1 /*
   2  * Copyright (c) 1997, 2011, 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/nmethod.hpp"
  29 #include "code/scopeDesc.hpp"
  30 #include "compiler/abstractCompiler.hpp"
  31 #include "compiler/compileLog.hpp"
  32 #include "compiler/compilerOracle.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "interpreter/bytecode.hpp"
  35 #include "oops/methodDataOop.hpp"
  36 #include "prims/jvmtiRedefineClassesTrace.hpp"
  37 #include "prims/jvmtiImpl.hpp"
  38 #include "runtime/sharedRuntime.hpp"
  39 #include "runtime/sweeper.hpp"
  40 #include "utilities/dtrace.hpp"
  41 #include "utilities/events.hpp"
  42 #include "utilities/xmlstream.hpp"
  43 #ifdef SHARK
  44 #include "shark/sharkCompiler.hpp"
  45 #endif
  46 
  47 #ifdef DTRACE_ENABLED
  48 
  49 // Only bother with this argument setup if dtrace is available
  50 
  51 HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
  52   const char*, int, const char*, int, const char*, int, void*, size_t);
  53 
  54 HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
  55   char*, int, char*, int, char*, int);
  56 
  57 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  58   {                                                                       \
  59     methodOop m = (method);                                               \
  60     if (m != NULL) {                                                      \
  61       symbolOop klass_name = m->klass_name();                             \
  62       symbolOop name = m->name();                                         \
  63       symbolOop signature = m->signature();                               \
  64       HS_DTRACE_PROBE6(hotspot, compiled__method__unload,                 \
  65         klass_name->bytes(), klass_name->utf8_length(),                   \
  66         name->bytes(), name->utf8_length(),                               \
  67         signature->bytes(), signature->utf8_length());                    \
  68     }                                                                     \
  69   }
  70 
  71 #else //  ndef DTRACE_ENABLED
  72 
  73 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  74 
  75 #endif
  76 
  77 bool nmethod::is_compiled_by_c1() const {
  78   if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
  79   if (is_native_method()) return false;
  80   return compiler()->is_c1();
  81 }
  82 bool nmethod::is_compiled_by_c2() const {
  83   if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
  84   if (is_native_method()) return false;
  85   return compiler()->is_c2();
  86 }
  87 bool nmethod::is_compiled_by_shark() const {
  88   if (is_native_method()) return false;
  89   assert(compiler() != NULL, "must be");
  90   return compiler()->is_shark();
  91 }
  92 
  93 
  94 
  95 //---------------------------------------------------------------------------------
  96 // NMethod statistics
  97 // They are printed under various flags, including:
  98 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  99 // (In the latter two cases, they like other stats are printed to the log only.)
 100 
 101 #ifndef PRODUCT
 102 // These variables are put into one block to reduce relocations
 103 // and make it simpler to print from the debugger.
 104 static
 105 struct nmethod_stats_struct {
 106   int nmethod_count;
 107   int total_size;
 108   int relocation_size;
 109   int consts_size;
 110   int insts_size;
 111   int stub_size;
 112   int scopes_data_size;
 113   int scopes_pcs_size;
 114   int dependencies_size;
 115   int handler_table_size;
 116   int nul_chk_table_size;
 117   int oops_size;
 118 
 119   void note_nmethod(nmethod* nm) {
 120     nmethod_count += 1;
 121     total_size          += nm->size();
 122     relocation_size     += nm->relocation_size();
 123     consts_size         += nm->consts_size();
 124     insts_size          += nm->insts_size();
 125     stub_size           += nm->stub_size();
 126     oops_size           += nm->oops_size();
 127     scopes_data_size    += nm->scopes_data_size();
 128     scopes_pcs_size     += nm->scopes_pcs_size();
 129     dependencies_size   += nm->dependencies_size();
 130     handler_table_size  += nm->handler_table_size();
 131     nul_chk_table_size  += nm->nul_chk_table_size();
 132   }
 133   void print_nmethod_stats() {
 134     if (nmethod_count == 0)  return;
 135     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
 136     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 137     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 138     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 139     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 140     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 141     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 142     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 143     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 144     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 145     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 146     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 147   }
 148 
 149   int native_nmethod_count;
 150   int native_total_size;
 151   int native_relocation_size;
 152   int native_insts_size;
 153   int native_oops_size;
 154   void note_native_nmethod(nmethod* nm) {
 155     native_nmethod_count += 1;
 156     native_total_size       += nm->size();
 157     native_relocation_size  += nm->relocation_size();
 158     native_insts_size       += nm->insts_size();
 159     native_oops_size        += nm->oops_size();
 160   }
 161   void print_native_nmethod_stats() {
 162     if (native_nmethod_count == 0)  return;
 163     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 164     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 165     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 166     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 167     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 168   }
 169 
 170   int pc_desc_resets;   // number of resets (= number of caches)
 171   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 172   int pc_desc_approx;   // number of those which have approximate true
 173   int pc_desc_repeats;  // number of _last_pc_desc hits
 174   int pc_desc_hits;     // number of LRU cache hits
 175   int pc_desc_tests;    // total number of PcDesc examinations
 176   int pc_desc_searches; // total number of quasi-binary search steps
 177   int pc_desc_adds;     // number of LUR cache insertions
 178 
 179   void print_pc_stats() {
 180     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 181                   pc_desc_queries,
 182                   (double)(pc_desc_tests + pc_desc_searches)
 183                   / pc_desc_queries);
 184     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 185                   pc_desc_resets,
 186                   pc_desc_queries, pc_desc_approx,
 187                   pc_desc_repeats, pc_desc_hits,
 188                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 189   }
 190 } nmethod_stats;
 191 #endif //PRODUCT
 192 
 193 //---------------------------------------------------------------------------------
 194 
 195 
 196 // The _unwind_handler is a special marker address, which says that
 197 // for given exception oop and address, the frame should be removed
 198 // as the tuple cannot be caught in the nmethod
 199 address ExceptionCache::_unwind_handler = (address) -1;
 200 
 201 
 202 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 203   assert(pc != NULL, "Must be non null");
 204   assert(exception.not_null(), "Must be non null");
 205   assert(handler != NULL, "Must be non null");
 206 
 207   _count = 0;
 208   _exception_type = exception->klass();
 209   _next = NULL;
 210 
 211   add_address_and_handler(pc,handler);
 212 }
 213 
 214 
 215 address ExceptionCache::match(Handle exception, address pc) {
 216   assert(pc != NULL,"Must be non null");
 217   assert(exception.not_null(),"Must be non null");
 218   if (exception->klass() == exception_type()) {
 219     return (test_address(pc));
 220   }
 221 
 222   return NULL;
 223 }
 224 
 225 
 226 bool ExceptionCache::match_exception_with_space(Handle exception) {
 227   assert(exception.not_null(),"Must be non null");
 228   if (exception->klass() == exception_type() && count() < cache_size) {
 229     return true;
 230   }
 231   return false;
 232 }
 233 
 234 
 235 address ExceptionCache::test_address(address addr) {
 236   for (int i=0; i<count(); i++) {
 237     if (pc_at(i) == addr) {
 238       return handler_at(i);
 239     }
 240   }
 241   return NULL;
 242 }
 243 
 244 
 245 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 246   if (test_address(addr) == handler) return true;
 247   if (count() < cache_size) {
 248     set_pc_at(count(),addr);
 249     set_handler_at(count(), handler);
 250     increment_count();
 251     return true;
 252   }
 253   return false;
 254 }
 255 
 256 
 257 // private method for handling exception cache
 258 // These methods are private, and used to manipulate the exception cache
 259 // directly.
 260 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 261   ExceptionCache* ec = exception_cache();
 262   while (ec != NULL) {
 263     if (ec->match_exception_with_space(exception)) {
 264       return ec;
 265     }
 266     ec = ec->next();
 267   }
 268   return NULL;
 269 }
 270 
 271 
 272 //-----------------------------------------------------------------------------
 273 
 274 
 275 // Helper used by both find_pc_desc methods.
 276 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 277   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
 278   if (!approximate)
 279     return pc->pc_offset() == pc_offset;
 280   else
 281     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 282 }
 283 
 284 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 285   if (initial_pc_desc == NULL) {
 286     _last_pc_desc = NULL;  // native method
 287     return;
 288   }
 289   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
 290   // reset the cache by filling it with benign (non-null) values
 291   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 292   _last_pc_desc = initial_pc_desc + 1;  // first valid one is after sentinel
 293   for (int i = 0; i < cache_size; i++)
 294     _pc_descs[i] = initial_pc_desc;
 295 }
 296 
 297 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 298   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
 299   NOT_PRODUCT(if (approximate)  ++nmethod_stats.pc_desc_approx);
 300 
 301   // In order to prevent race conditions do not load cache elements
 302   // repeatedly, but use a local copy:
 303   PcDesc* res;
 304 
 305   // Step one:  Check the most recently returned value.
 306   res = _last_pc_desc;
 307   if (res == NULL)  return NULL;  // native method; no PcDescs at all
 308   if (match_desc(res, pc_offset, approximate)) {
 309     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
 310     return res;
 311   }
 312 
 313   // Step two:  Check the LRU cache.
 314   for (int i = 0; i < cache_size; i++) {
 315     res = _pc_descs[i];
 316     if (res->pc_offset() < 0)  break;  // optimization: skip empty cache
 317     if (match_desc(res, pc_offset, approximate)) {
 318       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
 319       _last_pc_desc = res;  // record this cache hit in case of repeat
 320       return res;
 321     }
 322   }
 323 
 324   // Report failure.
 325   return NULL;
 326 }
 327 
 328 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 329   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
 330   // Update the LRU cache by shifting pc_desc forward:
 331   for (int i = 0; i < cache_size; i++)  {
 332     PcDesc* next = _pc_descs[i];
 333     _pc_descs[i] = pc_desc;
 334     pc_desc = next;
 335   }
 336   // Note:  Do not update _last_pc_desc.  It fronts for the LRU cache.
 337 }
 338 
 339 // adjust pcs_size so that it is a multiple of both oopSize and
 340 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 341 // of oopSize, then 2*sizeof(PcDesc) is)
 342 static int  adjust_pcs_size(int pcs_size) {
 343   int nsize = round_to(pcs_size,   oopSize);
 344   if ((nsize % sizeof(PcDesc)) != 0) {
 345     nsize = pcs_size + sizeof(PcDesc);
 346   }
 347   assert((nsize %  oopSize) == 0, "correct alignment");
 348   return nsize;
 349 }
 350 
 351 //-----------------------------------------------------------------------------
 352 
 353 
 354 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 355   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 356   assert(new_entry != NULL,"Must be non null");
 357   assert(new_entry->next() == NULL, "Must be null");
 358 
 359   if (exception_cache() != NULL) {
 360     new_entry->set_next(exception_cache());
 361   }
 362   set_exception_cache(new_entry);
 363 }
 364 
 365 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
 366   ExceptionCache* prev = NULL;
 367   ExceptionCache* curr = exception_cache();
 368   assert(curr != NULL, "nothing to remove");
 369   // find the previous and next entry of ec
 370   while (curr != ec) {
 371     prev = curr;
 372     curr = curr->next();
 373     assert(curr != NULL, "ExceptionCache not found");
 374   }
 375   // now: curr == ec
 376   ExceptionCache* next = curr->next();
 377   if (prev == NULL) {
 378     set_exception_cache(next);
 379   } else {
 380     prev->set_next(next);
 381   }
 382   delete curr;
 383 }
 384 
 385 
 386 // public method for accessing the exception cache
 387 // These are the public access methods.
 388 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 389   // We never grab a lock to read the exception cache, so we may
 390   // have false negatives. This is okay, as it can only happen during
 391   // the first few exception lookups for a given nmethod.
