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       Symbol* klass_name = m->klass_name();                               \
  62       Symbol* name = m->name();                                           \
  63       Symbol* 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 
 197 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 198   assert(pc != NULL, "Must be non null");
 199   assert(exception.not_null(), "Must be non null");
 200   assert(handler != NULL, "Must be non null");
 201 
 202   _count = 0;
 203   _exception_type = exception->klass();
 204   _next = NULL;
 205 
 206   add_address_and_handler(pc,handler);
 207 }
 208 
 209 
 210 address ExceptionCache::match(Handle exception, address pc) {
 211   assert(pc != NULL,"Must be non null");
 212   assert(exception.not_null(),"Must be non null");
 213   if (exception->klass() == exception_type()) {
 214     return (test_address(pc));
 215   }
 216 
 217   return NULL;
 218 }
 219 
 220 
 221 bool ExceptionCache::match_exception_with_space(Handle exception) {
 222   assert(exception.not_null(),"Must be non null");
 223   if (exception->klass() == exception_type() && count() < cache_size) {
 224     return true;
 225   }
 226   return false;
 227 }
 228 
 229 
 230 address ExceptionCache::test_address(address addr) {
 231   for (int i=0; i<count(); i++) {
 232     if (pc_at(i) == addr) {
 233       return handler_at(i);
 234     }
 235   }
 236   return NULL;
 237 }
 238 
 239 
 240 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 241   if (test_address(addr) == handler) return true;
 242   if (count() < cache_size) {
 243     set_pc_at(count(),addr);
 244     set_handler_at(count(), handler);
 245     increment_count();
 246     return true;
 247   }
 248   return false;
 249 }
 250 
 251 
 252 // private method for handling exception cache
 253 // These methods are private, and used to manipulate the exception cache
 254 // directly.
 255 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
 256   ExceptionCache* ec = exception_cache();
 257   while (ec != NULL) {
 258     if (ec->match_exception_with_space(exception)) {
 259       return ec;
 260     }
 261     ec = ec->next();
 262   }
 263   return NULL;
 264 }
 265 
 266 
 267 //-----------------------------------------------------------------------------
 268 
 269 
 270 // Helper used by both find_pc_desc methods.
 271 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 272   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
 273   if (!approximate)
 274     return pc->pc_offset() == pc_offset;
 275   else
 276     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 277 }
 278 
 279 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 280   if (initial_pc_desc == NULL) {
 281     _last_pc_desc = NULL;  // native method
 282     return;
 283   }
 284   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
 285   // reset the cache by filling it with benign (non-null) values
 286   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 287   _last_pc_desc = initial_pc_desc + 1;  // first valid one is after sentinel
 288   for (int i = 0; i < cache_size; i++)
 289     _pc_descs[i] = initial_pc_desc;
 290 }
 291 
 292 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 293   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
 294   NOT_PRODUCT(if (approximate)  ++nmethod_stats.pc_desc_approx);
 295 
 296   // In order to prevent race conditions do not load cache elements
 297   // repeatedly, but use a local copy:
 298   PcDesc* res;
 299 
 300   // Step one:  Check the most recently returned value.
 301   res = _last_pc_desc;
 302   if (res == NULL)  return NULL;  // native method; no PcDescs at all
 303   if (match_desc(res, pc_offset, approximate)) {
 304     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
 305     return res;
 306   }
 307 
 308   // Step two:  Check the LRU cache.
 309   for (int i = 0; i < cache_size; i++) {
 310     res = _pc_descs[i];
 311     if (res->pc_offset() < 0)  break;  // optimization: skip empty cache
 312     if (match_desc(res, pc_offset, approximate)) {
 313       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
 314       _last_pc_desc = res;  // record this cache hit in case of repeat
 315       return res;
 316     }
 317   }
 318 
 319   // Report failure.
 320   return NULL;
 321 }
 322 
 323 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 324   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
 325   // Update the LRU cache by shifting pc_desc forward:
 326   for (int i = 0; i < cache_size; i++)  {
 327     PcDesc* next = _pc_descs[i];
 328     _pc_descs[i] = pc_desc;
 329     pc_desc = next;
 330   }
 331   // Note:  Do not update _last_pc_desc.  It fronts for the LRU cache.
 332 }
 333 
 334 // adjust pcs_size so that it is a multiple of both oopSize and
 335 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 336 // of oopSize, then 2*sizeof(PcDesc) is)
 337 static int  adjust_pcs_size(int pcs_size) {
 338   int nsize = round_to(pcs_size,   oopSize);
 339   if ((nsize % sizeof(PcDesc)) != 0) {
 340     nsize = pcs_size + sizeof(PcDesc);
 341   }
 342   assert((nsize %  oopSize) == 0, "correct alignment");
 343   return nsize;
 344 }
 345 
 346 //-----------------------------------------------------------------------------
 347 
 348 
 349 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
 350   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
 351   assert(new_entry != NULL,"Must be non null");
 352   assert(new_entry->next() == NULL, "Must be null");
 353 
 354   if (exception_cache() != NULL) {
 355     new_entry->set_next(exception_cache());
 356   }
 357   set_exception_cache(new_entry);
 358 }
 359 
 360 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
 361   ExceptionCache* prev = NULL;
 362   ExceptionCache* curr = exception_cache();
 363   assert(curr != NULL, "nothing to remove");
 364   // find the previous and next entry of ec
 365   while (curr != ec) {
 366     prev = curr;
 367     curr = curr->next();
 368     assert(curr != NULL, "ExceptionCache not found");
 369   }
 370   // now: curr == ec
 371   ExceptionCache* next = curr->next();
 372   if (prev == NULL) {
 373     set_exception_cache(next);
 374   } else {
 375     prev->set_next(next);
 376   }
 377   delete curr;
 378 }
 379 
 380 
 381 // public method for accessing the exception cache
 382 // These are the public access methods.
 383 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
 384   // We never grab a lock to read the exception cache, so we may
 385   // have false negatives. This is okay, as it can only happen during
 386   // the first few exception lookups for a given nmethod.
 387   ExceptionCache* ec = exception_cache();
 388   while (ec != NULL) {
 389     address ret_val;
 390     if ((ret_val = ec->match(exception,pc)) != NULL) {
 391       return ret_val;
 392     }
 393     ec = ec->next();
 394   }
 395   return NULL;
 396 }
 397 
 398 
 399 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
 400   // There are potential race conditions during exception cache updates, so we
 401   // must own the ExceptionCache_lock before doing ANY modifications. Because
 402   // we don't lock during reads, it is possible to have several threads attempt
 403   // to update the cache with the same data. We need to check for already inserted
 404   // copies of the current data before adding it.
 405 
 406   MutexLocker ml(ExceptionCache_lock);
 407   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
 408 
 409   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
 410     target_entry = new ExceptionCache(exception,pc,handler);
 411     add_exception_cache_entry(target_entry);
 412   }
 413 }
 414 
 415 
 416 //-------------end of code for ExceptionCache--------------
 417 
 418 
 419 int nmethod::total_size() const {
 420   return
 421     consts_size()        +
 422     insts_size()         +
 423     stub_size()          +
 424     scopes_data_size()   +
 425     scopes_pcs_size()    +
 426     handler_table_size() +
 427     nul_chk_table_size();
 428 }
 429 
 430 const char* nmethod::compile_kind() const {
 431   if (is_osr_method())     return "osr";
 432   if (method() != NULL && is_native_method())  return "c2n";
 433   return NULL;
 434 }
 435 
 436 // Fill in default values for various flag fields
 437 void nmethod::init_defaults() {
 438   _state                      = alive;
 439   _marked_for_reclamation     = 0;
 440   _has_flushed_dependencies   = 0;
 441   _speculatively_disconnected = 0;
 442   _has_unsafe_access          = 0;
 443   _has_method_handle_invokes  = 0;
 444   _marked_for_deoptimization  = 0;
 445   _lock_count                 = 0;
 446   _stack_traversal_mark       = 0;
 447   _unload_reported            = false;           // jvmti state
 448 
 449   NOT_PRODUCT(_has_debug_info = false);
 450 #ifdef ASSERT
 451   _oops_are_stale             = false;
 452 #endif
 453 
 454   _oops_do_mark_link       = NULL;
 455   _jmethod_id              = NULL;
 456   _osr_link                = NULL;
 457   _scavenge_root_link      = NULL;
 458   _scavenge_root_state     = 0;
 459   _saved_nmethod_link      = NULL;
 460   _compiler                = NULL;
 461 
 462 #ifdef HAVE_DTRACE_H
 463   _trap_offset             = 0;
 464 #endif // def HAVE_DTRACE_H
 465 }
 466 
 467 
 468 nmethod* nmethod::new_native_nmethod(methodHandle method,
 469   CodeBuffer *code_buffer,
 470   int vep_offset,
 471   int frame_complete,
 472   int frame_size,
 473   ByteSize basic_lock_owner_sp_offset,
 474   ByteSize basic_lock_sp_offset,
 475   OopMapSet* oop_maps) {
 476   // create nmethod
 477   nmethod* nm = NULL;
 478   {
 479     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 480     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 481     CodeOffsets offsets;
 482     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 483     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 484     nm = new (native_nmethod_size)
 485       nmethod(method(), native_nmethod_size, &offsets,
 486               code_buffer, frame_size,
 487               basic_lock_owner_sp_offset, basic_lock_sp_offset,
 488               oop_maps);
 489     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
 490     if (PrintAssembly && nm != NULL)
 491       Disassembler::decode(nm);
 492   }
 493   // verify nmethod
 494   debug_only(if (nm) nm->verify();) // might block
 495 
 496   if (nm != NULL) {
 497     nm->log_new_nmethod();
 498   }
 499 
 500   return nm;
 501 }
 502 
 503 #ifdef HAVE_DTRACE_H
 504 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
 505                                      CodeBuffer *code_buffer,
 506                                      int vep_offset,
 507                                      int trap_offset,
 508                                      int frame_complete,
 509                                      int frame_size) {
 510   // create nmethod
 511   nmethod* nm = NULL;
 512   {
 513     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 514     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
 515     CodeOffsets offsets;
 516     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 517     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
 518     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 519 
 520     nm = new (nmethod_size) nmethod(method(), nmethod_size, &offsets, code_buffer, frame_size);
 521 
 522     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 523     if (PrintAssembly && nm != NULL)
 524       Disassembler::decode(nm);
 525   }
 526   // verify nmethod
 527   debug_only(if (nm) nm->verify();) // might block
 528 
 529   if (nm != NULL) {
 530     nm->log_new_nmethod();
 531   }
 532 
 533   return nm;
 534 }
 535 
 536 #endif // def HAVE_DTRACE_H
 537 
 538 nmethod* nmethod::new_nmethod(methodHandle method,
 539   int compile_id,
 540   int entry_bci,
 541   CodeOffsets* offsets,
 542   int orig_pc_offset,
 543   DebugInformationRecorder* debug_info,
 544   Dependencies* dependencies,
 545   CodeBuffer* code_buffer, int frame_size,
 546   OopMapSet* oop_maps,
 547   ExceptionHandlerTable* handler_table,
 548   ImplicitExceptionTable* nul_chk_table,
 549   AbstractCompiler* compiler,
 550   int comp_level
 551 )
 552 {
 553   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 554   // create nmethod
 555   nmethod* nm = NULL;
 556   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 557     int nmethod_size =
 558       allocation_size(code_buffer, sizeof(nmethod))
 559       + adjust_pcs_size(debug_info->pcs_size())
 560       + round_to(dependencies->size_in_bytes() , oopSize)
 561       + round_to(handler_table->size_in_bytes(), oopSize)
 562       + round_to(nul_chk_table->size_in_bytes(), oopSize)
 563       + round_to(debug_info->data_size()       , oopSize);
 564     nm = new (nmethod_size)
 565       nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
 566               orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 567               oop_maps,
 568               handler_table,
 569               nul_chk_table,
 570               compiler,
 571               comp_level);
 572     if (nm != NULL) {
 573       // To make dependency checking during class loading fast, record
 574       // the nmethod dependencies in the classes it is dependent on.
