1 /*
   2  * Copyright (c) 1997, 2012, 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 #ifndef USDT2
  54 HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
  55   const char*, int, const char*, int, const char*, int, void*, size_t);
  56 
  57 HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
  58   char*, int, char*, int, char*, int);
  59 
  60 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  61   {                                                                       \
  62     Method* m = (method);                                                 \
  63     if (m != NULL) {                                                      \
  64       Symbol* klass_name = m->klass_name();                               \
  65       Symbol* name = m->name();                                           \
  66       Symbol* signature = m->signature();                                 \
  67       HS_DTRACE_PROBE6(hotspot, compiled__method__unload,                 \
  68         klass_name->bytes(), klass_name->utf8_length(),                   \
  69         name->bytes(), name->utf8_length(),                               \
  70         signature->bytes(), signature->utf8_length());                    \
  71     }                                                                     \
  72   }
  73 #else /* USDT2 */
  74 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  75   {                                                                       \
  76     Method* m = (method);                                                 \
  77     if (m != NULL) {                                                      \
  78       Symbol* klass_name = m->klass_name();                               \
  79       Symbol* name = m->name();                                           \
  80       Symbol* signature = m->signature();                                 \
  81       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  82         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  83         (char *) name->bytes(), name->utf8_length(),                               \
  84         (char *) signature->bytes(), signature->utf8_length());                    \
  85     }                                                                     \
  86   }
  87 #endif /* USDT2 */
  88 
  89 #else //  ndef DTRACE_ENABLED
  90 
  91 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  92 
  93 #endif
  94 
  95 bool nmethod::is_compiled_by_c1() const {
  96   if (compiler() == NULL) {
  97     return false;
  98   }
  99   return compiler()->is_c1();
 100 }
 101 bool nmethod::is_compiled_by_c2() const {
 102   if (compiler() == NULL) {
 103     return false;
 104   }
 105   return compiler()->is_c2();
 106 }
 107 bool nmethod::is_compiled_by_shark() const {
 108   if (compiler() == NULL) {
 109     return false;
 110   }
 111   return compiler()->is_shark();
 112 }
 113 
 114 
 115 
 116 //---------------------------------------------------------------------------------
 117 // NMethod statistics
 118 // They are printed under various flags, including:
 119 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
 120 // (In the latter two cases, they like other stats are printed to the log only.)
 121 
 122 #ifndef PRODUCT
 123 // These variables are put into one block to reduce relocations
 124 // and make it simpler to print from the debugger.
 125 static
 126 struct nmethod_stats_struct {
 127   int nmethod_count;
 128   int total_size;
 129   int relocation_size;
 130   int consts_size;
 131   int insts_size;
 132   int stub_size;
 133   int scopes_data_size;
 134   int scopes_pcs_size;
 135   int dependencies_size;
 136   int handler_table_size;
 137   int nul_chk_table_size;
 138   int oops_size;
 139 
 140   void note_nmethod(nmethod* nm) {
 141     nmethod_count += 1;
 142     total_size          += nm->size();
 143     relocation_size     += nm->relocation_size();
 144     consts_size         += nm->consts_size();
 145     insts_size          += nm->insts_size();
 146     stub_size           += nm->stub_size();
 147     oops_size           += nm->oops_size();
 148     scopes_data_size    += nm->scopes_data_size();
 149     scopes_pcs_size     += nm->scopes_pcs_size();
 150     dependencies_size   += nm->dependencies_size();
 151     handler_table_size  += nm->handler_table_size();
 152     nul_chk_table_size  += nm->nul_chk_table_size();
 153   }
 154   void print_nmethod_stats() {
 155     if (nmethod_count == 0)  return;
 156     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
 157     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 158     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 159     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 160     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 161     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 162     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 163     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 164     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 165     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 166     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 167     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 168   }
 169 
 170   int native_nmethod_count;
 171   int native_total_size;
 172   int native_relocation_size;
 173   int native_insts_size;
 174   int native_oops_size;
 175   void note_native_nmethod(nmethod* nm) {
 176     native_nmethod_count += 1;
 177     native_total_size       += nm->size();
 178     native_relocation_size  += nm->relocation_size();
 179     native_insts_size       += nm->insts_size();
 180     native_oops_size        += nm->oops_size();
 181   }
 182   void print_native_nmethod_stats() {
 183     if (native_nmethod_count == 0)  return;
 184     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 185     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 186     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 187     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 188     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 189   }
 190 
 191   int pc_desc_resets;   // number of resets (= number of caches)
 192   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 193   int pc_desc_approx;   // number of those which have approximate true
 194   int pc_desc_repeats;  // number of _pc_descs[0] hits
 195   int pc_desc_hits;     // number of LRU cache hits
 196   int pc_desc_tests;    // total number of PcDesc examinations
 197   int pc_desc_searches; // total number of quasi-binary search steps
 198   int pc_desc_adds;     // number of LUR cache insertions
 199 
 200   void print_pc_stats() {
 201     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 202                   pc_desc_queries,
 203                   (double)(pc_desc_tests + pc_desc_searches)
 204                   / pc_desc_queries);
 205     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 206                   pc_desc_resets,
 207                   pc_desc_queries, pc_desc_approx,
 208                   pc_desc_repeats, pc_desc_hits,
 209                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 210   }
 211 } nmethod_stats;
 212 #endif //PRODUCT
 213 
 214 
 215 //---------------------------------------------------------------------------------
 216 
 217 
 218 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 219   assert(pc != NULL, "Must be non null");
 220   assert(exception.not_null(), "Must be non null");
 221   assert(handler != NULL, "Must be non null");
 222 
 223   _count = 0;
 224   _exception_type = exception->klass();
 225   _next = NULL;
 226 
 227   add_address_and_handler(pc,handler);
 228 }
 229 
 230 
 231 address ExceptionCache::match(Handle exception, address pc) {
 232   assert(pc != NULL,"Must be non null");
 233   assert(exception.not_null(),"Must be non null");
 234   if (exception->klass() == exception_type()) {
 235     return (test_address(pc));
 236   }
 237 
 238   return NULL;
 239 }
 240 
 241 
 242 bool ExceptionCache::match_exception_with_space(Handle exception) {
 243   assert(exception.not_null(),"Must be non null");
 244   if (exception->klass() == exception_type() && count() < cache_size) {
 245     return true;
 246   }
 247   return false;
 248 }
 249 
 250 
 251 address ExceptionCache::test_address(address addr) {
 252   for (int i=0; i<count(); i++) {
 253     if (pc_at(i) == addr) {
 254       return handler_at(i);
 255     }
 256   }
 257   return NULL;
 258 }
 259 
 260 
 261 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 262   if (test_address(addr) == handler) return true;
 263   if (count() < cache_size) {
 264     set_pc_at(count(),addr);
 265     set_handler_at(count(), handler);
 266     increment_count();
 267     return true;
 268   }
 269   return false;
 270 }
 271 
 272 
 273 // private method for handling exception cache
 274 // These methods are private, and used to manipulate the exception cache
 275 // directly.
 276 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 277   ExceptionCache* ec = exception_cache();
 278   while (ec != NULL) {
 279     if (ec->match_exception_with_space(exception)) {
 280       return ec;
 281     }
 282     ec = ec->next();
 283   }
 284   return NULL;
 285 }
 286 
 287 
 288 //-----------------------------------------------------------------------------
 289 
 290 
 291 // Helper used by both find_pc_desc methods.
 292 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 293   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
 294   if (!approximate)
 295     return pc->pc_offset() == pc_offset;
 296   else
 297     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 298 }
 299 
 300 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 301   if (initial_pc_desc == NULL) {
 302     _pc_descs[0] = NULL; // native method; no PcDescs at all
 303     return;
 304   }
 305   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
 306   // reset the cache by filling it with benign (non-null) values
 307   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 308   for (int i = 0; i < cache_size; i++)
 309     _pc_descs[i] = initial_pc_desc;
 310 }
 311 
 312 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 313   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
 314   NOT_PRODUCT(if (approximate) ++nmethod_stats.pc_desc_approx);
 315 
 316   // Note: one might think that caching the most recently
 317   // read value separately would be a win, but one would be
 318   // wrong.  When many threads are updating it, the cache
 319   // line it's in would bounce between caches, negating
 320   // any benefit.
 321 
 322   // In order to prevent race conditions do not load cache elements
 323   // repeatedly, but use a local copy:
 324   PcDesc* res;
 325 
 326   // Step one:  Check the most recently added value.
 327   res = _pc_descs[0];
 328   if (res == NULL) return NULL;  // native method; no PcDescs at all
 329   if (match_desc(res, pc_offset, approximate)) {
 330     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
 331     return res;
 332   }
 333 
 334   // Step two:  Check the rest of the LRU cache.
 335   for (int i = 1; i < cache_size; ++i) {
 336     res = _pc_descs[i];
 337     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 338     if (match_desc(res, pc_offset, approximate)) {
 339       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
 340       return res;
 341     }
 342   }
 343 
 344   // Report failure.
 345   return NULL;
 346 }
 347 
 348 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 349   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
 350   // Update the LRU cache by shifting pc_desc forward.
 351   for (int i = 0; i < cache_size; i++)  {
 352     PcDesc* next = _pc_descs[i];
 353     _pc_descs[i] = pc_desc;
 354     pc_desc = next;
 355   }
 356 }
 357 
 358 // adjust pcs_size so that it is a multiple of both oopSize and
 359 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 360 // of oopSize, then 2*sizeof(PcDesc) is)
 361 static int adjust_pcs_size(int pcs_size) {
 362   int nsize = round_to(pcs_size,   oopSize);
 363   if ((nsize % sizeof(PcDesc)) != 0) {
 364     nsize = pcs_size + sizeof(PcDesc);
 365   }
 366   assert((nsize % oopSize) == 0, "correct alignment");
 367   return nsize;
 368 }
 369 
 370 //-----------------------------------------------------------------------------
 371 
 372 
 373 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 374   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 375   assert(new_entry != NULL,"Must be non null");
 376   assert(new_entry->next() == NULL, "Must be null");
 377 
 378   if (exception_cache() != NULL) {
 379     new_entry->set_next(exception_cache());
 380   }
 381   set_exception_cache(new_entry);
 382 }
 383 
 384 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
 385   ExceptionCache* prev = NULL;
 386   ExceptionCache* curr = exception_cache();
 387   assert(curr != NULL, "nothing to remove");
 388   // find the previous and next entry of ec
 389   while (curr != ec) {
 390     prev = curr;
 391     curr = curr->next();
 392     assert(curr != NULL, "ExceptionCache not found");
 393   }
 394   // now: curr == ec
 395   ExceptionCache* next = curr->next();
 396   if (prev == NULL) {
 397     set_exception_cache(next);
 398   } else {
 399     prev->set_next(next);
 400   }
 401   delete curr;
 402 }
 403 
 404 
 405 // public method for accessing the exception cache
 406 // These are the public access methods.
 407 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 408   // We never grab a lock to read the exception cache, so we may
 409   // have false negatives. This is okay, as it can only happen during
 410   // the first few exception lookups for a given nmethod.
 411   ExceptionCache* ec = exception_cache();
 412   while (ec != NULL) {
 413     address ret_val;
 414     if ((ret_val = ec->match(exception,pc)) != NULL) {
 415       return ret_val;
 416     }
 417     ec = ec->next();
 418   }
 419   return NULL;
 420 }
 421 
 422 
 423 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 424   // There are potential race conditions during exception cache updates, so we
 425   // must own the ExceptionCache_lock before doing ANY modifications. Because
 426   // we don't lock during reads, it is possible to have several threads attempt
 427   // to update the cache with the same data. We need to check for already inserted
 428   // copies of the current data before adding it.