 392   ExceptionCache* ec = exception_cache();
 393   while (ec != NULL) {
 394     address ret_val;
 395     if ((ret_val = ec->match(exception,pc)) != NULL) {
 396       return ret_val;
 397     }
 398     ec = ec->next();
 399   }
 400   return NULL;
 401 }
 402 
 403 
 404 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 405   // There are potential race conditions during exception cache updates, so we
 406   // must own the ExceptionCache_lock before doing ANY modifications. Because
 407   // we don't lock during reads, it is possible to have several threads attempt
 408   // to update the cache with the same data. We need to check for already inserted
 409   // copies of the current data before adding it.
 410 
 411   MutexLocker ml(ExceptionCache_lock);
 412   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 413 
 414   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
 415     target_entry = new ExceptionCache(exception,pc,handler);
 416     add_exception_cache_entry(target_entry);
 417   }
 418 }
 419 
 420 
 421 //-------------end of code for ExceptionCache--------------
 422 
 423 
 424 int nmethod::total_size() const {
 425   return
 426     consts_size()        +
 427     insts_size()         +
 428     stub_size()          +
 429     scopes_data_size()   +
 430     scopes_pcs_size()    +
 431     handler_table_size() +
 432     nul_chk_table_size();
 433 }
 434 
 435 const char* nmethod::compile_kind() const {
 436   if (is_osr_method())     return "osr";
 437   if (method() != NULL && is_native_method())  return "c2n";
 438   return NULL;
 439 }
 440 
 441 // Fill in default values for various flag fields
 442 void nmethod::init_defaults() {
 443   _state                      = alive;
 444   _marked_for_reclamation     = 0;
 445   _has_flushed_dependencies   = 0;
 446   _speculatively_disconnected = 0;
 447   _has_unsafe_access          = 0;
 448   _has_method_handle_invokes  = 0;
 449   _marked_for_deoptimization  = 0;
 450   _lock_count                 = 0;
 451   _stack_traversal_mark       = 0;
 452   _unload_reported            = false;           // jvmti state
 453 
 454   NOT_PRODUCT(_has_debug_info = false);
 455 #ifdef ASSERT
 456   _oops_are_stale             = false;
 457 #endif
 458 
 459   _oops_do_mark_link       = NULL;
 460   _jmethod_id              = NULL;
 461   _osr_link                = NULL;
 462   _scavenge_root_link      = NULL;
 463   _scavenge_root_state     = 0;
 464   _saved_nmethod_link      = NULL;
 465   _compiler                = NULL;
 466 
 467 #ifdef HAVE_DTRACE_H
 468   _trap_offset             = 0;
 469 #endif // def HAVE_DTRACE_H
 470 }
 471 
 472 
 473 nmethod* nmethod::new_native_nmethod(methodHandle method,
 474   CodeBuffer *code_buffer,
 475   int vep_offset,
 476   int frame_complete,
 477   int frame_size,
 478   ByteSize basic_lock_owner_sp_offset,
 479   ByteSize basic_lock_sp_offset,
 480   OopMapSet* oop_maps) {
 481   // create nmethod
 482   nmethod* nm = NULL;
 483   {
 484     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 485     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 486     CodeOffsets offsets;
 487     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 488     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 489     nm = new (native_nmethod_size)
 490       nmethod(method(), native_nmethod_size, &offsets,
 491               code_buffer, frame_size,
 492               basic_lock_owner_sp_offset, basic_lock_sp_offset,
 493               oop_maps);
 494     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
 495     if (PrintAssembly && nm != NULL)
 496       Disassembler::decode(nm);
 497   }
 498   // verify nmethod
 499   debug_only(if (nm) nm->verify();) // might block
 500 
 501   if (nm != NULL) {
 502     nm->log_new_nmethod();
 503   }
 504 
 505   return nm;
 506 }
 507 
 508 #ifdef HAVE_DTRACE_H
 509 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
 510                                      CodeBuffer *code_buffer,
 511                                      int vep_offset,
 512                                      int trap_offset,
 513                                      int frame_complete,
 514                                      int frame_size) {
 515   // create nmethod
 516   nmethod* nm = NULL;
 517   {
 518     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 519     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 520     CodeOffsets offsets;
 521     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 522     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
 523     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 524 
 525     nm = new (nmethod_size) nmethod(method(), nmethod_size, &offsets, code_buffer, frame_size);
 526 
 527     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 528     if (PrintAssembly && nm != NULL)
 529       Disassembler::decode(nm);
 530   }
 531   // verify nmethod
 532   debug_only(if (nm) nm->verify();) // might block
 533 
 534   if (nm != NULL) {
 535     nm->log_new_nmethod();
 536   }
 537 
 538   return nm;
 539 }
 540 
 541 #endif // def HAVE_DTRACE_H
 542 
 543 nmethod* nmethod::new_nmethod(methodHandle method,
 544   int compile_id,
 545   int entry_bci,
 546   CodeOffsets* offsets,
 547   int orig_pc_offset,
 548   DebugInformationRecorder* debug_info,
 549   Dependencies* dependencies,
 550   CodeBuffer* code_buffer, int frame_size,
 551   OopMapSet* oop_maps,
 552   ExceptionHandlerTable* handler_table,
 553   ImplicitExceptionTable* nul_chk_table,
 554   AbstractCompiler* compiler,
 555   int comp_level
 556 )
 557 {
 558   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 559   // create nmethod
 560   nmethod* nm = NULL;
 561   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 562     int nmethod_size =
 563       allocation_size(code_buffer, sizeof(nmethod))
 564       + adjust_pcs_size(debug_info->pcs_size())
 565       + round_to(dependencies->size_in_bytes() , oopSize)
 566       + round_to(handler_table->size_in_bytes(), oopSize)
 567       + round_to(nul_chk_table->size_in_bytes(), oopSize)
 568       + round_to(debug_info->data_size()       , oopSize);
 569     nm = new (nmethod_size)
 570       nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
 571               orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 572               oop_maps,
 573               handler_table,
 574               nul_chk_table,
 575               compiler,
 576               comp_level);
 577     if (nm != NULL) {
 578       // To make dependency checking during class loading fast, record
 579       // the nmethod dependencies in the classes it is dependent on.
 580       // This allows the dependency checking code to simply walk the
 581       // class hierarchy above the loaded class, checking only nmethods
 582       // which are dependent on those classes.  The slow way is to
 583       // check every nmethod for dependencies which makes it linear in
 584       // the number of methods compiled.  For applications with a lot
 585       // classes the slow way is too slow.
 586       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 587         klassOop klass = deps.context_type();
 588         if (klass == NULL)  continue;  // ignore things like evol_method
 589 
 590         // record this nmethod as dependent on this klass
 591         instanceKlass::cast(klass)->add_dependent_nmethod(nm);
 592       }
 593     }
 594     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 595     if (PrintAssembly && nm != NULL)
 596       Disassembler::decode(nm);
 597   }
 598 
 599   // verify nmethod
 600   debug_only(if (nm) nm->verify();) // might block
 601 
 602   if (nm != NULL) {
 603     nm->log_new_nmethod();
 604   }
 605 
 606   // done
 607   return nm;
 608 }
 609 
 610 
 611 // For native wrappers
 612 nmethod::nmethod(
 613   methodOop method,
 614   int nmethod_size,
 615   CodeOffsets* offsets,
 616   CodeBuffer* code_buffer,
 617   int frame_size,
 618   ByteSize basic_lock_owner_sp_offset,
 619   ByteSize basic_lock_sp_offset,
 620   OopMapSet* oop_maps )
 621   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
 622              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 623   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 624   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 625 {
 626   {
 627     debug_only(No_Safepoint_Verifier nsv;)
 628     assert_locked_or_safepoint(CodeCache_lock);
 629 
 630     init_defaults();
 631     _method                  = method;
 632     _entry_bci               = InvocationEntryBci;
 633     // We have no exception handler or deopt handler make the
 634     // values something that will never match a pc like the nmethod vtable entry
 635     _exception_offset        = 0;
 636     _deoptimize_offset       = 0;
 637     _deoptimize_mh_offset    = 0;
 638     _orig_pc_offset          = 0;
 639 
 640     _consts_offset           = data_offset();
 641     _stub_offset             = data_offset();
 642     _oops_offset             = data_offset();
 643     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 644     _scopes_pcs_offset       = _scopes_data_offset;
 645     _dependencies_offset     = _scopes_pcs_offset;
 646     _handler_table_offset    = _dependencies_offset;
 647     _nul_chk_table_offset    = _handler_table_offset;
 648     _nmethod_end_offset      = _nul_chk_table_offset;
 649     _compile_id              = 0;  // default
 650     _comp_level              = CompLevel_none;
 651     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 652     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 653     _osr_entry_point         = NULL;
 654     _exception_cache         = NULL;
 655     _pc_desc_cache.reset_to(NULL);
 656 
 657     code_buffer->copy_oops_to(this);
 658     debug_only(verify_scavenge_root_oops());
 659     CodeCache::commit(this);
 660   }
 661 
 662   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 663     ttyLocker ttyl;  // keep the following output all in one block
 664     // This output goes directly to the tty, not the compiler log.
 665     // To enable tools to match it up with the compilation activity,
 666     // be sure to tag this tty output with the compile ID.
 667     if (xtty != NULL) {
 668       xtty->begin_head("print_native_nmethod");
 669       xtty->method(_method);
 670       xtty->stamp();
 671       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 672     }
 673     // print the header part first
 674     print();
 675     // then print the requested information
 676     if (PrintNativeNMethods) {
 677       print_code();
 678       oop_maps->print();
 679     }
 680     if (PrintRelocations) {
 681       print_relocations();
 682     }
 683     if (xtty != NULL) {
 684       xtty->tail("print_native_nmethod");
 685     }
 686   }
 687   Events::log("Create nmethod " INTPTR_FORMAT, this);
 688 }
 689 
 690 // For dtrace wrappers
 691 #ifdef HAVE_DTRACE_H
 692 nmethod::nmethod(
 693   methodOop method,
 694   int nmethod_size,
 695   CodeOffsets* offsets,
 696   CodeBuffer* code_buffer,
 697   int frame_size)
 698   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
 699              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
 700   _native_receiver_sp_offset(in_ByteSize(-1)),
 701   _native_basic_lock_sp_offset(in_ByteSize(-1))
 702 {
 703   {
 704     debug_only(No_Safepoint_Verifier nsv;)
 705     assert_locked_or_safepoint(CodeCache_lock);
 706 
 707     init_defaults();
 708     _method                  = method;
 709     _entry_bci               = InvocationEntryBci;
 710     // We have no exception handler or deopt handler make the
 711     // values something that will never match a pc like the nmethod vtable entry
 712     _exception_offset        = 0;
 713     _deoptimize_offset       = 0;
 714     _deoptimize_mh_offset    = 0;
 715     _unwind_handler_offset   = -1;
 716     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
 717     _orig_pc_offset          = 0;
 718     _consts_offset           = data_offset();
 719     _stub_offset             = data_offset();
 720     _oops_offset             = data_offset();
 721     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 722     _scopes_pcs_offset       = _scopes_data_offset;
 723     _dependencies_offset     = _scopes_pcs_offset;
 724     _handler_table_offset    = _dependencies_offset;
 725     _nul_chk_table_offset    = _handler_table_offset;
 726     _nmethod_end_offset      = _nul_chk_table_offset;
 727     _compile_id              = 0;  // default
 728     _comp_level              = CompLevel_none;
 729     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 730     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 731     _osr_entry_point         = NULL;
 732     _exception_cache         = NULL;
 733     _pc_desc_cache.reset_to(NULL);
 734 
 735     code_buffer->copy_oops_to(this);
 736     debug_only(verify_scavenge_root_oops());
 737     CodeCache::commit(this);
 738   }
 739 
 740   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 741     ttyLocker ttyl;  // keep the following output all in one block
 742     // This output goes directly to the tty, not the compiler log.
