718   Atomic::dec(&nm->_lock_count);
2719   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2720 }
2721 
2722 // -----------------------------------------------------------------------------
2723 // nmethod::get_deopt_original_pc
2724 //
2725 // Return the original PC for the given PC if:
2726 // (a) the given PC belongs to a nmethod and
2727 // (b) it is a deopt PC
2728 address nmethod::get_deopt_original_pc(const frame* fr) {
2729   if (fr->cb() == NULL)  return NULL;
2730 
2731   nmethod* nm = fr->cb()->as_nmethod_or_null();
2732   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
2733     return nm->get_original_pc(fr);
2734 
2735   return NULL;
2736 }
2737 
2738 
2739 // -----------------------------------------------------------------------------
2740 // MethodHandle
2741 
2742 bool nmethod::is_method_handle_return(address return_pc) {
2743   if (!has_method_handle_invokes())  return false;
2744   PcDesc* pd = pc_desc_at(return_pc);
2745   if (pd == NULL)
2746     return false;
2747   return pd->is_method_handle_invoke();
2748 }
2749 
2750 
2751 // -----------------------------------------------------------------------------
2752 // Verification
2753 
2754 class VerifyOopsClosure: public OopClosure {
2755   nmethod* _nm;
2756   bool     _ok;
2757 public:
2758   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2759   bool ok() { return _ok; }
2760   virtual void do_oop(oop* p) {
2761     if ((*p) == NULL || (*p)->is_oop())  return;
2762     if (_ok) {
2763       _nm->print_nmethod(true);
2764       _ok = false;
2765     }
2766     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2767                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2768   }
2769   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2770 };
2771 
2772 void nmethod::verify() {
2773 
2774   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2775   // seems odd.
2776 
2777   if (is_zombie() || is_not_entrant() || is_unloaded())
2778     return;
2779 
2780   // Make sure all the entry points are correctly aligned for patching.
2781   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2782 
2783   // assert(method()->is_oop(), "must be valid");
2784 
2785   ResourceMark rm;
2786 
2787   if (!CodeCache::contains(this)) {
2788     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2789   }
2790 
2791   if(is_native_method() )
2792     return;
2793 
2794   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2795   if (nm != this) {
2796     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2797   }
2798 
2799   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2800     if (! p->verify(this)) {
2801       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2802     }
2803   }
2804 
2805   VerifyOopsClosure voc(this);
2806   oops_do(&voc);
2807   assert(voc.ok(), "embedded oops must be OK");
2808   verify_scavenge_root_oops();
2809 
2810   verify_scopes();
2811 }
2812 
2813 
2814 void nmethod::verify_interrupt_point(address call_site) {
2815   // Verify IC only when nmethod installation is finished.
2816   bool is_installed = (method()->code() == this) // nmethod is in state 'in_use' and installed
2817                       || !this->is_in_use();     // nmethod is installed, but not in 'in_use' state
2818   if (is_installed) {
2819     Thread *cur = Thread::current();
2820     if (CompiledIC_lock->owner() == cur ||
2821         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2822          SafepointSynchronize::is_at_safepoint())) {
2823       CompiledIC_at(this, call_site);
2824       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2825     } else {
2826       MutexLocker ml_verify (CompiledIC_lock);
2827       CompiledIC_at(this, call_site);
2828     }
2829   }
2830 
2831   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2832   assert(pd != NULL, "PcDesc must exist");
2833   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2834                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2835                                      pd->return_oop());
2836        !sd->is_top(); sd = sd->sender()) {
2837     sd->verify();
2838   }
2839 }
2840 
2841 void nmethod::verify_scopes() {
2842   if( !method() ) return;       // Runtime stubs have no scope
2843   if (method()->is_native()) return; // Ignore stub methods.
2844   // iterate through all interrupt point
2845   // and verify the debug information is valid.