 429 
 430   MutexLocker ml(ExceptionCache_lock);
 431   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 432 
 433   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
 434     target_entry = new ExceptionCache(exception,pc,handler);
 435     add_exception_cache_entry(target_entry);
 436   }
 437 }
 438 
 439 
 440 //-------------end of code for ExceptionCache--------------
 441 
 442 
 443 int nmethod::total_size() const {
 444   return
 445     consts_size()        +
 446     insts_size()         +
 447     stub_size()          +
 448     scopes_data_size()   +
 449     scopes_pcs_size()    +
 450     handler_table_size() +
 451     nul_chk_table_size();
 452 }
 453 
 454 const char* nmethod::compile_kind() const {
 455   if (is_osr_method())     return "osr";
 456   if (method() != NULL && is_native_method())  return "c2n";
 457   return NULL;
 458 }
 459 
 460 // Fill in default values for various flag fields
 461 void nmethod::init_defaults() {
 462   _state                      = alive;
 463   _marked_for_reclamation     = 0;
 464   _has_flushed_dependencies   = 0;
 465   _has_unsafe_access          = 0;
 466   _has_method_handle_invokes  = 0;
 467   _lazy_critical_native       = 0;
 468   _has_wide_vectors           = 0;
 469   _marked_for_deoptimization  = 0;
 470   _lock_count                 = 0;
 471   _stack_traversal_mark       = 0;
 472   _unload_reported            = false;           // jvmti state
 473 
 474 #ifdef ASSERT
 475   _oops_are_stale             = false;
 476 #endif
 477 
 478   _oops_do_mark_link       = NULL;
 479   _jmethod_id              = NULL;
 480   _osr_link                = NULL;
 481   _scavenge_root_link      = NULL;
 482   _scavenge_root_state     = 0;
 483   _compiler                = NULL;
 484 
 485 #ifdef HAVE_DTRACE_H
 486   _trap_offset             = 0;
 487 #endif // def HAVE_DTRACE_H
 488 }
 489 
 490 nmethod* nmethod::new_native_nmethod(methodHandle method,
 491   int compile_id,
 492   CodeBuffer *code_buffer,
 493   int vep_offset,
 494   int frame_complete,
 495   int frame_size,
 496   ByteSize basic_lock_owner_sp_offset,
 497   ByteSize basic_lock_sp_offset,
 498   OopMapSet* oop_maps) {
 499   code_buffer->finalize_oop_references(method);
 500   // create nmethod
 501   nmethod* nm = NULL;
 502   {
 503     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 504     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 505     CodeOffsets offsets;
 506     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 507     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 508     nm = new (native_nmethod_size) nmethod(method(), native_nmethod_size,
 509                                             compile_id, &offsets,
 510                                             code_buffer, frame_size,
 511                                             basic_lock_owner_sp_offset,
 512                                             basic_lock_sp_offset, oop_maps);
 513     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
 514     if (PrintAssembly && nm != NULL) {
 515       Disassembler::decode(nm);
 516     }
 517   }
 518   // verify nmethod
 519   debug_only(if (nm) nm->verify();) // might block
 520 
 521   if (nm != NULL) {
 522     nm->log_new_nmethod();
 523   }
 524 
 525   return nm;
 526 }
 527 
 528 #ifdef HAVE_DTRACE_H
 529 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
 530                                      CodeBuffer *code_buffer,
 531                                      int vep_offset,
 532                                      int trap_offset,
 533                                      int frame_complete,
 534                                      int frame_size) {
 535   code_buffer->finalize_oop_references(method);
 536   // create nmethod
 537   nmethod* nm = NULL;
 538   {
 539     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 540     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 541     CodeOffsets offsets;
 542     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 543     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
 544     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 545 
 546     nm = new (nmethod_size) nmethod(method(), nmethod_size,
 547                                     &offsets, code_buffer, frame_size);
 548 
 549     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 550     if (PrintAssembly && nm != NULL) {
 551       Disassembler::decode(nm);
 552     }
 553   }
 554   // verify nmethod
 555   debug_only(if (nm) nm->verify();) // might block
 556 
 557   if (nm != NULL) {
 558     nm->log_new_nmethod();
 559   }
 560 
 561   return nm;
 562 }
 563 
 564 #endif // def HAVE_DTRACE_H
 565 
 566 nmethod* nmethod::new_nmethod(methodHandle method,
 567   int compile_id,
 568   int entry_bci,
 569   CodeOffsets* offsets,
 570   int orig_pc_offset,
 571   DebugInformationRecorder* debug_info,
 572   Dependencies* dependencies,
 573   CodeBuffer* code_buffer, int frame_size,
 574   OopMapSet* oop_maps,
 575   ExceptionHandlerTable* handler_table,
 576   ImplicitExceptionTable* nul_chk_table,
 577   AbstractCompiler* compiler,
 578   int comp_level
 579 )
 580 {
 581   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 582   code_buffer->finalize_oop_references(method);
 583   // create nmethod
 584   nmethod* nm = NULL;
 585   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 586     int nmethod_size =
 587       allocation_size(code_buffer, sizeof(nmethod))
 588       + adjust_pcs_size(debug_info->pcs_size())
 589       + round_to(dependencies->size_in_bytes() , oopSize)
 590       + round_to(handler_table->size_in_bytes(), oopSize)
 591       + round_to(nul_chk_table->size_in_bytes(), oopSize)
 592       + round_to(debug_info->data_size()       , oopSize);
 593 
 594     nm = new (nmethod_size)
 595     nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
 596             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 597             oop_maps,
 598             handler_table,
 599             nul_chk_table,
 600             compiler,
 601             comp_level);
 602 
 603     if (nm != NULL) {
 604       // To make dependency checking during class loading fast, record
 605       // the nmethod dependencies in the classes it is dependent on.
 606       // This allows the dependency checking code to simply walk the
 607       // class hierarchy above the loaded class, checking only nmethods
 608       // which are dependent on those classes.  The slow way is to
 609       // check every nmethod for dependencies which makes it linear in
 610       // the number of methods compiled.  For applications with a lot
 611       // classes the slow way is too slow.
 612       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 613         Klass* klass = deps.context_type();
 614         if (klass == NULL) {
 615           continue;  // ignore things like evol_method
 616         }
 617 
 618         // record this nmethod as dependent on this klass
 619         InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 620       }
 621     }
 622     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 623     if (PrintAssembly && nm != NULL) {
 624       Disassembler::decode(nm);
 625     }
 626   }
 627 
 628   // verify nmethod
 629   debug_only(if (nm) nm->verify();) // might block
 630 
 631   if (nm != NULL) {
 632     nm->log_new_nmethod();
 633   }
 634 
 635   // done
 636   return nm;
 637 }
 638 
 639 
 640 // For native wrappers
 641 nmethod::nmethod(
 642   Method* method,
 643   int nmethod_size,
 644   int compile_id,
 645   CodeOffsets* offsets,
 646   CodeBuffer* code_buffer,
 647   int frame_size,
 648   ByteSize basic_lock_owner_sp_offset,
 649   ByteSize basic_lock_sp_offset,
 650   OopMapSet* oop_maps )
 651   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
 652              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 653   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 654   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 655 {
 656   {
 657     debug_only(No_Safepoint_Verifier nsv;)
 658     assert_locked_or_safepoint(CodeCache_lock);
 659 
 660     init_defaults();
 661     _method                  = method;
 662     _entry_bci               = InvocationEntryBci;
 663     // We have no exception handler or deopt handler make the
 664     // values something that will never match a pc like the nmethod vtable entry
 665     _exception_offset        = 0;
 666     _deoptimize_offset       = 0;
 667     _deoptimize_mh_offset    = 0;
 668     _orig_pc_offset          = 0;
 669 
 670     _consts_offset           = data_offset();
 671     _stub_offset             = data_offset();
 672     _oops_offset             = data_offset();
 673     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
 674     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
 675     _scopes_pcs_offset       = _scopes_data_offset;
 676     _dependencies_offset     = _scopes_pcs_offset;
 677     _handler_table_offset    = _dependencies_offset;
 678     _nul_chk_table_offset    = _handler_table_offset;
 679     _nmethod_end_offset      = _nul_chk_table_offset;
 680     _compile_id              = compile_id;
 681     _comp_level              = CompLevel_none;
 682     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 683     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 684     _osr_entry_point         = NULL;
 685     _exception_cache         = NULL;
 686     _pc_desc_cache.reset_to(NULL);
 687     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 688 
 689     code_buffer->copy_values_to(this);
 690     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
 691       CodeCache::add_scavenge_root_nmethod(this);
 692       Universe::heap()->register_nmethod(this);
 693     }
 694     debug_only(verify_scavenge_root_oops());
 695     CodeCache::commit(this);
 696   }
 697 
 698   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 699     ttyLocker ttyl;  // keep the following output all in one block
 700     // This output goes directly to the tty, not the compiler log.
 701     // To enable tools to match it up with the compilation activity,
 702     // be sure to tag this tty output with the compile ID.
 703     if (xtty != NULL) {
 704       xtty->begin_head("print_native_nmethod");
 705       xtty->method(_method);
 706       xtty->stamp();
 707       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 708     }
 709     // print the header part first
 710     print();
 711     // then print the requested information
 712     if (PrintNativeNMethods) {
 713       print_code();
 714       if (oop_maps != NULL) {
 715         oop_maps->print();
 716       }
 717     }
 718     if (PrintRelocations) {
 719       print_relocations();
 720     }
 721     if (xtty != NULL) {
 722       xtty->tail("print_native_nmethod");
 723     }
 724   }
 725 }
 726 
 727 // For dtrace wrappers
 728 #ifdef HAVE_DTRACE_H
 729 nmethod::nmethod(
 730   Method* method,
 731   int nmethod_size,
 732   CodeOffsets* offsets,
 733   CodeBuffer* code_buffer,
 734   int frame_size)
 735   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
 736              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
 737   _native_receiver_sp_offset(in_ByteSize(-1)),
 738   _native_basic_lock_sp_offset(in_ByteSize(-1))
 739 {
 740   {
 741     debug_only(No_Safepoint_Verifier nsv;)
 742     assert_locked_or_safepoint(CodeCache_lock);
 743 
 744     init_defaults();
 745     _method                  = method;
 746     _entry_bci               = InvocationEntryBci;
 747     // We have no exception handler or deopt handler make the
 748     // values something that will never match a pc like the nmethod vtable entry
 749     _exception_offset        = 0;
 750     _deoptimize_offset       = 0;
 751     _deoptimize_mh_offset    = 0;
 752     _unwind_handler_offset   = -1;
 753     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
 754     _orig_pc_offset          = 0;
 755     _consts_offset           = data_offset();
 756     _stub_offset             = data_offset();
 757     _oops_offset             = data_offset();
 758     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
 759     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
 760     _scopes_pcs_offset       = _scopes_data_offset;
 761     _dependencies_offset     = _scopes_pcs_offset;
 762     _handler_table_offset    = _dependencies_offset;
 763     _nul_chk_table_offset    = _handler_table_offset;
 764     _nmethod_end_offset      = _nul_chk_table_offset;
 765     _compile_id              = 0;  // default
 766     _comp_level              = CompLevel_none;
 767     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 768     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 769     _osr_entry_point         = NULL;
 770     _exception_cache         = NULL;
 771     _pc_desc_cache.reset_to(NULL);
 772     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 773 
 774     code_buffer->copy_values_to(this);
 775     debug_only(verify_scavenge_root_oops());
 776     CodeCache::commit(this);
 777   }
 778 
 779   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 780     ttyLocker ttyl;  // keep the following output all in one block
 781     // This output goes directly to the tty, not the compiler log.
 782     // To enable tools to match it up with the compilation activity,
 783     // be sure to tag this tty output with the compile ID.
