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