src/share/vm/code/nmethod.cpp

Mon, 10 Jun 2013 11:30:51 +0200

author
sla
date
Mon, 10 Jun 2013 11:30:51 +0200
changeset 5237
f2110083203d
parent 5222
28e5aed7f3a6
child 5259
ef57c43512d6
permissions
-rw-r--r--

8005849: JEP 167: Event-Based JVM Tracing
Reviewed-by: acorn, coleenp, sla
Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "code/codeCache.hpp"
    27 #include "code/compiledIC.hpp"
    28 #include "code/dependencies.hpp"
    29 #include "code/nmethod.hpp"
    30 #include "code/scopeDesc.hpp"
    31 #include "compiler/abstractCompiler.hpp"
    32 #include "compiler/compileBroker.hpp"
    33 #include "compiler/compileLog.hpp"
    34 #include "compiler/compilerOracle.hpp"
    35 #include "compiler/disassembler.hpp"
    36 #include "interpreter/bytecode.hpp"
    37 #include "oops/methodData.hpp"
    38 #include "prims/jvmtiRedefineClassesTrace.hpp"
    39 #include "prims/jvmtiImpl.hpp"
    40 #include "runtime/sharedRuntime.hpp"
    41 #include "runtime/sweeper.hpp"
    42 #include "utilities/dtrace.hpp"
    43 #include "utilities/events.hpp"
    44 #include "utilities/xmlstream.hpp"
    45 #ifdef SHARK
    46 #include "shark/sharkCompiler.hpp"
    47 #endif
    49 #ifdef DTRACE_ENABLED
    51 // Only bother with this argument setup if dtrace is available
    53 #ifndef USDT2
    54 HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
    55   const char*, int, const char*, int, const char*, int, void*, size_t);
    57 HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
    58   char*, int, char*, int, char*, int);
    60 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
    61   {                                                                       \
    62     Method* m = (method);                                                 \
    63     if (m != NULL) {                                                      \
    64       Symbol* klass_name = m->klass_name();                               \
    65       Symbol* name = m->name();                                           \
    66       Symbol* signature = m->signature();                                 \
    67       HS_DTRACE_PROBE6(hotspot, compiled__method__unload,                 \
    68         klass_name->bytes(), klass_name->utf8_length(),                   \
    69         name->bytes(), name->utf8_length(),                               \
    70         signature->bytes(), signature->utf8_length());                    \
    71     }                                                                     \
    72   }
    73 #else /* USDT2 */
    74 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
    75   {                                                                       \
    76     Method* m = (method);                                                 \
    77     if (m != NULL) {                                                      \
    78       Symbol* klass_name = m->klass_name();                               \
    79       Symbol* name = m->name();                                           \
    80       Symbol* signature = m->signature();                                 \
    81       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
    82         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
    83         (char *) name->bytes(), name->utf8_length(),                               \
    84         (char *) signature->bytes(), signature->utf8_length());                    \
    85     }                                                                     \
    86   }
    87 #endif /* USDT2 */
    89 #else //  ndef DTRACE_ENABLED
    91 #define DTRACE_METHOD_UNLOAD_PROBE(method)
    93 #endif
    95 bool nmethod::is_compiled_by_c1() const {
    96   if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
    97   if (is_native_method()) return false;
    98   return compiler()->is_c1();
    99 }
   100 bool nmethod::is_compiled_by_c2() const {
   101   if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
   102   if (is_native_method()) return false;
   103   return compiler()->is_c2();
   104 }
   105 bool nmethod::is_compiled_by_shark() const {
   106   if (is_native_method()) return false;
   107   assert(compiler() != NULL, "must be");
   108   return compiler()->is_shark();
   109 }
   113 //---------------------------------------------------------------------------------
   114 // NMethod statistics
   115 // They are printed under various flags, including:
   116 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
   117 // (In the latter two cases, they like other stats are printed to the log only.)
   119 #ifndef PRODUCT
   120 // These variables are put into one block to reduce relocations
   121 // and make it simpler to print from the debugger.
   122 static
   123 struct nmethod_stats_struct {
   124   int nmethod_count;
   125   int total_size;
   126   int relocation_size;
   127   int consts_size;
   128   int insts_size;
   129   int stub_size;
   130   int scopes_data_size;
   131   int scopes_pcs_size;
   132   int dependencies_size;
   133   int handler_table_size;
   134   int nul_chk_table_size;
   135   int oops_size;
   137   void note_nmethod(nmethod* nm) {
   138     nmethod_count += 1;
   139     total_size          += nm->size();
   140     relocation_size     += nm->relocation_size();
   141     consts_size         += nm->consts_size();
   142     insts_size          += nm->insts_size();
   143     stub_size           += nm->stub_size();
   144     oops_size           += nm->oops_size();
   145     scopes_data_size    += nm->scopes_data_size();
   146     scopes_pcs_size     += nm->scopes_pcs_size();
   147     dependencies_size   += nm->dependencies_size();
   148     handler_table_size  += nm->handler_table_size();
   149     nul_chk_table_size  += nm->nul_chk_table_size();
   150   }
   151   void print_nmethod_stats() {
   152     if (nmethod_count == 0)  return;
   153     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
   154     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
   155     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
   156     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
   157     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
   158     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
   159     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
   160     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
   161     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
   162     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
   163     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
   164     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
   165   }
   167   int native_nmethod_count;
   168   int native_total_size;
   169   int native_relocation_size;
   170   int native_insts_size;
   171   int native_oops_size;
   172   void note_native_nmethod(nmethod* nm) {
   173     native_nmethod_count += 1;
   174     native_total_size       += nm->size();
   175     native_relocation_size  += nm->relocation_size();
   176     native_insts_size       += nm->insts_size();
   177     native_oops_size        += nm->oops_size();
   178   }
   179   void print_native_nmethod_stats() {
   180     if (native_nmethod_count == 0)  return;
   181     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
   182     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
   183     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
   184     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
   185     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
   186   }
   188   int pc_desc_resets;   // number of resets (= number of caches)
   189   int pc_desc_queries;  // queries to nmethod::find_pc_desc
   190   int pc_desc_approx;   // number of those which have approximate true
   191   int pc_desc_repeats;  // number of _pc_descs[0] hits
   192   int pc_desc_hits;     // number of LRU cache hits
   193   int pc_desc_tests;    // total number of PcDesc examinations
   194   int pc_desc_searches; // total number of quasi-binary search steps
   195   int pc_desc_adds;     // number of LUR cache insertions
   197   void print_pc_stats() {
   198     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
   199                   pc_desc_queries,
   200                   (double)(pc_desc_tests + pc_desc_searches)
   201                   / pc_desc_queries);
   202     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
   203                   pc_desc_resets,
   204                   pc_desc_queries, pc_desc_approx,
   205                   pc_desc_repeats, pc_desc_hits,
   206                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
   207   }
   208 } nmethod_stats;
   209 #endif //PRODUCT
   212 //---------------------------------------------------------------------------------
   215 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
   216   assert(pc != NULL, "Must be non null");
   217   assert(exception.not_null(), "Must be non null");
   218   assert(handler != NULL, "Must be non null");
   220   _count = 0;
   221   _exception_type = exception->klass();
   222   _next = NULL;
   224   add_address_and_handler(pc,handler);
   225 }
   228 address ExceptionCache::match(Handle exception, address pc) {
   229   assert(pc != NULL,"Must be non null");
   230   assert(exception.not_null(),"Must be non null");
   231   if (exception->klass() == exception_type()) {
   232     return (test_address(pc));
   233   }
   235   return NULL;
   236 }
   239 bool ExceptionCache::match_exception_with_space(Handle exception) {
   240   assert(exception.not_null(),"Must be non null");
   241   if (exception->klass() == exception_type() && count() < cache_size) {
   242     return true;
   243   }
   244   return false;
   245 }
   248 address ExceptionCache::test_address(address addr) {
   249   for (int i=0; i<count(); i++) {
   250     if (pc_at(i) == addr) {
   251       return handler_at(i);
   252     }
   253   }
   254   return NULL;
   255 }
   258 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
   259   if (test_address(addr) == handler) return true;
   260   if (count() < cache_size) {
   261     set_pc_at(count(),addr);
   262     set_handler_at(count(), handler);
   263     increment_count();
   264     return true;
   265   }
   266   return false;
   267 }
   270 // private method for handling exception cache
   271 // These methods are private, and used to manipulate the exception cache
   272 // directly.
   273 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
   274   ExceptionCache* ec = exception_cache();
   275   while (ec != NULL) {
   276     if (ec->match_exception_with_space(exception)) {
   277       return ec;
   278     }
   279     ec = ec->next();
   280   }
   281   return NULL;
   282 }
   285 //-----------------------------------------------------------------------------
   288 // Helper used by both find_pc_desc methods.
   289 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
   290   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
   291   if (!approximate)
   292     return pc->pc_offset() == pc_offset;
   293   else
   294     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
   295 }
   297 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
   298   if (initial_pc_desc == NULL) {
   299     _pc_descs[0] = NULL; // native method; no PcDescs at all
   300     return;
   301   }
   302   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
   303   // reset the cache by filling it with benign (non-null) values
   304   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
   305   for (int i = 0; i < cache_size; i++)
   306     _pc_descs[i] = initial_pc_desc;
   307 }
   309 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
   310   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
   311   NOT_PRODUCT(if (approximate) ++nmethod_stats.pc_desc_approx);
   313   // Note: one might think that caching the most recently
   314   // read value separately would be a win, but one would be
   315   // wrong.  When many threads are updating it, the cache
   316   // line it's in would bounce between caches, negating
   317   // any benefit.
   319   // In order to prevent race conditions do not load cache elements
   320   // repeatedly, but use a local copy:
   321   PcDesc* res;
   323   // Step one:  Check the most recently added value.
   324   res = _pc_descs[0];
   325   if (res == NULL) return NULL;  // native method; no PcDescs at all
   326   if (match_desc(res, pc_offset, approximate)) {
   327     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
   328     return res;
   329   }
   331   // Step two:  Check the rest of the LRU cache.
   332   for (int i = 1; i < cache_size; ++i) {
   333     res = _pc_descs[i];
   334     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
   335     if (match_desc(res, pc_offset, approximate)) {
   336       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
   337       return res;
   338     }
   339   }
   341   // Report failure.
   342   return NULL;
   343 }
   345 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
   346   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
   347   // Update the LRU cache by shifting pc_desc forward.
   348   for (int i = 0; i < cache_size; i++)  {
   349     PcDesc* next = _pc_descs[i];
   350     _pc_descs[i] = pc_desc;
   351     pc_desc = next;
   352   }
   353 }
   355 // adjust pcs_size so that it is a multiple of both oopSize and
   356 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
   357 // of oopSize, then 2*sizeof(PcDesc) is)
   358 static int adjust_pcs_size(int pcs_size) {
   359   int nsize = round_to(pcs_size,   oopSize);
   360   if ((nsize % sizeof(PcDesc)) != 0) {
   361     nsize = pcs_size + sizeof(PcDesc);
   362   }
   363   assert((nsize % oopSize) == 0, "correct alignment");
   364   return nsize;
   365 }
   367 //-----------------------------------------------------------------------------
   370 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
   371   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
   372   assert(new_entry != NULL,"Must be non null");
   373   assert(new_entry->next() == NULL, "Must be null");
   375   if (exception_cache() != NULL) {
   376     new_entry->set_next(exception_cache());
   377   }
   378   set_exception_cache(new_entry);
   379 }
   381 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
   382   ExceptionCache* prev = NULL;
   383   ExceptionCache* curr = exception_cache();
   384   assert(curr != NULL, "nothing to remove");
   385   // find the previous and next entry of ec
   386   while (curr != ec) {
   387     prev = curr;
   388     curr = curr->next();
   389     assert(curr != NULL, "ExceptionCache not found");
   390   }
   391   // now: curr == ec
   392   ExceptionCache* next = curr->next();
   393   if (prev == NULL) {
   394     set_exception_cache(next);
   395   } else {
   396     prev->set_next(next);
   397   }
   398   delete curr;
   399 }
   402 // public method for accessing the exception cache
   403 // These are the public access methods.