2846   RelocIterator iter((nmethod*)this);
2847   while (iter.next()) {
2848     address stub = NULL;
2849     switch (iter.type()) {
2850       case relocInfo::virtual_call_type:
2851         verify_interrupt_point(iter.addr());
2852         break;
2853       case relocInfo::opt_virtual_call_type:
2854         stub = iter.opt_virtual_call_reloc()->static_stub();
2855         verify_interrupt_point(iter.addr());
2856         break;
2857       case relocInfo::static_call_type:
2858         stub = iter.static_call_reloc()->static_stub();
2859         //verify_interrupt_point(iter.addr());
2860         break;
2861       case relocInfo::runtime_call_type:
2862         address destination = iter.reloc()->value();
2863         // Right now there is no way to find out which entries support
2864         // an interrupt point.  It would be nice if we had this
2865         // information in a table.
2866         break;
2867     }
2868     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2869   }
2870 }
2871 
2872 
2873 // -----------------------------------------------------------------------------
2874 // Non-product code
2875 #ifndef PRODUCT
2876 
2877 class DebugScavengeRoot: public OopClosure {
2878   nmethod* _nm;
2879   bool     _ok;
2880 public:
2881   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2882   bool ok() { return _ok; }
2883   virtual void do_oop(oop* p) {
2884     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2885     if (_ok) {
2886       _nm->print_nmethod(true);
2887       _ok = false;
2888     }
2889     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2890                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2891     (*p)->print();
2892   }
2893   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2894 };
2895 
2896 void nmethod::verify_scavenge_root_oops() {
2897   if (UseG1GC) {
2898     return;
2899   }
2900 
2901   if (!on_scavenge_root_list()) {
2902     // Actually look inside, to verify the claim that it's clean.
2903     DebugScavengeRoot debug_scavenge_root(this);
2904     oops_do(&debug_scavenge_root);
2905     if (!debug_scavenge_root.ok())
2906       fatal("found an unadvertised bad scavengable oop in the code cache");
2907   }
2908   assert(scavenge_root_not_marked(), "");
2909 }
2910 
2911 #endif // PRODUCT
2912 
2913 // Printing operations
2914 
2915 void nmethod::print() const {
2916   ResourceMark rm;
2917   ttyLocker ttyl;   // keep the following output all in one block
2918 
2919   tty->print("Compiled method ");
2920 
2921   if (is_compiled_by_c1()) {
2922     tty->print("(c1) ");
2923   } else if (is_compiled_by_c2()) {
2924     tty->print("(c2) ");
2925   } else if (is_compiled_by_shark()) {
2926     tty->print("(shark) ");
2927   } else if (is_compiled_by_jvmci()) {
2928     tty->print("(JVMCI) ");
2929   } else {
2930     tty->print("(nm) ");
2931   }
2932 
2933   print_on(tty, NULL);
2934 
2935   if (WizardMode) {
2936     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2937     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2938     tty->print(" { ");
2939     tty->print_cr("%s ", state());
2940     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2941     tty->print_cr("}:");
2942   }
2943   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2944                                               p2i(this),
2945                                               p2i(this) + size(),
2946                                               size());
2947   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2948                                               p2i(relocation_begin()),
2949                                               p2i(relocation_end()),
2950                                               relocation_size());
2951   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2952                                               p2i(consts_begin()),
2953                                               p2i(consts_end()),
2954                                               consts_size());
2955   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2956                                               p2i(insts_begin()),
2957                                               p2i(insts_end()),
2958                                               insts_size());
2959   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2960                                               p2i(stub_begin()),
2961                                               p2i(stub_end()),
2962                                               stub_size());
2963   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2964                                               p2i(oops_begin()),
2965                                               p2i(oops_end()),
2966                                               oops_size());
2967   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2968                                               p2i(metadata_begin()),
2969                                               p2i(metadata_end()),
2970                                               metadata_size());
2971   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2972                                               p2i(scopes_data_begin()),
2973                                               p2i(scopes_data_end()),
2974                                               scopes_data_size());
2975   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2976                                               p2i(scopes_pcs_begin()),
2977                                               p2i(scopes_pcs_end()),
2978                                               scopes_pcs_size());
2979   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2980                                               p2i(dependencies_begin()),
2981                                               p2i(dependencies_end()),
2982                                               dependencies_size());
2983   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2984                                               p2i(handler_table_begin()),
2985                                               p2i(handler_table_end()),
2986                                               handler_table_size());
2987   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2988                                               p2i(nul_chk_table_begin()),
2989                                               p2i(nul_chk_table_end()),
2990                                               nul_chk_table_size());
2991 }
2992 
2993 #ifndef PRODUCT
2994 
2995 void nmethod::print_scopes() {
2996   // Find the first pc desc for all scopes in the code and print it.