 575       // This allows the dependency checking code to simply walk the
 576       // class hierarchy above the loaded class, checking only nmethods
 577       // which are dependent on those classes.  The slow way is to
 578       // check every nmethod for dependencies which makes it linear in
 579       // the number of methods compiled.  For applications with a lot
 580       // classes the slow way is too slow.
 581       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 582         klassOop klass = deps.context_type();
 583         if (klass == NULL)  continue;  // ignore things like evol_method
 584 
 585         // record this nmethod as dependent on this klass
 586         instanceKlass::cast(klass)->add_dependent_nmethod(nm);
 587       }
 588     }
 589     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
 590     if (PrintAssembly && nm != NULL)
 591       Disassembler::decode(nm);
 592   }
 593 
 594   // verify nmethod
 595   debug_only(if (nm) nm->verify();) // might block
 596 
 597   if (nm != NULL) {
 598     nm->log_new_nmethod();
 599   }
 600 
 601   // done
 602   return nm;
 603 }
 604 
 605 
 606 // For native wrappers
 607 nmethod::nmethod(
 608   methodOop method,
 609   int nmethod_size,
 610   CodeOffsets* offsets,
 611   CodeBuffer* code_buffer,
 612   int frame_size,
 613   ByteSize basic_lock_owner_sp_offset,
 614   ByteSize basic_lock_sp_offset,
 615   OopMapSet* oop_maps )
 616   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
 617              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 618   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 619   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 620 {
 621   {
 622     debug_only(No_Safepoint_Verifier nsv;)
 623     assert_locked_or_safepoint(CodeCache_lock);
 624 
 625     init_defaults();
 626     _method                  = method;
 627     _entry_bci               = InvocationEntryBci;
 628     // We have no exception handler or deopt handler make the
 629     // values something that will never match a pc like the nmethod vtable entry
 630     _exception_offset        = 0;
 631     _deoptimize_offset       = 0;
 632     _deoptimize_mh_offset    = 0;
 633     _orig_pc_offset          = 0;
 634 
 635     _consts_offset           = data_offset();
 636     _stub_offset             = data_offset();
 637     _oops_offset             = data_offset();
 638     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 639     _scopes_pcs_offset       = _scopes_data_offset;
 640     _dependencies_offset     = _scopes_pcs_offset;
 641     _handler_table_offset    = _dependencies_offset;
 642     _nul_chk_table_offset    = _handler_table_offset;
 643     _nmethod_end_offset      = _nul_chk_table_offset;
 644     _compile_id              = 0;  // default
 645     _comp_level              = CompLevel_none;
 646     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 647     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 648     _osr_entry_point         = NULL;
 649     _exception_cache         = NULL;
 650     _pc_desc_cache.reset_to(NULL);
 651 
 652     code_buffer->copy_oops_to(this);
 653     debug_only(verify_scavenge_root_oops());
 654     CodeCache::commit(this);
 655   }
 656 
 657   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 658     ttyLocker ttyl;  // keep the following output all in one block
 659     // This output goes directly to the tty, not the compiler log.
 660     // To enable tools to match it up with the compilation activity,
 661     // be sure to tag this tty output with the compile ID.
 662     if (xtty != NULL) {
 663       xtty->begin_head("print_native_nmethod");
 664       xtty->method(_method);
 665       xtty->stamp();
 666       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 667     }
 668     // print the header part first
 669     print();
 670     // then print the requested information
 671     if (PrintNativeNMethods) {
 672       print_code();
 673       oop_maps->print();
 674     }
 675     if (PrintRelocations) {
 676       print_relocations();
 677     }
 678     if (xtty != NULL) {
 679       xtty->tail("print_native_nmethod");
 680     }
 681   }
 682   Events::log("Create nmethod " INTPTR_FORMAT, this);
 683 }
 684 
 685 // For dtrace wrappers
 686 #ifdef HAVE_DTRACE_H
 687 nmethod::nmethod(
 688   methodOop method,
 689   int nmethod_size,
 690   CodeOffsets* offsets,
 691   CodeBuffer* code_buffer,
 692   int frame_size)
 693   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
 694              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
 695   _native_receiver_sp_offset(in_ByteSize(-1)),
 696   _native_basic_lock_sp_offset(in_ByteSize(-1))
 697 {
 698   {
 699     debug_only(No_Safepoint_Verifier nsv;)
 700     assert_locked_or_safepoint(CodeCache_lock);
 701 
 702     init_defaults();
 703     _method                  = method;
 704     _entry_bci               = InvocationEntryBci;
 705     // We have no exception handler or deopt handler make the
 706     // values something that will never match a pc like the nmethod vtable entry
 707     _exception_offset        = 0;
 708     _deoptimize_offset       = 0;
 709     _deoptimize_mh_offset    = 0;
 710     _unwind_handler_offset   = -1;
 711     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
 712     _orig_pc_offset          = 0;
 713     _consts_offset           = data_offset();
 714     _stub_offset             = data_offset();
 715     _oops_offset             = data_offset();
 716     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
 717     _scopes_pcs_offset       = _scopes_data_offset;
 718     _dependencies_offset     = _scopes_pcs_offset;
 719     _handler_table_offset    = _dependencies_offset;
 720     _nul_chk_table_offset    = _handler_table_offset;
 721     _nmethod_end_offset      = _nul_chk_table_offset;
 722     _compile_id              = 0;  // default
 723     _comp_level              = CompLevel_none;
 724     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 725     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 726     _osr_entry_point         = NULL;
 727     _exception_cache         = NULL;
 728     _pc_desc_cache.reset_to(NULL);
 729 
 730     code_buffer->copy_oops_to(this);
 731     debug_only(verify_scavenge_root_oops());
 732     CodeCache::commit(this);
 733   }
 734 
 735   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 736     ttyLocker ttyl;  // keep the following output all in one block
 737     // This output goes directly to the tty, not the compiler log.
 738     // To enable tools to match it up with the compilation activity,
 739     // be sure to tag this tty output with the compile ID.
 740     if (xtty != NULL) {
 741       xtty->begin_head("print_dtrace_nmethod");
 742       xtty->method(_method);
 743       xtty->stamp();
 744       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 745     }
 746     // print the header part first
 747     print();
 748     // then print the requested information
 749     if (PrintNMethods) {
 750       print_code();
 751     }
 752     if (PrintRelocations) {
 753       print_relocations();
 754     }
 755     if (xtty != NULL) {
 756       xtty->tail("print_dtrace_nmethod");
 757     }
 758   }
 759   Events::log("Create nmethod " INTPTR_FORMAT, this);
 760 }
 761 #endif // def HAVE_DTRACE_H
 762 
 763 void* nmethod::operator new(size_t size, int nmethod_size) {
 764   // Always leave some room in the CodeCache for I2C/C2I adapters
 765   if (CodeCache::unallocated_capacity() < CodeCacheMinimumFreeSpace) return NULL;
 766   return CodeCache::allocate(nmethod_size);
 767 }
 768 
 769 
 770 nmethod::nmethod(
 771   methodOop method,
 772   int nmethod_size,
 773   int compile_id,
 774   int entry_bci,
 775   CodeOffsets* offsets,
 776   int orig_pc_offset,
 777   DebugInformationRecorder* debug_info,
 778   Dependencies* dependencies,
 779   CodeBuffer *code_buffer,
 780   int frame_size,
 781   OopMapSet* oop_maps,
 782   ExceptionHandlerTable* handler_table,
 783   ImplicitExceptionTable* nul_chk_table,
 784   AbstractCompiler* compiler,
 785   int comp_level
 786   )
 787   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
 788              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
 789   _native_receiver_sp_offset(in_ByteSize(-1)),
 790   _native_basic_lock_sp_offset(in_ByteSize(-1))
 791 {
 792   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 793   {
 794     debug_only(No_Safepoint_Verifier nsv;)
 795     assert_locked_or_safepoint(CodeCache_lock);
 796 
 797     init_defaults();
 798     _method                  = method;
 799     _entry_bci               = entry_bci;
 800     _compile_id              = compile_id;
 801     _comp_level              = comp_level;
 802     _compiler                = compiler;
 803     _orig_pc_offset          = orig_pc_offset;
 804 
 805     // Section offsets
 806     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 807     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 808 
 809     // Exception handler and deopt handler are in the stub section
 810     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 811     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 812     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 813     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
 814     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 815       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 816     } else {
 817       _deoptimize_mh_offset  = -1;
 818     }
 819     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 820       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 821     } else {
 822       _unwind_handler_offset = -1;
 823     }
 824 
 825     _oops_offset             = data_offset();
 826     _scopes_data_offset      = _oops_offset          + round_to(code_buffer->total_oop_size (), oopSize);
 827     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
 828     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 829     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
 830     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
 831     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
 832 
 833     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 834     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 835     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 836     _exception_cache         = NULL;
 837     _pc_desc_cache.reset_to(scopes_pcs_begin());
 838 
 839     // Copy contents of ScopeDescRecorder to nmethod
 840     code_buffer->copy_oops_to(this);
 841     debug_info->copy_to(this);
 842     dependencies->copy_to(this);
 843     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
 844       CodeCache::add_scavenge_root_nmethod(this);
 845     }
 846     debug_only(verify_scavenge_root_oops());
 847 
 848     CodeCache::commit(this);
 849 
 850     // Copy contents of ExceptionHandlerTable to nmethod
 851     handler_table->copy_to(this);
 852     nul_chk_table->copy_to(this);
 853 
 854     // we use the information of entry points to find out if a method is
 855     // static or non static
 856     assert(compiler->is_c2() ||
 857            _method->is_static() == (entry_point() == _verified_entry_point),
 858            " entry points must be same for static methods and vice versa");
 859   }
 860 
 861   bool printnmethods = PrintNMethods
 862     || CompilerOracle::should_print(_method)
 863     || CompilerOracle::has_option_string(_method, "PrintNMethods");
 864   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 865     print_nmethod(printnmethods);
 866   }
 867 
 868   // Note: Do not verify in here as the CodeCache_lock is
 869   //       taken which would conflict with the CompiledIC_lock
 870   //       which taken during the verification of call sites.
 871   //       (was bug - gri 10/25/99)
 872 
 873   Events::log("Create nmethod " INTPTR_FORMAT, this);
 874 }
 875 
 876 
 877 // Print a short set of xml attributes to identify this nmethod.  The
 878 // output should be embedded in some other element.