 784     if (xtty != NULL) {
 785       xtty->begin_head("print_dtrace_nmethod");
 786       xtty->method(_method);
 787       xtty->stamp();
 788       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 789     }
 790     // print the header part first
 791     print();
 792     // then print the requested information
 793     if (PrintNMethods) {
 794       print_code();
 795     }
 796     if (PrintRelocations) {
 797       print_relocations();
 798     }
 799     if (xtty != NULL) {
 800       xtty->tail("print_dtrace_nmethod");
 801     }
 802   }
 803 }
 804 #endif // def HAVE_DTRACE_H
 805 
 806 void* nmethod::operator new(size_t size, int nmethod_size) throw () {
 807   // Not critical, may return null if there is too little continuous memory
 808   return CodeCache::allocate(nmethod_size);
 809 }
 810 
 811 nmethod::nmethod(
 812   Method* method,
 813   int nmethod_size,
 814   int compile_id,
 815   int entry_bci,
 816   CodeOffsets* offsets,
 817   int orig_pc_offset,
 818   DebugInformationRecorder* debug_info,
 819   Dependencies* dependencies,
 820   CodeBuffer *code_buffer,
 821   int frame_size,
 822   OopMapSet* oop_maps,
 823   ExceptionHandlerTable* handler_table,
 824   ImplicitExceptionTable* nul_chk_table,
 825   AbstractCompiler* compiler,
 826   int comp_level
 827   )
 828   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
 829              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 830   _native_receiver_sp_offset(in_ByteSize(-1)),
 831   _native_basic_lock_sp_offset(in_ByteSize(-1))
 832 {
 833   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 834   {
 835     debug_only(No_Safepoint_Verifier nsv;)
 836     assert_locked_or_safepoint(CodeCache_lock);
 837 
 838     init_defaults();
 839     _method                  = method;
 840     _entry_bci               = entry_bci;
 841     _compile_id              = compile_id;
 842     _comp_level              = comp_level;
 843     _compiler                = compiler;
 844     _orig_pc_offset          = orig_pc_offset;
 845     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 846 
 847     // Section offsets
 848     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 849     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 850 
 851     // Exception handler and deopt handler are in the stub section
 852     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 853     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 854     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 855     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
 856     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 857       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 858     } else {
 859       _deoptimize_mh_offset  = -1;
 860     }
 861     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 862       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 863     } else {
 864       _unwind_handler_offset = -1;
 865     }
 866 
 867     _oops_offset             = data_offset();
 868     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 869     _scopes_data_offset      = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
 870 
 871     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
 872     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 873     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
 874     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
 875     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
 876 
 877     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 878     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 879     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 880     _exception_cache         = NULL;
 881     _pc_desc_cache.reset_to(scopes_pcs_begin());
 882 
 883     // Copy contents of ScopeDescRecorder to nmethod
 884     code_buffer->copy_values_to(this);
 885     debug_info->copy_to(this);
 886     dependencies->copy_to(this);
 887     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
 888       CodeCache::add_scavenge_root_nmethod(this);
 889       Universe::heap()->register_nmethod(this);
 890     }
 891     debug_only(verify_scavenge_root_oops());
 892 
 893     CodeCache::commit(this);
 894 
 895     // Copy contents of ExceptionHandlerTable to nmethod
 896     handler_table->copy_to(this);
 897     nul_chk_table->copy_to(this);
 898 
 899     // we use the information of entry points to find out if a method is
 900     // static or non static
 901     assert(compiler->is_c2() ||
 902            _method->is_static() == (entry_point() == _verified_entry_point),
 903            " entry points must be same for static methods and vice versa");
 904   }
 905 
 906   bool printnmethods = PrintNMethods
 907     || CompilerOracle::should_print(_method)
 908     || CompilerOracle::has_option_string(_method, "PrintNMethods");
 909   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 910     print_nmethod(printnmethods);
 911   }
 912 }
 913 
 914 
 915 // Print a short set of xml attributes to identify this nmethod.  The
 916 // output should be embedded in some other element.
 917 void nmethod::log_identity(xmlStream* log) const {
 918   log->print(" compile_id='%d'", compile_id());
 919   const char* nm_kind = compile_kind();
 920   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 921   if (compiler() != NULL) {
 922     log->print(" compiler='%s'", compiler()->name());
 923   }
 924   if (TieredCompilation) {
 925     log->print(" level='%d'", comp_level());
 926   }
 927 }
 928 
 929 
 930 #define LOG_OFFSET(log, name)                    \
 931   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
 932     log->print(" " XSTR(name) "_offset='%d'"    , \
 933                (intptr_t)name##_begin() - (intptr_t)this)
 934 
 935 
 936 void nmethod::log_new_nmethod() const {
 937   if (LogCompilation && xtty != NULL) {
 938     ttyLocker ttyl;
 939     HandleMark hm;
 940     xtty->begin_elem("nmethod");
 941     log_identity(xtty);
 942     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
 943     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 944 
 945     LOG_OFFSET(xtty, relocation);
 946     LOG_OFFSET(xtty, consts);
 947     LOG_OFFSET(xtty, insts);
 948     LOG_OFFSET(xtty, stub);
 949     LOG_OFFSET(xtty, scopes_data);
 950     LOG_OFFSET(xtty, scopes_pcs);
 951     LOG_OFFSET(xtty, dependencies);
 952     LOG_OFFSET(xtty, handler_table);
 953     LOG_OFFSET(xtty, nul_chk_table);
 954     LOG_OFFSET(xtty, oops);
 955 
 956     xtty->method(method());
 957     xtty->stamp();
 958     xtty->end_elem();
 959   }
 960 }
 961 
 962 #undef LOG_OFFSET
 963 
 964 
 965 // Print out more verbose output usually for a newly created nmethod.
 966 void nmethod::print_on(outputStream* st, const char* msg) const {
 967   if (st != NULL) {
 968     ttyLocker ttyl;
 969     if (WizardMode) {
 970       CompileTask::print_compilation(st, this, msg, /*short_form:*/ true);
 971       st->print_cr(" (" INTPTR_FORMAT ")", this);
 972     } else {
 973       CompileTask::print_compilation(st, this, msg, /*short_form:*/ false);
 974     }
 975   }
 976 }
 977 
 978 
 979 void nmethod::print_nmethod(bool printmethod) {
 980   ttyLocker ttyl;  // keep the following output all in one block
 981   if (xtty != NULL) {
 982     xtty->begin_head("print_nmethod");
 983     xtty->stamp();
 984     xtty->end_head();
 985   }
 986   // print the header part first
 987   print();
 988   // then print the requested information
 989   if (printmethod) {
 990     print_code();
 991     print_pcs();
 992     if (oop_maps()) {
 993       oop_maps()->print();
 994     }
 995   }
 996   if (PrintDebugInfo) {
 997     print_scopes();
 998   }
 999   if (PrintRelocations) {
1000     print_relocations();
1001   }
1002   if (PrintDependencies) {
1003     print_dependencies();
1004   }
1005   if (PrintExceptionHandlers) {
1006     print_handler_table();
1007     print_nul_chk_table();
1008   }
1009   if (xtty != NULL) {
1010     xtty->tail("print_nmethod");
1011   }
1012 }
1013 
1014 
1015 // Promote one word from an assembly-time handle to a live embedded oop.
1016 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1017   if (handle == NULL ||
1018       // As a special case, IC oops are initialized to 1 or -1.
1019       handle == (jobject) Universe::non_oop_word()) {
1020     (*dest) = (oop) handle;
1021   } else {
1022     (*dest) = JNIHandles::resolve_non_null(handle);
1023   }
1024 }
1025 
1026 
1027 // Have to have the same name because it's called by a template
1028 void nmethod::copy_values(GrowableArray<jobject>* array) {
1029   int length = array->length();
1030   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
1031   oop* dest = oops_begin();
1032   for (int index = 0 ; index < length; index++) {
1033     initialize_immediate_oop(&dest[index], array->at(index));
1034   }
1035 
1036   // Now we can fix up all the oops in the code.  We need to do this
1037   // in the code because the assembler uses jobjects as placeholders.
1038   // The code and relocations have already been initialized by the
1039   // CodeBlob constructor, so it is valid even at this early point to
1040   // iterate over relocations and patch the code.
1041   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
1042 }
1043 
1044 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
1045   int length = array->length();
1046   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
1047   Metadata** dest = metadata_begin();
1048   for (int index = 0 ; index < length; index++) {
1049     dest[index] = array->at(index);
1050   }
1051 }
1052 
1053 bool nmethod::is_at_poll_return(address pc) {
1054   RelocIterator iter(this, pc, pc+1);
1055   while (iter.next()) {
1056     if (iter.type() == relocInfo::poll_return_type)
1057       return true;
1058   }
1059   return false;
1060 }
1061 
1062 
1063 bool nmethod::is_at_poll_or_poll_return(address pc) {
1064   RelocIterator iter(this, pc, pc+1);
1065   while (iter.next()) {
1066     relocInfo::relocType t = iter.type();
1067     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
1068       return true;
1069   }
1070   return false;
1071 }
1072 
1073 
1074 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1075   // re-patch all oop-bearing instructions, just in case some oops moved
1076   RelocIterator iter(this, begin, end);
1077   while (iter.next()) {
1078     if (iter.type() == relocInfo::oop_type) {
1079       oop_Relocation* reloc = iter.oop_reloc();
1080       if (initialize_immediates && reloc->oop_is_immediate()) {
1081         oop* dest = reloc->oop_addr();
1082         initialize_immediate_oop(dest, (jobject) *dest);
1083       }
1084       // Refresh the oop-related bits of this instruction.
1085       reloc->fix_oop_relocation();
1086     } else if (iter.type() == relocInfo::metadata_type) {
1087       metadata_Relocation* reloc = iter.metadata_reloc();
1088       reloc->fix_metadata_relocation();
1089     }
1090   }
1091 }
1092 
1093 
1094 void nmethod::verify_oop_relocations() {
1095   // Ensure sure that the code matches the current oop values
1096   RelocIterator iter(this, NULL, NULL);
1097   while (iter.next()) {
1098     if (iter.type() == relocInfo::oop_type) {
1099       oop_Relocation* reloc = iter.oop_reloc();
1100       if (!reloc->oop_is_immediate()) {
1101         reloc->verify_oop_relocation();
1102       }
1103     }
1104   }
1105 }
1106 
1107 
1108 ScopeDesc* nmethod::scope_desc_at(address pc) {
1109   PcDesc* pd = pc_desc_at(pc);
1110   guarantee(pd != NULL, "scope must be present");
1111   return new ScopeDesc(this, pd->scope_decode_offset(),
1112                        pd->obj_decode_offset(), pd->should_reexecute(),
1113                        pd->return_oop());
1114 }
1115 
1116 
1117 void nmethod::clear_inline_caches() {
1118   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
1119   if (is_zombie()) {
1120     return;
1121   }
1122 
1123   RelocIterator iter(this);
1124   while (iter.next()) {
1125     iter.reloc()->clear_inline_cache();
1126   }
1127 }
1128 
1129 
1130 void nmethod::cleanup_inline_caches() {
1131 
1132   assert_locked_or_safepoint(CompiledIC_lock);
1133 
1134   // If the method is not entrant or zombie then a JMP is plastered over the
1135   // first few bytes.  If an oop in the old code was there, that oop
1136   // should not get GC'd.  Skip the first few bytes of oops on
1137   // not-entrant methods.
1138   address low_boundary = verified_entry_point();
1139   if (!is_in_use()) {
1140     low_boundary += NativeJump::instruction_size;
1141     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1142     // This means that the low_boundary is going to be a little too high.
1143     // This shouldn't matter, since oops of non-entrant methods are never used.
1144     // In fact, why are we bothering to look at oops in a non-entrant method??
1145   }
1146 
1147   // Find all calls in an nmethod, and clear the ones that points to zombie methods
1148   ResourceMark rm;
1149   RelocIterator iter(this, low_boundary);
1150   while(iter.next()) {
1151     switch(iter.type()) {
1152       case relocInfo::virtual_call_type:
1153       case relocInfo::opt_virtual_call_type: {
1154         CompiledIC *ic = CompiledIC_at(iter.reloc());
1155         // Ok, to lookup references to zombies here
1156         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1157         if( cb != NULL && cb->is_nmethod() ) {
1158           nmethod* nm = (nmethod*)cb;
1159           // Clean inline caches pointing to both zombie and not_entrant methods
1160           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
1161         }
1162         break;
1163       }
1164       case relocInfo::static_call_type: {
1165         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1166         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1167         if( cb != NULL && cb->is_nmethod() ) {
1168           nmethod* nm = (nmethod*)cb;
1169           // Clean inline caches pointing to both zombie and not_entrant methods
1170           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
1171         }
1172         break;
1173       }
1174     }
1175   }
1176 }
1177 
1178 // This is a private interface with the sweeper.