2997   ResourceMark rm;
2998   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2999     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
3000       continue;
3001 
3002     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
3003     while (sd != NULL) {
3004       sd->print_on(tty, p);
3005       sd = sd->sender();
3006     }
3007   }
3008 }
3009 
3010 void nmethod::print_dependencies() {
3011   ResourceMark rm;
3012   ttyLocker ttyl;   // keep the following output all in one block
3013   tty->print_cr("Dependencies:");
3014   for (Dependencies::DepStream deps(this); deps.next(); ) {
3015     deps.print_dependency();
3016     Klass* ctxk = deps.context_type();
3017     if (ctxk != NULL) {
3018       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
3019         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
3020       }
3021     }
3022     deps.log_dependency();  // put it into the xml log also
3023   }
3024 }
3025 
3026 
3027 void nmethod::print_relocations() {
3028   ResourceMark m;       // in case methods get printed via the debugger
3029   tty->print_cr("relocations:");
3030   RelocIterator iter(this);
3031   iter.print();
3032   if (UseRelocIndex) {
3033     jint* index_end   = (jint*)relocation_end() - 1;
3034     jint  index_size  = *index_end;
3035     jint* index_start = (jint*)( (address)index_end - index_size );
3036     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", p2i(index_start), index_size);
3037     if (index_size > 0) {
3038       jint* ip;
3039       for (ip = index_start; ip+2 <= index_end; ip += 2)
3040         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
3041                       ip[0],
3042                       ip[1],
3043                       p2i(header_end()+ip[0]),
3044                       p2i(relocation_begin()-1+ip[1]));
3045       for (; ip < index_end; ip++)
3046         tty->print_cr("  (%d ?)", ip[0]);
3047       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", p2i(ip), *ip);
3048       ip++;
3049       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", p2i(ip));
3050     }
3051   }
3052 }
3053 
3054 
3055 void nmethod::print_pcs() {
3056   ResourceMark m;       // in case methods get printed via debugger
3057   tty->print_cr("pc-bytecode offsets:");
3058   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
3059     p->print(this);
3060   }
3061 }
3062 
3063 void nmethod::print_recorded_oops() {
3064   tty->print_cr("Recorded oops:");
3065   for (int i = 0; i < oops_count(); i++) {
3066     oop o = oop_at(i);
3067     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
3068     if (o == (oop)Universe::non_oop_word()) {
3069       tty->print("non-oop word");
3070     } else {
3071       o->print_value();
3072     }
3073     tty->cr();
3074   }
3075 }
3076 
3077 void nmethod::print_recorded_metadata() {
3078   tty->print_cr("Recorded metadata:");
3079   for (int i = 0; i < metadata_count(); i++) {
3080     Metadata* m = metadata_at(i);
3081     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
3082     if (m == (Metadata*)Universe::non_oop_word()) {
3083       tty->print("non-metadata word");
3084     } else {
3085       m->print_value_on_maybe_null(tty);
3086     }
3087     tty->cr();
3088   }
3089 }
3090 
3091 #endif // PRODUCT
3092 
3093 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
3094   RelocIterator iter(this, begin, end);
3095   bool have_one = false;
3096   while (iter.next()) {
3097     have_one = true;
3098     switch (iter.type()) {
3099         case relocInfo::none:                  return "no_reloc";
3100         case relocInfo::oop_type: {
3101           stringStream st;
3102           oop_Relocation* r = iter.oop_reloc();
3103           oop obj = r->oop_value();
3104           st.print("oop(");
3105           if (obj == NULL) st.print("NULL");
3106           else obj->print_value_on(&st);
3107           st.print(")");
3108           return st.as_string();
3109         }
3110         case relocInfo::metadata_type: {
3111           stringStream st;
3112           metadata_Relocation* r = iter.metadata_reloc();
3113           Metadata* obj = r->metadata_value();
3114           st.print("metadata(");
3115           if (obj == NULL) st.print("NULL");
3116           else obj->print_value_on(&st);
3117           st.print(")");
3118           return st.as_string();
3119         }
3120         case relocInfo::runtime_call_type: {
3121           stringStream st;
3122           st.print("runtime_call");
3123           runtime_call_Relocation* r = iter.runtime_call_reloc();
3124           address dest = r->destination();