 743     // To enable tools to match it up with the compilation activity,
 744     // be sure to tag this tty output with the compile ID.
 745     if (xtty != NULL) {
 746       xtty->begin_head("print_dtrace_nmethod");
 747       xtty->method(_method);
 748       xtty->stamp();
 749       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 750     }
 751     // print the header part first
 752     print();
 753     // then print the requested information
 754     if (PrintNMethods) {
 755       print_code();
 756     }
 757     if (PrintRelocations) {
 758       print_relocations();
 759     }
 760     if (xtty != NULL) {
 761       xtty->tail("print_dtrace_nmethod");
 762     }
 763   }
 764   Events::log("Create nmethod " INTPTR_FORMAT, this);
 765 }
 766 #endif // def HAVE_DTRACE_H
 767 
 768 void* nmethod::operator new(size_t size, int nmethod_size) {
 769   // Always leave some room in the CodeCache for I2C/C2I adapters
 770   if (CodeCache::unallocated_capacity() < CodeCacheMinimumFreeSpace) return NULL;
 771   return CodeCache::allocate(nmethod_size);
 772 }
 773 
 774 
 775 nmethod::nmethod(
 776   methodOop method,
 777   int nmethod_size,
 778   int compile_id,
 779   int entry_bci,
 780   CodeOffsets* offsets,
 781   int orig_pc_offset,
 782   DebugInformationRecorder* debug_info,
 783   Dependencies* dependencies,
 784   CodeBuffer *code_buffer,
 785   int frame_size,
 786   OopMapSet* oop_maps,
 787   ExceptionHandlerTable* handler_table,
 788   ImplicitExceptionTable* nul_chk_table,
 789   AbstractCompiler* compiler,
 790   int comp_level
 791   )
 792   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
 793              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 794   _native_receiver_sp_offset(in_ByteSize(-1)),
 795   _native_basic_lock_sp_offset(in_ByteSize(-1))
 796 {
 797   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 798   {
 799     debug_only(No_Safepoint_Verifier nsv;)
 800     assert_locked_or_safepoint(CodeCache_lock);
 801 
 802     init_defaults();
 803     _method                  = method;
 804     _entry_bci               = entry_bci;
 805     _compile_id              = compile_id;
 806     _comp_level              = comp_level;
 807     _compiler                = compiler;
 808     _orig_pc_offset          = orig_pc_offset;
 809 
 810     // Section offsets
 811     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 812     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 813 
 814     // Exception handler and deopt handler are in the stub section
 815     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 816     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 817     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 818     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
 819     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 820       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 821     } else {
 822       _deoptimize_mh_offset  = -1;
 823     }
 824     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 825       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 826     } else {
 827       _unwind_handler_offset = -1;
 828     }
 829 
 830     _oops_offset             = data_offset();
 831     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size (), oopSize);
 832     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
 833     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 834     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
 835     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
 836     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
 837 
 838     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 839     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 840     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 841     _exception_cache         = NULL;
 842     _pc_desc_cache.reset_to(scopes_pcs_begin());
 843 
 844     // Copy contents of ScopeDescRecorder to nmethod
 845     code_buffer->copy_oops_to(this);
 846     debug_info->copy_to(this);
 847     dependencies->copy_to(this);
 848     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
 849       CodeCache::add_scavenge_root_nmethod(this);
 850     }
 851     debug_only(verify_scavenge_root_oops());
 852 
 853     CodeCache::commit(this);
 854 
 855     // Copy contents of ExceptionHandlerTable to nmethod
 856     handler_table->copy_to(this);
 857     nul_chk_table->copy_to(this);
 858 
 859     // we use the information of entry points to find out if a method is
 860     // static or non static
 861     assert(compiler->is_c2() ||
 862            _method->is_static() == (entry_point() == _verified_entry_point),
 863            " entry points must be same for static methods and vice versa");
 864   }
 865 
 866   bool printnmethods = PrintNMethods
 867     || CompilerOracle::should_print(_method)
 868     || CompilerOracle::has_option_string(_method, "PrintNMethods");
 869   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 870     print_nmethod(printnmethods);
 871   }
 872 
 873   // Note: Do not verify in here as the CodeCache_lock is
 874   //       taken which would conflict with the CompiledIC_lock
 875   //       which taken during the verification of call sites.
 876   //       (was bug - gri 10/25/99)
 877 
 878   Events::log("Create nmethod " INTPTR_FORMAT, this);
 879 }
 880 
 881 
 882 // Print a short set of xml attributes to identify this nmethod.  The
 883 // output should be embedded in some other element.
 884 void nmethod::log_identity(xmlStream* log) const {
 885   log->print(" compile_id='%d'", compile_id());
 886   const char* nm_kind = compile_kind();
 887   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 888   if (compiler() != NULL) {
 889     log->print(" compiler='%s'", compiler()->name());
 890   }
 891   if (TieredCompilation) {
 892     log->print(" level='%d'", comp_level());
 893   }
 894 }
 895 
 896 
 897 #define LOG_OFFSET(log, name)                    \
 898   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
 899     log->print(" " XSTR(name) "_offset='%d'"    , \
 900                (intptr_t)name##_begin() - (intptr_t)this)
 901 
 902 
 903 void nmethod::log_new_nmethod() const {
 904   if (LogCompilation && xtty != NULL) {
 905     ttyLocker ttyl;
 906     HandleMark hm;
 907     xtty->begin_elem("nmethod");
 908     log_identity(xtty);
 909     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
 910     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 911 
 912     LOG_OFFSET(xtty, relocation);
 913     LOG_OFFSET(xtty, consts);
 914     LOG_OFFSET(xtty, insts);
 915     LOG_OFFSET(xtty, stub);
 916     LOG_OFFSET(xtty, scopes_data);
 917     LOG_OFFSET(xtty, scopes_pcs);
 918     LOG_OFFSET(xtty, dependencies);
 919     LOG_OFFSET(xtty, handler_table);
 920     LOG_OFFSET(xtty, nul_chk_table);
 921     LOG_OFFSET(xtty, oops);
 922 
 923     xtty->method(method());
 924     xtty->stamp();
 925     xtty->end_elem();
 926   }
 927 }
 928 
 929 #undef LOG_OFFSET
 930 
 931 
 932 void nmethod::print_compilation(outputStream *st, const char *method_name, const char *title,
 933                                 methodOop method, bool is_blocking, int compile_id, int bci, int comp_level) {
 934   bool is_synchronized = false, has_xhandler = false, is_native = false;
 935   int code_size = -1;
 936   if (method != NULL) {
 937     is_synchronized = method->is_synchronized();
 938     has_xhandler    = method->has_exception_handler();
 939     is_native       = method->is_native();
 940     code_size       = method->code_size();
 941   }
 942   // print compilation number
 943   st->print("%7d %3d", (int)tty->time_stamp().milliseconds(), compile_id);
 944 
 945   // print method attributes
 946   const bool is_osr = bci != InvocationEntryBci;
 947   const char blocking_char  = is_blocking     ? 'b' : ' ';
 948   const char compile_type   = is_osr          ? '%' : ' ';
 949   const char sync_char      = is_synchronized ? 's' : ' ';
 950   const char exception_char = has_xhandler    ? '!' : ' ';
 951   const char native_char    = is_native       ? 'n' : ' ';
 952   st->print("%c%c%c%c%c ", compile_type, sync_char, exception_char, blocking_char, native_char);
 953   if (TieredCompilation) {
 954     st->print("%d ", comp_level);
 955   }
 956 
 957   // print optional title
 958   bool do_nl = false;
 959   if (title != NULL) {
 960     int tlen = (int) strlen(title);
 961     bool do_nl = false;
 962     if (tlen > 0 && title[tlen-1] == '\n') { tlen--; do_nl = true; }
 963     st->print("%.*s", tlen, title);
 964   } else {
 965     do_nl = true;
 966   }
 967 
 968   // print method name string if given
 969   if (method_name != NULL) {
 970     st->print(method_name);
 971   } else {
 972     // otherwise as the method to print itself
 973     if (method != NULL && !Universe::heap()->is_gc_active()) {
 974       method->print_short_name(st);
 975     } else {
 976       st->print("(method)");
 977     }
 978   }
 979 
 980   if (method != NULL) {
 981     // print osr_bci if any
 982     if (is_osr) st->print(" @ %d", bci);
 983     // print method size
 984     st->print(" (%d bytes)", code_size);
 985   }
 986   if (do_nl) st->cr();
 987 }
 988 
 989 // Print out more verbose output usually for a newly created nmethod.
 990 void nmethod::print_on(outputStream* st, const char* title) const {
 991   if (st != NULL) {
 992     ttyLocker ttyl;
 993     print_compilation(st, /*method_name*/NULL, title,
 994                       method(), /*is_blocking*/false,
 995                       compile_id(),
 996                       is_osr_method() ? osr_entry_bci() : InvocationEntryBci,
 997                       comp_level());
 998     if (WizardMode) st->print(" (" INTPTR_FORMAT ")", this);
 999   }
1000 }
1001 
1002 
1003 void nmethod::print_nmethod(bool printmethod) {
1004   ttyLocker ttyl;  // keep the following output all in one block
1005   if (xtty != NULL) {
1006     xtty->begin_head("print_nmethod");
1007     xtty->stamp();
1008     xtty->end_head();
1009   }
1010   // print the header part first
1011   print();
1012   // then print the requested information
1013   if (printmethod) {
1014     print_code();
1015     print_pcs();
1016     oop_maps()->print();
1017   }
1018   if (PrintDebugInfo) {
1019     print_scopes();
1020   }
1021   if (PrintRelocations) {
1022     print_relocations();
1023   }
1024   if (PrintDependencies) {
1025     print_dependencies();
1026   }
1027   if (PrintExceptionHandlers) {
1028     print_handler_table();
1029     print_nul_chk_table();
1030   }
1031   if (xtty != NULL) {
1032     xtty->tail("print_nmethod");
1033   }
1034 }
1035 
1036 
1037 // Promote one word from an assembly-time handle to a live embedded oop.
1038 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1039   if (handle == NULL ||
1040       // As a special case, IC oops are initialized to 1 or -1.
1041       handle == (jobject) Universe::non_oop_word()) {
1042     (*dest) = (oop) handle;
1043   } else {
1044     (*dest) = JNIHandles::resolve_non_null(handle);
1045   }
1046 }
1047 
1048 
1049 void nmethod::copy_oops(GrowableArray<jobject>* array) {
1050   //assert(oops_size() == 0, "do this handshake just once, please");
1051   int length = array->length();
1052   assert((address)(oops_begin() + length) <= data_end(), "oops big enough");
1053   oop* dest = oops_begin();
1054   for (int index = 0 ; index < length; index++) {
1055     initialize_immediate_oop(&dest[index], array->at(index));
1056   }
1057 
1058   // Now we can fix up all the oops in the code.  We need to do this
1059   // in the code because the assembler uses jobjects as placeholders.
1060   // The code and relocations have already been initialized by the
1061   // CodeBlob constructor, so it is valid even at this early point to
1062   // iterate over relocations and patch the code.
1063   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
1064 }
1065 
1066 
1067 bool nmethod::is_at_poll_return(address pc) {
1068   RelocIterator iter(this, pc, pc+1);
1069   while (iter.next()) {
1070     if (iter.type() == relocInfo::poll_return_type)
1071       return true;
1072   }
1073   return false;
1074 }
1075 
1076 
1077 bool nmethod::is_at_poll_or_poll_return(address pc) {
1078   RelocIterator iter(this, pc, pc+1);
1079   while (iter.next()) {
1080     relocInfo::relocType t = iter.type();
1081     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
1082       return true;
1083   }
1084   return false;
1085 }
1086 
1087 
1088 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1089   // re-patch all oop-bearing instructions, just in case some oops moved
1090   RelocIterator iter(this, begin, end);
1091   while (iter.next()) {
1092     if (iter.type() == relocInfo::oop_type) {
1093       oop_Relocation* reloc = iter.oop_reloc();
1094       if (initialize_immediates && reloc->oop_is_immediate()) {
1095         oop* dest = reloc->oop_addr();
1096         initialize_immediate_oop(dest, (jobject) *dest);
1097       }
1098       // Refresh the oop-related bits of this instruction.