1179 void nmethod::mark_as_seen_on_stack() {
1180   assert(is_not_entrant(), "must be a non-entrant method");
1181   // Set the traversal mark to ensure that the sweeper does 2
1182   // cleaning passes before moving to zombie.
1183   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1184 }
1185 
1186 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1187 // there are no activations on the stack, not in use by the VM,
1188 // and not in use by the ServiceThread)
1189 bool nmethod::can_not_entrant_be_converted() {
1190   assert(is_not_entrant(), "must be a non-entrant method");
1191 
1192   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1193   // count can be greater than the stack traversal count before it hits the
1194   // nmethod for the second time.
1195   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1196          !is_locked_by_vm();
1197 }
1198 
1199 void nmethod::inc_decompile_count() {
1200   if (!is_compiled_by_c2()) return;
1201   // Could be gated by ProfileTraps, but do not bother...
1202   Method* m = method();
1203   if (m == NULL)  return;
1204   MethodData* mdo = m->method_data();
1205   if (mdo == NULL)  return;
1206   // There is a benign race here.  See comments in methodData.hpp.
1207   mdo->inc_decompile_count();
1208 }
1209 
1210 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1211 
1212   post_compiled_method_unload();
1213 
1214   // Since this nmethod is being unloaded, make sure that dependencies
1215   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1216   // indicate that this work is being done during a GC.
1217   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1218   assert(is_alive != NULL, "Should be non-NULL");
1219   // A non-NULL is_alive closure indicates that this is being called during GC.
1220   flush_dependencies(is_alive);
1221 
1222   // Break cycle between nmethod & method
1223   if (TraceClassUnloading && WizardMode) {
1224     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
1225                   " unloadable], Method*(" INTPTR_FORMAT
1226                   "), cause(" INTPTR_FORMAT ")",
1227                   this, (address)_method, (address)cause);
1228     if (!Universe::heap()->is_gc_active())
1229       cause->klass()->print();
1230   }
1231   // Unlink the osr method, so we do not look this up again
1232   if (is_osr_method()) {
1233     invalidate_osr_method();
1234   }
1235   // If _method is already NULL the Method* is about to be unloaded,
1236   // so we don't have to break the cycle. Note that it is possible to
1237   // have the Method* live here, in case we unload the nmethod because
1238   // it is pointing to some oop (other than the Method*) being unloaded.
1239   if (_method != NULL) {
1240     // OSR methods point to the Method*, but the Method* does not
1241     // point back!
1242     if (_method->code() == this) {
1243       _method->clear_code(); // Break a cycle
1244     }
1245     _method = NULL;            // Clear the method of this dead nmethod
1246   }
1247   // Make the class unloaded - i.e., change state and notify sweeper
1248   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1249   if (is_in_use()) {
1250     // Transitioning directly from live to unloaded -- so
1251     // we need to force a cache clean-up; remember this
1252     // for later on.
1253     CodeCache::set_needs_cache_clean(true);
1254   }
1255   _state = unloaded;
1256 
1257   // Log the unloading.
1258   log_state_change();
1259 
1260   // The Method* is gone at this point
1261   assert(_method == NULL, "Tautology");
1262 
1263   set_osr_link(NULL);
1264   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
1265   NMethodSweeper::notify();
1266 }
1267 
1268 void nmethod::invalidate_osr_method() {
1269   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1270   // Remove from list of active nmethods
1271   if (method() != NULL)
1272     method()->method_holder()->remove_osr_nmethod(this);
1273   // Set entry as invalid
1274   _entry_bci = InvalidOSREntryBci;
1275 }
1276 
1277 void nmethod::log_state_change() const {
1278   if (LogCompilation) {
1279     if (xtty != NULL) {
1280       ttyLocker ttyl;  // keep the following output all in one block
1281       if (_state == unloaded) {
1282         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1283                          os::current_thread_id());
1284       } else {
1285         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1286                          os::current_thread_id(),
1287                          (_state == zombie ? " zombie='1'" : ""));
1288       }
1289       log_identity(xtty);
1290       xtty->stamp();
1291       xtty->end_elem();
1292     }
1293   }
1294   if (PrintCompilation && _state != unloaded) {
1295     print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
1296   }
1297 }
1298 
1299 // Common functionality for both make_not_entrant and make_zombie
1300 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1301   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1302   assert(!is_zombie(), "should not already be a zombie");
1303 
1304   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1305   nmethodLocker nml(this);
1306   methodHandle the_method(method());
1307   No_Safepoint_Verifier nsv;
1308 
1309   // during patching, depending on the nmethod state we must notify the GC that
1310   // code has been unloaded, unregistering it. We cannot do this right while
1311   // holding the Patching_lock because we need to use the CodeCache_lock. This
1312   // would be prone to deadlocks.
1313   // This flag is used to remember whether we need to later lock and unregister.
1314   bool nmethod_needs_unregister = false;
1315 
1316   {
1317     // invalidate osr nmethod before acquiring the patching lock since
1318     // they both acquire leaf locks and we don't want a deadlock.
1319     // This logic is equivalent to the logic below for patching the
1320     // verified entry point of regular methods.
1321     if (is_osr_method()) {
1322       // this effectively makes the osr nmethod not entrant
1323       invalidate_osr_method();
1324     }
1325 
1326     // Enter critical section.  Does not block for safepoint.
1327     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1328 
1329     if (_state == state) {
1330       // another thread already performed this transition so nothing
1331       // to do, but return false to indicate this.
1332       return false;
1333     }
1334 
1335     // The caller can be calling the method statically or through an inline
1336     // cache call.
1337     if (!is_osr_method() && !is_not_entrant()) {
1338       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1339                   SharedRuntime::get_handle_wrong_method_stub());
1340     }
1341 
1342     if (is_in_use()) {
1343       // It's a true state change, so mark the method as decompiled.
1344       // Do it only for transition from alive.
1345       inc_decompile_count();
1346     }
1347 
1348     // If the state is becoming a zombie, signal to unregister the nmethod with
1349     // the heap.
1350     // This nmethod may have already been unloaded during a full GC.
1351     if ((state == zombie) && !is_unloaded()) {
1352       nmethod_needs_unregister = true;
1353     }
1354 
1355     // Must happen before state change. Otherwise we have a race condition in
1356     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1357     // transition its state from 'not_entrant' to 'zombie' without having to wait
1358     // for stack scanning.
1359     if (state == not_entrant) {
1360       mark_as_seen_on_stack();
1361     }
1362 
1363     // Change state
1364     _state = state;
1365 
1366     // Log the transition once
1367     log_state_change();
1368 
1369     // Remove nmethod from method.
1370     // We need to check if both the _code and _from_compiled_code_entry_point
1371     // refer to this nmethod because there is a race in setting these two fields
1372     // in Method* as seen in bugid 4947125.
1373     // If the vep() points to the zombie nmethod, the memory for the nmethod
1374     // could be flushed and the compiler and vtable stubs could still call
1375     // through it.
1376     if (method() != NULL && (method()->code() == this ||
1377                              method()->from_compiled_entry() == verified_entry_point())) {
1378       HandleMark hm;
1379       method()->clear_code();
1380     }
1381   } // leave critical region under Patching_lock
1382 
1383   // When the nmethod becomes zombie it is no longer alive so the
1384   // dependencies must be flushed.  nmethods in the not_entrant
1385   // state will be flushed later when the transition to zombie
1386   // happens or they get unloaded.
1387   if (state == zombie) {
1388     {
1389       // Flushing dependecies must be done before any possible
1390       // safepoint can sneak in, otherwise the oops used by the
1391       // dependency logic could have become stale.
1392       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1393       if (nmethod_needs_unregister) {
1394         Universe::heap()->unregister_nmethod(this);
1395       }
1396       flush_dependencies(NULL);
1397     }
1398 
1399     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1400     // event and it hasn't already been reported for this nmethod then
1401     // report it now. The event may have been reported earilier if the GC
1402     // marked it for unloading). JvmtiDeferredEventQueue support means
1403     // we no longer go to a safepoint here.
1404     post_compiled_method_unload();
1405 
1406 #ifdef ASSERT
1407     // It's no longer safe to access the oops section since zombie
1408     // nmethods aren't scanned for GC.
1409     _oops_are_stale = true;
1410 #endif
1411      // the Method may be reclaimed by class unloading now that the
1412      // nmethod is in zombie state
1413     set_method(NULL);
1414   } else {
1415     assert(state == not_entrant, "other cases may need to be handled differently");
1416   }
1417 
1418   if (TraceCreateZombies) {
1419     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
1420   }
1421 
1422   // Make sweeper aware that there is a zombie method that needs to be removed
1423   NMethodSweeper::notify();
1424 
1425   return true;
1426 }
1427 
1428 void nmethod::flush() {
1429   // Note that there are no valid oops in the nmethod anymore.
1430   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
1431   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
1432 
1433   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1434   assert_locked_or_safepoint(CodeCache_lock);
1435 
1436   // completely deallocate this method
1437   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, this);
1438   if (PrintMethodFlushing) {
1439     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
1440         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
1441   }
1442 
1443   // We need to deallocate any ExceptionCache data.
1444   // Note that we do not need to grab the nmethod lock for this, it
1445   // better be thread safe if we're disposing of it!
1446   ExceptionCache* ec = exception_cache();
1447   set_exception_cache(NULL);
1448   while(ec != NULL) {
1449     ExceptionCache* next = ec->next();
1450     delete ec;
1451     ec = next;
1452   }
1453 
1454   if (on_scavenge_root_list()) {
1455     CodeCache::drop_scavenge_root_nmethod(this);
1456   }
1457 
1458 #ifdef SHARK
1459   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1460 #endif // SHARK
1461 
1462   ((CodeBlob*)(this))->flush();
1463 
1464   CodeCache::free(this);
1465 }
1466 
1467 
1468 //
1469 // Notify all classes this nmethod is dependent on that it is no
1470 // longer dependent. This should only be called in two situations.
1471 // First, when a nmethod transitions to a zombie all dependents need
1472 // to be clear.  Since zombification happens at a safepoint there's no
1473 // synchronization issues.  The second place is a little more tricky.
1474 // During phase 1 of mark sweep class unloading may happen and as a
1475 // result some nmethods may get unloaded.  In this case the flushing
1476 // of dependencies must happen during phase 1 since after GC any
1477 // dependencies in the unloaded nmethod won't be updated, so
1478 // traversing the dependency information in unsafe.  In that case this
1479 // function is called with a non-NULL argument and this function only
1480 // notifies instanceKlasses that are reachable
1481 
1482 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1483   assert_locked_or_safepoint(CodeCache_lock);
1484   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1485   "is_alive is non-NULL if and only if we are called during GC");
1486   if (!has_flushed_dependencies()) {
1487     set_has_flushed_dependencies();
1488     for (Dependencies::DepStream deps(this); deps.next(); ) {
1489       Klass* klass = deps.context_type();
1490       if (klass == NULL)  continue;  // ignore things like evol_method
1491 
1492       // During GC the is_alive closure is non-NULL, and is used to
1493       // determine liveness of dependees that need to be updated.
1494       if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
1495         InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
1496       }
1497     }
1498   }
1499 }
1500 
1501 
1502 // If this oop is not live, the nmethod can be unloaded.
1503 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
1504   assert(root != NULL, "just checking");
1505   oop obj = *root;
1506   if (obj == NULL || is_alive->do_object_b(obj)) {
1507       return false;
1508   }
1509 
1510   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1511   // simply because one of its constant oops has gone dead.
1512   // No actual classes need to be unloaded in order for this to occur.