   404 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
   405   // We never grab a lock to read the exception cache, so we may
   406   // have false negatives. This is okay, as it can only happen during
   407   // the first few exception lookups for a given nmethod.
   408   ExceptionCache* ec = exception_cache();
   409   while (ec != NULL) {
   410     address ret_val;
   411     if ((ret_val = ec->match(exception,pc)) != NULL) {
   412       return ret_val;
   413     }
   414     ec = ec->next();
   415   }
   416   return NULL;
   417 }
   420 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
   421   // There are potential race conditions during exception cache updates, so we
   422   // must own the ExceptionCache_lock before doing ANY modifications. Because
   423   // we don't lock during reads, it is possible to have several threads attempt
   424   // to update the cache with the same data. We need to check for already inserted
   425   // copies of the current data before adding it.
   427   MutexLocker ml(ExceptionCache_lock);
   428   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
   430   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
   431     target_entry = new ExceptionCache(exception,pc,handler);
   432     add_exception_cache_entry(target_entry);
   433   }
   434 }
   437 //-------------end of code for ExceptionCache--------------
   440 int nmethod::total_size() const {
   441   return
   442     consts_size()        +
   443     insts_size()         +
   444     stub_size()          +
   445     scopes_data_size()   +
   446     scopes_pcs_size()    +
   447     handler_table_size() +
   448     nul_chk_table_size();
   449 }
   451 const char* nmethod::compile_kind() const {
   452   if (is_osr_method())     return "osr";
   453   if (method() != NULL && is_native_method())  return "c2n";
   454   return NULL;
   455 }
   457 // Fill in default values for various flag fields
   458 void nmethod::init_defaults() {
   459   _state                      = alive;
   460   _marked_for_reclamation     = 0;
   461   _has_flushed_dependencies   = 0;
   462   _speculatively_disconnected = 0;
   463   _has_unsafe_access          = 0;
   464   _has_method_handle_invokes  = 0;
   465   _lazy_critical_native       = 0;
   466   _has_wide_vectors           = 0;
   467   _marked_for_deoptimization  = 0;
   468   _lock_count                 = 0;
   469   _stack_traversal_mark       = 0;
   470   _unload_reported            = false;           // jvmti state
   472 #ifdef ASSERT
   473   _oops_are_stale             = false;
   474 #endif
   476   _oops_do_mark_link       = NULL;
   477   _jmethod_id              = NULL;
   478   _osr_link                = NULL;
   479   _scavenge_root_link      = NULL;
   480   _scavenge_root_state     = 0;
   481   _saved_nmethod_link      = NULL;
   482   _compiler                = NULL;
   484 #ifdef HAVE_DTRACE_H
   485   _trap_offset             = 0;
   486 #endif // def HAVE_DTRACE_H
   487 }
   489 nmethod* nmethod::new_native_nmethod(methodHandle method,
   490   int compile_id,
   491   CodeBuffer *code_buffer,
   492   int vep_offset,
   493   int frame_complete,
   494   int frame_size,
   495   ByteSize basic_lock_owner_sp_offset,
   496   ByteSize basic_lock_sp_offset,
   497   OopMapSet* oop_maps) {
   498   code_buffer->finalize_oop_references(method);
   499   // create nmethod
   500   nmethod* nm = NULL;
   501   {
   502     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   503     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   504     CodeOffsets offsets;
   505     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   506     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   507     nm = new (native_nmethod_size) nmethod(method(), native_nmethod_size,
   508                                             compile_id, &offsets,
   509                                             code_buffer, frame_size,
   510                                             basic_lock_owner_sp_offset,
   511                                             basic_lock_sp_offset, oop_maps);
   512     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
   513     if (PrintAssembly && nm != NULL) {
   514       Disassembler::decode(nm);
   515     }
   516   }
   517   // verify nmethod
   518   debug_only(if (nm) nm->verify();) // might block
   520   if (nm != NULL) {
   521     nm->log_new_nmethod();
   522   }
   524   return nm;
   525 }
   527 #ifdef HAVE_DTRACE_H
   528 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
   529                                      CodeBuffer *code_buffer,
   530                                      int vep_offset,
   531                                      int trap_offset,
   532                                      int frame_complete,
   533                                      int frame_size) {
   534   code_buffer->finalize_oop_references(method);
   535   // create nmethod
   536   nmethod* nm = NULL;
   537   {
   538     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   539     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   540     CodeOffsets offsets;
   541     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   542     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
   543     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   545     nm = new (nmethod_size) nmethod(method(), nmethod_size,
   546                                     &offsets, code_buffer, frame_size);
   548     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
   549     if (PrintAssembly && nm != NULL) {
   550       Disassembler::decode(nm);
   551     }
   552   }
   553   // verify nmethod
   554   debug_only(if (nm) nm->verify();) // might block
   556   if (nm != NULL) {
   557     nm->log_new_nmethod();
   558   }
   560   return nm;
   561 }
   563 #endif // def HAVE_DTRACE_H
   565 nmethod* nmethod::new_nmethod(methodHandle method,
   566   int compile_id,
   567   int entry_bci,
   568   CodeOffsets* offsets,
   569   int orig_pc_offset,
   570   DebugInformationRecorder* debug_info,
   571   Dependencies* dependencies,
   572   CodeBuffer* code_buffer, int frame_size,
   573   OopMapSet* oop_maps,
   574   ExceptionHandlerTable* handler_table,
   575   ImplicitExceptionTable* nul_chk_table,
   576   AbstractCompiler* compiler,
   577   int comp_level
   578 )
   579 {
   580   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   581   code_buffer->finalize_oop_references(method);
   582   // create nmethod
   583   nmethod* nm = NULL;
   584   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   585     int nmethod_size =
   586       allocation_size(code_buffer, sizeof(nmethod))
   587       + adjust_pcs_size(debug_info->pcs_size())
   588       + round_to(dependencies->size_in_bytes() , oopSize)
   589       + round_to(handler_table->size_in_bytes(), oopSize)
   590       + round_to(nul_chk_table->size_in_bytes(), oopSize)
   591       + round_to(debug_info->data_size()       , oopSize);
   593     nm = new (nmethod_size)
   594     nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
   595             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
   596             oop_maps,
   597             handler_table,
   598             nul_chk_table,
   599             compiler,
   600             comp_level);
   602     if (nm != NULL) {
   603       // To make dependency checking during class loading fast, record
   604       // the nmethod dependencies in the classes it is dependent on.
   605       // This allows the dependency checking code to simply walk the
   606       // class hierarchy above the loaded class, checking only nmethods
   607       // which are dependent on those classes.  The slow way is to
   608       // check every nmethod for dependencies which makes it linear in
   609       // the number of methods compiled.  For applications with a lot
   610       // classes the slow way is too slow.
   611       for (Dependencies::DepStream deps(nm); deps.next(); ) {
   612         Klass* klass = deps.context_type();
   613         if (klass == NULL) {
   614           continue;  // ignore things like evol_method
   615         }
   617         // record this nmethod as dependent on this klass
   618         InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
   619       }
   620     }
   621     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
   622     if (PrintAssembly && nm != NULL) {
   623       Disassembler::decode(nm);
   624     }
   625   }
   627   // verify nmethod
   628   debug_only(if (nm) nm->verify();) // might block
   630   if (nm != NULL) {
   631     nm->log_new_nmethod();
   632   }
   634   // done
   635   return nm;
   636 }
   639 // For native wrappers
   640 nmethod::nmethod(
   641   Method* method,
   642   int nmethod_size,
   643   int compile_id,
   644   CodeOffsets* offsets,
   645   CodeBuffer* code_buffer,
   646   int frame_size,
   647   ByteSize basic_lock_owner_sp_offset,
   648   ByteSize basic_lock_sp_offset,
   649   OopMapSet* oop_maps )
   650   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
   651              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   652   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
   653   _native_basic_lock_sp_offset(basic_lock_sp_offset)
   654 {
   655   {
   656     debug_only(No_Safepoint_Verifier nsv;)
   657     assert_locked_or_safepoint(CodeCache_lock);
   659     init_defaults();
   660     _method                  = method;
   661     _entry_bci               = InvocationEntryBci;
   662     // We have no exception handler or deopt handler make the
   663     // values something that will never match a pc like the nmethod vtable entry
   664     _exception_offset        = 0;
   665     _deoptimize_offset       = 0;
   666     _deoptimize_mh_offset    = 0;
   667     _orig_pc_offset          = 0;
   669     _consts_offset           = data_offset();
   670     _stub_offset             = data_offset();
   671     _oops_offset             = data_offset();
   672     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
   673     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
   674     _scopes_pcs_offset       = _scopes_data_offset;
   675     _dependencies_offset     = _scopes_pcs_offset;
   676     _handler_table_offset    = _dependencies_offset;
   677     _nul_chk_table_offset    = _handler_table_offset;
   678     _nmethod_end_offset      = _nul_chk_table_offset;
   679     _compile_id              = compile_id;
   680     _comp_level              = CompLevel_none;
   681     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
   682     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
   683     _osr_entry_point         = NULL;
   684     _exception_cache         = NULL;
   685     _pc_desc_cache.reset_to(NULL);
   687     code_buffer->copy_values_to(this);
   688     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
   689       CodeCache::add_scavenge_root_nmethod(this);
   690     }
   691     debug_only(verify_scavenge_root_oops());
   692     CodeCache::commit(this);
   693   }
   695   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
   696     ttyLocker ttyl;  // keep the following output all in one block
   697     // This output goes directly to the tty, not the compiler log.
   698     // To enable tools to match it up with the compilation activity,
   699     // be sure to tag this tty output with the compile ID.
   700     if (xtty != NULL) {
   701       xtty->begin_head("print_native_nmethod");
   702       xtty->method(_method);
   703       xtty->stamp();
   704       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   705     }
   706     // print the header part first
   707     print();
   708     // then print the requested information
   709     if (PrintNativeNMethods) {
   710       print_code();
   711       if (oop_maps != NULL) {
   712         oop_maps->print();
   713       }
   714     }
   715     if (PrintRelocations) {
   716       print_relocations();
   717     }
   718     if (xtty != NULL) {
   719       xtty->tail("print_native_nmethod");
   720     }
   721   }
   722 }
   724 // For dtrace wrappers
   725 #ifdef HAVE_DTRACE_H
   726 nmethod::nmethod(
   727   Method* method,
   728   int nmethod_size,
   729   CodeOffsets* offsets,
   730   CodeBuffer* code_buffer,
   731   int frame_size)
   732   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
   733              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
   734   _native_receiver_sp_offset(in_ByteSize(-1)),
   735   _native_basic_lock_sp_offset(in_ByteSize(-1))
   736 {
   737   {
   738     debug_only(No_Safepoint_Verifier nsv;)
   739     assert_locked_or_safepoint(CodeCache_lock);
   741     init_defaults();
   742     _method                  = method;
   743     _entry_bci               = InvocationEntryBci;
   744     // We have no exception handler or deopt handler make the
   745     // values something that will never match a pc like the nmethod vtable entry
   746     _exception_offset        = 0;
   747     _deoptimize_offset       = 0;
   748     _deoptimize_mh_offset    = 0;
   749     _unwind_handler_offset   = -1;
   750     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
   751     _orig_pc_offset          = 0;
   752     _consts_offset           = data_offset();
   753     _stub_offset             = data_offset();
   754     _oops_offset             = data_offset();
   755     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
   756     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
   757     _scopes_pcs_offset       = _scopes_data_offset;
   758     _dependencies_offset     = _scopes_pcs_offset;
   759     _handler_table_offset    = _dependencies_offset;
   760     _nul_chk_table_offset    = _handler_table_offset;
   761     _nmethod_end_offset      = _nul_chk_table_offset;
   762     _compile_id              = 0;  // default
   763     _comp_level              = CompLevel_none;
   764     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
   765     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
   766     _osr_entry_point         = NULL;
   767     _exception_cache         = NULL;
   768     _pc_desc_cache.reset_to(NULL);
   770     code_buffer->copy_values_to(this);
   771     debug_only(verify_scavenge_root_oops());
   772     CodeCache::commit(this);
   773   }
   775   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
   776     ttyLocker ttyl;  // keep the following output all in one block
   777     // This output goes directly to the tty, not the compiler log.