1099       reloc->fix_oop_relocation();
1100     }
1101 
1102     // There must not be any interfering patches or breakpoints.
1103     assert(!(iter.type() == relocInfo::breakpoint_type
1104              && iter.breakpoint_reloc()->active()),
1105            "no active breakpoint");
1106   }
1107 }
1108 
1109 
1110 ScopeDesc* nmethod::scope_desc_at(address pc) {
1111   PcDesc* pd = pc_desc_at(pc);
1112   guarantee(pd != NULL, "scope must be present");
1113   return new ScopeDesc(this, pd->scope_decode_offset(),
1114                        pd->obj_decode_offset(), pd->should_reexecute(),
1115                        pd->return_oop());
1116 }
1117 
1118 
1119 void nmethod::clear_inline_caches() {
1120   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
1121   if (is_zombie()) {
1122     return;
1123   }
1124 
1125   RelocIterator iter(this);
1126   while (iter.next()) {
1127     iter.reloc()->clear_inline_cache();
1128   }
1129 }
1130 
1131 
1132 void nmethod::cleanup_inline_caches() {
1133 
1134   assert_locked_or_safepoint(CompiledIC_lock);
1135 
1136   // If the method is not entrant or zombie then a JMP is plastered over the
1137   // first few bytes.  If an oop in the old code was there, that oop
1138   // should not get GC'd.  Skip the first few bytes of oops on
1139   // not-entrant methods.
1140   address low_boundary = verified_entry_point();
1141   if (!is_in_use()) {
1142     low_boundary += NativeJump::instruction_size;
1143     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1144     // This means that the low_boundary is going to be a little too high.
1145     // This shouldn't matter, since oops of non-entrant methods are never used.
1146     // In fact, why are we bothering to look at oops in a non-entrant method??
1147   }
1148 
1149   // Find all calls in an nmethod, and clear the ones that points to zombie methods
1150   ResourceMark rm;
1151   RelocIterator iter(this, low_boundary);
1152   while(iter.next()) {
1153     switch(iter.type()) {
1154       case relocInfo::virtual_call_type:
1155       case relocInfo::opt_virtual_call_type: {
1156         CompiledIC *ic = CompiledIC_at(iter.reloc());
1157         // Ok, to lookup references to zombies here
1158         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1159         if( cb != NULL && cb->is_nmethod() ) {
1160           nmethod* nm = (nmethod*)cb;
1161           // Clean inline caches pointing to both zombie and not_entrant methods
1162           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
1163         }
1164         break;
1165       }
1166       case relocInfo::static_call_type: {
1167         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1168         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1169         if( cb != NULL && cb->is_nmethod() ) {
1170           nmethod* nm = (nmethod*)cb;
1171           // Clean inline caches pointing to both zombie and not_entrant methods
1172           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
1173         }
1174         break;
1175       }
1176     }
1177   }
1178 }
1179 
1180 // This is a private interface with the sweeper.
1181 void nmethod::mark_as_seen_on_stack() {
1182   assert(is_not_entrant(), "must be a non-entrant method");
1183   // Set the traversal mark to ensure that the sweeper does 2
1184   // cleaning passes before moving to zombie.
1185   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1186 }
1187 
1188 // Tell if a non-entrant method can be converted to a zombie (i.e., there is no activations on the stack)
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 }
1197 
1198 void nmethod::inc_decompile_count() {
1199   if (!is_compiled_by_c2()) return;
1200   // Could be gated by ProfileTraps, but do not bother...
1201   methodOop m = method();
1202   if (m == NULL)  return;
1203   methodDataOop mdo = m->method_data();
1204   if (mdo == NULL)  return;
1205   // There is a benign race here.  See comments in methodDataOop.hpp.
1206   mdo->inc_decompile_count();
1207 }
1208 
1209 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1210 
1211   post_compiled_method_unload();
1212 
1213   // Since this nmethod is being unloaded, make sure that dependencies
1214   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1215   // indicate that this work is being done during a GC.
1216   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1217   assert(is_alive != NULL, "Should be non-NULL");
1218   // A non-NULL is_alive closure indicates that this is being called during GC.
1219   flush_dependencies(is_alive);
1220 
1221   // Break cycle between nmethod & method
1222   if (TraceClassUnloading && WizardMode) {
1223     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
1224                   " unloadable], methodOop(" INTPTR_FORMAT
1225                   "), cause(" INTPTR_FORMAT ")",
1226                   this, (address)_method, (address)cause);
1227     if (!Universe::heap()->is_gc_active())
1228       cause->klass()->print();
1229   }
1230   // Unlink the osr method, so we do not look this up again
1231   if (is_osr_method()) {
1232     invalidate_osr_method();
1233   }
1234   // If _method is already NULL the methodOop is about to be unloaded,
1235   // so we don't have to break the cycle. Note that it is possible to
1236   // have the methodOop live here, in case we unload the nmethod because
1237   // it is pointing to some oop (other than the methodOop) being unloaded.
1238   if (_method != NULL) {
1239     // OSR methods point to the methodOop, but the methodOop does not
1240     // point back!
1241     if (_method->code() == this) {
1242       _method->clear_code(); // Break a cycle
1243     }
1244     _method = NULL;            // Clear the method of this dead nmethod
1245   }
1246   // Make the class unloaded - i.e., change state and notify sweeper
1247   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1248   if (is_in_use()) {
1249     // Transitioning directly from live to unloaded -- so
1250     // we need to force a cache clean-up; remember this
1251     // for later on.
1252     CodeCache::set_needs_cache_clean(true);
1253   }
1254   _state = unloaded;
1255 
1256   // Log the unloading.
1257   log_state_change();
1258 
1259   // The methodOop is gone at this point
1260   assert(_method == NULL, "Tautology");
1261 
1262   set_osr_link(NULL);
1263   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
1264   NMethodSweeper::notify(this);
1265 }
1266 
1267 void nmethod::invalidate_osr_method() {
1268   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1269   // Remove from list of active nmethods
1270   if (method() != NULL)
1271     instanceKlass::cast(method()->method_holder())->remove_osr_nmethod(this);
1272   // Set entry as invalid
1273   _entry_bci = InvalidOSREntryBci;
1274 }
1275 
1276 void nmethod::log_state_change() const {
1277   if (LogCompilation) {
1278     if (xtty != NULL) {
1279       ttyLocker ttyl;  // keep the following output all in one block
1280       if (_state == unloaded) {
1281         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1282                          os::current_thread_id());
1283       } else {
1284         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1285                          os::current_thread_id(),
1286                          (_state == zombie ? " zombie='1'" : ""));
1287       }
1288       log_identity(xtty);
1289       xtty->stamp();
1290       xtty->end_elem();
1291     }
1292   }
1293   if (PrintCompilation && _state != unloaded) {
1294     print_on(tty, _state == zombie ? "made zombie " : "made not entrant ");
1295     tty->cr();
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 
1303   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1304   nmethodLocker nml(this);
1305   methodHandle the_method(method());
1306   No_Safepoint_Verifier nsv;
1307 
1308   {
1309     // If the method is already zombie there is nothing to do
1310     if (is_zombie()) {
1311       return false;
1312     }
1313 
1314     // invalidate osr nmethod before acquiring the patching lock since
1315     // they both acquire leaf locks and we don't want a deadlock.
1316     // This logic is equivalent to the logic below for patching the
1317     // verified entry point of regular methods.
1318     if (is_osr_method()) {
1319       // this effectively makes the osr nmethod not entrant
1320       invalidate_osr_method();
1321     }
1322 
1323     // Enter critical section.  Does not block for safepoint.
1324     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1325 
1326     if (_state == state) {
1327       // another thread already performed this transition so nothing
1328       // to do, but return false to indicate this.
1329       return false;
1330     }
1331 
1332     // The caller can be calling the method statically or through an inline
1333     // cache call.
1334     if (!is_osr_method() && !is_not_entrant()) {
1335       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1336                   SharedRuntime::get_handle_wrong_method_stub());
1337     }
1338 
1339     if (is_in_use()) {
1340       // It's a true state change, so mark the method as decompiled.
1341       // Do it only for transition from alive.
1342       inc_decompile_count();
1343     }
1344 
1345     // Change state
1346     _state = state;
1347 
1348     // Log the transition once
1349     log_state_change();
1350 
1351     // Remove nmethod from method.
1352     // We need to check if both the _code and _from_compiled_code_entry_point
1353     // refer to this nmethod because there is a race in setting these two fields
1354     // in methodOop as seen in bugid 4947125.
1355     // If the vep() points to the zombie nmethod, the memory for the nmethod
1356     // could be flushed and the compiler and vtable stubs could still call
1357     // through it.
1358     if (method() != NULL && (method()->code() == this ||
1359                              method()->from_compiled_entry() == verified_entry_point())) {
1360       HandleMark hm;
1361       method()->clear_code();
1362     }
1363 
1364     if (state == not_entrant) {
1365       mark_as_seen_on_stack();
1366     }
1367 
1368   } // leave critical region under Patching_lock
1369 
1370   // When the nmethod becomes zombie it is no longer alive so the
1371   // dependencies must be flushed.  nmethods in the not_entrant
1372   // state will be flushed later when the transition to zombie
1373   // happens or they get unloaded.
1374   if (state == zombie) {
1375     {
1376       // Flushing dependecies must be done before any possible
1377       // safepoint can sneak in, otherwise the oops used by the
1378       // dependency logic could have become stale.
1379       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1380       flush_dependencies(NULL);
1381     }
1382 
1383     {
1384       // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload event
1385       // and it hasn't already been reported for this nmethod then report it now.
1386       // (the event may have been reported earilier if the GC marked it for unloading).
1387       Pause_No_Safepoint_Verifier pnsv(&nsv);
1388       post_compiled_method_unload();
1389     }
1390 
1391 #ifdef ASSERT
1392     // It's no longer safe to access the oops section since zombie
1393     // nmethods aren't scanned for GC.
1394     _oops_are_stale = true;
1395 #endif
1396   } else {
1397     assert(state == not_entrant, "other cases may need to be handled differently");
1398   }
1399 
1400   if (TraceCreateZombies) {
1401     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
1402   }
1403 
1404   // Make sweeper aware that there is a zombie method that needs to be removed
1405   NMethodSweeper::notify(this);
1406 
1407   return true;
1408 }
1409 
1410 void nmethod::flush() {
1411   // Note that there are no valid oops in the nmethod anymore.
1412   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
1413   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
1414 
1415   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1416   assert_locked_or_safepoint(CodeCache_lock);
1417 
1418   // completely deallocate this method
1419   EventMark m("flushing nmethod " INTPTR_FORMAT " %s", this, "");
1420   if (PrintMethodFlushing) {
1421     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
1422         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
1423   }
1424 
1425   // We need to deallocate any ExceptionCache data.
1426   // Note that we do not need to grab the nmethod lock for this, it
1427   // better be thread safe if we're disposing of it!