1513   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1514   make_unloaded(is_alive, obj);
1515   return true;
1516 }
1517 
1518 // ------------------------------------------------------------------
1519 // post_compiled_method_load_event
1520 // new method for install_code() path
1521 // Transfer information from compilation to jvmti
1522 void nmethod::post_compiled_method_load_event() {
1523 
1524   Method* moop = method();
1525 #ifndef USDT2
1526   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
1527       moop->klass_name()->bytes(),
1528       moop->klass_name()->utf8_length(),
1529       moop->name()->bytes(),
1530       moop->name()->utf8_length(),
1531       moop->signature()->bytes(),
1532       moop->signature()->utf8_length(),
1533       insts_begin(), insts_size());
1534 #else /* USDT2 */
1535   HOTSPOT_COMPILED_METHOD_LOAD(
1536       (char *) moop->klass_name()->bytes(),
1537       moop->klass_name()->utf8_length(),
1538       (char *) moop->name()->bytes(),
1539       moop->name()->utf8_length(),
1540       (char *) moop->signature()->bytes(),
1541       moop->signature()->utf8_length(),
1542       insts_begin(), insts_size());
1543 #endif /* USDT2 */
1544 
1545   if (JvmtiExport::should_post_compiled_method_load() ||
1546       JvmtiExport::should_post_compiled_method_unload()) {
1547     get_and_cache_jmethod_id();
1548   }
1549 
1550   if (JvmtiExport::should_post_compiled_method_load()) {
1551     // Let the Service thread (which is a real Java thread) post the event
1552     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1553     JvmtiDeferredEventQueue::enqueue(
1554       JvmtiDeferredEvent::compiled_method_load_event(this));
1555   }
1556 }
1557 
1558 jmethodID nmethod::get_and_cache_jmethod_id() {
1559   if (_jmethod_id == NULL) {
1560     // Cache the jmethod_id since it can no longer be looked up once the
1561     // method itself has been marked for unloading.
1562     _jmethod_id = method()->jmethod_id();
1563   }
1564   return _jmethod_id;
1565 }
1566 
1567 void nmethod::post_compiled_method_unload() {
1568   if (unload_reported()) {
1569     // During unloading we transition to unloaded and then to zombie
1570     // and the unloading is reported during the first transition.
1571     return;
1572   }
1573 
1574   assert(_method != NULL && !is_unloaded(), "just checking");
1575   DTRACE_METHOD_UNLOAD_PROBE(method());
1576 
1577   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1578   // post the event. Sometime later this nmethod will be made a zombie
1579   // by the sweeper but the Method* will not be valid at that point.
1580   // If the _jmethod_id is null then no load event was ever requested
1581   // so don't bother posting the unload.  The main reason for this is
1582   // that the jmethodID is a weak reference to the Method* so if
1583   // it's being unloaded there's no way to look it up since the weak
1584   // ref will have been cleared.
1585   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1586     assert(!unload_reported(), "already unloaded");
1587     JvmtiDeferredEvent event =
1588       JvmtiDeferredEvent::compiled_method_unload_event(this,
1589           _jmethod_id, insts_begin());
1590     if (SafepointSynchronize::is_at_safepoint()) {
1591       // Don't want to take the queueing lock. Add it as pending and
1592       // it will get enqueued later.
1593       JvmtiDeferredEventQueue::add_pending_event(event);
1594     } else {
1595       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1596       JvmtiDeferredEventQueue::enqueue(event);
1597     }
1598   }
1599 
1600   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1601   // any time. As the nmethod is being unloaded now we mark it has
1602   // having the unload event reported - this will ensure that we don't
1603   // attempt to report the event in the unlikely scenario where the
1604   // event is enabled at the time the nmethod is made a zombie.
1605   set_unload_reported();
1606 }
1607 
1608 // This is called at the end of the strong tracing/marking phase of a
1609 // GC to unload an nmethod if it contains otherwise unreachable
1610 // oops.
1611 
1612 void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
1613   // Make sure the oop's ready to receive visitors
1614   assert(!is_zombie() && !is_unloaded(),
1615          "should not call follow on zombie or unloaded nmethod");
1616 
1617   // If the method is not entrant then a JMP is plastered over the
1618   // first few bytes.  If an oop in the old code was there, that oop
1619   // should not get GC'd.  Skip the first few bytes of oops on
1620   // not-entrant methods.
1621   address low_boundary = verified_entry_point();
1622   if (is_not_entrant()) {
1623     low_boundary += NativeJump::instruction_size;
1624     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1625     // (See comment above.)
1626   }
1627 
1628   // The RedefineClasses() API can cause the class unloading invariant
1629   // to no longer be true. See jvmtiExport.hpp for details.
1630   // Also, leave a debugging breadcrumb in local flag.
1631   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
1632   if (a_class_was_redefined) {
1633     // This set of the unloading_occurred flag is done before the
1634     // call to post_compiled_method_unload() so that the unloading
1635     // of this nmethod is reported.
1636     unloading_occurred = true;
1637   }
1638 
1639   // Exception cache
1640   ExceptionCache* ec = exception_cache();
1641   while (ec != NULL) {
1642     Klass* ex_klass = ec->exception_type();
1643     ExceptionCache* next_ec = ec->next();
1644     if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
1645       remove_from_exception_cache(ec);
1646     }
1647     ec = next_ec;
1648   }
1649 
1650   // If class unloading occurred we first iterate over all inline caches and
1651   // clear ICs where the cached oop is referring to an unloaded klass or method.
1652   // The remaining live cached oops will be traversed in the relocInfo::oop_type
1653   // iteration below.
1654   if (unloading_occurred) {
1655     RelocIterator iter(this, low_boundary);
1656     while(iter.next()) {
1657       if (iter.type() == relocInfo::virtual_call_type) {
1658         CompiledIC *ic = CompiledIC_at(iter.reloc());
1659         if (ic->is_icholder_call()) {
1660           // The only exception is compiledICHolder oops which may
1661           // yet be marked below. (We check this further below).
1662           CompiledICHolder* cichk_oop = ic->cached_icholder();
1663           if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
1664               cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
1665               continue;
1666             }
1667         } else {
1668           Metadata* ic_oop = ic->cached_metadata();
1669           if (ic_oop != NULL) {
1670             if (ic_oop->is_klass()) {
1671               if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
1672                 continue;
1673               }
1674             } else if (ic_oop->is_method()) {
1675               if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
1676                 continue;
1677               }
1678             } else {
1679               ShouldNotReachHere();
1680             }
1681           }
1682           }
1683           ic->set_to_clean();
1684       }
1685     }
1686   }
1687 
1688   // Compiled code
1689   {
1690   RelocIterator iter(this, low_boundary);
1691   while (iter.next()) {
1692     if (iter.type() == relocInfo::oop_type) {
1693       oop_Relocation* r = iter.oop_reloc();
1694       // In this loop, we must only traverse those oops directly embedded in
1695       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1696       assert(1 == (r->oop_is_immediate()) +
1697                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1698              "oop must be found in exactly one place");
1699       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1700         if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
1701           return;
1702         }
1703       }
1704     }
1705   }
1706   }
1707 
1708 
1709   // Scopes
1710   for (oop* p = oops_begin(); p < oops_end(); p++) {
1711     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1712     if (can_unload(is_alive, p, unloading_occurred)) {
1713       return;
1714     }
1715   }
1716 
1717   // Ensure that all metadata is still alive
1718   verify_metadata_loaders(low_boundary, is_alive);
1719 }
1720 
1721 #ifdef ASSERT
1722 
1723 class CheckClass : AllStatic {
1724   static BoolObjectClosure* _is_alive;
1725 
1726   // Check class_loader is alive for this bit of metadata.
1727   static void check_class(Metadata* md) {
1728     Klass* klass = NULL;
1729     if (md->is_klass()) {
1730       klass = ((Klass*)md);
1731     } else if (md->is_method()) {
1732       klass = ((Method*)md)->method_holder();
1733     } else if (md->is_methodData()) {
1734       klass = ((MethodData*)md)->method()->method_holder();
1735     } else {
1736       md->print();
1737       ShouldNotReachHere();
1738     }
1739     assert(klass->is_loader_alive(_is_alive), "must be alive");
1740   }
1741  public:
1742   static void do_check_class(BoolObjectClosure* is_alive, nmethod* nm) {
1743     assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
1744     _is_alive = is_alive;
1745     nm->metadata_do(check_class);
1746   }
1747 };
1748 
1749 // This is called during a safepoint so can use static data
1750 BoolObjectClosure* CheckClass::_is_alive = NULL;
1751 #endif // ASSERT
1752 
1753 
1754 // Processing of oop references should have been sufficient to keep
1755 // all strong references alive.  Any weak references should have been
1756 // cleared as well.  Visit all the metadata and ensure that it's
1757 // really alive.
1758 void nmethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
1759 #ifdef ASSERT
1760     RelocIterator iter(this, low_boundary);
1761     while (iter.next()) {
1762     // static_stub_Relocations may have dangling references to
1763     // Method*s so trim them out here.  Otherwise it looks like
1764     // compiled code is maintaining a link to dead metadata.
1765     address static_call_addr = NULL;
1766     if (iter.type() == relocInfo::opt_virtual_call_type) {
1767       CompiledIC* cic = CompiledIC_at(iter.reloc());
1768       if (!cic->is_call_to_interpreted()) {
1769         static_call_addr = iter.addr();
1770       }
1771     } else if (iter.type() == relocInfo::static_call_type) {
1772       CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
1773       if (!csc->is_call_to_interpreted()) {
1774         static_call_addr = iter.addr();
1775       }
1776     }
1777     if (static_call_addr != NULL) {
1778       RelocIterator sciter(this, low_boundary);
1779       while (sciter.next()) {
1780         if (sciter.type() == relocInfo::static_stub_type &&
1781             sciter.static_stub_reloc()->static_call() == static_call_addr) {
1782           sciter.static_stub_reloc()->clear_inline_cache();
1783         }
1784       }
1785     }
1786   }
1787   // Check that the metadata embedded in the nmethod is alive
1788   CheckClass::do_check_class(is_alive, this);
1789 #endif
1790 }
1791 
1792 
1793 // Iterate over metadata calling this function.   Used by RedefineClasses
1794 void nmethod::metadata_do(void f(Metadata*)) {
1795   address low_boundary = verified_entry_point();
1796   if (is_not_entrant()) {
1797     low_boundary += NativeJump::instruction_size;
1798     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1799     // (See comment above.)
1800   }
1801   {
1802     // Visit all immediate references that are embedded in the instruction stream.
1803     RelocIterator iter(this, low_boundary);
1804     while (iter.next()) {
1805       if (iter.type() == relocInfo::metadata_type ) {
1806         metadata_Relocation* r = iter.metadata_reloc();
1807         // In this lmetadata, we must only follow those metadatas directly embedded in
1808         // the code.  Other metadatas (oop_index>0) are seen as part of
1809         // the metadata section below.
1810         assert(1 == (r->metadata_is_immediate()) +
1811                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1812                "metadata must be found in exactly one place");
1813         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1814           Metadata* md = r->metadata_value();
1815           f(md);
1816         }
1817       } else if (iter.type() == relocInfo::virtual_call_type) {
1818         // Check compiledIC holders associated with this nmethod
1819         CompiledIC *ic = CompiledIC_at(iter.reloc());
1820         if (ic->is_icholder_call()) {
1821           CompiledICHolder* cichk = ic->cached_icholder();
1822           f(cichk->holder_method());
1823           f(cichk->holder_klass());
1824         } else {
1825           Metadata* ic_oop = ic->cached_metadata();
1826           if (ic_oop != NULL) {
1827             f(ic_oop);
1828           }
1829         }
1830       }
1831     }
1832   }
1833 
1834   // Visit the metadata section
1835   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1836     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1837     Metadata* md = *p;
1838     f(md);
1839   }
1840 
1841   // Call function Method*, not embedded in these other places.