3125           CodeBlob* cb = CodeCache::find_blob(dest);
3126           if (cb != NULL) {
3127             st.print(" %s", cb->name());
3128           } else {
3129             ResourceMark rm;
3130             const int buflen = 1024;
3131             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
3132             int offset;
3133             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
3134               st.print(" %s", buf);
3135               if (offset != 0) {
3136                 st.print("+%d", offset);
3137               }
3138             }
3139           }
3140           return st.as_string();
3141         }
3142         case relocInfo::virtual_call_type: {
3143           stringStream st;
3144           st.print_raw("virtual_call");
3145           virtual_call_Relocation* r = iter.virtual_call_reloc();
3146           Method* m = r->method_value();
3147           if (m != NULL) {
3148             assert(m->is_method(), "");
3149             m->print_short_name(&st);
3150           }
3151           return st.as_string();
3152         }
3153         case relocInfo::opt_virtual_call_type: {
3154           stringStream st;
3155           st.print_raw("optimized virtual_call");
3156           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
3157           Method* m = r->method_value();
3158           if (m != NULL) {
3159             assert(m->is_method(), "");
3160             m->print_short_name(&st);
3161           }
3162           return st.as_string();
3163         }
3164         case relocInfo::static_call_type: {
3165           stringStream st;
3166           st.print_raw("static_call");
3167           static_call_Relocation* r = iter.static_call_reloc();
3168           Method* m = r->method_value();
3169           if (m != NULL) {
3170             assert(m->is_method(), "");
3171             m->print_short_name(&st);
3172           }
3173           return st.as_string();
3174         }
3175         case relocInfo::static_stub_type:      return "static_stub";
3176         case relocInfo::external_word_type:    return "external_word";
3177         case relocInfo::internal_word_type:    return "internal_word";
3178         case relocInfo::section_word_type:     return "section_word";
3179         case relocInfo::poll_type:             return "poll";
3180         case relocInfo::poll_return_type:      return "poll_return";
3181         case relocInfo::type_mask:             return "type_bit_mask";
3182     }
3183   }
3184   return have_one ? "other" : NULL;
3185 }
3186 
3187 // Return a the last scope in (begin..end]
3188 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
3189   PcDesc* p = pc_desc_near(begin+1);
3190   if (p != NULL && p->real_pc(this) <= end) {
3191     return new ScopeDesc(this, p->scope_decode_offset(),
3192                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
3193                          p->return_oop());
3194   }
3195   return NULL;
3196 }
3197 
3198 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
3199   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
3200   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
3201   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
3202   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
3203   if (JVMCI_ONLY(_deoptimize_offset >= 0 &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
3204 
3205   if (has_method_handle_invokes())
3206     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
3207 
3208   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
3209 
3210   if (block_begin == entry_point()) {
3211     methodHandle m = method();
3212     if (m.not_null()) {
3213       stream->print("  # ");
3214       m->print_value_on(stream);
3215       stream->cr();
3216     }
3217     if (m.not_null() && !is_osr_method()) {
3218       ResourceMark rm;
3219       int sizeargs = m->size_of_parameters();
3220       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
3221       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
3222       {
3223         int sig_index = 0;
3224         if (!m->is_static())
3225           sig_bt[sig_index++] = T_OBJECT; // 'this'
3226         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
3227           BasicType t = ss.type();
3228           sig_bt[sig_index++] = t;
3229           if (type2size[t] == 2) {
3230             sig_bt[sig_index++] = T_VOID;
3231           } else {
3232             assert(type2size[t] == 1, "size is 1 or 2");
3233           }
3234         }
3235         assert(sig_index == sizeargs, "");
3236       }
3237       const char* spname = "sp"; // make arch-specific?