   778     // To enable tools to match it up with the compilation activity,
   779     // be sure to tag this tty output with the compile ID.
   780     if (xtty != NULL) {
   781       xtty->begin_head("print_dtrace_nmethod");
   782       xtty->method(_method);
   783       xtty->stamp();
   784       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   785     }
   786     // print the header part first
   787     print();
   788     // then print the requested information
   789     if (PrintNMethods) {
   790       print_code();
   791     }
   792     if (PrintRelocations) {
   793       print_relocations();
   794     }
   795     if (xtty != NULL) {
   796       xtty->tail("print_dtrace_nmethod");
   797     }
   798   }
   799 }
   800 #endif // def HAVE_DTRACE_H
   802 void* nmethod::operator new(size_t size, int nmethod_size) throw () {
   803   // Not critical, may return null if there is too little continuous memory
   804   return CodeCache::allocate(nmethod_size);
   805 }
   807 nmethod::nmethod(
   808   Method* method,
   809   int nmethod_size,
   810   int compile_id,
   811   int entry_bci,
   812   CodeOffsets* offsets,
   813   int orig_pc_offset,
   814   DebugInformationRecorder* debug_info,
   815   Dependencies* dependencies,
   816   CodeBuffer *code_buffer,
   817   int frame_size,
   818   OopMapSet* oop_maps,
   819   ExceptionHandlerTable* handler_table,
   820   ImplicitExceptionTable* nul_chk_table,
   821   AbstractCompiler* compiler,
   822   int comp_level
   823   )
   824   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
   825              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   826   _native_receiver_sp_offset(in_ByteSize(-1)),
   827   _native_basic_lock_sp_offset(in_ByteSize(-1))
   828 {
   829   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   830   {
   831     debug_only(No_Safepoint_Verifier nsv;)
   832     assert_locked_or_safepoint(CodeCache_lock);
   834     init_defaults();
   835     _method                  = method;
   836     _entry_bci               = entry_bci;
   837     _compile_id              = compile_id;
   838     _comp_level              = comp_level;
   839     _compiler                = compiler;
   840     _orig_pc_offset          = orig_pc_offset;
   842     // Section offsets
   843     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
   844     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
   846     // Exception handler and deopt handler are in the stub section
   847     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
   848     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
   849     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
   850     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
   851     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
   852       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
   853     } else {
   854       _deoptimize_mh_offset  = -1;
   855     }
   856     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
   857       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
   858     } else {
   859       _unwind_handler_offset = -1;
   860     }
   862     _oops_offset             = data_offset();
   863     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
   864     _scopes_data_offset      = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
   866     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
   867     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
   868     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
   869     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
   870     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
   872     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
   873     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
   874     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
   875     _exception_cache         = NULL;
   876     _pc_desc_cache.reset_to(scopes_pcs_begin());
   878     // Copy contents of ScopeDescRecorder to nmethod
   879     code_buffer->copy_values_to(this);
   880     debug_info->copy_to(this);
   881     dependencies->copy_to(this);
   882     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
   883       CodeCache::add_scavenge_root_nmethod(this);
   884     }
   885     debug_only(verify_scavenge_root_oops());
   887     CodeCache::commit(this);
   889     // Copy contents of ExceptionHandlerTable to nmethod
   890     handler_table->copy_to(this);
   891     nul_chk_table->copy_to(this);
   893     // we use the information of entry points to find out if a method is
   894     // static or non static
   895     assert(compiler->is_c2() ||
   896            _method->is_static() == (entry_point() == _verified_entry_point),
   897            " entry points must be same for static methods and vice versa");
   898   }
   900   bool printnmethods = PrintNMethods
   901     || CompilerOracle::should_print(_method)
   902     || CompilerOracle::has_option_string(_method, "PrintNMethods");
   903   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
   904     print_nmethod(printnmethods);
   905   }
   906 }
   909 // Print a short set of xml attributes to identify this nmethod.  The
   910 // output should be embedded in some other element.
   911 void nmethod::log_identity(xmlStream* log) const {
   912   log->print(" compile_id='%d'", compile_id());
   913   const char* nm_kind = compile_kind();
   914   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
   915   if (compiler() != NULL) {
   916     log->print(" compiler='%s'", compiler()->name());
   917   }
   918   if (TieredCompilation) {
   919     log->print(" level='%d'", comp_level());
   920   }
   921 }
   924 #define LOG_OFFSET(log, name)                    \
   925   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
   926     log->print(" " XSTR(name) "_offset='%d'"    , \
   927                (intptr_t)name##_begin() - (intptr_t)this)
   930 void nmethod::log_new_nmethod() const {
   931   if (LogCompilation && xtty != NULL) {
   932     ttyLocker ttyl;
   933     HandleMark hm;
   934     xtty->begin_elem("nmethod");
   935     log_identity(xtty);
   936     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
   937     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   939     LOG_OFFSET(xtty, relocation);
   940     LOG_OFFSET(xtty, consts);
   941     LOG_OFFSET(xtty, insts);
   942     LOG_OFFSET(xtty, stub);
   943     LOG_OFFSET(xtty, scopes_data);
   944     LOG_OFFSET(xtty, scopes_pcs);
   945     LOG_OFFSET(xtty, dependencies);
   946     LOG_OFFSET(xtty, handler_table);
   947     LOG_OFFSET(xtty, nul_chk_table);
   948     LOG_OFFSET(xtty, oops);
   950     xtty->method(method());
   951     xtty->stamp();
   952     xtty->end_elem();
   953   }
   954 }
   956 #undef LOG_OFFSET
   959 // Print out more verbose output usually for a newly created nmethod.
   960 void nmethod::print_on(outputStream* st, const char* msg) const {
   961   if (st != NULL) {
   962     ttyLocker ttyl;
   963     if (WizardMode) {
   964       CompileTask::print_compilation(st, this, msg, /*short_form:*/ true);
   965       st->print_cr(" (" INTPTR_FORMAT ")", this);
   966     } else {
   967       CompileTask::print_compilation(st, this, msg, /*short_form:*/ false);
   968     }
   969   }
   970 }
   973 void nmethod::print_nmethod(bool printmethod) {
   974   ttyLocker ttyl;  // keep the following output all in one block
   975   if (xtty != NULL) {
   976     xtty->begin_head("print_nmethod");
   977     xtty->stamp();
   978     xtty->end_head();
   979   }
   980   // print the header part first
   981   print();
   982   // then print the requested information
   983   if (printmethod) {
   984     print_code();
   985     print_pcs();
   986     if (oop_maps()) {
   987       oop_maps()->print();
   988     }
   989   }
   990   if (PrintDebugInfo) {
   991     print_scopes();
   992   }
   993   if (PrintRelocations) {
   994     print_relocations();
   995   }
   996   if (PrintDependencies) {
   997     print_dependencies();
   998   }
   999   if (PrintExceptionHandlers) {
  1000     print_handler_table();
  1001     print_nul_chk_table();
  1003   if (xtty != NULL) {
  1004     xtty->tail("print_nmethod");
  1009 // Promote one word from an assembly-time handle to a live embedded oop.
  1010 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
  1011   if (handle == NULL ||
  1012       // As a special case, IC oops are initialized to 1 or -1.
  1013       handle == (jobject) Universe::non_oop_word()) {
  1014     (*dest) = (oop) handle;
  1015   } else {
  1016     (*dest) = JNIHandles::resolve_non_null(handle);
  1021 // Have to have the same name because it's called by a template
  1022 void nmethod::copy_values(GrowableArray<jobject>* array) {
  1023   int length = array->length();
  1024   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
  1025   oop* dest = oops_begin();
  1026   for (int index = 0 ; index < length; index++) {
  1027     initialize_immediate_oop(&dest[index], array->at(index));
  1030   // Now we can fix up all the oops in the code.  We need to do this
  1031   // in the code because the assembler uses jobjects as placeholders.
  1032   // The code and relocations have already been initialized by the
  1033   // CodeBlob constructor, so it is valid even at this early point to
  1034   // iterate over relocations and patch the code.
  1035   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
  1038 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
  1039   int length = array->length();
  1040   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
  1041   Metadata** dest = metadata_begin();
  1042   for (int index = 0 ; index < length; index++) {
  1043     dest[index] = array->at(index);
  1047 bool nmethod::is_at_poll_return(address pc) {
  1048   RelocIterator iter(this, pc, pc+1);
  1049   while (iter.next()) {
  1050     if (iter.type() == relocInfo::poll_return_type)
  1051       return true;
  1053   return false;
  1057 bool nmethod::is_at_poll_or_poll_return(address pc) {
  1058   RelocIterator iter(this, pc, pc+1);
  1059   while (iter.next()) {
  1060     relocInfo::relocType t = iter.type();
  1061     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
  1062       return true;
  1064   return false;
  1068 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
  1069   // re-patch all oop-bearing instructions, just in case some oops moved
  1070   RelocIterator iter(this, begin, end);
  1071   while (iter.next()) {
  1072     if (iter.type() == relocInfo::oop_type) {
  1073       oop_Relocation* reloc = iter.oop_reloc();
  1074       if (initialize_immediates && reloc->oop_is_immediate()) {
  1075         oop* dest = reloc->oop_addr();
  1076         initialize_immediate_oop(dest, (jobject) *dest);
  1078       // Refresh the oop-related bits of this instruction.
  1079       reloc->fix_oop_relocation();
  1080     } else if (iter.type() == relocInfo::metadata_type) {
  1081       metadata_Relocation* reloc = iter.metadata_reloc();
  1082       reloc->fix_metadata_relocation();
  1085     // There must not be any interfering patches or breakpoints.
  1086     assert(!(iter.type() == relocInfo::breakpoint_type
  1087              && iter.breakpoint_reloc()->active()),
  1088            "no active breakpoint");
  1093 void nmethod::verify_oop_relocations() {
  1094   // Ensure sure that the code matches the current oop values
  1095   RelocIterator iter(this, NULL, NULL);
  1096   while (iter.next()) {
  1097     if (iter.type() == relocInfo::oop_type) {
  1098       oop_Relocation* reloc = iter.oop_reloc();
  1099       if (!reloc->oop_is_immediate()) {
  1100         reloc->verify_oop_relocation();
  1107 ScopeDesc* nmethod::scope_desc_at(address pc) {
  1108   PcDesc* pd = pc_desc_at(pc);
  1109   guarantee(pd != NULL, "scope must be present");
  1110   return new ScopeDesc(this, pd->scope_decode_offset(),
  1111                        pd->obj_decode_offset(), pd->should_reexecute(),
  1112                        pd->return_oop());
  1116 void nmethod::clear_inline_caches() {
  1117   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
  1118   if (is_zombie()) {
  1119     return;
  1122   RelocIterator iter(this);
  1123   while (iter.next()) {
  1124     iter.reloc()->clear_inline_cache();
  1129 void nmethod::cleanup_inline_caches() {
  1131   assert_locked_or_safepoint(CompiledIC_lock);
  1133   // If the method is not entrant or zombie then a JMP is plastered over the
  1134   // first few bytes.  If an oop in the old code was there, that oop
  1135   // should not get GC'd.  Skip the first few bytes of oops on
  1136   // not-entrant methods.