1842   if (_method != NULL) f(_method);
1843 }
1844 
1845 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1846   // make sure the oops ready to receive visitors
1847   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1848   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1849 
1850   // If the method is not entrant or zombie then a JMP is plastered over the
1851   // first few bytes.  If an oop in the old code was there, that oop
1852   // should not get GC'd.  Skip the first few bytes of oops on
1853   // not-entrant methods.
1854   address low_boundary = verified_entry_point();
1855   if (is_not_entrant()) {
1856     low_boundary += NativeJump::instruction_size;
1857     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1858     // (See comment above.)
1859   }
1860 
1861   RelocIterator iter(this, low_boundary);
1862 
1863   while (iter.next()) {
1864     if (iter.type() == relocInfo::oop_type ) {
1865       oop_Relocation* r = iter.oop_reloc();
1866       // In this loop, we must only follow those oops directly embedded in
1867       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1868       assert(1 == (r->oop_is_immediate()) +
1869                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1870              "oop must be found in exactly one place");
1871       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1872         f->do_oop(r->oop_addr());
1873       }
1874     }
1875   }
1876 
1877   // Scopes
1878   // This includes oop constants not inlined in the code stream.
1879   for (oop* p = oops_begin(); p < oops_end(); p++) {
1880     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1881     f->do_oop(p);
1882   }
1883 }
1884 
1885 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1886 
1887 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1888 
1889 // An nmethod is "marked" if its _mark_link is set non-null.
1890 // Even if it is the end of the linked list, it will have a non-null link value,
1891 // as long as it is on the list.
1892 // This code must be MP safe, because it is used from parallel GC passes.
1893 bool nmethod::test_set_oops_do_mark() {
1894   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1895   nmethod* observed_mark_link = _oops_do_mark_link;
1896   if (observed_mark_link == NULL) {
1897     // Claim this nmethod for this thread to mark.
1898     observed_mark_link = (nmethod*)
1899       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1900     if (observed_mark_link == NULL) {
1901 
1902       // Atomically append this nmethod (now claimed) to the head of the list:
1903       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1904       for (;;) {
1905         nmethod* required_mark_nmethods = observed_mark_nmethods;
1906         _oops_do_mark_link = required_mark_nmethods;
1907         observed_mark_nmethods = (nmethod*)
1908           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1909         if (observed_mark_nmethods == required_mark_nmethods)
1910           break;
1911       }
1912       // Mark was clear when we first saw this guy.
1913       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark"));
1914       return false;
1915     }
1916   }
1917   // On fall through, another racing thread marked this nmethod before we did.
1918   return true;
1919 }
1920 
1921 void nmethod::oops_do_marking_prologue() {
1922   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
1923   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1924   // We use cmpxchg_ptr instead of regular assignment here because the user
1925   // may fork a bunch of threads, and we need them all to see the same state.
1926   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1927   guarantee(observed == NULL, "no races in this sequential code");
1928 }
1929 
1930 void nmethod::oops_do_marking_epilogue() {
1931   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1932   nmethod* cur = _oops_do_mark_nmethods;
1933   while (cur != NMETHOD_SENTINEL) {
1934     assert(cur != NULL, "not NULL-terminated");
1935     nmethod* next = cur->_oops_do_mark_link;
1936     cur->_oops_do_mark_link = NULL;
1937     cur->fix_oop_relocations();
1938     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
1939     cur = next;
1940   }
1941   void* required = _oops_do_mark_nmethods;
1942   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1943   guarantee(observed == required, "no races in this sequential code");
1944   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
1945 }
1946 
1947 class DetectScavengeRoot: public OopClosure {
1948   bool     _detected_scavenge_root;
1949 public:
1950   DetectScavengeRoot() : _detected_scavenge_root(false)
1951   { NOT_PRODUCT(_print_nm = NULL); }
1952   bool detected_scavenge_root() { return _detected_scavenge_root; }
1953   virtual void do_oop(oop* p) {
1954     if ((*p) != NULL && (*p)->is_scavengable()) {
1955       NOT_PRODUCT(maybe_print(p));
1956       _detected_scavenge_root = true;
1957     }
1958   }
1959   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1960 
1961 #ifndef PRODUCT
1962   nmethod* _print_nm;
1963   void maybe_print(oop* p) {
1964     if (_print_nm == NULL)  return;
1965     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1966     tty->print_cr(""PTR_FORMAT"[offset=%d] detected scavengable oop "PTR_FORMAT" (found at "PTR_FORMAT")",
1967                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
1968                   (intptr_t)(*p), (intptr_t)p);
1969     (*p)->print();
1970   }
1971 #endif //PRODUCT
1972 };
1973 
1974 bool nmethod::detect_scavenge_root_oops() {
1975   DetectScavengeRoot detect_scavenge_root;
1976   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1977   oops_do(&detect_scavenge_root);
1978   return detect_scavenge_root.detected_scavenge_root();
1979 }
1980 
1981 // Method that knows how to preserve outgoing arguments at call. This method must be
1982 // called with a frame corresponding to a Java invoke
1983 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
1984 #ifndef SHARK
1985   if (!method()->is_native()) {
1986     SimpleScopeDesc ssd(this, fr.pc());
1987     Bytecode_invoke call(ssd.method(), ssd.bci());
1988     bool has_receiver = call.has_receiver();
1989     bool has_appendix = call.has_appendix();
1990     Symbol* signature = call.signature();
1991     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
1992   }
1993 #endif // !SHARK
1994 }
1995 
1996 
1997 oop nmethod::embeddedOop_at(u_char* p) {
1998   RelocIterator iter(this, p, p + 1);
1999   while (iter.next())
2000     if (iter.type() == relocInfo::oop_type) {
2001       return iter.oop_reloc()->oop_value();
2002     }
2003   return NULL;
2004 }
2005 
2006 
2007 inline bool includes(void* p, void* from, void* to) {
2008   return from <= p && p < to;
2009 }
2010 
2011 
2012 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
2013   assert(count >= 2, "must be sentinel values, at least");
2014 
2015 #ifdef ASSERT
2016   // must be sorted and unique; we do a binary search in find_pc_desc()
2017   int prev_offset = pcs[0].pc_offset();
2018   assert(prev_offset == PcDesc::lower_offset_limit,
2019          "must start with a sentinel");
2020   for (int i = 1; i < count; i++) {
2021     int this_offset = pcs[i].pc_offset();
2022     assert(this_offset > prev_offset, "offsets must be sorted");
2023     prev_offset = this_offset;
2024   }
2025   assert(prev_offset == PcDesc::upper_offset_limit,
2026          "must end with a sentinel");
2027 #endif //ASSERT
2028 
2029   // Search for MethodHandle invokes and tag the nmethod.
2030   for (int i = 0; i < count; i++) {
2031     if (pcs[i].is_method_handle_invoke()) {
2032       set_has_method_handle_invokes(true);
2033       break;
2034     }
2035   }
2036   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
2037 
2038   int size = count * sizeof(PcDesc);
2039   assert(scopes_pcs_size() >= size, "oob");
2040   memcpy(scopes_pcs_begin(), pcs, size);
2041 
2042   // Adjust the final sentinel downward.
2043   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
2044   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
2045   last_pc->set_pc_offset(content_size() + 1);
2046   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
2047     // Fill any rounding gaps with copies of the last record.
2048     last_pc[1] = last_pc[0];
2049   }
2050   // The following assert could fail if sizeof(PcDesc) is not
2051   // an integral multiple of oopSize (the rounding term).
2052   // If it fails, change the logic to always allocate a multiple
2053   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
2054   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
2055 }
2056 
2057 void nmethod::copy_scopes_data(u_char* buffer, int size) {
2058   assert(scopes_data_size() >= size, "oob");
2059   memcpy(scopes_data_begin(), buffer, size);
2060 }
2061 
2062 
2063 #ifdef ASSERT
2064 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
2065   PcDesc* lower = nm->scopes_pcs_begin();
2066   PcDesc* upper = nm->scopes_pcs_end();
2067   lower += 1; // exclude initial sentinel
2068   PcDesc* res = NULL;
2069   for (PcDesc* p = lower; p < upper; p++) {
2070     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
2071     if (match_desc(p, pc_offset, approximate)) {
2072       if (res == NULL)
2073         res = p;
2074       else
2075         res = (PcDesc*) badAddress;
2076     }
2077   }
2078   return res;
2079 }
2080 #endif
2081 
2082 
2083 // Finds a PcDesc with real-pc equal to "pc"
2084 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
2085   address base_address = code_begin();
2086   if ((pc < base_address) ||
2087       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
2088     return NULL;  // PC is wildly out of range
2089   }
2090   int pc_offset = (int) (pc - base_address);
2091 
2092   // Check the PcDesc cache if it contains the desired PcDesc
2093   // (This as an almost 100% hit rate.)
2094   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
2095   if (res != NULL) {
2096     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
2097     return res;
2098   }
2099 
2100   // Fallback algorithm: quasi-linear search for the PcDesc
2101   // Find the last pc_offset less than the given offset.
2102   // The successor must be the required match, if there is a match at all.
2103   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
2104   PcDesc* lower = scopes_pcs_begin();
2105   PcDesc* upper = scopes_pcs_end();
2106   upper -= 1; // exclude final sentinel
2107   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
2108 
2109 #define assert_LU_OK \
2110   /* invariant on lower..upper during the following search: */ \
2111   assert(lower->pc_offset() <  pc_offset, "sanity"); \
2112   assert(upper->pc_offset() >= pc_offset, "sanity")
2113   assert_LU_OK;
2114 
2115   // Use the last successful return as a split point.
2116   PcDesc* mid = _pc_desc_cache.last_pc_desc();
2117   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2118   if (mid->pc_offset() < pc_offset) {
2119     lower = mid;
2120   } else {
2121     upper = mid;
2122   }
2123 
2124   // Take giant steps at first (4096, then 256, then 16, then 1)
2125   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
2126   const int RADIX = (1 << LOG2_RADIX);
2127   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
2128     while ((mid = lower + step) < upper) {
2129       assert_LU_OK;
2130       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2131       if (mid->pc_offset() < pc_offset) {
2132         lower = mid;
2133       } else {
2134         upper = mid;
2135         break;
2136       }
2137     }
2138     assert_LU_OK;
2139   }
2140 
2141   // Sneak up on the value with a linear search of length ~16.
2142   while (true) {
2143     assert_LU_OK;
2144     mid = lower + 1;
2145     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2146     if (mid->pc_offset() < pc_offset) {
2147       lower = mid;
2148     } else {
2149       upper = mid;
2150       break;
2151     }
2152   }
2153 #undef assert_LU_OK
2154 
2155   if (match_desc(upper, pc_offset, approximate)) {
2156     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
2157     _pc_desc_cache.add_pc_desc(upper);
2158     return upper;
2159   } else {
2160     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
2161     return NULL;
2162   }
2163 }
2164 
2165 
2166 bool nmethod::check_all_dependencies() {
2167   bool found_check = false;
2168   // wholesale check of all dependencies
2169   for (Dependencies::DepStream deps(this); deps.next(); ) {
2170     if (deps.check_dependency() != NULL) {
2171       found_check = true;
2172       NOT_DEBUG(break);
2173     }
2174   }
2175   return found_check;  // tell caller if we found anything
2176 }
2177 
2178 bool nmethod::check_dependency_on(DepChange& changes) {
2179   // What has happened:
2180   // 1) a new class dependee has been added
2181   // 2) dependee and all its super classes have been marked
2182   bool found_check = false;  // set true if we are upset
2183   for (Dependencies::DepStream deps(this); deps.next(); ) {
2184     // Evaluate only relevant dependencies.