3238       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
3239       int stack_slot_offset = this->frame_size() * wordSize;
3240       int tab1 = 14, tab2 = 24;
3241       int sig_index = 0;
3242       int arg_index = (m->is_static() ? 0 : -1);
3243       bool did_old_sp = false;
3244       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
3245         bool at_this = (arg_index == -1);
3246         bool at_old_sp = false;
3247         BasicType t = (at_this ? T_OBJECT : ss.type());
3248         assert(t == sig_bt[sig_index], "sigs in sync");
3249         if (at_this)
3250           stream->print("  # this: ");
3251         else
3252           stream->print("  # parm%d: ", arg_index);
3253         stream->move_to(tab1);
3254         VMReg fst = regs[sig_index].first();
3255         VMReg snd = regs[sig_index].second();
3256         if (fst->is_reg()) {
3257           stream->print("%s", fst->name());
3258           if (snd->is_valid())  {
3259             stream->print(":%s", snd->name());
3260           }
3261         } else if (fst->is_stack()) {
3262           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
3263           if (offset == stack_slot_offset)  at_old_sp = true;
3264           stream->print("[%s+0x%x]", spname, offset);
3265         } else {
3266           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
3267         }
3268         stream->print(" ");
3269         stream->move_to(tab2);
3270         stream->print("= ");
3271         if (at_this) {
3272           m->method_holder()->print_value_on(stream);
3273         } else {
3274           bool did_name = false;
3275           if (!at_this && ss.is_object()) {
3276             Symbol* name = ss.as_symbol_or_null();
3277             if (name != NULL) {
3278               name->print_value_on(stream);
3279               did_name = true;
3280             }
3281           }
3282           if (!did_name)
3283             stream->print("%s", type2name(t));
3284         }
3285         if (at_old_sp) {
3286           stream->print("  (%s of caller)", spname);
3287           did_old_sp = true;
3288         }
3289         stream->cr();
3290         sig_index += type2size[t];
3291         arg_index += 1;
3292         if (!at_this)  ss.next();
3293       }
3294       if (!did_old_sp) {
3295         stream->print("  # ");
3296         stream->move_to(tab1);
3297         stream->print("[%s+0x%x]", spname, stack_slot_offset);
3298         stream->print("  (%s of caller)", spname);
3299         stream->cr();
3300       }
3301     }
3302   }
3303 }
3304 
3305 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
3306   // First, find an oopmap in (begin, end].
3307   // We use the odd half-closed interval so that oop maps and scope descs
3308   // which are tied to the byte after a call are printed with the call itself.
3309   address base = code_begin();
3310   ImmutableOopMapSet* oms = oop_maps();
3311   if (oms != NULL) {
3312     for (int i = 0, imax = oms->count(); i < imax; i++) {
3313       const ImmutableOopMapPair* pair = oms->pair_at(i);
3314       const ImmutableOopMap* om = pair->get_from(oms);
3315       address pc = base + pair->pc_offset();
3316       if (pc > begin) {
3317         if (pc <= end) {
3318           st->move_to(column);
3319           st->print("; ");
3320           om->print_on(st);
3321         }
3322         break;
3323       }
3324     }
3325   }
3326 
3327   // Print any debug info present at this pc.