 879 void nmethod::log_identity(xmlStream* log) const {
 880   log->print(" compile_id='%d'", compile_id());
 881   const char* nm_kind = compile_kind();
 882   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 883   if (compiler() != NULL) {
 884     log->print(" compiler='%s'", compiler()->name());
 885   }
 886   if (TieredCompilation) {
 887     log->print(" level='%d'", comp_level());
 888   }
 889 }
 890 
 891 
 892 #define LOG_OFFSET(log, name)                    \
 893   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
 894     log->print(" " XSTR(name) "_offset='%d'"    , \
 895                (intptr_t)name##_begin() - (intptr_t)this)
 896 
 897 
 898 void nmethod::log_new_nmethod() const {
 899   if (LogCompilation && xtty != NULL) {
 900     ttyLocker ttyl;
 901     HandleMark hm;
 902     xtty->begin_elem("nmethod");
 903     log_identity(xtty);
 904     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
 905     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 906 
 907     LOG_OFFSET(xtty, relocation);
 908     LOG_OFFSET(xtty, consts);
 909     LOG_OFFSET(xtty, insts);
 910     LOG_OFFSET(xtty, stub);
 911     LOG_OFFSET(xtty, scopes_data);
 912     LOG_OFFSET(xtty, scopes_pcs);
 913     LOG_OFFSET(xtty, dependencies);
 914     LOG_OFFSET(xtty, handler_table);
 915     LOG_OFFSET(xtty, nul_chk_table);
 916     LOG_OFFSET(xtty, oops);
 917 
 918     xtty->method(method());
 919     xtty->stamp();
 920     xtty->end_elem();
 921   }
 922 }
 923 
 924 #undef LOG_OFFSET
 925 
 926 
 927 void nmethod::print_compilation(outputStream *st, const char *method_name, const char *title,
 928                                 methodOop method, bool is_blocking, int compile_id, int bci, int comp_level) {
 929   bool is_synchronized = false, has_xhandler = false, is_native = false;
 930   int code_size = -1;
 931   if (method != NULL) {
 932     is_synchronized = method->is_synchronized();
 933     has_xhandler    = method->has_exception_handler();
 934     is_native       = method->is_native();
 935     code_size       = method->code_size();
 936   }
 937   // print compilation number
 938   st->print("%7d %3d", (int)tty->time_stamp().milliseconds(), compile_id);
 939 
 940   // print method attributes
 941   const bool is_osr = bci != InvocationEntryBci;
 942   const char blocking_char  = is_blocking     ? 'b' : ' ';
 943   const char compile_type   = is_osr          ? '%' : ' ';
 944   const char sync_char      = is_synchronized ? 's' : ' ';
 945   const char exception_char = has_xhandler    ? '!' : ' ';
 946   const char native_char    = is_native       ? 'n' : ' ';
 947   st->print("%c%c%c%c%c ", compile_type, sync_char, exception_char, blocking_char, native_char);
 948   if (TieredCompilation) {
 949     st->print("%d ", comp_level);
 950   }
 951 
 952   // print optional title
 953   bool do_nl = false;
 954   if (title != NULL) {
 955     int tlen = (int) strlen(title);
 956     bool do_nl = false;
 957     if (tlen > 0 && title[tlen-1] == '\n') { tlen--; do_nl = true; }
 958     st->print("%.*s", tlen, title);
 959   } else {
 960     do_nl = true;
 961   }
 962 
 963   // print method name string if given
 964   if (method_name != NULL) {
 965     st->print(method_name);
 966   } else {
 967     // otherwise as the method to print itself
 968     if (method != NULL && !Universe::heap()->is_gc_active()) {
 969       method->print_short_name(st);
 970     } else {
 971       st->print("(method)");
 972     }
 973   }
 974 
 975   if (method != NULL) {
 976     // print osr_bci if any
 977     if (is_osr) st->print(" @ %d", bci);
 978     // print method size
 979     st->print(" (%d bytes)", code_size);
 980   }
 981   if (do_nl) st->cr();
 982 }
 983 
 984 // Print out more verbose output usually for a newly created nmethod.
 985 void nmethod::print_on(outputStream* st, const char* title) const {
 986   if (st != NULL) {
 987     ttyLocker ttyl;
 988     print_compilation(st, /*method_name*/NULL, title,
 989                       method(), /*is_blocking*/false,
 990                       compile_id(),
 991                       is_osr_method() ? osr_entry_bci() : InvocationEntryBci,
 992                       comp_level());
 993     if (WizardMode) st->print(" (" INTPTR_FORMAT ")", this);
 994   }
 995 }
 996 
 997 
 998 void nmethod::print_nmethod(bool printmethod) {
 999   ttyLocker ttyl;  // keep the following output all in one block
1000   if (xtty != NULL) {
1001     xtty->begin_head("print_nmethod");
1002     xtty->stamp();
1003     xtty->end_head();
1004   }
1005   // print the header part first
1006   print();
1007   // then print the requested information
1008   if (printmethod) {
1009     print_code();
1010     print_pcs();
1011     oop_maps()->print();
1012   }
1013   if (PrintDebugInfo) {
1014     print_scopes();
1015   }
1016   if (PrintRelocations) {
1017     print_relocations();
1018   }
1019   if (PrintDependencies) {
1020     print_dependencies();
1021   }
1022   if (PrintExceptionHandlers) {
1023     print_handler_table();
1024     print_nul_chk_table();
1025   }
1026   if (xtty != NULL) {
1027     xtty->tail("print_nmethod");
1028   }
1029 }
1030 
1031 
1032 // Promote one word from an assembly-time handle to a live embedded oop.
1033 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1034   if (handle == NULL ||
1035       // As a special case, IC oops are initialized to 1 or -1.
1036       handle == (jobject) Universe::non_oop_word()) {
1037     (*dest) = (oop) handle;
1038   } else {
1039     (*dest) = JNIHandles::resolve_non_null(handle);
1040   }
1041 }
1042 
1043 
1044 void nmethod::copy_oops(GrowableArray<jobject>* array) {
1045   //assert(oops_size() == 0, "do this handshake just once, please");
1046   int length = array->length();
1047   assert((address)(oops_begin() + length) <= data_end(), "oops big enough");
1048   oop* dest = oops_begin();
1049   for (int index = 0 ; index < length; index++) {
1050     initialize_immediate_oop(&dest[index], array->at(index));
1051   }
1052 
1053   // Now we can fix up all the oops in the code.  We need to do this
1054   // in the code because the assembler uses jobjects as placeholders.
1055   // The code and relocations have already been initialized by the
1056   // CodeBlob constructor, so it is valid even at this early point to
1057   // iterate over relocations and patch the code.
1058   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
1059 }
1060 
1061 
1062 bool nmethod::is_at_poll_return(address pc) {
1063   RelocIterator iter(this, pc, pc+1);
1064   while (iter.next()) {
1065     if (iter.type() == relocInfo::poll_return_type)
1066       return true;
1067   }
1068   return false;
1069 }
1070 
1071 
1072 bool nmethod::is_at_poll_or_poll_return(address pc) {
1073   RelocIterator iter(this, pc, pc+1);
1074   while (iter.next()) {
1075     relocInfo::relocType t = iter.type();
1076     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
1077       return true;
1078   }
1079   return false;
1080 }
1081 
1082 
1083 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1084   // re-patch all oop-bearing instructions, just in case some oops moved
1085   RelocIterator iter(this, begin, end);
1086   while (iter.next()) {
1087     if (iter.type() == relocInfo::oop_type) {
1088       oop_Relocation* reloc = iter.oop_reloc();
1089       if (initialize_immediates && reloc->oop_is_immediate()) {
1090         oop* dest = reloc->oop_addr();
1091         initialize_immediate_oop(dest, (jobject) *dest);
1092       }
1093       // Refresh the oop-related bits of this instruction.
1094       reloc->fix_oop_relocation();
1095     }
1096 
1097     // There must not be any interfering patches or breakpoints.
1098     assert(!(iter.type() == relocInfo::breakpoint_type
1099              && iter.breakpoint_reloc()->active()),
1100            "no active breakpoint");
1101   }
1102 }
1103 
1104 
1105 ScopeDesc* nmethod::scope_desc_at(address pc) {
1106   PcDesc* pd = pc_desc_at(pc);
1107   guarantee(pd != NULL, "scope must be present");
1108   return new ScopeDesc(this, pd->scope_decode_offset(),
1109                        pd->obj_decode_offset(), pd->should_reexecute(),
1110                        pd->return_oop());
1111 }
1112 
1113 
1114 void nmethod::clear_inline_caches() {
1115   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
1116   if (is_zombie()) {
1117     return;
1118   }
1119 
1120   RelocIterator iter(this);
1121   while (iter.next()) {
1122     iter.reloc()->clear_inline_cache();
1123   }
1124 }
1125 
1126 
1127 void nmethod::cleanup_inline_caches() {
1128 
1129   assert_locked_or_safepoint(CompiledIC_lock);
1130 
1131   // If the method is not entrant or zombie then a JMP is plastered over the
1132   // first few bytes.  If an oop in the old code was there, that oop
1133   // should not get GC'd.  Skip the first few bytes of oops on
1134   // not-entrant methods.
1135   address low_boundary = verified_entry_point();
1136   if (!is_in_use()) {
1137     low_boundary += NativeJump::instruction_size;
1138     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1139     // This means that the low_boundary is going to be a little too high.
1140     // This shouldn't matter, since oops of non-entrant methods are never used.
1141     // In fact, why are we bothering to look at oops in a non-entrant method??
1142   }
1143 
1144   // Find all calls in an nmethod, and clear the ones that points to zombie methods
1145   ResourceMark rm;
1146   RelocIterator iter(this, low_boundary);
1147   while(iter.next()) {
1148     switch(iter.type()) {
1149       case relocInfo::virtual_call_type:
1150       case relocInfo::opt_virtual_call_type: {
1151         CompiledIC *ic = CompiledIC_at(iter.reloc());
1152         // Ok, to lookup references to zombies here
1153         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1154         if( cb != NULL && cb->is_nmethod() ) {
1155           nmethod* nm = (nmethod*)cb;
1156           // Clean inline caches pointing to both zombie and not_entrant methods
1157           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
1158         }
1159         break;
1160       }
1161       case relocInfo::static_call_type: {
1162         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1163         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1164         if( cb != NULL && cb->is_nmethod() ) {
1165           nmethod* nm = (nmethod*)cb;
1166           // Clean inline caches pointing to both zombie and not_entrant methods
1167           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
1168         }
1169         break;
1170       }
1171     }
1172   }
1173 }
1174 
1175 // This is a private interface with the sweeper.
1176 void nmethod::mark_as_seen_on_stack() {
1177   assert(is_not_entrant(), "must be a non-entrant method");
1178   // Set the traversal mark to ensure that the sweeper does 2
1179   // cleaning passes before moving to zombie.
1180   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1181 }
1182 
1183 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1184 // there are no activations on the stack, not in use by the VM,
1185 // and not in use by the ServiceThread)
1186 bool nmethod::can_not_entrant_be_converted() {
1187   assert(is_not_entrant(), "must be a non-entrant method");
1188 
1189   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1190   // count can be greater than the stack traversal count before it hits the
1191   // nmethod for the second time.