1428   ExceptionCache* ec = exception_cache();
1429   set_exception_cache(NULL);
1430   while(ec != NULL) {
1431     ExceptionCache* next = ec->next();
1432     delete ec;
1433     ec = next;
1434   }
1435 
1436   if (on_scavenge_root_list()) {
1437     CodeCache::drop_scavenge_root_nmethod(this);
1438   }
1439 
1440   if (is_speculatively_disconnected()) {
1441     CodeCache::remove_saved_code(this);
1442   }
1443 
1444 #ifdef SHARK
1445   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1446 #endif // SHARK
1447 
1448   ((CodeBlob*)(this))->flush();
1449 
1450   CodeCache::free(this);
1451 }
1452 
1453 
1454 //
1455 // Notify all classes this nmethod is dependent on that it is no
1456 // longer dependent. This should only be called in two situations.
1457 // First, when a nmethod transitions to a zombie all dependents need
1458 // to be clear.  Since zombification happens at a safepoint there's no
1459 // synchronization issues.  The second place is a little more tricky.
1460 // During phase 1 of mark sweep class unloading may happen and as a
1461 // result some nmethods may get unloaded.  In this case the flushing
1462 // of dependencies must happen during phase 1 since after GC any
1463 // dependencies in the unloaded nmethod won't be updated, so
1464 // traversing the dependency information in unsafe.  In that case this
1465 // function is called with a non-NULL argument and this function only
1466 // notifies instanceKlasses that are reachable
1467 
1468 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1469   assert_locked_or_safepoint(CodeCache_lock);
1470   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1471   "is_alive is non-NULL if and only if we are called during GC");
1472   if (!has_flushed_dependencies()) {
1473     set_has_flushed_dependencies();
1474     for (Dependencies::DepStream deps(this); deps.next(); ) {
1475       klassOop klass = deps.context_type();
1476       if (klass == NULL)  continue;  // ignore things like evol_method
1477 
1478       // During GC the is_alive closure is non-NULL, and is used to
1479       // determine liveness of dependees that need to be updated.
1480       if (is_alive == NULL || is_alive->do_object_b(klass)) {
1481         instanceKlass::cast(klass)->remove_dependent_nmethod(this);
1482       }
1483     }
1484   }
1485 }
1486 
1487 
1488 // If this oop is not live, the nmethod can be unloaded.
1489 bool nmethod::can_unload(BoolObjectClosure* is_alive,
1490                          OopClosure* keep_alive,
1491                          oop* root, bool unloading_occurred) {
1492   assert(root != NULL, "just checking");
1493   oop obj = *root;
1494   if (obj == NULL || is_alive->do_object_b(obj)) {
1495       return false;
1496   }
1497   if (obj->is_compiledICHolder()) {
1498     compiledICHolderOop cichk_oop = compiledICHolderOop(obj);
1499     if (is_alive->do_object_b(
1500           cichk_oop->holder_method()->method_holder()) &&
1501         is_alive->do_object_b(cichk_oop->holder_klass())) {
1502       // The oop should be kept alive
1503       keep_alive->do_oop(root);
1504       return false;
1505     }
1506   }
1507   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1508   // simply because one of its constant oops has gone dead.
1509   // No actual classes need to be unloaded in order for this to occur.
1510   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1511   make_unloaded(is_alive, obj);
1512   return true;
1513 }
1514 
1515 // ------------------------------------------------------------------
1516 // post_compiled_method_load_event
1517 // new method for install_code() path
1518 // Transfer information from compilation to jvmti
1519 void nmethod::post_compiled_method_load_event() {
1520 
1521   methodOop moop = method();
1522   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
1523       moop->klass_name()->bytes(),
1524       moop->klass_name()->utf8_length(),
1525       moop->name()->bytes(),
1526       moop->name()->utf8_length(),
1527       moop->signature()->bytes(),
1528       moop->signature()->utf8_length(),
1529       insts_begin(), insts_size());
1530 
1531   if (JvmtiExport::should_post_compiled_method_load() ||
1532       JvmtiExport::should_post_compiled_method_unload()) {
1533     get_and_cache_jmethod_id();
1534   }
1535 
1536   if (JvmtiExport::should_post_compiled_method_load()) {
1537     // Let the Service thread (which is a real Java thread) post the event
1538     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1539     JvmtiDeferredEventQueue::enqueue(
1540       JvmtiDeferredEvent::compiled_method_load(this));
1541   }
1542 }
1543 
1544 jmethodID nmethod::get_and_cache_jmethod_id() {
1545   if (_jmethod_id == NULL) {
1546     // Cache the jmethod_id since it can no longer be looked up once the
1547     // method itself has been marked for unloading.
1548     _jmethod_id = method()->jmethod_id();
1549   }
1550   return _jmethod_id;
1551 }
1552 
1553 void nmethod::post_compiled_method_unload() {
1554   if (unload_reported()) {
1555     // During unloading we transition to unloaded and then to zombie
1556     // and the unloading is reported during the first transition.
1557     return;
1558   }
1559 
1560   assert(_method != NULL && !is_unloaded(), "just checking");
1561   DTRACE_METHOD_UNLOAD_PROBE(method());
1562 
1563   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1564   // post the event. Sometime later this nmethod will be made a zombie
1565   // by the sweeper but the methodOop will not be valid at that point.
1566   // If the _jmethod_id is null then no load event was ever requested
1567   // so don't bother posting the unload.  The main reason for this is
1568   // that the jmethodID is a weak reference to the methodOop so if
1569   // it's being unloaded there's no way to look it up since the weak
1570   // ref will have been cleared.
1571   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1572     assert(!unload_reported(), "already unloaded");
1573     HandleMark hm;
1574     JvmtiExport::post_compiled_method_unload(_jmethod_id, insts_begin());
1575   }
1576 
1577   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1578   // any time. As the nmethod is being unloaded now we mark it has
1579   // having the unload event reported - this will ensure that we don't
1580   // attempt to report the event in the unlikely scenario where the
1581   // event is enabled at the time the nmethod is made a zombie.
1582   set_unload_reported();
1583 }
1584 
1585 // This is called at the end of the strong tracing/marking phase of a
1586 // GC to unload an nmethod if it contains otherwise unreachable
1587 // oops.
1588 
1589 void nmethod::do_unloading(BoolObjectClosure* is_alive,
1590                            OopClosure* keep_alive, bool unloading_occurred) {
1591   // Make sure the oop's ready to receive visitors
1592   assert(!is_zombie() && !is_unloaded(),
1593          "should not call follow on zombie or unloaded nmethod");
1594 
1595   // If the method is not entrant then a JMP is plastered over the
1596   // first few bytes.  If an oop in the old code was there, that oop
1597   // should not get GC'd.  Skip the first few bytes of oops on
1598   // not-entrant methods.
1599   address low_boundary = verified_entry_point();
1600   if (is_not_entrant()) {
1601     low_boundary += NativeJump::instruction_size;
1602     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1603     // (See comment above.)
1604   }
1605 
1606   // The RedefineClasses() API can cause the class unloading invariant
1607   // to no longer be true. See jvmtiExport.hpp for details.
1608   // Also, leave a debugging breadcrumb in local flag.
1609   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
1610   if (a_class_was_redefined) {
1611     // This set of the unloading_occurred flag is done before the
1612     // call to post_compiled_method_unload() so that the unloading
1613     // of this nmethod is reported.
1614     unloading_occurred = true;
1615   }
1616 
1617   // Follow methodOop
1618   if (can_unload(is_alive, keep_alive, (oop*)&_method, unloading_occurred)) {
1619     return;
1620   }
1621 
1622   // Exception cache
1623   ExceptionCache* ec = exception_cache();
1624   while (ec != NULL) {
1625     oop* ex_addr = (oop*)ec->exception_type_addr();
1626     oop ex = *ex_addr;
1627     ExceptionCache* next_ec = ec->next();
1628     if (ex != NULL && !is_alive->do_object_b(ex)) {
1629       assert(!ex->is_compiledICHolder(), "Possible error here");
1630       remove_from_exception_cache(ec);
1631     }
1632     ec = next_ec;
1633   }
1634 
1635   // If class unloading occurred we first iterate over all inline caches and
1636   // clear ICs where the cached oop is referring to an unloaded klass or method.
1637   // The remaining live cached oops will be traversed in the relocInfo::oop_type
1638   // iteration below.
1639   if (unloading_occurred) {
1640     RelocIterator iter(this, low_boundary);
1641     while(iter.next()) {
1642       if (iter.type() == relocInfo::virtual_call_type) {
1643         CompiledIC *ic = CompiledIC_at(iter.reloc());
1644         oop ic_oop = ic->cached_oop();
1645         if (ic_oop != NULL && !is_alive->do_object_b(ic_oop)) {
1646           // The only exception is compiledICHolder oops which may
1647           // yet be marked below. (We check this further below).
1648           if (ic_oop->is_compiledICHolder()) {
1649             compiledICHolderOop cichk_oop = compiledICHolderOop(ic_oop);
1650             if (is_alive->do_object_b(
1651                   cichk_oop->holder_method()->method_holder()) &&
1652                 is_alive->do_object_b(cichk_oop->holder_klass())) {
1653               continue;
1654             }
1655           }
1656           ic->set_to_clean();
1657           assert(ic->cached_oop() == NULL,
1658                  "cached oop in IC should be cleared");
1659         }
1660       }
1661     }
1662   }
1663 
1664   // Compiled code
1665   RelocIterator iter(this, low_boundary);
1666   while (iter.next()) {
1667     if (iter.type() == relocInfo::oop_type) {
1668       oop_Relocation* r = iter.oop_reloc();
1669       // In this loop, we must only traverse those oops directly embedded in
1670       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1671       assert(1 == (r->oop_is_immediate()) +
1672                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1673              "oop must be found in exactly one place");
1674       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1675         if (can_unload(is_alive, keep_alive, r->oop_addr(), unloading_occurred)) {
1676           return;
1677         }
1678       }
1679     }
1680   }
1681 
1682 
1683   // Scopes
1684   for (oop* p = oops_begin(); p < oops_end(); p++) {
1685     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1686     if (can_unload(is_alive, keep_alive, p, unloading_occurred)) {
1687       return;
1688     }
1689   }
1690 
1691 #ifndef PRODUCT
1692   // This nmethod was not unloaded; check below that all CompiledICs
1693   // refer to marked oops.
1694   {
1695     RelocIterator iter(this, low_boundary);
1696     while (iter.next()) {
1697       if (iter.type() == relocInfo::virtual_call_type) {
1698          CompiledIC *ic = CompiledIC_at(iter.reloc());
1699          oop ic_oop = ic->cached_oop();
1700          assert(ic_oop == NULL || is_alive->do_object_b(ic_oop),
1701                 "Found unmarked ic_oop in reachable nmethod");
1702        }
1703     }
1704   }
1705 #endif // !PRODUCT
1706 }
1707 
1708 // This method is called twice during GC -- once while
1709 // tracing the "active" nmethods on thread stacks during
1710 // the (strong) marking phase, and then again when walking
1711 // the code cache contents during the weak roots processing
1712 // phase. The two uses are distinguished by means of the
1713 // 'do_strong_roots_only' flag, which is true in the first
1714 // case. We want to walk the weak roots in the nmethod
1715 // only in the second case. The weak roots in the nmethod
1716 // are the oops in the ExceptionCache and the InlineCache
1717 // oops.
1718 void nmethod::oops_do(OopClosure* f, bool do_strong_roots_only) {
1719   // make sure the oops ready to receive visitors
1720   assert(!is_zombie() && !is_unloaded(),
1721          "should not call follow on zombie or unloaded nmethod");
1722 
1723   // If the method is not entrant or zombie then a JMP is plastered over the
1724   // first few bytes.  If an oop in the old code was there, that oop
1725   // should not get GC'd.  Skip the first few bytes of oops on
1726   // not-entrant methods.
1727   address low_boundary = verified_entry_point();
1728   if (is_not_entrant()) {
1729     low_boundary += NativeJump::instruction_size;
1730     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1731     // (See comment above.)
