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