2185     if (deps.spot_check_dependency_at(changes) != NULL) {
2186       found_check = true;
2187       NOT_DEBUG(break);
2188     }
2189   }
2190   return found_check;
2191 }
2192 
2193 bool nmethod::is_evol_dependent_on(Klass* dependee) {
2194   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
2195   Array<Method*>* dependee_methods = dependee_ik->methods();
2196   for (Dependencies::DepStream deps(this); deps.next(); ) {
2197     if (deps.type() == Dependencies::evol_method) {
2198       Method* method = deps.method_argument(0);
2199       for (int j = 0; j < dependee_methods->length(); j++) {
2200         if (dependee_methods->at(j) == method) {
2201           // RC_TRACE macro has an embedded ResourceMark
2202           RC_TRACE(0x01000000,
2203             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2204             _method->method_holder()->external_name(),
2205             _method->name()->as_C_string(),
2206             _method->signature()->as_C_string(), compile_id(),
2207             method->method_holder()->external_name(),
2208             method->name()->as_C_string(),
2209             method->signature()->as_C_string()));
2210           if (TraceDependencies || LogCompilation)
2211             deps.log_dependency(dependee);
2212           return true;
2213         }
2214       }
2215     }
2216   }
2217   return false;
2218 }
2219 
2220 // Called from mark_for_deoptimization, when dependee is invalidated.
2221 bool nmethod::is_dependent_on_method(Method* dependee) {
2222   for (Dependencies::DepStream deps(this); deps.next(); ) {
2223     if (deps.type() != Dependencies::evol_method)
2224       continue;
2225     Method* method = deps.method_argument(0);
2226     if (method == dependee) return true;
2227   }
2228   return false;
2229 }
2230 
2231 
2232 bool nmethod::is_patchable_at(address instr_addr) {
2233   assert(insts_contains(instr_addr), "wrong nmethod used");
2234   if (is_zombie()) {
2235     // a zombie may never be patched
2236     return false;
2237   }
2238   return true;
2239 }
2240 
2241 
2242 address nmethod::continuation_for_implicit_exception(address pc) {
2243   // Exception happened outside inline-cache check code => we are inside
2244   // an active nmethod => use cpc to determine a return address
2245   int exception_offset = pc - code_begin();
2246   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2247 #ifdef ASSERT
2248   if (cont_offset == 0) {
2249     Thread* thread = ThreadLocalStorage::get_thread_slow();
2250     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2251     HandleMark hm(thread);
2252     ResourceMark rm(thread);
2253     CodeBlob* cb = CodeCache::find_blob(pc);
2254     assert(cb != NULL && cb == this, "");
2255     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
2256     print();
2257     method()->print_codes();
2258     print_code();
2259     print_pcs();
2260   }
2261 #endif
2262   if (cont_offset == 0) {
2263     // Let the normal error handling report the exception
2264     return NULL;
2265   }
2266   return code_begin() + cont_offset;
2267 }
2268 
2269 
2270 
2271 void nmethod_init() {
2272   // make sure you didn't forget to adjust the filler fields
2273   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2274 }
2275 
2276 
2277 //-------------------------------------------------------------------------------------------
2278 
2279 
2280 // QQQ might we make this work from a frame??
2281 nmethodLocker::nmethodLocker(address pc) {
2282   CodeBlob* cb = CodeCache::find_blob(pc);
2283   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
2284   _nm = (nmethod*)cb;
2285   lock_nmethod(_nm);
2286 }
2287 
2288 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2289 // should pass zombie_ok == true.
2290 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
2291   if (nm == NULL)  return;
2292   Atomic::inc(&nm->_lock_count);
2293   guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2294 }
2295 
2296 void nmethodLocker::unlock_nmethod(nmethod* nm) {
2297   if (nm == NULL)  return;
2298   Atomic::dec(&nm->_lock_count);
2299   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2300 }
2301 
2302 
2303 // -----------------------------------------------------------------------------
2304 // nmethod::get_deopt_original_pc
2305 //
2306 // Return the original PC for the given PC if:
2307 // (a) the given PC belongs to a nmethod and
2308 // (b) it is a deopt PC
2309 address nmethod::get_deopt_original_pc(const frame* fr) {
2310   if (fr->cb() == NULL)  return NULL;
2311 
2312   nmethod* nm = fr->cb()->as_nmethod_or_null();
2313   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
2314     return nm->get_original_pc(fr);
2315 
2316   return NULL;
2317 }
2318 
2319 
2320 // -----------------------------------------------------------------------------
2321 // MethodHandle
2322 
2323 bool nmethod::is_method_handle_return(address return_pc) {
2324   if (!has_method_handle_invokes())  return false;
2325   PcDesc* pd = pc_desc_at(return_pc);
2326   if (pd == NULL)
2327     return false;
2328   return pd->is_method_handle_invoke();
2329 }
2330 
2331 
2332 // -----------------------------------------------------------------------------
2333 // Verification
2334 
2335 class VerifyOopsClosure: public OopClosure {
2336   nmethod* _nm;
2337   bool     _ok;
2338 public:
2339   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2340   bool ok() { return _ok; }
2341   virtual void do_oop(oop* p) {
2342     if ((*p) == NULL || (*p)->is_oop())  return;
2343     if (_ok) {
2344       _nm->print_nmethod(true);
2345       _ok = false;
2346     }
2347     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2348                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2349   }
2350   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2351 };
2352 
2353 void nmethod::verify() {
2354 
2355   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2356   // seems odd.
2357 
2358   if( is_zombie() || is_not_entrant() )
2359     return;
2360 
2361   // Make sure all the entry points are correctly aligned for patching.
2362   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2363 
2364   // assert(method()->is_oop(), "must be valid");
2365 
2366   ResourceMark rm;
2367 
2368   if (!CodeCache::contains(this)) {
2369     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
2370   }
2371 
2372   if(is_native_method() )
2373     return;
2374 
2375   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2376   if (nm != this) {
2377     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
2378                   this));
2379   }
2380 
2381   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2382     if (! p->verify(this)) {
2383       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
2384     }
2385   }
2386 
2387   VerifyOopsClosure voc(this);
2388   oops_do(&voc);
2389   assert(voc.ok(), "embedded oops must be OK");
2390   verify_scavenge_root_oops();
2391 
2392   verify_scopes();
2393 }
2394 
2395 
2396 void nmethod::verify_interrupt_point(address call_site) {
2397   // This code does not work in release mode since
2398   // owns_lock only is available in debug mode.
2399   CompiledIC* ic = NULL;
2400   Thread *cur = Thread::current();
2401   if (CompiledIC_lock->owner() == cur ||
2402       ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2403        SafepointSynchronize::is_at_safepoint())) {
2404     ic = CompiledIC_at(this, call_site);
2405     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2406   } else {
2407     MutexLocker ml_verify (CompiledIC_lock);
2408     ic = CompiledIC_at(this, call_site);
2409   }
2410   PcDesc* pd = pc_desc_at(ic->end_of_call());
2411   assert(pd != NULL, "PcDesc must exist");
2412   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2413                                      pd->obj_decode_offset(), pd->should_reexecute(),
2414                                      pd->return_oop());
2415        !sd->is_top(); sd = sd->sender()) {
2416     sd->verify();
2417   }
2418 }
2419 
2420 void nmethod::verify_scopes() {
2421   if( !method() ) return;       // Runtime stubs have no scope
2422   if (method()->is_native()) return; // Ignore stub methods.
2423   // iterate through all interrupt point
2424   // and verify the debug information is valid.
2425   RelocIterator iter((nmethod*)this);
2426   while (iter.next()) {
2427     address stub = NULL;
2428     switch (iter.type()) {
2429       case relocInfo::virtual_call_type:
2430         verify_interrupt_point(iter.addr());
2431         break;
2432       case relocInfo::opt_virtual_call_type:
2433         stub = iter.opt_virtual_call_reloc()->static_stub();
2434         verify_interrupt_point(iter.addr());
2435         break;
2436       case relocInfo::static_call_type:
2437         stub = iter.static_call_reloc()->static_stub();
2438         //verify_interrupt_point(iter.addr());
2439         break;
2440       case relocInfo::runtime_call_type:
2441         address destination = iter.reloc()->value();
2442         // Right now there is no way to find out which entries support
2443         // an interrupt point.  It would be nice if we had this
2444         // information in a table.
2445         break;
2446     }
2447     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2448   }
2449 }
2450 
2451 
2452 // -----------------------------------------------------------------------------
2453 // Non-product code
2454 #ifndef PRODUCT
2455 
2456 class DebugScavengeRoot: public OopClosure {
2457   nmethod* _nm;
2458   bool     _ok;
2459 public:
2460   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2461   bool ok() { return _ok; }
2462   virtual void do_oop(oop* p) {
2463     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2464     if (_ok) {
2465       _nm->print_nmethod(true);
2466       _ok = false;
2467     }
2468     tty->print_cr("*** scavengable oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2469                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2470     (*p)->print();
2471   }
2472   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2473 };
2474 
2475 void nmethod::verify_scavenge_root_oops() {
2476   if (!on_scavenge_root_list()) {
2477     // Actually look inside, to verify the claim that it's clean.
2478     DebugScavengeRoot debug_scavenge_root(this);
2479     oops_do(&debug_scavenge_root);
2480     if (!debug_scavenge_root.ok())
2481       fatal("found an unadvertised bad scavengable oop in the code cache");
2482   }
2483   assert(scavenge_root_not_marked(), "");
2484 }
2485 
2486 #endif // PRODUCT
2487 
2488 // Printing operations
2489 
2490 void nmethod::print() const {
2491   ResourceMark rm;
2492   ttyLocker ttyl;   // keep the following output all in one block
2493 
2494   tty->print("Compiled method ");
2495 
2496   if (is_compiled_by_c1()) {
2497     tty->print("(c1) ");
2498   } else if (is_compiled_by_c2()) {
2499     tty->print("(c2) ");
2500   } else if (is_compiled_by_shark()) {
2501     tty->print("(shark) ");
2502   } else {
2503     tty->print("(nm) ");
2504   }
2505 
2506   print_on(tty, NULL);
2507 
2508   if (WizardMode) {
2509     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
2510     tty->print(" for method " INTPTR_FORMAT , (address)method());
2511     tty->print(" { ");
2512     if (is_in_use())      tty->print("in_use ");
2513     if (is_not_entrant()) tty->print("not_entrant ");
2514     if (is_zombie())      tty->print("zombie ");
2515     if (is_unloaded())    tty->print("unloaded ");
2516     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2517     tty->print_cr("}:");
2518   }
2519   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2520                                               (address)this,
2521                                               (address)this + size(),
2522                                               size());
2523   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2524                                               relocation_begin(),
2525                                               relocation_end(),
2526                                               relocation_size());
2527   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2528                                               consts_begin(),
2529                                               consts_end(),
2530                                               consts_size());
2531   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2532                                               insts_begin(),
2533                                               insts_end(),
2534                                               insts_size());
2535   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2536                                               stub_begin(),
2537                                               stub_end(),
2538                                               stub_size());
2539   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2540                                               oops_begin(),
2541                                               oops_end(),
2542                                               oops_size());
2543   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2544                                               metadata_begin(),
2545                                               metadata_end(),
2546                                               metadata_size());
2547   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2548                                               scopes_data_begin(),
2549                                               scopes_data_end(),
2550                                               scopes_data_size());
2551   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2552                                               scopes_pcs_begin(),
2553                                               scopes_pcs_end(),
2554                                               scopes_pcs_size());
2555   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2556                                               dependencies_begin(),
2557                                               dependencies_end(),
2558                                               dependencies_size());
2559   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2560                                               handler_table_begin(),
2561                                               handler_table_end(),
2562                                               handler_table_size());
2563   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2564                                               nul_chk_table_begin(),
2565                                               nul_chk_table_end(),
2566                                               nul_chk_table_size());
2567 }
2568 
2569 void nmethod::print_code() {
2570   HandleMark hm;
2571   ResourceMark m;
2572   Disassembler::decode(this);
2573 }
2574 
2575 
2576 #ifndef PRODUCT
2577 
2578 void nmethod::print_scopes() {
2579   // Find the first pc desc for all scopes in the code and print it.