  1137   address low_boundary = verified_entry_point();
  1138   if (!is_in_use()) {
  1139     low_boundary += NativeJump::instruction_size;
  1140     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1141     // This means that the low_boundary is going to be a little too high.
  1142     // This shouldn't matter, since oops of non-entrant methods are never used.
  1143     // In fact, why are we bothering to look at oops in a non-entrant method??
  1146   // Find all calls in an nmethod, and clear the ones that points to zombie methods
  1147   ResourceMark rm;
  1148   RelocIterator iter(this, low_boundary);
  1149   while(iter.next()) {
  1150     switch(iter.type()) {
  1151       case relocInfo::virtual_call_type:
  1152       case relocInfo::opt_virtual_call_type: {
  1153         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1154         // Ok, to lookup references to zombies here
  1155         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
  1156         if( cb != NULL && cb->is_nmethod() ) {
  1157           nmethod* nm = (nmethod*)cb;
  1158           // Clean inline caches pointing to both zombie and not_entrant methods
  1159           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
  1161         break;
  1163       case relocInfo::static_call_type: {
  1164         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
  1165         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
  1166         if( cb != NULL && cb->is_nmethod() ) {
  1167           nmethod* nm = (nmethod*)cb;
  1168           // Clean inline caches pointing to both zombie and not_entrant methods
  1169           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
  1171         break;
  1177 // This is a private interface with the sweeper.
  1178 void nmethod::mark_as_seen_on_stack() {
  1179   assert(is_not_entrant(), "must be a non-entrant method");
  1180   // Set the traversal mark to ensure that the sweeper does 2
  1181   // cleaning passes before moving to zombie.
  1182   set_stack_traversal_mark(NMethodSweeper::traversal_count());
  1185 // Tell if a non-entrant method can be converted to a zombie (i.e.,
  1186 // there are no activations on the stack, not in use by the VM,
  1187 // and not in use by the ServiceThread)
  1188 bool nmethod::can_not_entrant_be_converted() {
  1189   assert(is_not_entrant(), "must be a non-entrant method");
  1191   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
  1192   // count can be greater than the stack traversal count before it hits the
  1193   // nmethod for the second time.
  1194   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
  1195          !is_locked_by_vm();
  1198 void nmethod::inc_decompile_count() {
  1199   if (!is_compiled_by_c2()) return;
  1200   // Could be gated by ProfileTraps, but do not bother...
  1201   Method* m = method();
  1202   if (m == NULL)  return;
  1203   MethodData* mdo = m->method_data();
  1204   if (mdo == NULL)  return;
  1205   // There is a benign race here.  See comments in methodData.hpp.
  1206   mdo->inc_decompile_count();
  1209 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
  1211   post_compiled_method_unload();
  1213   // Since this nmethod is being unloaded, make sure that dependencies
  1214   // recorded in instanceKlasses get flushed and pass non-NULL closure to
  1215   // indicate that this work is being done during a GC.
  1216   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
  1217   assert(is_alive != NULL, "Should be non-NULL");
  1218   // A non-NULL is_alive closure indicates that this is being called during GC.
  1219   flush_dependencies(is_alive);
  1221   // Break cycle between nmethod & method
  1222   if (TraceClassUnloading && WizardMode) {
  1223     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
  1224                   " unloadable], Method*(" INTPTR_FORMAT
  1225                   "), cause(" INTPTR_FORMAT ")",
  1226                   this, (address)_method, (address)cause);
  1227     if (!Universe::heap()->is_gc_active())
  1228       cause->klass()->print();
  1230   // Unlink the osr method, so we do not look this up again
  1231   if (is_osr_method()) {
  1232     invalidate_osr_method();
  1234   // If _method is already NULL the Method* is about to be unloaded,
  1235   // so we don't have to break the cycle. Note that it is possible to
  1236   // have the Method* live here, in case we unload the nmethod because
  1237   // it is pointing to some oop (other than the Method*) being unloaded.
  1238   if (_method != NULL) {
  1239     // OSR methods point to the Method*, but the Method* does not
  1240     // point back!
  1241     if (_method->code() == this) {
  1242       _method->clear_code(); // Break a cycle
  1244     _method = NULL;            // Clear the method of this dead nmethod
  1246   // Make the class unloaded - i.e., change state and notify sweeper
  1247   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1248   if (is_in_use()) {
  1249     // Transitioning directly from live to unloaded -- so
  1250     // we need to force a cache clean-up; remember this
  1251     // for later on.
  1252     CodeCache::set_needs_cache_clean(true);
  1254   _state = unloaded;
  1256   // Log the unloading.
  1257   log_state_change();
  1259   // The Method* is gone at this point
  1260   assert(_method == NULL, "Tautology");
  1262   set_osr_link(NULL);
  1263   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
  1264   NMethodSweeper::notify(this);
  1267 void nmethod::invalidate_osr_method() {
  1268   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
  1269   // Remove from list of active nmethods
  1270   if (method() != NULL)
  1271     method()->method_holder()->remove_osr_nmethod(this);
  1272   // Set entry as invalid
  1273   _entry_bci = InvalidOSREntryBci;
  1276 void nmethod::log_state_change() const {
  1277   if (LogCompilation) {
  1278     if (xtty != NULL) {
  1279       ttyLocker ttyl;  // keep the following output all in one block
  1280       if (_state == unloaded) {
  1281         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
  1282                          os::current_thread_id());
  1283       } else {
  1284         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
  1285                          os::current_thread_id(),
  1286                          (_state == zombie ? " zombie='1'" : ""));
  1288       log_identity(xtty);
  1289       xtty->stamp();
  1290       xtty->end_elem();
  1293   if (PrintCompilation && _state != unloaded) {
  1294     print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
  1298 // Common functionality for both make_not_entrant and make_zombie
  1299 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
  1300   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
  1301   assert(!is_zombie(), "should not already be a zombie");
  1303   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
  1304   nmethodLocker nml(this);
  1305   methodHandle the_method(method());
  1306   No_Safepoint_Verifier nsv;
  1309     // invalidate osr nmethod before acquiring the patching lock since
  1310     // they both acquire leaf locks and we don't want a deadlock.
  1311     // This logic is equivalent to the logic below for patching the
  1312     // verified entry point of regular methods.
  1313     if (is_osr_method()) {
  1314       // this effectively makes the osr nmethod not entrant
  1315       invalidate_osr_method();
  1318     // Enter critical section.  Does not block for safepoint.
  1319     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
  1321     if (_state == state) {
  1322       // another thread already performed this transition so nothing
  1323       // to do, but return false to indicate this.
  1324       return false;
  1327     // The caller can be calling the method statically or through an inline
  1328     // cache call.
  1329     if (!is_osr_method() && !is_not_entrant()) {
  1330       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
  1331                   SharedRuntime::get_handle_wrong_method_stub());
  1334     if (is_in_use()) {
  1335       // It's a true state change, so mark the method as decompiled.
  1336       // Do it only for transition from alive.
  1337       inc_decompile_count();
  1340     // Change state
  1341     _state = state;
  1343     // Log the transition once
  1344     log_state_change();
  1346     // Remove nmethod from method.
  1347     // We need to check if both the _code and _from_compiled_code_entry_point
  1348     // refer to this nmethod because there is a race in setting these two fields
  1349     // in Method* as seen in bugid 4947125.
  1350     // If the vep() points to the zombie nmethod, the memory for the nmethod
  1351     // could be flushed and the compiler and vtable stubs could still call
  1352     // through it.
  1353     if (method() != NULL && (method()->code() == this ||
  1354                              method()->from_compiled_entry() == verified_entry_point())) {
  1355       HandleMark hm;
  1356       method()->clear_code();
  1359     if (state == not_entrant) {
  1360       mark_as_seen_on_stack();
  1363   } // leave critical region under Patching_lock
  1365   // When the nmethod becomes zombie it is no longer alive so the
  1366   // dependencies must be flushed.  nmethods in the not_entrant
  1367   // state will be flushed later when the transition to zombie
  1368   // happens or they get unloaded.
  1369   if (state == zombie) {
  1371       // Flushing dependecies must be done before any possible
  1372       // safepoint can sneak in, otherwise the oops used by the
  1373       // dependency logic could have become stale.
  1374       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
  1375       flush_dependencies(NULL);
  1378     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
  1379     // event and it hasn't already been reported for this nmethod then
  1380     // report it now. The event may have been reported earilier if the GC
  1381     // marked it for unloading). JvmtiDeferredEventQueue support means
  1382     // we no longer go to a safepoint here.
  1383     post_compiled_method_unload();
  1385 #ifdef ASSERT
  1386     // It's no longer safe to access the oops section since zombie
  1387     // nmethods aren't scanned for GC.
  1388     _oops_are_stale = true;
  1389 #endif
  1390   } else {
  1391     assert(state == not_entrant, "other cases may need to be handled differently");
  1394   if (TraceCreateZombies) {
  1395     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
  1398   // Make sweeper aware that there is a zombie method that needs to be removed
  1399   NMethodSweeper::notify(this);
  1401   return true;
  1404 void nmethod::flush() {
  1405   // Note that there are no valid oops in the nmethod anymore.
  1406   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
  1407   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
  1409   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
  1410   assert_locked_or_safepoint(CodeCache_lock);
  1412   // completely deallocate this method
  1413   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, this);
  1414   if (PrintMethodFlushing) {
  1415     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
  1416         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
  1419   // We need to deallocate any ExceptionCache data.
  1420   // Note that we do not need to grab the nmethod lock for this, it
  1421   // better be thread safe if we're disposing of it!
  1422   ExceptionCache* ec = exception_cache();
  1423   set_exception_cache(NULL);
  1424   while(ec != NULL) {
  1425     ExceptionCache* next = ec->next();
  1426     delete ec;
  1427     ec = next;
  1430   if (on_scavenge_root_list()) {
  1431     CodeCache::drop_scavenge_root_nmethod(this);
  1434   if (is_speculatively_disconnected()) {
  1435     CodeCache::remove_saved_code(this);
  1438 #ifdef SHARK
  1439   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
  1440 #endif // SHARK
  1442   ((CodeBlob*)(this))->flush();
  1444   CodeCache::free(this);
  1448 //
  1449 // Notify all classes this nmethod is dependent on that it is no
  1450 // longer dependent. This should only be called in two situations.
  1451 // First, when a nmethod transitions to a zombie all dependents need
  1452 // to be clear.  Since zombification happens at a safepoint there's no
  1453 // synchronization issues.  The second place is a little more tricky.
  1454 // During phase 1 of mark sweep class unloading may happen and as a
  1455 // result some nmethods may get unloaded.  In this case the flushing
  1456 // of dependencies must happen during phase 1 since after GC any
  1457 // dependencies in the unloaded nmethod won't be updated, so
  1458 // traversing the dependency information in unsafe.  In that case this
  1459 // function is called with a non-NULL argument and this function only
  1460 // notifies instanceKlasses that are reachable
  1462 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
  1463   assert_locked_or_safepoint(CodeCache_lock);
  1464   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
  1465   "is_alive is non-NULL if and only if we are called during GC");
  1466   if (!has_flushed_dependencies()) {
  1467     set_has_flushed_dependencies();
  1468     for (Dependencies::DepStream deps(this); deps.next(); ) {
  1469       Klass* klass = deps.context_type();
  1470       if (klass == NULL)  continue;  // ignore things like evol_method
  1472       // During GC the is_alive closure is non-NULL, and is used to
  1473       // determine liveness of dependees that need to be updated.