1192   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
1193          !is_locked_by_vm();
1194 }
1195 
1196 void nmethod::inc_decompile_count() {
1197   if (!is_compiled_by_c2()) return;
1198   // Could be gated by ProfileTraps, but do not bother...
1199   methodOop m = method();
1200   if (m == NULL)  return;
1201   methodDataOop mdo = m->method_data();
1202   if (mdo == NULL)  return;
1203   // There is a benign race here.  See comments in methodDataOop.hpp.
1204   mdo->inc_decompile_count();
1205 }
1206 
1207 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
1208 
1209   post_compiled_method_unload();
1210 
1211   // Since this nmethod is being unloaded, make sure that dependencies
1212   // recorded in instanceKlasses get flushed and pass non-NULL closure to
1213   // indicate that this work is being done during a GC.
1214   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
1215   assert(is_alive != NULL, "Should be non-NULL");
1216   // A non-NULL is_alive closure indicates that this is being called during GC.
1217   flush_dependencies(is_alive);
1218 
1219   // Break cycle between nmethod & method
1220   if (TraceClassUnloading && WizardMode) {
1221     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
1222                   " unloadable], methodOop(" INTPTR_FORMAT
1223                   "), cause(" INTPTR_FORMAT ")",
1224                   this, (address)_method, (address)cause);
1225     if (!Universe::heap()->is_gc_active())
1226       cause->klass()->print();
1227   }
1228   // Unlink the osr method, so we do not look this up again
1229   if (is_osr_method()) {
1230     invalidate_osr_method();
1231   }
1232   // If _method is already NULL the methodOop is about to be unloaded,
1233   // so we don't have to break the cycle. Note that it is possible to
1234   // have the methodOop live here, in case we unload the nmethod because
1235   // it is pointing to some oop (other than the methodOop) being unloaded.
1236   if (_method != NULL) {
1237     // OSR methods point to the methodOop, but the methodOop does not
1238     // point back!
1239     if (_method->code() == this) {
1240       _method->clear_code(); // Break a cycle
1241     }
1242     _method = NULL;            // Clear the method of this dead nmethod
1243   }
1244   // Make the class unloaded - i.e., change state and notify sweeper
1245   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1246   if (is_in_use()) {
1247     // Transitioning directly from live to unloaded -- so
1248     // we need to force a cache clean-up; remember this
1249     // for later on.
1250     CodeCache::set_needs_cache_clean(true);
1251   }
1252   _state = unloaded;
1253 
1254   // Log the unloading.
1255   log_state_change();
1256 
1257   // The methodOop is gone at this point
1258   assert(_method == NULL, "Tautology");
1259 
1260   set_osr_link(NULL);
1261   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
1262   NMethodSweeper::notify(this);
1263 }
1264 
1265 void nmethod::invalidate_osr_method() {
1266   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1267   // Remove from list of active nmethods
1268   if (method() != NULL)
1269     instanceKlass::cast(method()->method_holder())->remove_osr_nmethod(this);
1270   // Set entry as invalid
1271   _entry_bci = InvalidOSREntryBci;
1272 }
1273 
1274 void nmethod::log_state_change() const {
1275   if (LogCompilation) {
1276     if (xtty != NULL) {
1277       ttyLocker ttyl;  // keep the following output all in one block
1278       if (_state == unloaded) {
1279         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1280                          os::current_thread_id());
1281       } else {
1282         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1283                          os::current_thread_id(),
1284                          (_state == zombie ? " zombie='1'" : ""));
1285       }
1286       log_identity(xtty);
1287       xtty->stamp();
1288       xtty->end_elem();
1289     }
1290   }
1291   if (PrintCompilation && _state != unloaded) {
1292     print_on(tty, _state == zombie ? "made zombie " : "made not entrant ");
1293     tty->cr();
1294   }
1295 }
1296 
1297 // Common functionality for both make_not_entrant and make_zombie
1298 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
1299   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1300   assert(!is_zombie(), "should not already be a zombie");
1301 
1302   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1303   nmethodLocker nml(this);
1304   methodHandle the_method(method());
1305   No_Safepoint_Verifier nsv;
1306 
1307   {
1308     // invalidate osr nmethod before acquiring the patching lock since
1309     // they both acquire leaf locks and we don't want a deadlock.
1310     // This logic is equivalent to the logic below for patching the
1311     // verified entry point of regular methods.
1312     if (is_osr_method()) {
1313       // this effectively makes the osr nmethod not entrant
1314       invalidate_osr_method();
1315     }
1316 
1317     // Enter critical section.  Does not block for safepoint.
1318     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1319 
1320     if (_state == state) {
1321       // another thread already performed this transition so nothing
1322       // to do, but return false to indicate this.
1323       return false;
1324     }
1325 
1326     // The caller can be calling the method statically or through an inline
1327     // cache call.
1328     if (!is_osr_method() && !is_not_entrant()) {
1329       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1330                   SharedRuntime::get_handle_wrong_method_stub());
1331     }
1332 
1333     if (is_in_use()) {
1334       // It's a true state change, so mark the method as decompiled.
1335       // Do it only for transition from alive.
1336       inc_decompile_count();
1337     }
1338 
1339     // Change state
1340     _state = state;
1341 
1342     // Log the transition once
1343     log_state_change();
1344 
1345     // Remove nmethod from method.
1346     // We need to check if both the _code and _from_compiled_code_entry_point
1347     // refer to this nmethod because there is a race in setting these two fields
1348     // in methodOop as seen in bugid 4947125.
1349     // If the vep() points to the zombie nmethod, the memory for the nmethod
1350     // could be flushed and the compiler and vtable stubs could still call
1351     // through it.
1352     if (method() != NULL && (method()->code() == this ||
1353                              method()->from_compiled_entry() == verified_entry_point())) {
1354       HandleMark hm;
1355       method()->clear_code();
1356     }
1357 
1358     if (state == not_entrant) {
1359       mark_as_seen_on_stack();
1360     }
1361 
1362   } // leave critical region under Patching_lock
1363 
1364   // When the nmethod becomes zombie it is no longer alive so the
1365   // dependencies must be flushed.  nmethods in the not_entrant
1366   // state will be flushed later when the transition to zombie
1367   // happens or they get unloaded.
1368   if (state == zombie) {
1369     {
1370       // Flushing dependecies must be done before any possible
1371       // safepoint can sneak in, otherwise the oops used by the
1372       // dependency logic could have become stale.
1373       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1374       flush_dependencies(NULL);
1375     }
1376 
1377     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1378     // event and it hasn't already been reported for this nmethod then
1379     // report it now. The event may have been reported earilier if the GC
1380     // marked it for unloading). JvmtiDeferredEventQueue support means
1381     // we no longer go to a safepoint here.
1382     post_compiled_method_unload();
1383 
1384 #ifdef ASSERT
1385     // It's no longer safe to access the oops section since zombie
1386     // nmethods aren't scanned for GC.
1387     _oops_are_stale = true;
1388 #endif
1389   } else {
1390     assert(state == not_entrant, "other cases may need to be handled differently");
1391   }
1392 
1393   if (TraceCreateZombies) {
1394     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
1395   }
1396 
1397   // Make sweeper aware that there is a zombie method that needs to be removed
1398   NMethodSweeper::notify(this);
1399 
1400   return true;
1401 }
1402 
1403 void nmethod::flush() {
1404   // Note that there are no valid oops in the nmethod anymore.
1405   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
1406   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
1407 
1408   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1409   assert_locked_or_safepoint(CodeCache_lock);
1410 
1411   // completely deallocate this method
1412   EventMark m("flushing nmethod " INTPTR_FORMAT " %s", this, "");
1413   if (PrintMethodFlushing) {
1414     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
1415         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
1416   }
1417 
1418   // We need to deallocate any ExceptionCache data.
1419   // Note that we do not need to grab the nmethod lock for this, it
1420   // better be thread safe if we're disposing of it!
1421   ExceptionCache* ec = exception_cache();
1422   set_exception_cache(NULL);
1423   while(ec != NULL) {
1424     ExceptionCache* next = ec->next();
1425     delete ec;
1426     ec = next;
1427   }
1428 
1429   if (on_scavenge_root_list()) {
1430     CodeCache::drop_scavenge_root_nmethod(this);
1431   }
1432 
1433   if (is_speculatively_disconnected()) {
1434     CodeCache::remove_saved_code(this);
1435   }
1436 
1437 #ifdef SHARK
1438   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
1439 #endif // SHARK
1440 
1441   ((CodeBlob*)(this))->flush();
1442 
1443   CodeCache::free(this);
1444 }
1445 
1446 
1447 //
1448 // Notify all classes this nmethod is dependent on that it is no
1449 // longer dependent. This should only be called in two situations.
1450 // First, when a nmethod transitions to a zombie all dependents need
1451 // to be clear.  Since zombification happens at a safepoint there's no
1452 // synchronization issues.  The second place is a little more tricky.
1453 // During phase 1 of mark sweep class unloading may happen and as a
1454 // result some nmethods may get unloaded.  In this case the flushing
1455 // of dependencies must happen during phase 1 since after GC any
1456 // dependencies in the unloaded nmethod won't be updated, so
1457 // traversing the dependency information in unsafe.  In that case this
1458 // function is called with a non-NULL argument and this function only
1459 // notifies instanceKlasses that are reachable
1460 
1461 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
1462   assert_locked_or_safepoint(CodeCache_lock);
1463   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
1464   "is_alive is non-NULL if and only if we are called during GC");
1465   if (!has_flushed_dependencies()) {
1466     set_has_flushed_dependencies();
1467     for (Dependencies::DepStream deps(this); deps.next(); ) {
1468       klassOop klass = deps.context_type();
1469       if (klass == NULL)  continue;  // ignore things like evol_method
1470 
1471       // During GC the is_alive closure is non-NULL, and is used to
1472       // determine liveness of dependees that need to be updated.
1473       if (is_alive == NULL || is_alive->do_object_b(klass)) {
1474         instanceKlass::cast(klass)->remove_dependent_nmethod(this);
1475       }
1476     }
1477   }
1478 }
1479 
1480 
1481 // If this oop is not live, the nmethod can be unloaded.
1482 bool nmethod::can_unload(BoolObjectClosure* is_alive,
1483                          OopClosure* keep_alive,
1484                          oop* root, bool unloading_occurred) {
1485   assert(root != NULL, "just checking");
1486   oop obj = *root;
1487   if (obj == NULL || is_alive->do_object_b(obj)) {
1488       return false;
1489   }
1490   if (obj->is_compiledICHolder()) {
1491     compiledICHolderOop cichk_oop = compiledICHolderOop(obj);
1492     if (is_alive->do_object_b(
1493           cichk_oop->holder_method()->method_holder()) &&
1494         is_alive->do_object_b(cichk_oop->holder_klass())) {
1495       // The oop should be kept alive
1496       keep_alive->do_oop(root);
1497       return false;
1498     }
1499   }
1500   // If ScavengeRootsInCode is true, an nmethod might be unloaded
1501   // simply because one of its constant oops has gone dead.
1502   // No actual classes need to be unloaded in order for this to occur.