2580   ResourceMark rm;
2581   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2582     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2583       continue;
2584 
2585     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2586     sd->print_on(tty, p);
2587   }
2588 }
2589 
2590 void nmethod::print_dependencies() {
2591   ResourceMark rm;
2592   ttyLocker ttyl;   // keep the following output all in one block
2593   tty->print_cr("Dependencies:");
2594   for (Dependencies::DepStream deps(this); deps.next(); ) {
2595     deps.print_dependency();
2596     Klass* ctxk = deps.context_type();
2597     if (ctxk != NULL) {
2598       if (ctxk->oop_is_instance() && ((InstanceKlass*)ctxk)->is_dependent_nmethod(this)) {
2599         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2600       }
2601     }
2602     deps.log_dependency();  // put it into the xml log also
2603   }
2604 }
2605 
2606 
2607 void nmethod::print_relocations() {
2608   ResourceMark m;       // in case methods get printed via the debugger
2609   tty->print_cr("relocations:");
2610   RelocIterator iter(this);
2611   iter.print();
2612   if (UseRelocIndex) {
2613     jint* index_end   = (jint*)relocation_end() - 1;
2614     jint  index_size  = *index_end;
2615     jint* index_start = (jint*)( (address)index_end - index_size );
2616     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
2617     if (index_size > 0) {
2618       jint* ip;
2619       for (ip = index_start; ip+2 <= index_end; ip += 2)
2620         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
2621                       ip[0],
2622                       ip[1],
2623                       header_end()+ip[0],
2624                       relocation_begin()-1+ip[1]);
2625       for (; ip < index_end; ip++)
2626         tty->print_cr("  (%d ?)", ip[0]);
2627       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip);
2628       ip++;
2629       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
2630     }
2631   }
2632 }
2633 
2634 
2635 void nmethod::print_pcs() {
2636   ResourceMark m;       // in case methods get printed via debugger
2637   tty->print_cr("pc-bytecode offsets:");
2638   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2639     p->print(this);
2640   }
2641 }
2642 
2643 #endif // PRODUCT
2644 
2645 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2646   RelocIterator iter(this, begin, end);
2647   bool have_one = false;
2648   while (iter.next()) {
2649     have_one = true;
2650     switch (iter.type()) {
2651         case relocInfo::none:                  return "no_reloc";
2652         case relocInfo::oop_type: {
2653           stringStream st;
2654           oop_Relocation* r = iter.oop_reloc();
2655           oop obj = r->oop_value();
2656           st.print("oop(");
2657           if (obj == NULL) st.print("NULL");
2658           else obj->print_value_on(&st);
2659           st.print(")");
2660           return st.as_string();
2661         }
2662         case relocInfo::metadata_type: {
2663           stringStream st;
2664           metadata_Relocation* r = iter.metadata_reloc();
2665           Metadata* obj = r->metadata_value();
2666           st.print("metadata(");
2667           if (obj == NULL) st.print("NULL");
2668           else obj->print_value_on(&st);
2669           st.print(")");
2670           return st.as_string();
2671         }
2672         case relocInfo::virtual_call_type:     return "virtual_call";
2673         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
2674         case relocInfo::static_call_type:      return "static_call";
2675         case relocInfo::static_stub_type:      return "static_stub";
2676         case relocInfo::runtime_call_type:     return "runtime_call";
2677         case relocInfo::external_word_type:    return "external_word";
2678         case relocInfo::internal_word_type:    return "internal_word";
2679         case relocInfo::section_word_type:     return "section_word";
2680         case relocInfo::poll_type:             return "poll";
2681         case relocInfo::poll_return_type:      return "poll_return";
2682         case relocInfo::type_mask:             return "type_bit_mask";
2683     }
2684   }
2685   return have_one ? "other" : NULL;
2686 }
2687 
2688 // Return a the last scope in (begin..end]
2689 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2690   PcDesc* p = pc_desc_near(begin+1);
2691   if (p != NULL && p->real_pc(this) <= end) {
2692     return new ScopeDesc(this, p->scope_decode_offset(),
2693                          p->obj_decode_offset(), p->should_reexecute(),
2694                          p->return_oop());
2695   }
2696   return NULL;
2697 }
2698 
2699 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2700   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2701   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2702   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2703   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2704   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2705 
2706   if (has_method_handle_invokes())
2707     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2708 
2709   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2710 
2711   if (block_begin == entry_point()) {
2712     methodHandle m = method();
2713     if (m.not_null()) {
2714       stream->print("  # ");
2715       m->print_value_on(stream);
2716       stream->cr();
2717     }
2718     if (m.not_null() && !is_osr_method()) {
2719       ResourceMark rm;
2720       int sizeargs = m->size_of_parameters();
2721       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2722       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2723       {
2724         int sig_index = 0;
2725         if (!m->is_static())
2726           sig_bt[sig_index++] = T_OBJECT; // 'this'
2727         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2728           BasicType t = ss.type();
2729           sig_bt[sig_index++] = t;
2730           if (type2size[t] == 2) {
2731             sig_bt[sig_index++] = T_VOID;
2732           } else {
2733             assert(type2size[t] == 1, "size is 1 or 2");
2734           }
2735         }
2736         assert(sig_index == sizeargs, "");
2737       }
2738       const char* spname = "sp"; // make arch-specific?
2739       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2740       int stack_slot_offset = this->frame_size() * wordSize;
2741       int tab1 = 14, tab2 = 24;
2742       int sig_index = 0;
2743       int arg_index = (m->is_static() ? 0 : -1);
2744       bool did_old_sp = false;
2745       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2746         bool at_this = (arg_index == -1);
2747         bool at_old_sp = false;
2748         BasicType t = (at_this ? T_OBJECT : ss.type());
2749         assert(t == sig_bt[sig_index], "sigs in sync");
2750         if (at_this)
2751           stream->print("  # this: ");
2752         else
2753           stream->print("  # parm%d: ", arg_index);
2754         stream->move_to(tab1);
2755         VMReg fst = regs[sig_index].first();
2756         VMReg snd = regs[sig_index].second();
2757         if (fst->is_reg()) {
2758           stream->print("%s", fst->name());
2759           if (snd->is_valid())  {
2760             stream->print(":%s", snd->name());
2761           }
2762         } else if (fst->is_stack()) {
2763           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2764           if (offset == stack_slot_offset)  at_old_sp = true;
2765           stream->print("[%s+0x%x]", spname, offset);
2766         } else {
2767           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2768         }
2769         stream->print(" ");
2770         stream->move_to(tab2);
2771         stream->print("= ");
2772         if (at_this) {
2773           m->method_holder()->print_value_on(stream);
2774         } else {
2775           bool did_name = false;
2776           if (!at_this && ss.is_object()) {
2777             Symbol* name = ss.as_symbol_or_null();
2778             if (name != NULL) {
2779               name->print_value_on(stream);
2780               did_name = true;
2781             }
2782           }
2783           if (!did_name)
2784             stream->print("%s", type2name(t));
2785         }
2786         if (at_old_sp) {
2787           stream->print("  (%s of caller)", spname);
2788           did_old_sp = true;
2789         }
2790         stream->cr();
2791         sig_index += type2size[t];
2792         arg_index += 1;
2793         if (!at_this)  ss.next();
2794       }
2795       if (!did_old_sp) {
2796         stream->print("  # ");
2797         stream->move_to(tab1);
2798         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2799         stream->print("  (%s of caller)", spname);
2800         stream->cr();
2801       }
2802     }
2803   }
2804 }
2805 
2806 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2807   // First, find an oopmap in (begin, end].
2808   // We use the odd half-closed interval so that oop maps and scope descs
2809   // which are tied to the byte after a call are printed with the call itself.
2810   address base = code_begin();
2811   OopMapSet* oms = oop_maps();
2812   if (oms != NULL) {
2813     for (int i = 0, imax = oms->size(); i < imax; i++) {
2814       OopMap* om = oms->at(i);
2815       address pc = base + om->offset();
2816       if (pc > begin) {
2817         if (pc <= end) {
2818           st->move_to(column);
2819           st->print("; ");
2820           om->print_on(st);
2821         }
2822         break;
2823       }
2824     }
2825   }
2826 
2827   // Print any debug info present at this pc.
2828   ScopeDesc* sd  = scope_desc_in(begin, end);
2829   if (sd != NULL) {
2830     st->move_to(column);
2831     if (sd->bci() == SynchronizationEntryBCI) {
2832       st->print(";*synchronization entry");
2833     } else {
2834       if (sd->method() == NULL) {
2835         st->print("method is NULL");
2836       } else if (sd->method()->is_native()) {
2837         st->print("method is native");
2838       } else {
2839         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2840         st->print(";*%s", Bytecodes::name(bc));
2841         switch (bc) {
2842         case Bytecodes::_invokevirtual:
2843         case Bytecodes::_invokespecial:
2844         case Bytecodes::_invokestatic:
2845         case Bytecodes::_invokeinterface:
2846           {
2847             Bytecode_invoke invoke(sd->method(), sd->bci());
2848             st->print(" ");
2849             if (invoke.name() != NULL)
2850               invoke.name()->print_symbol_on(st);
2851             else
2852               st->print("<UNKNOWN>");
2853             break;
2854           }
2855         case Bytecodes::_getfield:
2856         case Bytecodes::_putfield:
2857         case Bytecodes::_getstatic:
2858         case Bytecodes::_putstatic:
2859           {
2860             Bytecode_field field(sd->method(), sd->bci());
2861             st->print(" ");
2862             if (field.name() != NULL)
2863               field.name()->print_symbol_on(st);
2864             else
2865               st->print("<UNKNOWN>");
2866           }
2867         }
2868       }
2869     }
2870 
2871     // Print all scopes
2872     for (;sd != NULL; sd = sd->sender()) {
2873       st->move_to(column);
2874       st->print("; -");
2875       if (sd->method() == NULL) {
2876         st->print("method is NULL");
2877       } else {
2878         sd->method()->print_short_name(st);
2879       }
2880       int lineno = sd->method()->line_number_from_bci(sd->bci());
2881       if (lineno != -1) {
2882         st->print("@%d (line %d)", sd->bci(), lineno);
2883       } else {
2884         st->print("@%d", sd->bci());
2885       }
2886       st->cr();
2887     }
2888   }
2889 
2890   // Print relocation information
2891   const char* str = reloc_string_for(begin, end);
2892   if (str != NULL) {
2893     if (sd != NULL) st->cr();
2894     st->move_to(column);
2895     st->print(";   {%s}", str);
2896   }
2897   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2898   if (cont_offset != 0) {
2899     st->move_to(column);
2900     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
2901   }
2902 
2903 }
2904 
2905 #ifndef PRODUCT
2906 
2907 void nmethod::print_value_on(outputStream* st) const {
2908   st->print("nmethod");
2909   print_on(st, NULL);
2910 }
2911 
2912 void nmethod::print_calls(outputStream* st) {
2913   RelocIterator iter(this);
2914   while (iter.next()) {
2915     switch (iter.type()) {
2916     case relocInfo::virtual_call_type:
2917     case relocInfo::opt_virtual_call_type: {
2918       VerifyMutexLocker mc(CompiledIC_lock);
2919       CompiledIC_at(iter.reloc())->print();
2920       break;
2921     }
2922     case relocInfo::static_call_type:
2923       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
2924       compiledStaticCall_at(iter.reloc())->print();
2925       break;
2926     }
2927   }
2928 }
2929 
2930 void nmethod::print_handler_table() {
2931   ExceptionHandlerTable(this).print();
2932 }
2933 
2934 void nmethod::print_nul_chk_table() {
2935   ImplicitExceptionTable(this).print(code_begin());
2936 }
2937 
2938 void nmethod::print_statistics() {
2939   ttyLocker ttyl;
2940   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2941   nmethod_stats.print_native_nmethod_stats();
2942   nmethod_stats.print_nmethod_stats();
2943   DebugInformationRecorder::print_statistics();
2944   nmethod_stats.print_pc_stats();
2945   Dependencies::print_statistics();
2946   if (xtty != NULL)  xtty->tail("statistics");
2947 }
2948 
2949 #endif // PRODUCT