  1474       if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
  1475         InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
  1482 // If this oop is not live, the nmethod can be unloaded.
  1483 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
  1484   assert(root != NULL, "just checking");
  1485   oop obj = *root;
  1486   if (obj == NULL || is_alive->do_object_b(obj)) {
  1487       return false;
  1490   // If ScavengeRootsInCode is true, an nmethod might be unloaded
  1491   // simply because one of its constant oops has gone dead.
  1492   // No actual classes need to be unloaded in order for this to occur.
  1493   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
  1494   make_unloaded(is_alive, obj);
  1495   return true;
  1498 // ------------------------------------------------------------------
  1499 // post_compiled_method_load_event
  1500 // new method for install_code() path
  1501 // Transfer information from compilation to jvmti
  1502 void nmethod::post_compiled_method_load_event() {
  1504   Method* moop = method();
  1505 #ifndef USDT2
  1506   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
  1507       moop->klass_name()->bytes(),
  1508       moop->klass_name()->utf8_length(),
  1509       moop->name()->bytes(),
  1510       moop->name()->utf8_length(),
  1511       moop->signature()->bytes(),
  1512       moop->signature()->utf8_length(),
  1513       insts_begin(), insts_size());
  1514 #else /* USDT2 */
  1515   HOTSPOT_COMPILED_METHOD_LOAD(
  1516       (char *) moop->klass_name()->bytes(),
  1517       moop->klass_name()->utf8_length(),
  1518       (char *) moop->name()->bytes(),
  1519       moop->name()->utf8_length(),
  1520       (char *) moop->signature()->bytes(),
  1521       moop->signature()->utf8_length(),
  1522       insts_begin(), insts_size());
  1523 #endif /* USDT2 */
  1525   if (JvmtiExport::should_post_compiled_method_load() ||
  1526       JvmtiExport::should_post_compiled_method_unload()) {
  1527     get_and_cache_jmethod_id();
  1530   if (JvmtiExport::should_post_compiled_method_load()) {
  1531     // Let the Service thread (which is a real Java thread) post the event
  1532     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  1533     JvmtiDeferredEventQueue::enqueue(
  1534       JvmtiDeferredEvent::compiled_method_load_event(this));
  1538 jmethodID nmethod::get_and_cache_jmethod_id() {
  1539   if (_jmethod_id == NULL) {
  1540     // Cache the jmethod_id since it can no longer be looked up once the
  1541     // method itself has been marked for unloading.
  1542     _jmethod_id = method()->jmethod_id();
  1544   return _jmethod_id;
  1547 void nmethod::post_compiled_method_unload() {
  1548   if (unload_reported()) {
  1549     // During unloading we transition to unloaded and then to zombie
  1550     // and the unloading is reported during the first transition.
  1551     return;
  1554   assert(_method != NULL && !is_unloaded(), "just checking");
  1555   DTRACE_METHOD_UNLOAD_PROBE(method());
  1557   // If a JVMTI agent has enabled the CompiledMethodUnload event then
  1558   // post the event. Sometime later this nmethod will be made a zombie
  1559   // by the sweeper but the Method* will not be valid at that point.
  1560   // If the _jmethod_id is null then no load event was ever requested
  1561   // so don't bother posting the unload.  The main reason for this is
  1562   // that the jmethodID is a weak reference to the Method* so if
  1563   // it's being unloaded there's no way to look it up since the weak
  1564   // ref will have been cleared.
  1565   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
  1566     assert(!unload_reported(), "already unloaded");
  1567     JvmtiDeferredEvent event =
  1568       JvmtiDeferredEvent::compiled_method_unload_event(this,
  1569           _jmethod_id, insts_begin());
  1570     if (SafepointSynchronize::is_at_safepoint()) {
  1571       // Don't want to take the queueing lock. Add it as pending and
  1572       // it will get enqueued later.
  1573       JvmtiDeferredEventQueue::add_pending_event(event);
  1574     } else {
  1575       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  1576       JvmtiDeferredEventQueue::enqueue(event);
  1580   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
  1581   // any time. As the nmethod is being unloaded now we mark it has
  1582   // having the unload event reported - this will ensure that we don't
  1583   // attempt to report the event in the unlikely scenario where the
  1584   // event is enabled at the time the nmethod is made a zombie.
  1585   set_unload_reported();
  1588 // This is called at the end of the strong tracing/marking phase of a
  1589 // GC to unload an nmethod if it contains otherwise unreachable
  1590 // oops.
  1592 void nmethod::do_unloading(BoolObjectClosure* is_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");
  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.)
  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;
  1619   // Exception cache
  1620   ExceptionCache* ec = exception_cache();
  1621   while (ec != NULL) {
  1622     Klass* ex_klass = ec->exception_type();
  1623     ExceptionCache* next_ec = ec->next();
  1624     if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
  1625       remove_from_exception_cache(ec);
  1627     ec = next_ec;
  1630   // If class unloading occurred we first iterate over all inline caches and
  1631   // clear ICs where the cached oop is referring to an unloaded klass or method.
  1632   // The remaining live cached oops will be traversed in the relocInfo::oop_type
  1633   // iteration below.
  1634   if (unloading_occurred) {
  1635     RelocIterator iter(this, low_boundary);
  1636     while(iter.next()) {
  1637       if (iter.type() == relocInfo::virtual_call_type) {
  1638         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1639         if (ic->is_icholder_call()) {
  1640           // The only exception is compiledICHolder oops which may
  1641           // yet be marked below. (We check this further below).
  1642           CompiledICHolder* cichk_oop = ic->cached_icholder();
  1643           if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
  1644               cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
  1645               continue;
  1647         } else {
  1648           Metadata* ic_oop = ic->cached_metadata();
  1649           if (ic_oop != NULL) {
  1650             if (ic_oop->is_klass()) {
  1651               if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
  1652                 continue;
  1654             } else if (ic_oop->is_method()) {
  1655               if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
  1656                 continue;
  1658             } else {
  1659               ShouldNotReachHere();
  1663           ic->set_to_clean();
  1668   // Compiled code
  1670   RelocIterator iter(this, low_boundary);
  1671   while (iter.next()) {
  1672     if (iter.type() == relocInfo::oop_type) {
  1673       oop_Relocation* r = iter.oop_reloc();
  1674       // In this loop, we must only traverse those oops directly embedded in
  1675       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1676       assert(1 == (r->oop_is_immediate()) +
  1677                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1678              "oop must be found in exactly one place");
  1679       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1680         if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
  1681           return;
  1689   // Scopes
  1690   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1691     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1692     if (can_unload(is_alive, p, unloading_occurred)) {
  1693       return;
  1697   // Ensure that all metadata is still alive
  1698   verify_metadata_loaders(low_boundary, is_alive);
  1701 #ifdef ASSERT
  1703 class CheckClass : AllStatic {
  1704   static BoolObjectClosure* _is_alive;
  1706   // Check class_loader is alive for this bit of metadata.
  1707   static void check_class(Metadata* md) {
  1708     Klass* klass = NULL;
  1709     if (md->is_klass()) {
  1710       klass = ((Klass*)md);
  1711     } else if (md->is_method()) {
  1712       klass = ((Method*)md)->method_holder();
  1713     } else if (md->is_methodData()) {
  1714       klass = ((MethodData*)md)->method()->method_holder();
  1715     } else {
  1716       md->print();
  1717       ShouldNotReachHere();
  1719     assert(klass->is_loader_alive(_is_alive), "must be alive");
  1721  public:
  1722   static void do_check_class(BoolObjectClosure* is_alive, nmethod* nm) {
  1723     assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
  1724     _is_alive = is_alive;
  1725     nm->metadata_do(check_class);
  1727 };
  1729 // This is called during a safepoint so can use static data
  1730 BoolObjectClosure* CheckClass::_is_alive = NULL;
  1731 #endif // ASSERT
  1734 // Processing of oop references should have been sufficient to keep
  1735 // all strong references alive.  Any weak references should have been
  1736 // cleared as well.  Visit all the metadata and ensure that it's
  1737 // really alive.
  1738 void nmethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
  1739 #ifdef ASSERT
  1740     RelocIterator iter(this, low_boundary);
  1741     while (iter.next()) {
  1742     // static_stub_Relocations may have dangling references to
  1743     // Method*s so trim them out here.  Otherwise it looks like
  1744     // compiled code is maintaining a link to dead metadata.
  1745     address static_call_addr = NULL;
  1746     if (iter.type() == relocInfo::opt_virtual_call_type) {
  1747       CompiledIC* cic = CompiledIC_at(iter.reloc());
  1748       if (!cic->is_call_to_interpreted()) {
  1749         static_call_addr = iter.addr();
  1751     } else if (iter.type() == relocInfo::static_call_type) {
  1752       CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
  1753       if (!csc->is_call_to_interpreted()) {
  1754         static_call_addr = iter.addr();
  1757     if (static_call_addr != NULL) {
  1758       RelocIterator sciter(this, low_boundary);
  1759       while (sciter.next()) {
  1760         if (sciter.type() == relocInfo::static_stub_type &&
  1761             sciter.static_stub_reloc()->static_call() == static_call_addr) {
  1762           sciter.static_stub_reloc()->clear_inline_cache();
  1767   // Check that the metadata embedded in the nmethod is alive
  1768   CheckClass::do_check_class(is_alive, this);
  1769 #endif
  1773 // Iterate over metadata calling this function.   Used by RedefineClasses
  1774 void nmethod::metadata_do(void f(Metadata*)) {
  1775   address low_boundary = verified_entry_point();
  1776   if (is_not_entrant()) {
  1777     low_boundary += NativeJump::instruction_size;
  1778     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1779     // (See comment above.)
  1782     // Visit all immediate references that are embedded in the instruction stream.
  1783     RelocIterator iter(this, low_boundary);
  1784     while (iter.next()) {
  1785       if (iter.type() == relocInfo::metadata_type ) {
  1786         metadata_Relocation* r = iter.metadata_reloc();
  1787         // In this lmetadata, we must only follow those metadatas directly embedded in
  1788         // the code.  Other metadatas (oop_index>0) are seen as part of
  1789         // the metadata section below.
  1790         assert(1 == (r->metadata_is_immediate()) +
  1791                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
  1792                "metadata must be found in exactly one place");
  1793         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
  1794           Metadata* md = r->metadata_value();
  1795           f(md);
  1797       } else if (iter.type() == relocInfo::virtual_call_type) {
  1798         // Check compiledIC holders associated with this nmethod
  1799         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1800         if (ic->is_icholder_call()) {
  1801           CompiledICHolder* cichk = ic->cached_icholder();
  1802           f(cichk->holder_method());
  1803           f(cichk->holder_klass());
  1804         } else {
  1805           Metadata* ic_oop = ic->cached_metadata();
  1806           if (ic_oop != NULL) {
  1807             f(ic_oop);
  1814   // Visit the metadata section
  1815   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
  1816     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
  1817     Metadata* md = *p;
  1818     f(md);
  1821   // Call function Method*, not embedded in these other places.
  1822   if (_method != NULL) f(_method);
  1826 // This method is called twice during GC -- once while
  1827 // tracing the "active" nmethods on thread stacks during
  1828 // the (strong) marking phase, and then again when walking
  1829 // the code cache contents during the weak roots processing
  1830 // phase. The two uses are distinguished by means of the
  1831 // 'do_strong_roots_only' flag, which is true in the first
  1832 // case. We want to walk the weak roots in the nmethod
  1833 // only in the second case. The weak roots in the nmethod
  1834 // are the oops in the ExceptionCache and the InlineCache
  1835 // oops.