1732   }
1733 
1734   // Compiled code
1735   f->do_oop((oop*) &_method);
1736   if (!do_strong_roots_only) {
1737     // weak roots processing phase -- update ExceptionCache oops
1738     ExceptionCache* ec = exception_cache();
1739     while(ec != NULL) {
1740       f->do_oop((oop*)ec->exception_type_addr());
1741       ec = ec->next();
1742     }
1743   } // Else strong roots phase -- skip oops in ExceptionCache
1744 
1745   RelocIterator iter(this, low_boundary);
1746 
1747   while (iter.next()) {
1748     if (iter.type() == relocInfo::oop_type ) {
1749       oop_Relocation* r = iter.oop_reloc();
1750       // In this loop, we must only follow those oops directly embedded in
1751       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1752       assert(1 == (r->oop_is_immediate()) +
1753                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1754              "oop must be found in exactly one place");
1755       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1756         f->do_oop(r->oop_addr());
1757       }
1758     }
1759   }
1760 
1761   // Scopes
1762   // This includes oop constants not inlined in the code stream.
1763   for (oop* p = oops_begin(); p < oops_end(); p++) {
1764     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1765     f->do_oop(p);
1766   }
1767 }
1768 
1769 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1770 
1771 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1772 
1773 // An nmethod is "marked" if its _mark_link is set non-null.
1774 // Even if it is the end of the linked list, it will have a non-null link value,
1775 // as long as it is on the list.
1776 // This code must be MP safe, because it is used from parallel GC passes.
1777 bool nmethod::test_set_oops_do_mark() {
1778   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1779   nmethod* observed_mark_link = _oops_do_mark_link;
1780   if (observed_mark_link == NULL) {
1781     // Claim this nmethod for this thread to mark.
1782     observed_mark_link = (nmethod*)
1783       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1784     if (observed_mark_link == NULL) {
1785 
1786       // Atomically append this nmethod (now claimed) to the head of the list:
1787       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1788       for (;;) {
1789         nmethod* required_mark_nmethods = observed_mark_nmethods;
1790         _oops_do_mark_link = required_mark_nmethods;
1791         observed_mark_nmethods = (nmethod*)
1792           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1793         if (observed_mark_nmethods == required_mark_nmethods)
1794           break;
1795       }
1796       // Mark was clear when we first saw this guy.
1797       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark\n"));
1798       return false;
1799     }
1800   }
1801   // On fall through, another racing thread marked this nmethod before we did.
1802   return true;
1803 }
1804 
1805 void nmethod::oops_do_marking_prologue() {
1806   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
1807   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1808   // We use cmpxchg_ptr instead of regular assignment here because the user
1809   // may fork a bunch of threads, and we need them all to see the same state.
1810   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1811   guarantee(observed == NULL, "no races in this sequential code");
1812 }
1813 
1814 void nmethod::oops_do_marking_epilogue() {
1815   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1816   nmethod* cur = _oops_do_mark_nmethods;
1817   while (cur != NMETHOD_SENTINEL) {
1818     assert(cur != NULL, "not NULL-terminated");
1819     nmethod* next = cur->_oops_do_mark_link;
1820     cur->_oops_do_mark_link = NULL;
1821     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark\n"));
1822     cur = next;
1823   }
1824   void* required = _oops_do_mark_nmethods;
1825   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1826   guarantee(observed == required, "no races in this sequential code");
1827   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
1828 }
1829 
1830 class DetectScavengeRoot: public OopClosure {
1831   bool     _detected_scavenge_root;
1832 public:
1833   DetectScavengeRoot() : _detected_scavenge_root(false)
1834   { NOT_PRODUCT(_print_nm = NULL); }
1835   bool detected_scavenge_root() { return _detected_scavenge_root; }
1836   virtual void do_oop(oop* p) {
1837     if ((*p) != NULL && (*p)->is_scavengable()) {
1838       NOT_PRODUCT(maybe_print(p));
1839       _detected_scavenge_root = true;
1840     }
1841   }
1842   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1843 
1844 #ifndef PRODUCT
1845   nmethod* _print_nm;
1846   void maybe_print(oop* p) {
1847     if (_print_nm == NULL)  return;
1848     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1849     tty->print_cr(""PTR_FORMAT"[offset=%d] detected non-perm oop "PTR_FORMAT" (found at "PTR_FORMAT")",
1850                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
1851                   (intptr_t)(*p), (intptr_t)p);
1852     (*p)->print();
1853   }
1854 #endif //PRODUCT
1855 };
1856 
1857 bool nmethod::detect_scavenge_root_oops() {
1858   DetectScavengeRoot detect_scavenge_root;
1859   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1860   oops_do(&detect_scavenge_root);
1861   return detect_scavenge_root.detected_scavenge_root();
1862 }
1863 
1864 // Method that knows how to preserve outgoing arguments at call. This method must be
1865 // called with a frame corresponding to a Java invoke
1866 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
1867 #ifndef SHARK
1868   if (!method()->is_native()) {
1869     SimpleScopeDesc ssd(this, fr.pc());
1870     Bytecode_invoke call(ssd.method(), ssd.bci());
1871     bool has_receiver = call.has_receiver();
1872     symbolOop signature = call.signature();
1873     fr.oops_compiled_arguments_do(signature, has_receiver, reg_map, f);
1874   }
1875 #endif // !SHARK
1876 }
1877 
1878 
1879 oop nmethod::embeddedOop_at(u_char* p) {
1880   RelocIterator iter(this, p, p + oopSize);
1881   while (iter.next())
1882     if (iter.type() == relocInfo::oop_type) {
1883       return iter.oop_reloc()->oop_value();
1884     }
1885   return NULL;
1886 }
1887 
1888 
1889 inline bool includes(void* p, void* from, void* to) {
1890   return from <= p && p < to;
1891 }
1892 
1893 
1894 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1895   assert(count >= 2, "must be sentinel values, at least");
1896 
1897 #ifdef ASSERT
1898   // must be sorted and unique; we do a binary search in find_pc_desc()
1899   int prev_offset = pcs[0].pc_offset();
1900   assert(prev_offset == PcDesc::lower_offset_limit,
1901          "must start with a sentinel");
1902   for (int i = 1; i < count; i++) {
1903     int this_offset = pcs[i].pc_offset();
1904     assert(this_offset > prev_offset, "offsets must be sorted");
1905     prev_offset = this_offset;
1906   }
1907   assert(prev_offset == PcDesc::upper_offset_limit,
1908          "must end with a sentinel");
1909 #endif //ASSERT
1910 
1911   // Search for MethodHandle invokes and tag the nmethod.
1912   for (int i = 0; i < count; i++) {
1913     if (pcs[i].is_method_handle_invoke()) {
1914       set_has_method_handle_invokes(true);
1915       break;
1916     }
1917   }
1918   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
1919 
1920   int size = count * sizeof(PcDesc);
1921   assert(scopes_pcs_size() >= size, "oob");
1922   memcpy(scopes_pcs_begin(), pcs, size);
1923 
1924   // Adjust the final sentinel downward.
1925   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1926   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1927   last_pc->set_pc_offset(content_size() + 1);
1928   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1929     // Fill any rounding gaps with copies of the last record.
1930     last_pc[1] = last_pc[0];
1931   }
1932   // The following assert could fail if sizeof(PcDesc) is not
1933   // an integral multiple of oopSize (the rounding term).
1934   // If it fails, change the logic to always allocate a multiple
1935   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1936   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1937 }
1938 
1939 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1940   assert(scopes_data_size() >= size, "oob");
1941   memcpy(scopes_data_begin(), buffer, size);
1942 }
1943 
1944 
1945 #ifdef ASSERT
1946 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
1947   PcDesc* lower = nm->scopes_pcs_begin();
1948   PcDesc* upper = nm->scopes_pcs_end();
1949   lower += 1; // exclude initial sentinel
1950   PcDesc* res = NULL;
1951   for (PcDesc* p = lower; p < upper; p++) {
1952     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1953     if (match_desc(p, pc_offset, approximate)) {
1954       if (res == NULL)
1955         res = p;
1956       else
1957         res = (PcDesc*) badAddress;
1958     }
1959   }
1960   return res;
1961 }
1962 #endif
1963 
1964 
1965 // Finds a PcDesc with real-pc equal to "pc"
1966 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
1967   address base_address = code_begin();
1968   if ((pc < base_address) ||
1969       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1970     return NULL;  // PC is wildly out of range
1971   }
1972   int pc_offset = (int) (pc - base_address);
1973 
1974   // Check the PcDesc cache if it contains the desired PcDesc
1975   // (This as an almost 100% hit rate.)
1976   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1977   if (res != NULL) {
1978     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
1979     return res;
1980   }
1981 
1982   // Fallback algorithm: quasi-linear search for the PcDesc
1983   // Find the last pc_offset less than the given offset.
1984   // The successor must be the required match, if there is a match at all.
1985   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1986   PcDesc* lower = scopes_pcs_begin();
1987   PcDesc* upper = scopes_pcs_end();
1988   upper -= 1; // exclude final sentinel
1989   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1990 
1991 #define assert_LU_OK \
1992   /* invariant on lower..upper during the following search: */ \
1993   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1994   assert(upper->pc_offset() >= pc_offset, "sanity")
1995   assert_LU_OK;
1996 
1997   // Use the last successful return as a split point.
1998   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1999   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2000   if (mid->pc_offset() < pc_offset) {
2001     lower = mid;
2002   } else {
2003     upper = mid;
2004   }
2005 
2006   // Take giant steps at first (4096, then 256, then 16, then 1)
2007   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
2008   const int RADIX = (1 << LOG2_RADIX);
2009   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
2010     while ((mid = lower + step) < upper) {
2011       assert_LU_OK;
2012       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2013       if (mid->pc_offset() < pc_offset) {
2014         lower = mid;
2015       } else {
2016         upper = mid;
2017         break;
2018       }
2019     }
2020     assert_LU_OK;
2021   }
2022 
2023   // Sneak up on the value with a linear search of length ~16.
2024   while (true) {
2025     assert_LU_OK;
2026     mid = lower + 1;
2027     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2028     if (mid->pc_offset() < pc_offset) {
2029       lower = mid;
2030     } else {
2031       upper = mid;
2032       break;
2033     }
2034   }
2035 #undef assert_LU_OK
2036 
2037   if (match_desc(upper, pc_offset, approximate)) {
2038     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
2039     _pc_desc_cache.add_pc_desc(upper);
2040     return upper;
2041   } else {
2042     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
2043     return NULL;
2044   }
2045 }
2046 
2047 
2048 bool nmethod::check_all_dependencies() {
2049   bool found_check = false;
2050   // wholesale check of all dependencies
2051   for (Dependencies::DepStream deps(this); deps.next(); ) {
2052     if (deps.check_dependency() != NULL) {
2053       found_check = true;
2054       NOT_DEBUG(break);
2055     }
2056   }
2057   return found_check;  // tell caller if we found anything
2058 }
2059 
2060 bool nmethod::check_dependency_on(DepChange& changes) {
2061   // What has happened:
2062   // 1) a new class dependee has been added
2063   // 2) dependee and all its super classes have been marked
2064   bool found_check = false;  // set true if we are upset
2065   for (Dependencies::DepStream deps(this); deps.next(); ) {
2066     // Evaluate only relevant dependencies.