3328   ScopeDesc* sd  = scope_desc_in(begin, end);
3329   if (sd != NULL) {
3330     st->move_to(column);
3331     if (sd->bci() == SynchronizationEntryBCI) {
3332       st->print(";*synchronization entry");
3333     } else {
3334       if (sd->method() == NULL) {
3335         st->print("method is NULL");
3336       } else if (sd->method()->is_native()) {
3337         st->print("method is native");
3338       } else {
3339         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
3340         st->print(";*%s", Bytecodes::name(bc));
3341         switch (bc) {
3342         case Bytecodes::_invokevirtual:
3343         case Bytecodes::_invokespecial:
3344         case Bytecodes::_invokestatic:
3345         case Bytecodes::_invokeinterface:
3346           {
3347             Bytecode_invoke invoke(sd->method(), sd->bci());
3348             st->print(" ");
3349             if (invoke.name() != NULL)
3350               invoke.name()->print_symbol_on(st);
3351             else
3352               st->print("<UNKNOWN>");
3353             break;
3354           }
3355         case Bytecodes::_getfield:
3356         case Bytecodes::_putfield:
3357         case Bytecodes::_getstatic:
3358         case Bytecodes::_putstatic:
3359           {
3360             Bytecode_field field(sd->method(), sd->bci());
3361             st->print(" ");
3362             if (field.name() != NULL)
3363               field.name()->print_symbol_on(st);
3364             else
3365               st->print("<UNKNOWN>");
3366           }
3367         }
3368       }
3369       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
3370     }
3371 
3372     // Print all scopes
3373     for (;sd != NULL; sd = sd->sender()) {
3374       st->move_to(column);
3375       st->print("; -");
3376       if (sd->method() == NULL) {
3377         st->print("method is NULL");
3378       } else {
3379         sd->method()->print_short_name(st);
3380       }
3381       int lineno = sd->method()->line_number_from_bci(sd->bci());
3382       if (lineno != -1) {
3383         st->print("@%d (line %d)", sd->bci(), lineno);
3384       } else {
3385         st->print("@%d", sd->bci());
3386       }
3387       st->cr();
3388     }
3389   }
3390 
3391   // Print relocation information
3392   const char* str = reloc_string_for(begin, end);
3393   if (str != NULL) {
3394     if (sd != NULL) st->cr();
3395     st->move_to(column);
3396     st->print(";   {%s}", str);
3397   }
3398   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
3399   if (cont_offset != 0) {
3400     st->move_to(column);
3401     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
3402   }
3403 
3404 }
3405 
3406 #ifndef PRODUCT
3407 
3408 void nmethod::print_value_on(outputStream* st) const {
3409   st->print("nmethod");
3410   print_on(st, NULL);
3411 }
3412 
3413 void nmethod::print_calls(outputStream* st) {
3414   RelocIterator iter(this);
3415   while (iter.next()) {
3416     switch (iter.type()) {
3417     case relocInfo::virtual_call_type:
3418     case relocInfo::opt_virtual_call_type: {
3419       VerifyMutexLocker mc(CompiledIC_lock);
3420       CompiledIC_at(&iter)->print();
3421       break;
3422     }
3423     case relocInfo::static_call_type:
3424       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
3425       compiledStaticCall_at(iter.reloc())->print();
3426       break;
3427     }
3428   }
3429 }
3430 
3431 void nmethod::print_handler_table() {
3432   ExceptionHandlerTable(this).print();
3433 }
3434 
3435 void nmethod::print_nul_chk_table() {
3436   ImplicitExceptionTable(this).print(code_begin());
3437 }
3438 
3439 void nmethod::print_statistics() {
3440   ttyLocker ttyl;
3441   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
3442   native_nmethod_stats.print_native_nmethod_stats();
3443 #ifdef COMPILER1
3444   c1_java_nmethod_stats.print_nmethod_stats("C1");
3445 #endif
3446 #ifdef COMPILER2
3447   c2_java_nmethod_stats.print_nmethod_stats("C2");
3448 #endif
3449 #if INCLUDE_JVMCI
3450   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
3451 #endif
3452 #ifdef SHARK
3453   shark_java_nmethod_stats.print_nmethod_stats("Shark");
3454 #endif
3455   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
3456   DebugInformationRecorder::print_statistics();
3457 #ifndef PRODUCT
3458   pc_nmethod_stats.print_pc_stats();
3459 #endif
3460   Dependencies::print_statistics();
3461   if (xtty != NULL)  xtty->tail("statistics");
3462 }
3463 
3464 #endif // !PRODUCT
3465 
3466 #if INCLUDE_JVMCI
3467 void nmethod::clear_jvmci_installed_code() {
3468   // write_ref_method_pre/post can only be safely called at a
3469   // safepoint or while holding the CodeCache_lock
3470   assert(CodeCache_lock->is_locked() ||
3471          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
3472   if (_jvmci_installed_code != NULL) {
3473     // This must be done carefully to maintain nmethod remembered sets properly
3474     BarrierSet* bs = Universe::heap()->barrier_set();
3475     bs->write_ref_nmethod_pre(&_jvmci_installed_code, this);
3476     _jvmci_installed_code = NULL;
3477     bs->write_ref_nmethod_post(&_jvmci_installed_code, this);
3478   }
3479 }
3480 
3481 void nmethod::maybe_invalidate_installed_code() {
3482   assert(Patching_lock->is_locked() ||
3483          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
3484   oop installed_code = jvmci_installed_code();
3485   if (installed_code != NULL) {
3486     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
3487     if (nm == NULL || nm != this) {
3488       // The link has been broken or the InstalledCode instance is
3489       // associated with another nmethod so do nothing.