  1836 void nmethod::oops_do(OopClosure* f, bool do_strong_roots_only) {
  1837   // make sure the oops ready to receive visitors
  1838   assert(!is_zombie() && !is_unloaded(),
  1839          "should not call follow on zombie or unloaded nmethod");
  1841   // If the method is not entrant or zombie then a JMP is plastered over the
  1842   // first few bytes.  If an oop in the old code was there, that oop
  1843   // should not get GC'd.  Skip the first few bytes of oops on
  1844   // not-entrant methods.
  1845   address low_boundary = verified_entry_point();
  1846   if (is_not_entrant()) {
  1847     low_boundary += NativeJump::instruction_size;
  1848     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1849     // (See comment above.)
  1852   RelocIterator iter(this, low_boundary);
  1854   while (iter.next()) {
  1855     if (iter.type() == relocInfo::oop_type ) {
  1856       oop_Relocation* r = iter.oop_reloc();
  1857       // In this loop, we must only follow those oops directly embedded in
  1858       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1859       assert(1 == (r->oop_is_immediate()) +
  1860                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1861              "oop must be found in exactly one place");
  1862       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1863         f->do_oop(r->oop_addr());
  1868   // Scopes
  1869   // This includes oop constants not inlined in the code stream.
  1870   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1871     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1872     f->do_oop(p);
  1876 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
  1878 nmethod* volatile nmethod::_oops_do_mark_nmethods;
  1880 // An nmethod is "marked" if its _mark_link is set non-null.
  1881 // Even if it is the end of the linked list, it will have a non-null link value,
  1882 // as long as it is on the list.
  1883 // This code must be MP safe, because it is used from parallel GC passes.
  1884 bool nmethod::test_set_oops_do_mark() {
  1885   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
  1886   nmethod* observed_mark_link = _oops_do_mark_link;
  1887   if (observed_mark_link == NULL) {
  1888     // Claim this nmethod for this thread to mark.
  1889     observed_mark_link = (nmethod*)
  1890       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
  1891     if (observed_mark_link == NULL) {
  1893       // Atomically append this nmethod (now claimed) to the head of the list:
  1894       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
  1895       for (;;) {
  1896         nmethod* required_mark_nmethods = observed_mark_nmethods;
  1897         _oops_do_mark_link = required_mark_nmethods;
  1898         observed_mark_nmethods = (nmethod*)
  1899           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
  1900         if (observed_mark_nmethods == required_mark_nmethods)
  1901           break;
  1903       // Mark was clear when we first saw this guy.
  1904       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark"));
  1905       return false;
  1908   // On fall through, another racing thread marked this nmethod before we did.
  1909   return true;
  1912 void nmethod::oops_do_marking_prologue() {
  1913   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
  1914   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
  1915   // We use cmpxchg_ptr instead of regular assignment here because the user
  1916   // may fork a bunch of threads, and we need them all to see the same state.
  1917   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
  1918   guarantee(observed == NULL, "no races in this sequential code");
  1921 void nmethod::oops_do_marking_epilogue() {
  1922   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
  1923   nmethod* cur = _oops_do_mark_nmethods;
  1924   while (cur != NMETHOD_SENTINEL) {
  1925     assert(cur != NULL, "not NULL-terminated");
  1926     nmethod* next = cur->_oops_do_mark_link;
  1927     cur->_oops_do_mark_link = NULL;
  1928     cur->fix_oop_relocations();
  1929     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
  1930     cur = next;
  1932   void* required = _oops_do_mark_nmethods;
  1933   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
  1934   guarantee(observed == required, "no races in this sequential code");
  1935   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
  1938 class DetectScavengeRoot: public OopClosure {
  1939   bool     _detected_scavenge_root;
  1940 public:
  1941   DetectScavengeRoot() : _detected_scavenge_root(false)
  1942   { NOT_PRODUCT(_print_nm = NULL); }
  1943   bool detected_scavenge_root() { return _detected_scavenge_root; }
  1944   virtual void do_oop(oop* p) {
  1945     if ((*p) != NULL && (*p)->is_scavengable()) {
  1946       NOT_PRODUCT(maybe_print(p));
  1947       _detected_scavenge_root = true;
  1950   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  1952 #ifndef PRODUCT
  1953   nmethod* _print_nm;
  1954   void maybe_print(oop* p) {
  1955     if (_print_nm == NULL)  return;
  1956     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
  1957     tty->print_cr(""PTR_FORMAT"[offset=%d] detected scavengable oop "PTR_FORMAT" (found at "PTR_FORMAT")",
  1958                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
  1959                   (intptr_t)(*p), (intptr_t)p);
  1960     (*p)->print();
  1962 #endif //PRODUCT
  1963 };
  1965 bool nmethod::detect_scavenge_root_oops() {
  1966   DetectScavengeRoot detect_scavenge_root;
  1967   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
  1968   oops_do(&detect_scavenge_root);
  1969   return detect_scavenge_root.detected_scavenge_root();
  1972 // Method that knows how to preserve outgoing arguments at call. This method must be
  1973 // called with a frame corresponding to a Java invoke
  1974 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
  1975 #ifndef SHARK
  1976   if (!method()->is_native()) {
  1977     SimpleScopeDesc ssd(this, fr.pc());
  1978     Bytecode_invoke call(ssd.method(), ssd.bci());
  1979     bool has_receiver = call.has_receiver();
  1980     bool has_appendix = call.has_appendix();
  1981     Symbol* signature = call.signature();
  1982     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
  1984 #endif // !SHARK
  1988 oop nmethod::embeddedOop_at(u_char* p) {
  1989   RelocIterator iter(this, p, p + 1);
  1990   while (iter.next())
  1991     if (iter.type() == relocInfo::oop_type) {
  1992       return iter.oop_reloc()->oop_value();
  1994   return NULL;
  1998 inline bool includes(void* p, void* from, void* to) {
  1999   return from <= p && p < to;
  2003 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
  2004   assert(count >= 2, "must be sentinel values, at least");
  2006 #ifdef ASSERT
  2007   // must be sorted and unique; we do a binary search in find_pc_desc()
  2008   int prev_offset = pcs[0].pc_offset();
  2009   assert(prev_offset == PcDesc::lower_offset_limit,
  2010          "must start with a sentinel");
  2011   for (int i = 1; i < count; i++) {
  2012     int this_offset = pcs[i].pc_offset();
  2013     assert(this_offset > prev_offset, "offsets must be sorted");
  2014     prev_offset = this_offset;
  2016   assert(prev_offset == PcDesc::upper_offset_limit,
  2017          "must end with a sentinel");
  2018 #endif //ASSERT
  2020   // Search for MethodHandle invokes and tag the nmethod.
  2021   for (int i = 0; i < count; i++) {
  2022     if (pcs[i].is_method_handle_invoke()) {
  2023       set_has_method_handle_invokes(true);
  2024       break;
  2027   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
  2029   int size = count * sizeof(PcDesc);
  2030   assert(scopes_pcs_size() >= size, "oob");
  2031   memcpy(scopes_pcs_begin(), pcs, size);
  2033   // Adjust the final sentinel downward.
  2034   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
  2035   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
  2036   last_pc->set_pc_offset(content_size() + 1);
  2037   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
  2038     // Fill any rounding gaps with copies of the last record.
  2039     last_pc[1] = last_pc[0];
  2041   // The following assert could fail if sizeof(PcDesc) is not
  2042   // an integral multiple of oopSize (the rounding term).
  2043   // If it fails, change the logic to always allocate a multiple
  2044   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
  2045   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
  2048 void nmethod::copy_scopes_data(u_char* buffer, int size) {
  2049   assert(scopes_data_size() >= size, "oob");
  2050   memcpy(scopes_data_begin(), buffer, size);
  2054 #ifdef ASSERT
  2055 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
  2056   PcDesc* lower = nm->scopes_pcs_begin();
  2057   PcDesc* upper = nm->scopes_pcs_end();
  2058   lower += 1; // exclude initial sentinel
  2059   PcDesc* res = NULL;
  2060   for (PcDesc* p = lower; p < upper; p++) {
  2061     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
  2062     if (match_desc(p, pc_offset, approximate)) {
  2063       if (res == NULL)
  2064         res = p;
  2065       else
  2066         res = (PcDesc*) badAddress;
  2069   return res;
  2071 #endif
  2074 // Finds a PcDesc with real-pc equal to "pc"
  2075 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
  2076   address base_address = code_begin();
  2077   if ((pc < base_address) ||
  2078       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
  2079     return NULL;  // PC is wildly out of range
  2081   int pc_offset = (int) (pc - base_address);
  2083   // Check the PcDesc cache if it contains the desired PcDesc
  2084   // (This as an almost 100% hit rate.)
  2085   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
  2086   if (res != NULL) {
  2087     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
  2088     return res;
  2091   // Fallback algorithm: quasi-linear search for the PcDesc
  2092   // Find the last pc_offset less than the given offset.
  2093   // The successor must be the required match, if there is a match at all.
  2094   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
  2095   PcDesc* lower = scopes_pcs_begin();
  2096   PcDesc* upper = scopes_pcs_end();
  2097   upper -= 1; // exclude final sentinel
  2098   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
  2100 #define assert_LU_OK \
  2101   /* invariant on lower..upper during the following search: */ \
  2102   assert(lower->pc_offset() <  pc_offset, "sanity"); \
  2103   assert(upper->pc_offset() >= pc_offset, "sanity")
  2104   assert_LU_OK;
  2106   // Use the last successful return as a split point.
  2107   PcDesc* mid = _pc_desc_cache.last_pc_desc();
  2108   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2109   if (mid->pc_offset() < pc_offset) {
  2110     lower = mid;
  2111   } else {
  2112     upper = mid;
  2115   // Take giant steps at first (4096, then 256, then 16, then 1)
  2116   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
  2117   const int RADIX = (1 << LOG2_RADIX);
  2118   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
  2119     while ((mid = lower + step) < upper) {
  2120       assert_LU_OK;
  2121       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2122       if (mid->pc_offset() < pc_offset) {
  2123         lower = mid;
  2124       } else {
  2125         upper = mid;
  2126         break;
  2129     assert_LU_OK;
  2132   // Sneak up on the value with a linear search of length ~16.
  2133   while (true) {
  2134     assert_LU_OK;
  2135     mid = lower + 1;
  2136     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2137     if (mid->pc_offset() < pc_offset) {
  2138       lower = mid;
  2139     } else {
  2140       upper = mid;
  2141       break;
  2144 #undef assert_LU_OK
  2146   if (match_desc(upper, pc_offset, approximate)) {
  2147     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
  2148     _pc_desc_cache.add_pc_desc(upper);
  2149     return upper;
  2150   } else {
  2151     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
  2152     return NULL;
  2157 bool nmethod::check_all_dependencies() {
  2158   bool found_check = false;
  2159   // wholesale check of all dependencies
  2160   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2161     if (deps.check_dependency() != NULL) {
  2162       found_check = true;
  2163       NOT_DEBUG(break);
  2166   return found_check;  // tell caller if we found anything
  2169 bool nmethod::check_dependency_on(DepChange& changes) {
  2170   // What has happened:
  2171   // 1) a new class dependee has been added
  2172   // 2) dependee and all its super classes have been marked
  2173   bool found_check = false;  // set true if we are upset
  2174   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2175     // Evaluate only relevant dependencies.