1503   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
1504   make_unloaded(is_alive, obj);
1505   return true;
1506 }
1507 
1508 // ------------------------------------------------------------------
1509 // post_compiled_method_load_event
1510 // new method for install_code() path
1511 // Transfer information from compilation to jvmti
1512 void nmethod::post_compiled_method_load_event() {
1513 
1514   methodOop moop = method();
1515   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
1516       moop->klass_name()->bytes(),
1517       moop->klass_name()->utf8_length(),
1518       moop->name()->bytes(),
1519       moop->name()->utf8_length(),
1520       moop->signature()->bytes(),
1521       moop->signature()->utf8_length(),
1522       insts_begin(), insts_size());
1523 
1524   if (JvmtiExport::should_post_compiled_method_load() ||
1525       JvmtiExport::should_post_compiled_method_unload()) {
1526     get_and_cache_jmethod_id();
1527   }
1528 
1529   if (JvmtiExport::should_post_compiled_method_load()) {
1530     // Let the Service thread (which is a real Java thread) post the event
1531     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1532     JvmtiDeferredEventQueue::enqueue(
1533       JvmtiDeferredEvent::compiled_method_load_event(this));
1534   }
1535 }
1536 
1537 jmethodID nmethod::get_and_cache_jmethod_id() {
1538   if (_jmethod_id == NULL) {
1539     // Cache the jmethod_id since it can no longer be looked up once the
1540     // method itself has been marked for unloading.
1541     _jmethod_id = method()->jmethod_id();
1542   }
1543   return _jmethod_id;
1544 }
1545 
1546 void nmethod::post_compiled_method_unload() {
1547   if (unload_reported()) {
1548     // During unloading we transition to unloaded and then to zombie
1549     // and the unloading is reported during the first transition.
1550     return;
1551   }
1552 
1553   assert(_method != NULL && !is_unloaded(), "just checking");
1554   DTRACE_METHOD_UNLOAD_PROBE(method());
1555 
1556   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1557   // post the event. Sometime later this nmethod will be made a zombie
1558   // by the sweeper but the methodOop will not be valid at that point.
1559   // If the _jmethod_id is null then no load event was ever requested
1560   // so don't bother posting the unload.  The main reason for this is
1561   // that the jmethodID is a weak reference to the methodOop so if
1562   // it's being unloaded there's no way to look it up since the weak
1563   // ref will have been cleared.
1564   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1565     assert(!unload_reported(), "already unloaded");
1566     JvmtiDeferredEvent event =
1567       JvmtiDeferredEvent::compiled_method_unload_event(this,
1568           _jmethod_id, insts_begin());
1569     if (SafepointSynchronize::is_at_safepoint()) {
1570       // Don't want to take the queueing lock. Add it as pending and
1571       // it will get enqueued later.
1572       JvmtiDeferredEventQueue::add_pending_event(event);
1573     } else {
1574       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1575       JvmtiDeferredEventQueue::enqueue(event);
1576     }
1577   }
1578 
1579   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1580   // any time. As the nmethod is being unloaded now we mark it has
1581   // having the unload event reported - this will ensure that we don't
1582   // attempt to report the event in the unlikely scenario where the
1583   // event is enabled at the time the nmethod is made a zombie.
1584   set_unload_reported();
1585 }
1586 
1587 // This is called at the end of the strong tracing/marking phase of a
1588 // GC to unload an nmethod if it contains otherwise unreachable
1589 // oops.
1590 
1591 void nmethod::do_unloading(BoolObjectClosure* is_alive,
1592                            OopClosure* keep_alive, bool unloading_occurred) {
1593   // Make sure the oop's ready to receive visitors
1594   assert(!is_zombie() && !is_unloaded(),
1595          "should not call follow on zombie or unloaded nmethod");
1596 
1597   // If the method is not entrant then a JMP is plastered over the
1598   // first few bytes.  If an oop in the old code was there, that oop
1599   // should not get GC'd.  Skip the first few bytes of oops on
1600   // not-entrant methods.
1601   address low_boundary = verified_entry_point();
1602   if (is_not_entrant()) {
1603     low_boundary += NativeJump::instruction_size;
1604     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1605     // (See comment above.)
1606   }
1607 
1608   // The RedefineClasses() API can cause the class unloading invariant
1609   // to no longer be true. See jvmtiExport.hpp for details.
1610   // Also, leave a debugging breadcrumb in local flag.
1611   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
1612   if (a_class_was_redefined) {
1613     // This set of the unloading_occurred flag is done before the
1614     // call to post_compiled_method_unload() so that the unloading
1615     // of this nmethod is reported.
1616     unloading_occurred = true;
1617   }
1618 
1619   // Follow methodOop
1620   if (can_unload(is_alive, keep_alive, (oop*)&_method, unloading_occurred)) {
1621     return;
1622   }
1623 
1624   // Exception cache
1625   ExceptionCache* ec = exception_cache();
1626   while (ec != NULL) {
1627     oop* ex_addr = (oop*)ec->exception_type_addr();
1628     oop ex = *ex_addr;
1629     ExceptionCache* next_ec = ec->next();
1630     if (ex != NULL && !is_alive->do_object_b(ex)) {
1631       assert(!ex->is_compiledICHolder(), "Possible error here");
1632       remove_from_exception_cache(ec);
1633     }
1634     ec = next_ec;
1635   }
1636 
1637   // If class unloading occurred we first iterate over all inline caches and
1638   // clear ICs where the cached oop is referring to an unloaded klass or method.
1639   // The remaining live cached oops will be traversed in the relocInfo::oop_type
1640   // iteration below.
1641   if (unloading_occurred) {
1642     RelocIterator iter(this, low_boundary);
1643     while(iter.next()) {
1644       if (iter.type() == relocInfo::virtual_call_type) {
1645         CompiledIC *ic = CompiledIC_at(iter.reloc());
1646         oop ic_oop = ic->cached_oop();
1647         if (ic_oop != NULL && !is_alive->do_object_b(ic_oop)) {
1648           // The only exception is compiledICHolder oops which may
1649           // yet be marked below. (We check this further below).
1650           if (ic_oop->is_compiledICHolder()) {
1651             compiledICHolderOop cichk_oop = compiledICHolderOop(ic_oop);
1652             if (is_alive->do_object_b(
1653                   cichk_oop->holder_method()->method_holder()) &&
1654                 is_alive->do_object_b(cichk_oop->holder_klass())) {
1655               continue;
1656             }
1657           }
1658           ic->set_to_clean();
1659           assert(ic->cached_oop() == NULL,
1660                  "cached oop in IC should be cleared");
1661         }
1662       }
1663     }
1664   }
1665 
1666   // Compiled code
1667   RelocIterator iter(this, low_boundary);
1668   while (iter.next()) {
1669     if (iter.type() == relocInfo::oop_type) {
1670       oop_Relocation* r = iter.oop_reloc();
1671       // In this loop, we must only traverse those oops directly embedded in
1672       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1673       assert(1 == (r->oop_is_immediate()) +
1674                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1675              "oop must be found in exactly one place");
1676       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1677         if (can_unload(is_alive, keep_alive, r->oop_addr(), unloading_occurred)) {
1678           return;
1679         }
1680       }
1681     }
1682   }
1683 
1684 
1685   // Scopes
1686   for (oop* p = oops_begin(); p < oops_end(); p++) {
1687     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1688     if (can_unload(is_alive, keep_alive, p, unloading_occurred)) {
1689       return;
1690     }
1691   }
1692 
1693 #ifndef PRODUCT
1694   // This nmethod was not unloaded; check below that all CompiledICs
1695   // refer to marked oops.
1696   {
1697     RelocIterator iter(this, low_boundary);
1698     while (iter.next()) {
1699       if (iter.type() == relocInfo::virtual_call_type) {
1700          CompiledIC *ic = CompiledIC_at(iter.reloc());
1701          oop ic_oop = ic->cached_oop();
1702          assert(ic_oop == NULL || is_alive->do_object_b(ic_oop),
1703                 "Found unmarked ic_oop in reachable nmethod");
1704        }
1705     }
1706   }
1707 #endif // !PRODUCT
1708 }
1709 
1710 // This method is called twice during GC -- once while
1711 // tracing the "active" nmethods on thread stacks during
1712 // the (strong) marking phase, and then again when walking
1713 // the code cache contents during the weak roots processing
1714 // phase. The two uses are distinguished by means of the
1715 // 'do_strong_roots_only' flag, which is true in the first
1716 // case. We want to walk the weak roots in the nmethod
1717 // only in the second case. The weak roots in the nmethod
1718 // are the oops in the ExceptionCache and the InlineCache
1719 // oops.
1720 void nmethod::oops_do(OopClosure* f, bool do_strong_roots_only) {
1721   // make sure the oops ready to receive visitors
1722   assert(!is_zombie() && !is_unloaded(),
1723          "should not call follow on zombie or unloaded nmethod");
1724 
1725   // If the method is not entrant or zombie then a JMP is plastered over the
1726   // first few bytes.  If an oop in the old code was there, that oop
1727   // should not get GC'd.  Skip the first few bytes of oops on
1728   // not-entrant methods.
1729   address low_boundary = verified_entry_point();
1730   if (is_not_entrant()) {
1731     low_boundary += NativeJump::instruction_size;
1732     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
1733     // (See comment above.)
1734   }
1735 
1736   // Compiled code
1737   f->do_oop((oop*) &_method);
1738   if (!do_strong_roots_only) {
1739     // weak roots processing phase -- update ExceptionCache oops
1740     ExceptionCache* ec = exception_cache();
1741     while(ec != NULL) {
1742       f->do_oop((oop*)ec->exception_type_addr());
1743       ec = ec->next();
1744     }
1745   } // Else strong roots phase -- skip oops in ExceptionCache
1746 
1747   RelocIterator iter(this, low_boundary);
1748 
1749   while (iter.next()) {
1750     if (iter.type() == relocInfo::oop_type ) {
1751       oop_Relocation* r = iter.oop_reloc();
1752       // In this loop, we must only follow those oops directly embedded in
1753       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1754       assert(1 == (r->oop_is_immediate()) +
1755                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1756              "oop must be found in exactly one place");
1757       if (r->oop_is_immediate() && r->oop_value() != NULL) {
1758         f->do_oop(r->oop_addr());
1759       }
1760     }
1761   }
1762 
1763   // Scopes
1764   // This includes oop constants not inlined in the code stream.
1765   for (oop* p = oops_begin(); p < oops_end(); p++) {
1766     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1767     f->do_oop(p);
1768   }
1769 }
1770 
1771 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1772 
1773 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1774 
1775 // An nmethod is "marked" if its _mark_link is set non-null.
1776 // Even if it is the end of the linked list, it will have a non-null link value,
1777 // as long as it is on the list.
1778 // This code must be MP safe, because it is used from parallel GC passes.
1779 bool nmethod::test_set_oops_do_mark() {
1780   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1781   nmethod* observed_mark_link = _oops_do_mark_link;
1782   if (observed_mark_link == NULL) {
1783     // Claim this nmethod for this thread to mark.