2067     if (deps.spot_check_dependency_at(changes) != NULL) {
2068       found_check = true;
2069       NOT_DEBUG(break);
2070     }
2071   }
2072   return found_check;
2073 }
2074 
2075 bool nmethod::is_evol_dependent_on(klassOop dependee) {
2076   instanceKlass *dependee_ik = instanceKlass::cast(dependee);
2077   objArrayOop dependee_methods = dependee_ik->methods();
2078   for (Dependencies::DepStream deps(this); deps.next(); ) {
2079     if (deps.type() == Dependencies::evol_method) {
2080       methodOop method = deps.method_argument(0);
2081       for (int j = 0; j < dependee_methods->length(); j++) {
2082         if ((methodOop) dependee_methods->obj_at(j) == method) {
2083           // RC_TRACE macro has an embedded ResourceMark
2084           RC_TRACE(0x01000000,
2085             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2086             _method->method_holder()->klass_part()->external_name(),
2087             _method->name()->as_C_string(),
2088             _method->signature()->as_C_string(), compile_id(),
2089             method->method_holder()->klass_part()->external_name(),
2090             method->name()->as_C_string(),
2091             method->signature()->as_C_string()));
2092           if (TraceDependencies || LogCompilation)
2093             deps.log_dependency(dependee);
2094           return true;
2095         }
2096       }
2097     }
2098   }
2099   return false;
2100 }
2101 
2102 // Called from mark_for_deoptimization, when dependee is invalidated.
2103 bool nmethod::is_dependent_on_method(methodOop dependee) {
2104   for (Dependencies::DepStream deps(this); deps.next(); ) {
2105     if (deps.type() != Dependencies::evol_method)
2106       continue;
2107     methodOop method = deps.method_argument(0);
2108     if (method == dependee) return true;
2109   }
2110   return false;
2111 }
2112 
2113 
2114 bool nmethod::is_patchable_at(address instr_addr) {
2115   assert(insts_contains(instr_addr), "wrong nmethod used");
2116   if (is_zombie()) {
2117     // a zombie may never be patched
2118     return false;
2119   }
2120   return true;
2121 }
2122 
2123 
2124 address nmethod::continuation_for_implicit_exception(address pc) {
2125   // Exception happened outside inline-cache check code => we are inside
2126   // an active nmethod => use cpc to determine a return address
2127   int exception_offset = pc - code_begin();
2128   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2129 #ifdef ASSERT
2130   if (cont_offset == 0) {
2131     Thread* thread = ThreadLocalStorage::get_thread_slow();
2132     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2133     HandleMark hm(thread);
2134     ResourceMark rm(thread);
2135     CodeBlob* cb = CodeCache::find_blob(pc);
2136     assert(cb != NULL && cb == this, "");
2137     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
2138     print();
2139     method()->print_codes();
2140     print_code();
2141     print_pcs();
2142   }
2143 #endif
2144   if (cont_offset == 0) {
2145     // Let the normal error handling report the exception
2146     return NULL;
2147   }
2148   return code_begin() + cont_offset;
2149 }
2150 
2151 
2152 
2153 void nmethod_init() {
2154   // make sure you didn't forget to adjust the filler fields
2155   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2156 }
2157 
2158 
2159 //-------------------------------------------------------------------------------------------
2160 
2161 
2162 // QQQ might we make this work from a frame??
2163 nmethodLocker::nmethodLocker(address pc) {
2164   CodeBlob* cb = CodeCache::find_blob(pc);
2165   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
2166   _nm = (nmethod*)cb;
2167   lock_nmethod(_nm);
2168 }
2169 
2170 void nmethodLocker::lock_nmethod(nmethod* nm) {
2171   if (nm == NULL)  return;
2172   Atomic::inc(&nm->_lock_count);
2173   guarantee(!nm->is_zombie(), "cannot lock a zombie method");
2174 }
2175 
2176 void nmethodLocker::unlock_nmethod(nmethod* nm) {
2177   if (nm == NULL)  return;
2178   Atomic::dec(&nm->_lock_count);
2179   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2180 }
2181 
2182 
2183 // -----------------------------------------------------------------------------
2184 // nmethod::get_deopt_original_pc
2185 //
2186 // Return the original PC for the given PC if:
2187 // (a) the given PC belongs to a nmethod and
2188 // (b) it is a deopt PC
2189 address nmethod::get_deopt_original_pc(const frame* fr) {
2190   if (fr->cb() == NULL)  return NULL;
2191 
2192   nmethod* nm = fr->cb()->as_nmethod_or_null();
2193   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
2194     return nm->get_original_pc(fr);
2195 
2196   return NULL;
2197 }
2198 
2199 
2200 // -----------------------------------------------------------------------------
2201 // MethodHandle
2202 
2203 bool nmethod::is_method_handle_return(address return_pc) {
2204   if (!has_method_handle_invokes())  return false;
2205   PcDesc* pd = pc_desc_at(return_pc);
2206   if (pd == NULL)
2207     return false;
2208   return pd->is_method_handle_invoke();
2209 }
2210 
2211 
2212 // -----------------------------------------------------------------------------
2213 // Verification
2214 
2215 class VerifyOopsClosure: public OopClosure {
2216   nmethod* _nm;
2217   bool     _ok;
2218 public:
2219   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2220   bool ok() { return _ok; }
2221   virtual void do_oop(oop* p) {
2222     if ((*p) == NULL || (*p)->is_oop())  return;
2223     if (_ok) {
2224       _nm->print_nmethod(true);
2225       _ok = false;
2226     }
2227     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2228                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2229   }
2230   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2231 };
2232 
2233 void nmethod::verify() {
2234 
2235   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2236   // seems odd.
2237 
2238   if( is_zombie() || is_not_entrant() )
2239     return;
2240 
2241   // Make sure all the entry points are correctly aligned for patching.
2242   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2243 
2244   assert(method()->is_oop(), "must be valid");
2245 
2246   ResourceMark rm;
2247 
2248   if (!CodeCache::contains(this)) {
2249     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
2250   }
2251 
2252   if(is_native_method() )
2253     return;
2254 
2255   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2256   if (nm != this) {
2257     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
2258                   this));
2259   }
2260 
2261   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2262     if (! p->verify(this)) {
2263       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
2264     }
2265   }
2266 
2267   VerifyOopsClosure voc(this);
2268   oops_do(&voc);
2269   assert(voc.ok(), "embedded oops must be OK");
2270   verify_scavenge_root_oops();
2271 
2272   verify_scopes();
2273 }
2274 
2275 
2276 void nmethod::verify_interrupt_point(address call_site) {
2277   // This code does not work in release mode since
2278   // owns_lock only is available in debug mode.
2279   CompiledIC* ic = NULL;
2280   Thread *cur = Thread::current();
2281   if (CompiledIC_lock->owner() == cur ||
2282       ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2283        SafepointSynchronize::is_at_safepoint())) {
2284     ic = CompiledIC_at(call_site);
2285     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2286   } else {
2287     MutexLocker ml_verify (CompiledIC_lock);
2288     ic = CompiledIC_at(call_site);
2289   }
2290   PcDesc* pd = pc_desc_at(ic->end_of_call());
2291   assert(pd != NULL, "PcDesc must exist");
2292   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2293                                      pd->obj_decode_offset(), pd->should_reexecute(),
2294                                      pd->return_oop());
2295        !sd->is_top(); sd = sd->sender()) {
2296     sd->verify();
2297   }
2298 }
2299 
2300 void nmethod::verify_scopes() {
2301   if( !method() ) return;       // Runtime stubs have no scope
2302   if (method()->is_native()) return; // Ignore stub methods.
2303   // iterate through all interrupt point
2304   // and verify the debug information is valid.
2305   RelocIterator iter((nmethod*)this);
2306   while (iter.next()) {
2307     address stub = NULL;
2308     switch (iter.type()) {
2309       case relocInfo::virtual_call_type:
2310         verify_interrupt_point(iter.addr());
2311         break;
2312       case relocInfo::opt_virtual_call_type:
2313         stub = iter.opt_virtual_call_reloc()->static_stub();
2314         verify_interrupt_point(iter.addr());
2315         break;
2316       case relocInfo::static_call_type:
2317         stub = iter.static_call_reloc()->static_stub();
2318         //verify_interrupt_point(iter.addr());
2319         break;
2320       case relocInfo::runtime_call_type:
2321         address destination = iter.reloc()->value();
2322         // Right now there is no way to find out which entries support
2323         // an interrupt point.  It would be nice if we had this
2324         // information in a table.
2325         break;
2326     }
2327     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2328   }
2329 }
2330 
2331 
2332 // -----------------------------------------------------------------------------
2333 // Non-product code
2334 #ifndef PRODUCT
2335 
2336 class DebugScavengeRoot: public OopClosure {
2337   nmethod* _nm;
2338   bool     _ok;
2339 public:
2340   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2341   bool ok() { return _ok; }
2342   virtual void do_oop(oop* p) {
2343     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2344     if (_ok) {
2345       _nm->print_nmethod(true);
2346       _ok = false;
2347     }
2348     tty->print_cr("*** non-perm oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2349                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2350     (*p)->print();
2351   }
2352   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2353 };
2354 
2355 void nmethod::verify_scavenge_root_oops() {
2356   if (!on_scavenge_root_list()) {
2357     // Actually look inside, to verify the claim that it's clean.
2358     DebugScavengeRoot debug_scavenge_root(this);
2359     oops_do(&debug_scavenge_root);
2360     if (!debug_scavenge_root.ok())
2361       fatal("found an unadvertised bad non-perm oop in the code cache");
2362   }
2363   assert(scavenge_root_not_marked(), "");
2364 }
2365 
2366 #endif // PRODUCT
2367 
2368 // Printing operations
2369 
2370 void nmethod::print() const {
2371   ResourceMark rm;
2372   ttyLocker ttyl;   // keep the following output all in one block
2373 
2374   tty->print("Compiled ");
2375 
2376   if (is_compiled_by_c1()) {
2377     tty->print("(c1) ");
2378   } else if (is_compiled_by_c2()) {
2379     tty->print("(c2) ");
2380   } else if (is_compiled_by_shark()) {
2381     tty->print("(shark) ");
2382   } else {
2383     tty->print("(nm) ");
2384   }
2385 
2386   print_on(tty, "nmethod");
2387   tty->cr();
2388   if (WizardMode) {
2389     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
2390     tty->print(" for method " INTPTR_FORMAT , (address)method());
2391     tty->print(" { ");
2392     if (is_in_use())      tty->print("in_use ");
2393     if (is_not_entrant()) tty->print("not_entrant ");
2394     if (is_zombie())      tty->print("zombie ");
2395     if (is_unloaded())    tty->print("unloaded ");
2396     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2397     tty->print_cr("}:");
2398   }
2399   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2400                                               (address)this,
2401                                               (address)this + size(),
2402                                               size());
2403   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2404                                               relocation_begin(),
2405                                               relocation_end(),
2406                                               relocation_size());
2407   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2408                                               consts_begin(),
2409                                               consts_end(),
2410                                               consts_size());
2411   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2412                                               insts_begin(),
2413                                               insts_end(),
2414                                               insts_size());
2415   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2416                                               stub_begin(),
2417                                               stub_end(),
2418                                               stub_size());
2419   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2420                                               oops_begin(),
2421                                               oops_end(),
2422                                               oops_size());
2423   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2424                                               scopes_data_begin(),
2425                                               scopes_data_end(),
2426                                               scopes_data_size());
2427   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2428                                               scopes_pcs_begin(),
2429                                               scopes_pcs_end(),
2430                                               scopes_pcs_size());
2431   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2432                                               dependencies_begin(),
2433                                               dependencies_end(),
2434                                               dependencies_size());
2435   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2436                                               handler_table_begin(),
2437                                               handler_table_end(),
2438                                               handler_table_size());
2439   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2440                                               nul_chk_table_begin(),
2441                                               nul_chk_table_end(),
2442                                               nul_chk_table_size());
2443 }
2444 
2445 void nmethod::print_code() {
2446   HandleMark hm;
2447   ResourceMark m;
2448   Disassembler::decode(this);
2449 }
2450 
2451 
2452 #ifndef PRODUCT
2453 
2454 void nmethod::print_scopes() {
2455   // Find the first pc desc for all scopes in the code and print it.
