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