1784     observed_mark_link = (nmethod*)
1785       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
1786     if (observed_mark_link == NULL) {
1787 
1788       // Atomically append this nmethod (now claimed) to the head of the list:
1789       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1790       for (;;) {
1791         nmethod* required_mark_nmethods = observed_mark_nmethods;
1792         _oops_do_mark_link = required_mark_nmethods;
1793         observed_mark_nmethods = (nmethod*)
1794           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1795         if (observed_mark_nmethods == required_mark_nmethods)
1796           break;
1797       }
1798       // Mark was clear when we first saw this guy.
1799       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark\n"));
1800       return false;
1801     }
1802   }
1803   // On fall through, another racing thread marked this nmethod before we did.
1804   return true;
1805 }
1806 
1807 void nmethod::oops_do_marking_prologue() {
1808   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
1809   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1810   // We use cmpxchg_ptr instead of regular assignment here because the user
1811   // may fork a bunch of threads, and we need them all to see the same state.
1812   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
1813   guarantee(observed == NULL, "no races in this sequential code");
1814 }
1815 
1816 void nmethod::oops_do_marking_epilogue() {
1817   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1818   nmethod* cur = _oops_do_mark_nmethods;
1819   while (cur != NMETHOD_SENTINEL) {
1820     assert(cur != NULL, "not NULL-terminated");
1821     nmethod* next = cur->_oops_do_mark_link;
1822     cur->_oops_do_mark_link = NULL;
1823     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark\n"));
1824     cur = next;
1825   }
1826   void* required = _oops_do_mark_nmethods;
1827   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
1828   guarantee(observed == required, "no races in this sequential code");
1829   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
1830 }
1831 
1832 class DetectScavengeRoot: public OopClosure {
1833   bool     _detected_scavenge_root;
1834 public:
1835   DetectScavengeRoot() : _detected_scavenge_root(false)
1836   { NOT_PRODUCT(_print_nm = NULL); }
1837   bool detected_scavenge_root() { return _detected_scavenge_root; }
1838   virtual void do_oop(oop* p) {
1839     if ((*p) != NULL && (*p)->is_scavengable()) {
1840       NOT_PRODUCT(maybe_print(p));
1841       _detected_scavenge_root = true;
1842     }
1843   }
1844   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1845 
1846 #ifndef PRODUCT
1847   nmethod* _print_nm;
1848   void maybe_print(oop* p) {
1849     if (_print_nm == NULL)  return;
1850     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
1851     tty->print_cr(""PTR_FORMAT"[offset=%d] detected non-perm oop "PTR_FORMAT" (found at "PTR_FORMAT")",
1852                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
1853                   (intptr_t)(*p), (intptr_t)p);
1854     (*p)->print();
1855   }
1856 #endif //PRODUCT
1857 };
1858 
1859 bool nmethod::detect_scavenge_root_oops() {
1860   DetectScavengeRoot detect_scavenge_root;
1861   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
1862   oops_do(&detect_scavenge_root);
1863   return detect_scavenge_root.detected_scavenge_root();
1864 }
1865 
1866 // Method that knows how to preserve outgoing arguments at call. This method must be
1867 // called with a frame corresponding to a Java invoke
1868 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
1869 #ifndef SHARK
1870   if (!method()->is_native()) {
1871     SimpleScopeDesc ssd(this, fr.pc());
1872     Bytecode_invoke call(ssd.method(), ssd.bci());
1873     bool has_receiver = call.has_receiver();
1874     Symbol* signature = call.signature();
1875     fr.oops_compiled_arguments_do(signature, has_receiver, reg_map, f);
1876   }
1877 #endif // !SHARK
1878 }
1879 
1880 
1881 oop nmethod::embeddedOop_at(u_char* p) {
1882   RelocIterator iter(this, p, p + oopSize);
1883   while (iter.next())
1884     if (iter.type() == relocInfo::oop_type) {
1885       return iter.oop_reloc()->oop_value();
1886     }
1887   return NULL;
1888 }
1889 
1890 
1891 inline bool includes(void* p, void* from, void* to) {
1892   return from <= p && p < to;
1893 }
1894 
1895 
1896 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1897   assert(count >= 2, "must be sentinel values, at least");
1898 
1899 #ifdef ASSERT
1900   // must be sorted and unique; we do a binary search in find_pc_desc()
1901   int prev_offset = pcs[0].pc_offset();
1902   assert(prev_offset == PcDesc::lower_offset_limit,
1903          "must start with a sentinel");
1904   for (int i = 1; i < count; i++) {
1905     int this_offset = pcs[i].pc_offset();
1906     assert(this_offset > prev_offset, "offsets must be sorted");
1907     prev_offset = this_offset;
1908   }
1909   assert(prev_offset == PcDesc::upper_offset_limit,
1910          "must end with a sentinel");
1911 #endif //ASSERT
1912 
1913   // Search for MethodHandle invokes and tag the nmethod.
1914   for (int i = 0; i < count; i++) {
1915     if (pcs[i].is_method_handle_invoke()) {
1916       set_has_method_handle_invokes(true);
1917       break;
1918     }
1919   }
1920   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
1921 
1922   int size = count * sizeof(PcDesc);
1923   assert(scopes_pcs_size() >= size, "oob");
1924   memcpy(scopes_pcs_begin(), pcs, size);
1925 
1926   // Adjust the final sentinel downward.
1927   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1928   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1929   last_pc->set_pc_offset(content_size() + 1);
1930   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1931     // Fill any rounding gaps with copies of the last record.
1932     last_pc[1] = last_pc[0];
1933   }
1934   // The following assert could fail if sizeof(PcDesc) is not
1935   // an integral multiple of oopSize (the rounding term).
1936   // If it fails, change the logic to always allocate a multiple
1937   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1938   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1939 }
1940 
1941 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1942   assert(scopes_data_size() >= size, "oob");
1943   memcpy(scopes_data_begin(), buffer, size);
1944 }
1945 
1946 
1947 #ifdef ASSERT
1948 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
1949   PcDesc* lower = nm->scopes_pcs_begin();
1950   PcDesc* upper = nm->scopes_pcs_end();
1951   lower += 1; // exclude initial sentinel
1952   PcDesc* res = NULL;
1953   for (PcDesc* p = lower; p < upper; p++) {
1954     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1955     if (match_desc(p, pc_offset, approximate)) {
1956       if (res == NULL)
1957         res = p;
1958       else
1959         res = (PcDesc*) badAddress;
1960     }
1961   }
1962   return res;
1963 }
1964 #endif
1965 
1966 
1967 // Finds a PcDesc with real-pc equal to "pc"
1968 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
1969   address base_address = code_begin();
1970   if ((pc < base_address) ||
1971       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1972     return NULL;  // PC is wildly out of range
1973   }
1974   int pc_offset = (int) (pc - base_address);
1975 
1976   // Check the PcDesc cache if it contains the desired PcDesc
1977   // (This as an almost 100% hit rate.)
1978   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1979   if (res != NULL) {
1980     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
1981     return res;
1982   }
1983 
1984   // Fallback algorithm: quasi-linear search for the PcDesc
1985   // Find the last pc_offset less than the given offset.
1986   // The successor must be the required match, if there is a match at all.
1987   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1988   PcDesc* lower = scopes_pcs_begin();
1989   PcDesc* upper = scopes_pcs_end();
1990   upper -= 1; // exclude final sentinel
1991   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1992 
1993 #define assert_LU_OK \
1994   /* invariant on lower..upper during the following search: */ \
1995   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1996   assert(upper->pc_offset() >= pc_offset, "sanity")
1997   assert_LU_OK;
1998 
1999   // Use the last successful return as a split point.
2000   PcDesc* mid = _pc_desc_cache.last_pc_desc();
2001   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2002   if (mid->pc_offset() < pc_offset) {
2003     lower = mid;
2004   } else {
2005     upper = mid;
2006   }
2007 
2008   // Take giant steps at first (4096, then 256, then 16, then 1)
2009   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
2010   const int RADIX = (1 << LOG2_RADIX);
2011   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
2012     while ((mid = lower + step) < upper) {
2013       assert_LU_OK;
2014       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2015       if (mid->pc_offset() < pc_offset) {
2016         lower = mid;
2017       } else {
2018         upper = mid;
2019         break;
2020       }
2021     }
2022     assert_LU_OK;
2023   }
2024 
2025   // Sneak up on the value with a linear search of length ~16.
2026   while (true) {
2027     assert_LU_OK;
2028     mid = lower + 1;
2029     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
2030     if (mid->pc_offset() < pc_offset) {
2031       lower = mid;
2032     } else {
2033       upper = mid;
2034       break;
2035     }
2036   }
2037 #undef assert_LU_OK
2038 
2039   if (match_desc(upper, pc_offset, approximate)) {
2040     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
2041     _pc_desc_cache.add_pc_desc(upper);
2042     return upper;
2043   } else {
2044     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
2045     return NULL;
2046   }
2047 }
2048 
2049 
2050 bool nmethod::check_all_dependencies() {
2051   bool found_check = false;
2052   // wholesale check of all dependencies
2053   for (Dependencies::DepStream deps(this); deps.next(); ) {
2054     if (deps.check_dependency() != NULL) {
2055       found_check = true;
2056       NOT_DEBUG(break);
2057     }
2058   }
2059   return found_check;  // tell caller if we found anything
2060 }
2061 
2062 bool nmethod::check_dependency_on(DepChange& changes) {
2063   // What has happened:
2064   // 1) a new class dependee has been added
2065   // 2) dependee and all its super classes have been marked
2066   bool found_check = false;  // set true if we are upset
2067   for (Dependencies::DepStream deps(this); deps.next(); ) {
2068     // Evaluate only relevant dependencies.
2069     if (deps.spot_check_dependency_at(changes) != NULL) {
2070       found_check = true;
2071       NOT_DEBUG(break);
2072     }
2073   }
2074   return found_check;
2075 }
2076 
2077 bool nmethod::is_evol_dependent_on(klassOop dependee) {
2078   instanceKlass *dependee_ik = instanceKlass::cast(dependee);
2079   objArrayOop dependee_methods = dependee_ik->methods();
2080   for (Dependencies::DepStream deps(this); deps.next(); ) {
2081     if (deps.type() == Dependencies::evol_method) {
2082       methodOop method = deps.method_argument(0);
2083       for (int j = 0; j < dependee_methods->length(); j++) {
2084         if ((methodOop) dependee_methods->obj_at(j) == method) {
2085           // RC_TRACE macro has an embedded ResourceMark
2086           RC_TRACE(0x01000000,
2087             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2088             _method->method_holder()->klass_part()->external_name(),
2089             _method->name()->as_C_string(),
2090             _method->signature()->as_C_string(), compile_id(),
2091             method->method_holder()->klass_part()->external_name(),
2092             method->name()->as_C_string(),
2093             method->signature()->as_C_string()));
2094           if (TraceDependencies || LogCompilation)
2095             deps.log_dependency(dependee);
2096           return true;
2097         }
2098       }
2099     }
2100   }
2101   return false;
2102 }
2103 
2104 // Called from mark_for_deoptimization, when dependee is invalidated.