2456   ResourceMark rm;
2457   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2458     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2459       continue;
2460 
2461     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2462     sd->print_on(tty, p);
2463   }
2464 }
2465 
2466 void nmethod::print_dependencies() {
2467   ResourceMark rm;
2468   ttyLocker ttyl;   // keep the following output all in one block
2469   tty->print_cr("Dependencies:");
2470   for (Dependencies::DepStream deps(this); deps.next(); ) {
2471     deps.print_dependency();
2472     klassOop ctxk = deps.context_type();
2473     if (ctxk != NULL) {
2474       Klass* k = Klass::cast(ctxk);
2475       if (k->oop_is_instance() && ((instanceKlass*)k)->is_dependent_nmethod(this)) {
2476         tty->print_cr("   [nmethod<=klass]%s", k->external_name());
2477       }
2478     }
2479     deps.log_dependency();  // put it into the xml log also
2480   }
2481 }
2482 
2483 
2484 void nmethod::print_relocations() {
2485   ResourceMark m;       // in case methods get printed via the debugger
2486   tty->print_cr("relocations:");
2487   RelocIterator iter(this);
2488   iter.print();
2489   if (UseRelocIndex) {
2490     jint* index_end   = (jint*)relocation_end() - 1;
2491     jint  index_size  = *index_end;
2492     jint* index_start = (jint*)( (address)index_end - index_size );
2493     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
2494     if (index_size > 0) {
2495       jint* ip;
2496       for (ip = index_start; ip+2 <= index_end; ip += 2)
2497         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
2498                       ip[0],
2499                       ip[1],
2500                       header_end()+ip[0],
2501                       relocation_begin()-1+ip[1]);
2502       for (; ip < index_end; ip++)
2503         tty->print_cr("  (%d ?)", ip[0]);
2504       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip++);
2505       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
2506     }
2507   }
2508 }
2509 
2510 
2511 void nmethod::print_pcs() {
2512   ResourceMark m;       // in case methods get printed via debugger
2513   tty->print_cr("pc-bytecode offsets:");
2514   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2515     p->print(this);
2516   }
2517 }
2518 
2519 #endif // PRODUCT
2520 
2521 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2522   RelocIterator iter(this, begin, end);
2523   bool have_one = false;
2524   while (iter.next()) {
2525     have_one = true;
2526     switch (iter.type()) {
2527         case relocInfo::none:                  return "no_reloc";
2528         case relocInfo::oop_type: {
2529           stringStream st;
2530           oop_Relocation* r = iter.oop_reloc();
2531           oop obj = r->oop_value();
2532           st.print("oop(");
2533           if (obj == NULL) st.print("NULL");
2534           else obj->print_value_on(&st);
2535           st.print(")");
2536           return st.as_string();
2537         }
2538         case relocInfo::virtual_call_type:     return "virtual_call";
2539         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
2540         case relocInfo::static_call_type:      return "static_call";
2541         case relocInfo::static_stub_type:      return "static_stub";
2542         case relocInfo::runtime_call_type:     return "runtime_call";
2543         case relocInfo::external_word_type:    return "external_word";
2544         case relocInfo::internal_word_type:    return "internal_word";
2545         case relocInfo::section_word_type:     return "section_word";
2546         case relocInfo::poll_type:             return "poll";
2547         case relocInfo::poll_return_type:      return "poll_return";
2548         case relocInfo::type_mask:             return "type_bit_mask";
2549     }
2550   }
2551   return have_one ? "other" : NULL;
2552 }
2553 
2554 // Return a the last scope in (begin..end]
2555 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2556   PcDesc* p = pc_desc_near(begin+1);
2557   if (p != NULL && p->real_pc(this) <= end) {
2558     return new ScopeDesc(this, p->scope_decode_offset(),
2559                          p->obj_decode_offset(), p->should_reexecute(),
2560                          p->return_oop());
2561   }
2562   return NULL;
2563 }
2564 
2565 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) {
2566   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2567   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2568   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2569   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2570   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2571 
2572   if (has_method_handle_invokes())
2573     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2574 
2575   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2576 
2577   if (block_begin == entry_point()) {
2578     methodHandle m = method();
2579     if (m.not_null()) {
2580       stream->print("  # ");
2581       m->print_value_on(stream);
2582       stream->cr();
2583     }
2584     if (m.not_null() && !is_osr_method()) {
2585       ResourceMark rm;
2586       int sizeargs = m->size_of_parameters();
2587       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2588       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2589       {
2590         int sig_index = 0;
2591         if (!m->is_static())
2592           sig_bt[sig_index++] = T_OBJECT; // 'this'
2593         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2594           BasicType t = ss.type();
2595           sig_bt[sig_index++] = t;
2596           if (type2size[t] == 2) {
2597             sig_bt[sig_index++] = T_VOID;
2598           } else {
2599             assert(type2size[t] == 1, "size is 1 or 2");
2600           }
2601         }
2602         assert(sig_index == sizeargs, "");
2603       }
2604       const char* spname = "sp"; // make arch-specific?
2605       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2606       int stack_slot_offset = this->frame_size() * wordSize;
2607       int tab1 = 14, tab2 = 24;
2608       int sig_index = 0;
2609       int arg_index = (m->is_static() ? 0 : -1);
2610       bool did_old_sp = false;
2611       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2612         bool at_this = (arg_index == -1);
2613         bool at_old_sp = false;
2614         BasicType t = (at_this ? T_OBJECT : ss.type());
2615         assert(t == sig_bt[sig_index], "sigs in sync");
2616         if (at_this)
2617           stream->print("  # this: ");
2618         else
2619           stream->print("  # parm%d: ", arg_index);
2620         stream->move_to(tab1);
2621         VMReg fst = regs[sig_index].first();
2622         VMReg snd = regs[sig_index].second();
2623         if (fst->is_reg()) {
2624           stream->print("%s", fst->name());
2625           if (snd->is_valid())  {
2626             stream->print(":%s", snd->name());
2627           }
2628         } else if (fst->is_stack()) {
2629           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2630           if (offset == stack_slot_offset)  at_old_sp = true;
2631           stream->print("[%s+0x%x]", spname, offset);
2632         } else {
2633           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2634         }
2635         stream->print(" ");
2636         stream->move_to(tab2);
2637         stream->print("= ");
2638         if (at_this) {
2639           m->method_holder()->print_value_on(stream);
2640         } else {
2641           bool did_name = false;
2642           if (!at_this && ss.is_object()) {
2643             symbolOop name = ss.as_symbol_or_null();
2644             if (name != NULL) {
2645               name->print_value_on(stream);
2646               did_name = true;
2647             }
2648           }
2649           if (!did_name)
2650             stream->print("%s", type2name(t));
2651         }
2652         if (at_old_sp) {
2653           stream->print("  (%s of caller)", spname);
2654           did_old_sp = true;
2655         }
2656         stream->cr();
2657         sig_index += type2size[t];
2658         arg_index += 1;
2659         if (!at_this)  ss.next();
2660       }
2661       if (!did_old_sp) {
2662         stream->print("  # ");
2663         stream->move_to(tab1);
2664         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2665         stream->print("  (%s of caller)", spname);
2666         stream->cr();
2667       }
2668     }
2669   }
2670 }
2671 
2672 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2673   // First, find an oopmap in (begin, end].
2674   // We use the odd half-closed interval so that oop maps and scope descs
2675   // which are tied to the byte after a call are printed with the call itself.
2676   address base = code_begin();
2677   OopMapSet* oms = oop_maps();
2678   if (oms != NULL) {
2679     for (int i = 0, imax = oms->size(); i < imax; i++) {
2680       OopMap* om = oms->at(i);
2681       address pc = base + om->offset();
2682       if (pc > begin) {
2683         if (pc <= end) {
2684           st->move_to(column);
2685           st->print("; ");
2686           om->print_on(st);
2687         }
2688         break;
2689       }
2690     }
2691   }
2692 
2693   // Print any debug info present at this pc.
2694   ScopeDesc* sd  = scope_desc_in(begin, end);
2695   if (sd != NULL) {
2696     st->move_to(column);
2697     if (sd->bci() == SynchronizationEntryBCI) {
2698       st->print(";*synchronization entry");
2699     } else {
2700       if (sd->method().is_null()) {
2701         st->print("method is NULL");
2702       } else if (sd->method()->is_native()) {
2703         st->print("method is native");
2704       } else {
2705         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2706         st->print(";*%s", Bytecodes::name(bc));
2707         switch (bc) {
2708         case Bytecodes::_invokevirtual:
2709         case Bytecodes::_invokespecial:
2710         case Bytecodes::_invokestatic:
2711         case Bytecodes::_invokeinterface:
2712           {
2713             Bytecode_invoke invoke(sd->method(), sd->bci());
2714             st->print(" ");
2715             if (invoke.name() != NULL)
2716               invoke.name()->print_symbol_on(st);
2717             else
2718               st->print("<UNKNOWN>");
2719             break;
2720           }
2721         case Bytecodes::_getfield:
2722         case Bytecodes::_putfield:
2723         case Bytecodes::_getstatic:
2724         case Bytecodes::_putstatic:
2725           {
2726             Bytecode_field field(sd->method(), sd->bci());
2727             st->print(" ");
2728             if (field.name() != NULL)
2729               field.name()->print_symbol_on(st);
2730             else
2731               st->print("<UNKNOWN>");
2732           }
2733         }
2734       }
2735     }
2736 
2737     // Print all scopes
2738     for (;sd != NULL; sd = sd->sender()) {
2739       st->move_to(column);
2740       st->print("; -");
2741       if (sd->method().is_null()) {
2742         st->print("method is NULL");
2743       } else {
2744         sd->method()->print_short_name(st);
2745       }
2746       int lineno = sd->method()->line_number_from_bci(sd->bci());
2747       if (lineno != -1) {
2748         st->print("@%d (line %d)", sd->bci(), lineno);
2749       } else {
2750         st->print("@%d", sd->bci());
2751       }
2752       st->cr();
2753     }
2754   }
2755 
2756   // Print relocation information
2757   const char* str = reloc_string_for(begin, end);
2758   if (str != NULL) {
2759     if (sd != NULL) st->cr();
2760     st->move_to(column);
2761     st->print(";   {%s}", str);
2762   }
2763   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2764   if (cont_offset != 0) {
2765     st->move_to(column);
2766     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
2767   }
2768 
2769 }
2770 
2771 #ifndef PRODUCT
2772 
2773 void nmethod::print_value_on(outputStream* st) const {
2774   print_on(st, "nmethod");
2775 }
2776 
2777 void nmethod::print_calls(outputStream* st) {
2778   RelocIterator iter(this);
2779   while (iter.next()) {
2780     switch (iter.type()) {
2781     case relocInfo::virtual_call_type:
2782     case relocInfo::opt_virtual_call_type: {
2783       VerifyMutexLocker mc(CompiledIC_lock);
2784       CompiledIC_at(iter.reloc())->print();
2785       break;
2786     }
2787     case relocInfo::static_call_type:
2788       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
2789       compiledStaticCall_at(iter.reloc())->print();
2790       break;
2791     }
2792   }
2793 }
2794 
2795 void nmethod::print_handler_table() {
2796   ExceptionHandlerTable(this).print();
2797 }
2798 
2799 void nmethod::print_nul_chk_table() {
2800   ImplicitExceptionTable(this).print(code_begin());
2801 }
2802 
2803 void nmethod::print_statistics() {
2804   ttyLocker ttyl;
2805   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2806   nmethod_stats.print_native_nmethod_stats();
2807   nmethod_stats.print_nmethod_stats();
2808   DebugInformationRecorder::print_statistics();
2809   nmethod_stats.print_pc_stats();
2810   Dependencies::print_statistics();
2811   if (xtty != NULL)  xtty->tail("statistics");
2812 }
2813 
2814 #endif // PRODUCT