  2176     if (deps.spot_check_dependency_at(changes) != NULL) {
  2177       found_check = true;
  2178       NOT_DEBUG(break);
  2181   return found_check;
  2184 bool nmethod::is_evol_dependent_on(Klass* dependee) {
  2185   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
  2186   Array<Method*>* dependee_methods = dependee_ik->methods();
  2187   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2188     if (deps.type() == Dependencies::evol_method) {
  2189       Method* method = deps.method_argument(0);
  2190       for (int j = 0; j < dependee_methods->length(); j++) {
  2191         if (dependee_methods->at(j) == method) {
  2192           // RC_TRACE macro has an embedded ResourceMark
  2193           RC_TRACE(0x01000000,
  2194             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
  2195             _method->method_holder()->external_name(),
  2196             _method->name()->as_C_string(),
  2197             _method->signature()->as_C_string(), compile_id(),
  2198             method->method_holder()->external_name(),
  2199             method->name()->as_C_string(),
  2200             method->signature()->as_C_string()));
  2201           if (TraceDependencies || LogCompilation)
  2202             deps.log_dependency(dependee);
  2203           return true;
  2208   return false;
  2211 // Called from mark_for_deoptimization, when dependee is invalidated.
  2212 bool nmethod::is_dependent_on_method(Method* dependee) {
  2213   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2214     if (deps.type() != Dependencies::evol_method)
  2215       continue;
  2216     Method* method = deps.method_argument(0);
  2217     if (method == dependee) return true;
  2219   return false;
  2223 bool nmethod::is_patchable_at(address instr_addr) {
  2224   assert(insts_contains(instr_addr), "wrong nmethod used");
  2225   if (is_zombie()) {
  2226     // a zombie may never be patched
  2227     return false;
  2229   return true;
  2233 address nmethod::continuation_for_implicit_exception(address pc) {
  2234   // Exception happened outside inline-cache check code => we are inside
  2235   // an active nmethod => use cpc to determine a return address
  2236   int exception_offset = pc - code_begin();
  2237   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
  2238 #ifdef ASSERT
  2239   if (cont_offset == 0) {
  2240     Thread* thread = ThreadLocalStorage::get_thread_slow();
  2241     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
  2242     HandleMark hm(thread);
  2243     ResourceMark rm(thread);
  2244     CodeBlob* cb = CodeCache::find_blob(pc);
  2245     assert(cb != NULL && cb == this, "");
  2246     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
  2247     print();
  2248     method()->print_codes();
  2249     print_code();
  2250     print_pcs();
  2252 #endif
  2253   if (cont_offset == 0) {
  2254     // Let the normal error handling report the exception
  2255     return NULL;
  2257   return code_begin() + cont_offset;
  2262 void nmethod_init() {
  2263   // make sure you didn't forget to adjust the filler fields
  2264   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
  2268 //-------------------------------------------------------------------------------------------
  2271 // QQQ might we make this work from a frame??
  2272 nmethodLocker::nmethodLocker(address pc) {
  2273   CodeBlob* cb = CodeCache::find_blob(pc);
  2274   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
  2275   _nm = (nmethod*)cb;
  2276   lock_nmethod(_nm);
  2279 // Only JvmtiDeferredEvent::compiled_method_unload_event()
  2280 // should pass zombie_ok == true.
  2281 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
  2282   if (nm == NULL)  return;
  2283   Atomic::inc(&nm->_lock_count);
  2284   guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
  2287 void nmethodLocker::unlock_nmethod(nmethod* nm) {
  2288   if (nm == NULL)  return;
  2289   Atomic::dec(&nm->_lock_count);
  2290   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
  2294 // -----------------------------------------------------------------------------
  2295 // nmethod::get_deopt_original_pc
  2296 //
  2297 // Return the original PC for the given PC if:
  2298 // (a) the given PC belongs to a nmethod and
  2299 // (b) it is a deopt PC
  2300 address nmethod::get_deopt_original_pc(const frame* fr) {
  2301   if (fr->cb() == NULL)  return NULL;
  2303   nmethod* nm = fr->cb()->as_nmethod_or_null();
  2304   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
  2305     return nm->get_original_pc(fr);
  2307   return NULL;
  2311 // -----------------------------------------------------------------------------
  2312 // MethodHandle
  2314 bool nmethod::is_method_handle_return(address return_pc) {
  2315   if (!has_method_handle_invokes())  return false;
  2316   PcDesc* pd = pc_desc_at(return_pc);
  2317   if (pd == NULL)
  2318     return false;
  2319   return pd->is_method_handle_invoke();
  2323 // -----------------------------------------------------------------------------
  2324 // Verification
  2326 class VerifyOopsClosure: public OopClosure {
  2327   nmethod* _nm;
  2328   bool     _ok;
  2329 public:
  2330   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
  2331   bool ok() { return _ok; }
  2332   virtual void do_oop(oop* p) {
  2333     if ((*p) == NULL || (*p)->is_oop())  return;
  2334     if (_ok) {
  2335       _nm->print_nmethod(true);
  2336       _ok = false;
  2338     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
  2339                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
  2341   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  2342 };
  2344 void nmethod::verify() {
  2346   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
  2347   // seems odd.
  2349   if( is_zombie() || is_not_entrant() )
  2350     return;
  2352   // Make sure all the entry points are correctly aligned for patching.
  2353   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
  2355   // assert(method()->is_oop(), "must be valid");
  2357   ResourceMark rm;
  2359   if (!CodeCache::contains(this)) {
  2360     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
  2363   if(is_native_method() )
  2364     return;
  2366   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
  2367   if (nm != this) {
  2368     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
  2369                   this));
  2372   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2373     if (! p->verify(this)) {
  2374       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
  2378   VerifyOopsClosure voc(this);
  2379   oops_do(&voc);
  2380   assert(voc.ok(), "embedded oops must be OK");
  2381   verify_scavenge_root_oops();
  2383   verify_scopes();
  2387 void nmethod::verify_interrupt_point(address call_site) {
  2388   // This code does not work in release mode since
  2389   // owns_lock only is available in debug mode.
  2390   CompiledIC* ic = NULL;
  2391   Thread *cur = Thread::current();
  2392   if (CompiledIC_lock->owner() == cur ||
  2393       ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
  2394        SafepointSynchronize::is_at_safepoint())) {
  2395     ic = CompiledIC_at(this, call_site);
  2396     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  2397   } else {
  2398     MutexLocker ml_verify (CompiledIC_lock);
  2399     ic = CompiledIC_at(this, call_site);
  2401   PcDesc* pd = pc_desc_at(ic->end_of_call());
  2402   assert(pd != NULL, "PcDesc must exist");
  2403   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
  2404                                      pd->obj_decode_offset(), pd->should_reexecute(),
  2405                                      pd->return_oop());
  2406        !sd->is_top(); sd = sd->sender()) {
  2407     sd->verify();
  2411 void nmethod::verify_scopes() {
  2412   if( !method() ) return;       // Runtime stubs have no scope
  2413   if (method()->is_native()) return; // Ignore stub methods.
  2414   // iterate through all interrupt point
  2415   // and verify the debug information is valid.
  2416   RelocIterator iter((nmethod*)this);
  2417   while (iter.next()) {
  2418     address stub = NULL;
  2419     switch (iter.type()) {
  2420       case relocInfo::virtual_call_type:
  2421         verify_interrupt_point(iter.addr());
  2422         break;
  2423       case relocInfo::opt_virtual_call_type:
  2424         stub = iter.opt_virtual_call_reloc()->static_stub();
  2425         verify_interrupt_point(iter.addr());
  2426         break;
  2427       case relocInfo::static_call_type:
  2428         stub = iter.static_call_reloc()->static_stub();
  2429         //verify_interrupt_point(iter.addr());
  2430         break;
  2431       case relocInfo::runtime_call_type:
  2432         address destination = iter.reloc()->value();
  2433         // Right now there is no way to find out which entries support
  2434         // an interrupt point.  It would be nice if we had this
  2435         // information in a table.
  2436         break;
  2438     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
  2443 // -----------------------------------------------------------------------------
  2444 // Non-product code
  2445 #ifndef PRODUCT
  2447 class DebugScavengeRoot: public OopClosure {
  2448   nmethod* _nm;
  2449   bool     _ok;
  2450 public:
  2451   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
  2452   bool ok() { return _ok; }
  2453   virtual void do_oop(oop* p) {
  2454     if ((*p) == NULL || !(*p)->is_scavengable())  return;
  2455     if (_ok) {
  2456       _nm->print_nmethod(true);
  2457       _ok = false;
  2459     tty->print_cr("*** scavengable oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
  2460                   (intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
  2461     (*p)->print();
  2463   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  2464 };
  2466 void nmethod::verify_scavenge_root_oops() {
  2467   if (!on_scavenge_root_list()) {
  2468     // Actually look inside, to verify the claim that it's clean.
  2469     DebugScavengeRoot debug_scavenge_root(this);
  2470     oops_do(&debug_scavenge_root);
  2471     if (!debug_scavenge_root.ok())
  2472       fatal("found an unadvertised bad scavengable oop in the code cache");
  2474   assert(scavenge_root_not_marked(), "");
  2477 #endif // PRODUCT
  2479 // Printing operations
  2481 void nmethod::print() const {
  2482   ResourceMark rm;
  2483   ttyLocker ttyl;   // keep the following output all in one block
  2485   tty->print("Compiled method ");
  2487   if (is_compiled_by_c1()) {
  2488     tty->print("(c1) ");
  2489   } else if (is_compiled_by_c2()) {
  2490     tty->print("(c2) ");
  2491   } else if (is_compiled_by_shark()) {
  2492     tty->print("(shark) ");
  2493   } else {
  2494     tty->print("(nm) ");
  2497   print_on(tty, NULL);
  2499   if (WizardMode) {
  2500     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
  2501     tty->print(" for method " INTPTR_FORMAT , (address)method());
  2502     tty->print(" { ");
  2503     if (is_in_use())      tty->print("in_use ");
  2504     if (is_not_entrant()) tty->print("not_entrant ");
  2505     if (is_zombie())      tty->print("zombie ");
  2506     if (is_unloaded())    tty->print("unloaded ");
  2507     if (on_scavenge_root_list())  tty->print("scavenge_root ");
  2508     tty->print_cr("}:");
  2510   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2511                                               (address)this,
  2512                                               (address)this + size(),
  2513                                               size());
  2514   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2515                                               relocation_begin(),
  2516                                               relocation_end(),
  2517                                               relocation_size());
  2518   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2519                                               consts_begin(),
  2520                                               consts_end(),
  2521                                               consts_size());
  2522   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2523                                               insts_begin(),
  2524                                               insts_end(),
  2525                                               insts_size());
  2526   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2527                                               stub_begin(),
  2528                                               stub_end(),
  2529                                               stub_size());
  2530   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2531                                               oops_begin(),
  2532                                               oops_end(),
  2533                                               oops_size());
  2534   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2535                                               metadata_begin(),
  2536                                               metadata_end(),
  2537                                               metadata_size());
  2538   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2539                                               scopes_data_begin(),
  2540                                               scopes_data_end(),
  2541                                               scopes_data_size());
  2542   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2543                                               scopes_pcs_begin(),
  2544                                               scopes_pcs_end(),
  2545                                               scopes_pcs_size());
  2546   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2547                                               dependencies_begin(),
  2548                                               dependencies_end(),
  2549                                               dependencies_size());
  2550   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2551                                               handler_table_begin(),
  2552                                               handler_table_end(),
  2553                                               handler_table_size());
  2554   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2555                                               nul_chk_table_begin(),
  2556                                               nul_chk_table_end(),
  2557                                               nul_chk_table_size());
  2560 void nmethod::print_code() {
  2561   HandleMark hm;
  2562   ResourceMark m;
  2563   Disassembler::decode(this);
  2567 #ifndef PRODUCT
  2569 void nmethod::print_scopes() {
  2570   // Find the first pc desc for all scopes in the code and print it.