2105 bool nmethod::is_dependent_on_method(methodOop dependee) {
2106   for (Dependencies::DepStream deps(this); deps.next(); ) {
2107     if (deps.type() != Dependencies::evol_method)
2108       continue;
2109     methodOop method = deps.method_argument(0);
2110     if (method == dependee) return true;
2111   }
2112   return false;
2113 }
2114 
2115 
2116 bool nmethod::is_patchable_at(address instr_addr) {
2117   assert(insts_contains(instr_addr), "wrong nmethod used");
2118   if (is_zombie()) {
2119     // a zombie may never be patched
2120     return false;
2121   }
2122   return true;
2123 }
2124 
2125 
2126 address nmethod::continuation_for_implicit_exception(address pc) {
2127   // Exception happened outside inline-cache check code => we are inside
2128   // an active nmethod => use cpc to determine a return address
2129   int exception_offset = pc - code_begin();
2130   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2131 #ifdef ASSERT
2132   if (cont_offset == 0) {
2133     Thread* thread = ThreadLocalStorage::get_thread_slow();
2134     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2135     HandleMark hm(thread);
2136     ResourceMark rm(thread);
2137     CodeBlob* cb = CodeCache::find_blob(pc);
2138     assert(cb != NULL && cb == this, "");
2139     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
2140     print();
2141     method()->print_codes();
2142     print_code();
2143     print_pcs();
2144   }
2145 #endif
2146   if (cont_offset == 0) {
2147     // Let the normal error handling report the exception
2148     return NULL;
2149   }
2150   return code_begin() + cont_offset;
2151 }
2152 
2153 
2154 
2155 void nmethod_init() {
2156   // make sure you didn't forget to adjust the filler fields
2157   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2158 }
2159 
2160 
2161 //-------------------------------------------------------------------------------------------
2162 
2163 
2164 // QQQ might we make this work from a frame??
2165 nmethodLocker::nmethodLocker(address pc) {
2166   CodeBlob* cb = CodeCache::find_blob(pc);
2167   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
2168   _nm = (nmethod*)cb;
2169   lock_nmethod(_nm);
2170 }
2171 
2172 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2173 // should pass zombie_ok == true.
2174 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
2175   if (nm == NULL)  return;
2176   Atomic::inc(&nm->_lock_count);
2177   guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2178 }
2179 
2180 void nmethodLocker::unlock_nmethod(nmethod* nm) {
2181   if (nm == NULL)  return;
2182   Atomic::dec(&nm->_lock_count);
2183   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2184 }
2185 
2186 
2187 // -----------------------------------------------------------------------------
2188 // nmethod::get_deopt_original_pc
2189 //
2190 // Return the original PC for the given PC if:
2191 // (a) the given PC belongs to a nmethod and
2192 // (b) it is a deopt PC
2193 address nmethod::get_deopt_original_pc(const frame* fr) {
2194   if (fr->cb() == NULL)  return NULL;
2195 
2196   nmethod* nm = fr->cb()->as_nmethod_or_null();
2197   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
2198     return nm->get_original_pc(fr);
2199 
2200   return NULL;
2201 }
2202 
2203 
2204 // -----------------------------------------------------------------------------
2205 // MethodHandle
2206 
2207 bool nmethod::is_method_handle_return(address return_pc) {
2208   if (!has_method_handle_invokes())  return false;
2209   PcDesc* pd = pc_desc_at(return_pc);
2210   if (pd == NULL)
2211     return false;
2212   return pd->is_method_handle_invoke();
2213 }
2214 
2215 
2216 // -----------------------------------------------------------------------------
2217 // Verification
2218 
2219 class VerifyOopsClosure: public OopClosure {
2220   nmethod* _nm;
2221   bool     _ok;
2222 public:
2223   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2224   bool ok() { return _ok; }
2225   virtual void do_oop(oop* p) {
2226     if ((*p) == NULL || (*p)->is_oop())  return;
2227     if (_ok) {
2228       _nm->print_nmethod(true);
2229       _ok = false;
2230     }
2231     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2232                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2233   }
2234   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2235 };
2236 
2237 void nmethod::verify() {
2238 
2239   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2240   // seems odd.
2241 
2242   if( is_zombie() || is_not_entrant() )
2243     return;
2244 
2245   // Make sure all the entry points are correctly aligned for patching.
2246   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2247 
2248   assert(method()->is_oop(), "must be valid");
2249 
2250   ResourceMark rm;
2251 
2252   if (!CodeCache::contains(this)) {
2253     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
2254   }
2255 
2256   if(is_native_method() )
2257     return;
2258 
2259   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2260   if (nm != this) {
2261     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
2262                   this));
2263   }
2264 
2265   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2266     if (! p->verify(this)) {
2267       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
2268     }
2269   }
2270 
2271   VerifyOopsClosure voc(this);
2272   oops_do(&voc);
2273   assert(voc.ok(), "embedded oops must be OK");
2274   verify_scavenge_root_oops();
2275 
2276   verify_scopes();
2277 }
2278 
2279 
2280 void nmethod::verify_interrupt_point(address call_site) {
2281   // This code does not work in release mode since
2282   // owns_lock only is available in debug mode.
2283   CompiledIC* ic = NULL;
2284   Thread *cur = Thread::current();
2285   if (CompiledIC_lock->owner() == cur ||
2286       ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
2287        SafepointSynchronize::is_at_safepoint())) {
2288     ic = CompiledIC_at(call_site);
2289     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2290   } else {
2291     MutexLocker ml_verify (CompiledIC_lock);
2292     ic = CompiledIC_at(call_site);
2293   }
2294   PcDesc* pd = pc_desc_at(ic->end_of_call());
2295   assert(pd != NULL, "PcDesc must exist");
2296   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2297                                      pd->obj_decode_offset(), pd->should_reexecute(),
2298                                      pd->return_oop());
2299        !sd->is_top(); sd = sd->sender()) {
2300     sd->verify();
2301   }
2302 }
2303 
2304 void nmethod::verify_scopes() {
2305   if( !method() ) return;       // Runtime stubs have no scope
2306   if (method()->is_native()) return; // Ignore stub methods.
2307   // iterate through all interrupt point
2308   // and verify the debug information is valid.
2309   RelocIterator iter((nmethod*)this);
2310   while (iter.next()) {
2311     address stub = NULL;
2312     switch (iter.type()) {
2313       case relocInfo::virtual_call_type:
2314         verify_interrupt_point(iter.addr());
2315         break;
2316       case relocInfo::opt_virtual_call_type:
2317         stub = iter.opt_virtual_call_reloc()->static_stub();
2318         verify_interrupt_point(iter.addr());
2319         break;
2320       case relocInfo::static_call_type:
2321         stub = iter.static_call_reloc()->static_stub();
2322         //verify_interrupt_point(iter.addr());
2323         break;
2324       case relocInfo::runtime_call_type:
2325         address destination = iter.reloc()->value();
2326         // Right now there is no way to find out which entries support
2327         // an interrupt point.  It would be nice if we had this
2328         // information in a table.
2329         break;
2330     }
2331     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2332   }
2333 }
2334 
2335 
2336 // -----------------------------------------------------------------------------
2337 // Non-product code
2338 #ifndef PRODUCT
2339 
2340 class DebugScavengeRoot: public OopClosure {
2341   nmethod* _nm;
2342   bool     _ok;
2343 public:
2344   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2345   bool ok() { return _ok; }
2346   virtual void do_oop(oop* p) {
2347     if ((*p) == NULL || !(*p)->is_scavengable())  return;
2348     if (_ok) {
2349       _nm->print_nmethod(true);
2350       _ok = false;
2351     }
2352     tty->print_cr("*** non-perm oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
2353                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
2354     (*p)->print();
2355   }
2356   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2357 };
2358 
2359 void nmethod::verify_scavenge_root_oops() {
2360   if (!on_scavenge_root_list()) {
2361     // Actually look inside, to verify the claim that it's clean.
2362     DebugScavengeRoot debug_scavenge_root(this);
2363     oops_do(&debug_scavenge_root);
2364     if (!debug_scavenge_root.ok())
2365       fatal("found an unadvertised bad non-perm oop in the code cache");
2366   }
2367   assert(scavenge_root_not_marked(), "");
2368 }
2369 
2370 #endif // PRODUCT
2371 
2372 // Printing operations
2373 
2374 void nmethod::print() const {
2375   ResourceMark rm;
2376   ttyLocker ttyl;   // keep the following output all in one block
2377 
2378   tty->print("Compiled ");
2379 
2380   if (is_compiled_by_c1()) {
2381     tty->print("(c1) ");
2382   } else if (is_compiled_by_c2()) {
2383     tty->print("(c2) ");
2384   } else if (is_compiled_by_shark()) {
2385     tty->print("(shark) ");
2386   } else {
2387     tty->print("(nm) ");
2388   }
2389 
2390   print_on(tty, "nmethod");
2391   tty->cr();
2392   if (WizardMode) {
2393     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
2394     tty->print(" for method " INTPTR_FORMAT , (address)method());
2395     tty->print(" { ");
2396     if (is_in_use())      tty->print("in_use ");
2397     if (is_not_entrant()) tty->print("not_entrant ");
2398     if (is_zombie())      tty->print("zombie ");
2399     if (is_unloaded())    tty->print("unloaded ");
2400     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2401     tty->print_cr("}:");
2402   }
2403   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2404                                               (address)this,
2405                                               (address)this + size(),
2406                                               size());
2407   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2408                                               relocation_begin(),
2409                                               relocation_end(),
2410                                               relocation_size());
2411   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2412                                               consts_begin(),
2413                                               consts_end(),
2414                                               consts_size());
2415   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2416                                               insts_begin(),
2417                                               insts_end(),
2418                                               insts_size());
2419   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2420                                               stub_begin(),
2421                                               stub_end(),
2422                                               stub_size());
2423   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2424                                               oops_begin(),
2425                                               oops_end(),
2426                                               oops_size());
2427   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2428                                               scopes_data_begin(),
2429                                               scopes_data_end(),
2430                                               scopes_data_size());
2431   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2432                                               scopes_pcs_begin(),
2433                                               scopes_pcs_end(),
2434                                               scopes_pcs_size());
2435   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2436                                               dependencies_begin(),
2437                                               dependencies_end(),
2438                                               dependencies_size());
2439   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2440                                               handler_table_begin(),
2441                                               handler_table_end(),
2442                                               handler_table_size());
2443   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2444                                               nul_chk_table_begin(),
2445                                               nul_chk_table_end(),
2446                                               nul_chk_table_size());
2447 }
2448 
2449 void nmethod::print_code() {
2450   HandleMark hm;
2451   ResourceMark m;
2452   Disassembler::decode(this);
2453 }
2454 
2455 
2456 #ifndef PRODUCT
2457 
2458 void nmethod::print_scopes() {
2459   // Find the first pc desc for all scopes in the code and print it.
