src/share/vm/code/nmethod.cpp

Tue, 12 Nov 2013 09:32:50 +0100

author
anoll
date
Tue, 12 Nov 2013 09:32:50 +0100
changeset 6099
78da3894b86f
parent 6096
e2509677809c
child 6172
df832bd8edb9
child 6485
da862781b584
permissions
-rw-r--r--

8027593: performance drop with constrained codecache starting with hs25 b111
Summary: Fixed proper sweeping of small code cache sizes
Reviewed-by: kvn, iveresov

     1 /*
     2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    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) {
    97     return false;
    98   }
    99   return compiler()->is_c1();
   100 }
   101 bool nmethod::is_compiled_by_c2() const {
   102   if (compiler() == NULL) {
   103     return false;
   104   }
   105   return compiler()->is_c2();
   106 }
   107 bool nmethod::is_compiled_by_shark() const {
   108   if (compiler() == NULL) {
   109     return false;
   110   }
   111   return compiler()->is_shark();
   112 }
   116 //---------------------------------------------------------------------------------
   117 // NMethod statistics
   118 // They are printed under various flags, including:
   119 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
   120 // (In the latter two cases, they like other stats are printed to the log only.)
   122 #ifndef PRODUCT
   123 // These variables are put into one block to reduce relocations
   124 // and make it simpler to print from the debugger.
   125 static
   126 struct nmethod_stats_struct {
   127   int nmethod_count;
   128   int total_size;
   129   int relocation_size;
   130   int consts_size;
   131   int insts_size;
   132   int stub_size;
   133   int scopes_data_size;
   134   int scopes_pcs_size;
   135   int dependencies_size;
   136   int handler_table_size;
   137   int nul_chk_table_size;
   138   int oops_size;
   140   void note_nmethod(nmethod* nm) {
   141     nmethod_count += 1;
   142     total_size          += nm->size();
   143     relocation_size     += nm->relocation_size();
   144     consts_size         += nm->consts_size();
   145     insts_size          += nm->insts_size();
   146     stub_size           += nm->stub_size();
   147     oops_size           += nm->oops_size();
   148     scopes_data_size    += nm->scopes_data_size();
   149     scopes_pcs_size     += nm->scopes_pcs_size();
   150     dependencies_size   += nm->dependencies_size();
   151     handler_table_size  += nm->handler_table_size();
   152     nul_chk_table_size  += nm->nul_chk_table_size();
   153   }
   154   void print_nmethod_stats() {
   155     if (nmethod_count == 0)  return;
   156     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
   157     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
   158     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
   159     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
   160     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
   161     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
   162     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
   163     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
   164     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
   165     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
   166     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
   167     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
   168   }
   170   int native_nmethod_count;
   171   int native_total_size;
   172   int native_relocation_size;
   173   int native_insts_size;
   174   int native_oops_size;
   175   void note_native_nmethod(nmethod* nm) {
   176     native_nmethod_count += 1;
   177     native_total_size       += nm->size();
   178     native_relocation_size  += nm->relocation_size();
   179     native_insts_size       += nm->insts_size();
   180     native_oops_size        += nm->oops_size();
   181   }
   182   void print_native_nmethod_stats() {
   183     if (native_nmethod_count == 0)  return;
   184     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
   185     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
   186     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
   187     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
   188     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
   189   }
   191   int pc_desc_resets;   // number of resets (= number of caches)
   192   int pc_desc_queries;  // queries to nmethod::find_pc_desc
   193   int pc_desc_approx;   // number of those which have approximate true
   194   int pc_desc_repeats;  // number of _pc_descs[0] hits
   195   int pc_desc_hits;     // number of LRU cache hits
   196   int pc_desc_tests;    // total number of PcDesc examinations
   197   int pc_desc_searches; // total number of quasi-binary search steps
   198   int pc_desc_adds;     // number of LUR cache insertions
   200   void print_pc_stats() {
   201     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
   202                   pc_desc_queries,
   203                   (double)(pc_desc_tests + pc_desc_searches)
   204                   / pc_desc_queries);
   205     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