  2571   ResourceMark rm;
  2572   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2573     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
  2574       continue;
  2576     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
  2577     sd->print_on(tty, p);
  2581 void nmethod::print_dependencies() {
  2582   ResourceMark rm;
  2583   ttyLocker ttyl;   // keep the following output all in one block
  2584   tty->print_cr("Dependencies:");
  2585   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2586     deps.print_dependency();
  2587     Klass* ctxk = deps.context_type();
  2588     if (ctxk != NULL) {
  2589       if (ctxk->oop_is_instance() && ((InstanceKlass*)ctxk)->is_dependent_nmethod(this)) {
  2590         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
  2593     deps.log_dependency();  // put it into the xml log also
  2598 void nmethod::print_relocations() {
  2599   ResourceMark m;       // in case methods get printed via the debugger
  2600   tty->print_cr("relocations:");
  2601   RelocIterator iter(this);
  2602   iter.print();
  2603   if (UseRelocIndex) {
  2604     jint* index_end   = (jint*)relocation_end() - 1;
  2605     jint  index_size  = *index_end;
  2606     jint* index_start = (jint*)( (address)index_end - index_size );
  2607     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
  2608     if (index_size > 0) {
  2609       jint* ip;
  2610       for (ip = index_start; ip+2 <= index_end; ip += 2)
  2611         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
  2612                       ip[0],
  2613                       ip[1],
  2614                       header_end()+ip[0],
  2615                       relocation_begin()-1+ip[1]);
  2616       for (; ip < index_end; ip++)
  2617         tty->print_cr("  (%d ?)", ip[0]);
  2618       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip++);
  2619       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
  2625 void nmethod::print_pcs() {
  2626   ResourceMark m;       // in case methods get printed via debugger
  2627   tty->print_cr("pc-bytecode offsets:");
  2628   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2629     p->print(this);
  2633 #endif // PRODUCT
  2635 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
  2636   RelocIterator iter(this, begin, end);
  2637   bool have_one = false;
  2638   while (iter.next()) {
  2639     have_one = true;
  2640     switch (iter.type()) {
  2641         case relocInfo::none:                  return "no_reloc";
  2642         case relocInfo::oop_type: {
  2643           stringStream st;
  2644           oop_Relocation* r = iter.oop_reloc();
  2645           oop obj = r->oop_value();
  2646           st.print("oop(");
  2647           if (obj == NULL) st.print("NULL");
  2648           else obj->print_value_on(&st);
  2649           st.print(")");
  2650           return st.as_string();
  2652         case relocInfo::metadata_type: {
  2653           stringStream st;
  2654           metadata_Relocation* r = iter.metadata_reloc();
  2655           Metadata* obj = r->metadata_value();
  2656           st.print("metadata(");
  2657           if (obj == NULL) st.print("NULL");
  2658           else obj->print_value_on(&st);
  2659           st.print(")");
  2660           return st.as_string();
  2662         case relocInfo::virtual_call_type:     return "virtual_call";
  2663         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
  2664         case relocInfo::static_call_type:      return "static_call";
  2665         case relocInfo::static_stub_type:      return "static_stub";
  2666         case relocInfo::runtime_call_type:     return "runtime_call";
  2667         case relocInfo::external_word_type:    return "external_word";
  2668         case relocInfo::internal_word_type:    return "internal_word";
  2669         case relocInfo::section_word_type:     return "section_word";
  2670         case relocInfo::poll_type:             return "poll";
  2671         case relocInfo::poll_return_type:      return "poll_return";
  2672         case relocInfo::type_mask:             return "type_bit_mask";
  2675   return have_one ? "other" : NULL;
  2678 // Return a the last scope in (begin..end]
  2679 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
  2680   PcDesc* p = pc_desc_near(begin+1);
  2681   if (p != NULL && p->real_pc(this) <= end) {
  2682     return new ScopeDesc(this, p->scope_decode_offset(),
  2683                          p->obj_decode_offset(), p->should_reexecute(),
  2684                          p->return_oop());
  2686   return NULL;
  2689 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
  2690   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
  2691   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
  2692   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
  2693   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
  2694   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
  2696   if (has_method_handle_invokes())
  2697     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
  2699   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
  2701   if (block_begin == entry_point()) {
  2702     methodHandle m = method();
  2703     if (m.not_null()) {
  2704       stream->print("  # ");
  2705       m->print_value_on(stream);
  2706       stream->cr();
  2708     if (m.not_null() && !is_osr_method()) {
  2709       ResourceMark rm;
  2710       int sizeargs = m->size_of_parameters();
  2711       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
  2712       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
  2714         int sig_index = 0;
  2715         if (!m->is_static())
  2716           sig_bt[sig_index++] = T_OBJECT; // 'this'
  2717         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
  2718           BasicType t = ss.type();
  2719           sig_bt[sig_index++] = t;
  2720           if (type2size[t] == 2) {
  2721             sig_bt[sig_index++] = T_VOID;
  2722           } else {
  2723             assert(type2size[t] == 1, "size is 1 or 2");
  2726         assert(sig_index == sizeargs, "");
  2728       const char* spname = "sp"; // make arch-specific?
  2729       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
  2730       int stack_slot_offset = this->frame_size() * wordSize;
  2731       int tab1 = 14, tab2 = 24;
  2732       int sig_index = 0;
  2733       int arg_index = (m->is_static() ? 0 : -1);
  2734       bool did_old_sp = false;
  2735       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
  2736         bool at_this = (arg_index == -1);
  2737         bool at_old_sp = false;
  2738         BasicType t = (at_this ? T_OBJECT : ss.type());
  2739         assert(t == sig_bt[sig_index], "sigs in sync");
  2740         if (at_this)
  2741           stream->print("  # this: ");
  2742         else
  2743           stream->print("  # parm%d: ", arg_index);
  2744         stream->move_to(tab1);
  2745         VMReg fst = regs[sig_index].first();
  2746         VMReg snd = regs[sig_index].second();
  2747         if (fst->is_reg()) {
  2748           stream->print("%s", fst->name());
  2749           if (snd->is_valid())  {
  2750             stream->print(":%s", snd->name());
  2752         } else if (fst->is_stack()) {
  2753           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
  2754           if (offset == stack_slot_offset)  at_old_sp = true;
  2755           stream->print("[%s+0x%x]", spname, offset);
  2756         } else {
  2757           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
  2759         stream->print(" ");
  2760         stream->move_to(tab2);
  2761         stream->print("= ");
  2762         if (at_this) {
  2763           m->method_holder()->print_value_on(stream);
  2764         } else {
  2765           bool did_name = false;
  2766           if (!at_this && ss.is_object()) {
  2767             Symbol* name = ss.as_symbol_or_null();
  2768             if (name != NULL) {
  2769               name->print_value_on(stream);
  2770               did_name = true;
  2773           if (!did_name)
  2774             stream->print("%s", type2name(t));
  2776         if (at_old_sp) {
  2777           stream->print("  (%s of caller)", spname);
  2778           did_old_sp = true;
  2780         stream->cr();
  2781         sig_index += type2size[t];
  2782         arg_index += 1;
  2783         if (!at_this)  ss.next();
  2785       if (!did_old_sp) {
  2786         stream->print("  # ");
  2787         stream->move_to(tab1);
  2788         stream->print("[%s+0x%x]", spname, stack_slot_offset);
  2789         stream->print("  (%s of caller)", spname);
  2790         stream->cr();
  2796 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
  2797   // First, find an oopmap in (begin, end].
  2798   // We use the odd half-closed interval so that oop maps and scope descs
  2799   // which are tied to the byte after a call are printed with the call itself.
  2800   address base = code_begin();
  2801   OopMapSet* oms = oop_maps();
  2802   if (oms != NULL) {
  2803     for (int i = 0, imax = oms->size(); i < imax; i++) {
  2804       OopMap* om = oms->at(i);
  2805       address pc = base + om->offset();
  2806       if (pc > begin) {
  2807         if (pc <= end) {
  2808           st->move_to(column);
  2809           st->print("; ");
  2810           om->print_on(st);
  2812         break;
  2817   // Print any debug info present at this pc.
  2818   ScopeDesc* sd  = scope_desc_in(begin, end);
  2819   if (sd != NULL) {
  2820     st->move_to(column);
  2821     if (sd->bci() == SynchronizationEntryBCI) {
  2822       st->print(";*synchronization entry");
  2823     } else {
  2824       if (sd->method() == NULL) {
  2825         st->print("method is NULL");
  2826       } else if (sd->method()->is_native()) {
  2827         st->print("method is native");
  2828       } else {
  2829         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
  2830         st->print(";*%s", Bytecodes::name(bc));
  2831         switch (bc) {
  2832         case Bytecodes::_invokevirtual:
  2833         case Bytecodes::_invokespecial:
  2834         case Bytecodes::_invokestatic:
  2835         case Bytecodes::_invokeinterface:
  2837             Bytecode_invoke invoke(sd->method(), sd->bci());
  2838             st->print(" ");
  2839             if (invoke.name() != NULL)
  2840               invoke.name()->print_symbol_on(st);
  2841             else
  2842               st->print("<UNKNOWN>");
  2843             break;
  2845         case Bytecodes::_getfield:
  2846         case Bytecodes::_putfield:
  2847         case Bytecodes::_getstatic:
  2848         case Bytecodes::_putstatic:
  2850             Bytecode_field field(sd->method(), sd->bci());
  2851             st->print(" ");
  2852             if (field.name() != NULL)
  2853               field.name()->print_symbol_on(st);
  2854             else
  2855               st->print("<UNKNOWN>");
  2861     // Print all scopes
  2862     for (;sd != NULL; sd = sd->sender()) {
  2863       st->move_to(column);
  2864       st->print("; -");
  2865       if (sd->method() == NULL) {
  2866         st->print("method is NULL");
  2867       } else {
  2868         sd->method()->print_short_name(st);
  2870       int lineno = sd->method()->line_number_from_bci(sd->bci());
  2871       if (lineno != -1) {
  2872         st->print("@%d (line %d)", sd->bci(), lineno);
  2873       } else {
  2874         st->print("@%d", sd->bci());
  2876       st->cr();
  2880   // Print relocation information
  2881   const char* str = reloc_string_for(begin, end);
  2882   if (str != NULL) {
  2883     if (sd != NULL) st->cr();
  2884     st->move_to(column);
  2885     st->print(";   {%s}", str);
  2887   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
  2888   if (cont_offset != 0) {
  2889     st->move_to(column);
  2890     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
  2895 #ifndef PRODUCT
  2897 void nmethod::print_value_on(outputStream* st) const {
  2898   st->print("nmethod");
  2899   print_on(st, NULL);
  2902 void nmethod::print_calls(outputStream* st) {
  2903   RelocIterator iter(this);
  2904   while (iter.next()) {
  2905     switch (iter.type()) {
  2906     case relocInfo::virtual_call_type:
  2907     case relocInfo::opt_virtual_call_type: {
  2908       VerifyMutexLocker mc(CompiledIC_lock);
  2909       CompiledIC_at(iter.reloc())->print();
  2910       break;
  2912     case relocInfo::static_call_type:
  2913       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
  2914       compiledStaticCall_at(iter.reloc())->print();
  2915       break;
  2920 void nmethod::print_handler_table() {
  2921   ExceptionHandlerTable(this).print();
  2924 void nmethod::print_nul_chk_table() {
  2925   ImplicitExceptionTable(this).print(code_begin());
  2928 void nmethod::print_statistics() {
  2929   ttyLocker ttyl;
  2930   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
  2931   nmethod_stats.print_native_nmethod_stats();
  2932   nmethod_stats.print_nmethod_stats();
  2933   DebugInformationRecorder::print_statistics();
  2934   nmethod_stats.print_pc_stats();
  2935   Dependencies::print_statistics();
  2936   if (xtty != NULL)  xtty->tail("statistics");
  2939 #endif // PRODUCT

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