3490       return;
3491     }
3492     if (!is_alive()) {
3493       // Break the link between nmethod and InstalledCode such that the nmethod
3494       // can subsequently be flushed safely.  The link must be maintained while
3495       // the method could have live activations since invalidateInstalledCode
3496       // might want to invalidate all existing activations.
3497       InstalledCode::set_address(installed_code, 0);
3498       InstalledCode::set_entryPoint(installed_code, 0);
3499     } else if (is_not_entrant()) {
3500       // Remove the entry point so any invocation will fail but keep
3501       // the address link around that so that existing activations can
3502       // be invalidated.
3503       InstalledCode::set_entryPoint(installed_code, 0);
3504     }
3505   }
3506 }
3507 
3508 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
3509   if (installedCode() == NULL) {
3510     THROW(vmSymbols::java_lang_NullPointerException());
3511   }
3512   jlong nativeMethod = InstalledCode::address(installedCode);
3513   nmethod* nm = (nmethod*)nativeMethod;
3514   if (nm == NULL) {
3515     // Nothing to do
3516     return;
3517   }
3518 
3519   nmethodLocker nml(nm);
3520 #ifdef ASSERT
3521   {
3522     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3523     // This relationship can only be checked safely under a lock
3524     assert(nm == NULL || !nm->is_alive() || nm->jvmci_installed_code() == installedCode(), "sanity check");
3525   }
3526 #endif
3527 
3528   if (nm->is_alive()) {
3529     // The nmethod state machinery maintains the link between the
3530     // HotSpotInstalledCode and nmethod* so as long as the nmethod appears to be
3531     // alive assume there is work to do and deoptimize the nmethod.
3532     nm->mark_for_deoptimization();
3533     VM_Deoptimize op;
3534     VMThread::execute(&op);
3535   }
3536 
3537   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3538   // Check that it's still associated with the same nmethod and break
3539   // the link if it is.
3540   if (InstalledCode::address(installedCode) == nativeMethod) {
3541     InstalledCode::set_address(installedCode, 0);
3542   }
3543 }
3544 
3545 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) {
3546   if (!this->is_compiled_by_jvmci()) {
3547     return NULL;
3548   }
3549   oop installedCode = this->jvmci_installed_code();
3550   if (installedCode != NULL) {
3551     oop installedCodeName = NULL;
3552     if (installedCode->is_a(InstalledCode::klass())) {
3553       installedCodeName = InstalledCode::name(installedCode);
3554     }
3555     if (installedCodeName != NULL) {
3556       return java_lang_String::as_utf8_string(installedCodeName, buf, (int)buflen);
3557     } else {
3558       jio_snprintf(buf, buflen, "null");
3559       return buf;
3560     }
3561   }
3562   jio_snprintf(buf, buflen, "noInstalledCode");
3563   return buf;
3564 }
3565 #endif
3566 
3567 Method* nmethod::attached_method(address call_instr) {
3568   assert(code_contains(call_instr), "not part of the nmethod");
3569   RelocIterator iter(this, call_instr, call_instr + 1);
3570   while (iter.next()) {
3571     if (iter.addr() == call_instr) {
3572       switch(iter.type()) {
3573         case relocInfo::static_call_type:      return iter.static_call_reloc()->method_value();
3574         case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
3575         case relocInfo::virtual_call_type:     return iter.virtual_call_reloc()->method_value();
3576       }
3577     }
3578   }
3579   return NULL; // not found
3580 }
3581 
3582 Method* nmethod::attached_method_before_pc(address pc) {
3583   if (NativeCall::is_call_before(pc)) {
3584     NativeCall* ncall = nativeCall_before(pc);
3585     return attached_method(ncall->instruction_address());
3586   }
3587   return NULL; // not a call
3588 }
3589