2460   ResourceMark rm;
2461   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2462     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2463       continue;
2464 
2465     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2466     sd->print_on(tty, p);
2467   }
2468 }
2469 
2470 void nmethod::print_dependencies() {
2471   ResourceMark rm;
2472   ttyLocker ttyl;   // keep the following output all in one block
2473   tty->print_cr("Dependencies:");
2474   for (Dependencies::DepStream deps(this); deps.next(); ) {
2475     deps.print_dependency();
2476     klassOop ctxk = deps.context_type();
2477     if (ctxk != NULL) {
2478       Klass* k = Klass::cast(ctxk);
2479       if (k->oop_is_instance() && ((instanceKlass*)k)->is_dependent_nmethod(this)) {
2480         tty->print_cr("   [nmethod<=klass]%s", k->external_name());
2481       }
2482     }
2483     deps.log_dependency();  // put it into the xml log also
2484   }
2485 }
2486 
2487 
2488 void nmethod::print_relocations() {
2489   ResourceMark m;       // in case methods get printed via the debugger
2490   tty->print_cr("relocations:");
2491   RelocIterator iter(this);
2492   iter.print();
2493   if (UseRelocIndex) {
2494     jint* index_end   = (jint*)relocation_end() - 1;
2495     jint  index_size  = *index_end;
2496     jint* index_start = (jint*)( (address)index_end - index_size );
2497     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
2498     if (index_size > 0) {
2499       jint* ip;
2500       for (ip = index_start; ip+2 <= index_end; ip += 2)
2501         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
2502                       ip[0],
2503                       ip[1],
2504                       header_end()+ip[0],
2505                       relocation_begin()-1+ip[1]);
2506       for (; ip < index_end; ip++)
2507         tty->print_cr("  (%d ?)", ip[0]);
2508       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip++);
2509       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
2510     }
2511   }
2512 }
2513 
2514 
2515 void nmethod::print_pcs() {
2516   ResourceMark m;       // in case methods get printed via debugger
2517   tty->print_cr("pc-bytecode offsets:");
2518   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2519     p->print(this);
2520   }
2521 }
2522 
2523 #endif // PRODUCT
2524 
2525 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2526   RelocIterator iter(this, begin, end);
2527   bool have_one = false;
2528   while (iter.next()) {
2529     have_one = true;
2530     switch (iter.type()) {
2531         case relocInfo::none:                  return "no_reloc";
2532         case relocInfo::oop_type: {
2533           stringStream st;
2534           oop_Relocation* r = iter.oop_reloc();
2535           oop obj = r->oop_value();
2536           st.print("oop(");
2537           if (obj == NULL) st.print("NULL");
2538           else obj->print_value_on(&st);
2539           st.print(")");
2540           return st.as_string();
2541         }
2542         case relocInfo::virtual_call_type:     return "virtual_call";
2543         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
2544         case relocInfo::static_call_type:      return "static_call";
2545         case relocInfo::static_stub_type:      return "static_stub";
2546         case relocInfo::runtime_call_type:     return "runtime_call";
2547         case relocInfo::external_word_type:    return "external_word";
2548         case relocInfo::internal_word_type:    return "internal_word";
2549         case relocInfo::section_word_type:     return "section_word";
2550         case relocInfo::poll_type:             return "poll";
2551         case relocInfo::poll_return_type:      return "poll_return";
2552         case relocInfo::type_mask:             return "type_bit_mask";
2553     }
2554   }
2555   return have_one ? "other" : NULL;
2556 }
2557 
2558 // Return a the last scope in (begin..end]
2559 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2560   PcDesc* p = pc_desc_near(begin+1);
2561   if (p != NULL && p->real_pc(this) <= end) {
2562     return new ScopeDesc(this, p->scope_decode_offset(),
2563                          p->obj_decode_offset(), p->should_reexecute(),
2564                          p->return_oop());
2565   }
2566   return NULL;
2567 }
2568 
2569 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) {
2570   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2571   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2572   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2573   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2574   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2575 
2576   if (has_method_handle_invokes())
2577     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2578 
2579   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2580 
2581   if (block_begin == entry_point()) {
2582     methodHandle m = method();
2583     if (m.not_null()) {
2584       stream->print("  # ");
2585       m->print_value_on(stream);
2586       stream->cr();
2587     }
2588     if (m.not_null() && !is_osr_method()) {
2589       ResourceMark rm;
2590       int sizeargs = m->size_of_parameters();
2591       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2592       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2593       {
2594         int sig_index = 0;
2595         if (!m->is_static())
2596           sig_bt[sig_index++] = T_OBJECT; // 'this'
2597         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2598           BasicType t = ss.type();
2599           sig_bt[sig_index++] = t;
2600           if (type2size[t] == 2) {
2601             sig_bt[sig_index++] = T_VOID;
2602           } else {
2603             assert(type2size[t] == 1, "size is 1 or 2");
2604           }
2605         }
2606         assert(sig_index == sizeargs, "");
2607       }
2608       const char* spname = "sp"; // make arch-specific?
2609       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2610       int stack_slot_offset = this->frame_size() * wordSize;
2611       int tab1 = 14, tab2 = 24;
2612       int sig_index = 0;
2613       int arg_index = (m->is_static() ? 0 : -1);
2614       bool did_old_sp = false;
2615       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2616         bool at_this = (arg_index == -1);
2617         bool at_old_sp = false;
2618         BasicType t = (at_this ? T_OBJECT : ss.type());
2619         assert(t == sig_bt[sig_index], "sigs in sync");
2620         if (at_this)
2621           stream->print("  # this: ");
2622         else
2623           stream->print("  # parm%d: ", arg_index);
2624         stream->move_to(tab1);
2625         VMReg fst = regs[sig_index].first();
2626         VMReg snd = regs[sig_index].second();
2627         if (fst->is_reg()) {
2628           stream->print("%s", fst->name());
2629           if (snd->is_valid())  {
2630             stream->print(":%s", snd->name());
2631           }
2632         } else if (fst->is_stack()) {
2633           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2634           if (offset == stack_slot_offset)  at_old_sp = true;
2635           stream->print("[%s+0x%x]", spname, offset);
2636         } else {
2637           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2638         }
2639         stream->print(" ");
2640         stream->move_to(tab2);
2641         stream->print("= ");
2642         if (at_this) {
2643           m->method_holder()->print_value_on(stream);
2644         } else {
2645           bool did_name = false;
2646           if (!at_this && ss.is_object()) {
2647             Symbol* name = ss.as_symbol_or_null();
2648             if (name != NULL) {
2649               name->print_value_on(stream);
2650               did_name = true;
2651             }
2652           }
2653           if (!did_name)
2654             stream->print("%s", type2name(t));
2655         }
2656         if (at_old_sp) {
2657           stream->print("  (%s of caller)", spname);
2658           did_old_sp = true;
2659         }
2660         stream->cr();
2661         sig_index += type2size[t];
2662         arg_index += 1;
2663         if (!at_this)  ss.next();
2664       }
2665       if (!did_old_sp) {
2666         stream->print("  # ");
2667         stream->move_to(tab1);
2668         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2669         stream->print("  (%s of caller)", spname);
2670         stream->cr();
2671       }
2672     }
2673   }
2674 }
2675 
2676 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2677   // First, find an oopmap in (begin, end].
2678   // We use the odd half-closed interval so that oop maps and scope descs
2679   // which are tied to the byte after a call are printed with the call itself.
2680   address base = code_begin();
2681   OopMapSet* oms = oop_maps();
2682   if (oms != NULL) {
2683     for (int i = 0, imax = oms->size(); i < imax; i++) {
2684       OopMap* om = oms->at(i);
2685       address pc = base + om->offset();
2686       if (pc > begin) {
2687         if (pc <= end) {
2688           st->move_to(column);
2689           st->print("; ");
2690           om->print_on(st);
2691         }
2692         break;
2693       }
2694     }
2695   }
2696 
2697   // Print any debug info present at this pc.
2698   ScopeDesc* sd  = scope_desc_in(begin, end);
2699   if (sd != NULL) {
2700     st->move_to(column);
2701     if (sd->bci() == SynchronizationEntryBCI) {
2702       st->print(";*synchronization entry");
2703     } else {
2704       if (sd->method().is_null()) {
2705         st->print("method is NULL");
2706       } else if (sd->method()->is_native()) {
2707         st->print("method is native");
2708       } else {
2709         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2710         st->print(";*%s", Bytecodes::name(bc));
2711         switch (bc) {
2712         case Bytecodes::_invokevirtual:
2713         case Bytecodes::_invokespecial:
2714         case Bytecodes::_invokestatic:
2715         case Bytecodes::_invokeinterface:
2716           {
2717             Bytecode_invoke invoke(sd->method(), sd->bci());
2718             st->print(" ");
2719             if (invoke.name() != NULL)
2720               invoke.name()->print_symbol_on(st);
2721             else
2722               st->print("<UNKNOWN>");
2723             break;
2724           }
2725         case Bytecodes::_getfield:
2726         case Bytecodes::_putfield:
2727         case Bytecodes::_getstatic:
2728         case Bytecodes::_putstatic:
2729           {
2730             Bytecode_field field(sd->method(), sd->bci());
2731             st->print(" ");
2732             if (field.name() != NULL)
2733               field.name()->print_symbol_on(st);
2734             else
2735               st->print("<UNKNOWN>");
2736           }
2737         }
2738       }
2739     }
2740 
2741     // Print all scopes
2742     for (;sd != NULL; sd = sd->sender()) {
2743       st->move_to(column);
2744       st->print("; -");
2745       if (sd->method().is_null()) {
2746         st->print("method is NULL");
2747       } else {
2748         sd->method()->print_short_name(st);
2749       }
2750       int lineno = sd->method()->line_number_from_bci(sd->bci());
2751       if (lineno != -1) {
2752         st->print("@%d (line %d)", sd->bci(), lineno);
2753       } else {
2754         st->print("@%d", sd->bci());
2755       }
2756       st->cr();
2757     }
2758   }
2759 
2760   // Print relocation information
2761   const char* str = reloc_string_for(begin, end);
2762   if (str != NULL) {
2763     if (sd != NULL) st->cr();
2764     st->move_to(column);
2765     st->print(";   {%s}", str);
2766   }
2767   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2768   if (cont_offset != 0) {
2769     st->move_to(column);
2770     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
2771   }
2772 
2773 }
2774 
2775 #ifndef PRODUCT
2776 
2777 void nmethod::print_value_on(outputStream* st) const {
2778   print_on(st, "nmethod");
2779 }
2780 
2781 void nmethod::print_calls(outputStream* st) {
2782   RelocIterator iter(this);
2783   while (iter.next()) {
2784     switch (iter.type()) {
2785     case relocInfo::virtual_call_type:
2786     case relocInfo::opt_virtual_call_type: {
2787       VerifyMutexLocker mc(CompiledIC_lock);
2788       CompiledIC_at(iter.reloc())->print();
2789       break;
2790     }
2791     case relocInfo::static_call_type:
2792       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
2793       compiledStaticCall_at(iter.reloc())->print();
2794       break;
2795     }
2796   }
2797 }
2798 
2799 void nmethod::print_handler_table() {
2800   ExceptionHandlerTable(this).print();
2801 }
2802 
2803 void nmethod::print_nul_chk_table() {
2804   ImplicitExceptionTable(this).print(code_begin());
2805 }
2806 
2807 void nmethod::print_statistics() {
2808   ttyLocker ttyl;
2809   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2810   nmethod_stats.print_native_nmethod_stats();
2811   nmethod_stats.print_nmethod_stats();
2812   DebugInformationRecorder::print_statistics();
2813   nmethod_stats.print_pc_stats();
2814   Dependencies::print_statistics();
2815   if (xtty != NULL)  xtty->tail("statistics");
2816 }
2817 
2818 #endif // PRODUCT