   206                   pc_desc_resets,
   207                   pc_desc_queries, pc_desc_approx,
   208                   pc_desc_repeats, pc_desc_hits,
   209                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
   210   }
   211 } nmethod_stats;
   212 #endif //PRODUCT
   215 //---------------------------------------------------------------------------------
   218 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
   219   assert(pc != NULL, "Must be non null");
   220   assert(exception.not_null(), "Must be non null");
   221   assert(handler != NULL, "Must be non null");
   223   _count = 0;
   224   _exception_type = exception->klass();
   225   _next = NULL;
   227   add_address_and_handler(pc,handler);
   228 }
   231 address ExceptionCache::match(Handle exception, address pc) {
   232   assert(pc != NULL,"Must be non null");
   233   assert(exception.not_null(),"Must be non null");
   234   if (exception->klass() == exception_type()) {
   235     return (test_address(pc));
   236   }
   238   return NULL;
   239 }
   242 bool ExceptionCache::match_exception_with_space(Handle exception) {
   243   assert(exception.not_null(),"Must be non null");
   244   if (exception->klass() == exception_type() && count() < cache_size) {
   245     return true;
   246   }
   247   return false;
   248 }
   251 address ExceptionCache::test_address(address addr) {
   252   for (int i=0; i<count(); i++) {
   253     if (pc_at(i) == addr) {
   254       return handler_at(i);
   255     }
   256   }
   257   return NULL;
   258 }
   261 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
   262   if (test_address(addr) == handler) return true;
   263   if (count() < cache_size) {
   264     set_pc_at(count(),addr);
   265     set_handler_at(count(), handler);
   266     increment_count();
   267     return true;
   268   }
   269   return false;
   270 }
   273 // private method for handling exception cache
   274 // These methods are private, and used to manipulate the exception cache
   275 // directly.
   276 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
   277   ExceptionCache* ec = exception_cache();
   278   while (ec != NULL) {
   279     if (ec->match_exception_with_space(exception)) {
   280       return ec;
   281     }
   282     ec = ec->next();
   283   }
   284   return NULL;
   285 }
   288 //-----------------------------------------------------------------------------
   291 // Helper used by both find_pc_desc methods.
   292 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
   293   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
   294   if (!approximate)
   295     return pc->pc_offset() == pc_offset;
   296   else
   297     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
   298 }
   300 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
   301   if (initial_pc_desc == NULL) {
   302     _pc_descs[0] = NULL; // native method; no PcDescs at all
   303     return;
   304   }
   305   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
   306   // reset the cache by filling it with benign (non-null) values
   307   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
   308   for (int i = 0; i < cache_size; i++)
   309     _pc_descs[i] = initial_pc_desc;
   310 }
   312 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
   313   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
   314   NOT_PRODUCT(if (approximate) ++nmethod_stats.pc_desc_approx);
   316   // Note: one might think that caching the most recently
   317   // read value separately would be a win, but one would be
   318   // wrong.  When many threads are updating it, the cache
   319   // line it's in would bounce between caches, negating
   320   // any benefit.
   322   // In order to prevent race conditions do not load cache elements
   323   // repeatedly, but use a local copy:
   324   PcDesc* res;
   326   // Step one:  Check the most recently added value.
   327   res = _pc_descs[0];
   328   if (res == NULL) return NULL;  // native method; no PcDescs at all
   329   if (match_desc(res, pc_offset, approximate)) {
   330     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
   331     return res;
   332   }
   334   // Step two:  Check the rest of the LRU cache.
   335   for (int i = 1; i < cache_size; ++i) {
   336     res = _pc_descs[i];
   337     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
   338     if (match_desc(res, pc_offset, approximate)) {
   339       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
   340       return res;
   341     }
   342   }
   344   // Report failure.
   345   return NULL;
   346 }
   348 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
   349   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
   350   // Update the LRU cache by shifting pc_desc forward.
   351   for (int i = 0; i < cache_size; i++)  {
   352     PcDesc* next = _pc_descs[i];
   353     _pc_descs[i] = pc_desc;
   354     pc_desc = next;
   355   }
   356 }
   358 // adjust pcs_size so that it is a multiple of both oopSize and
   359 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
   360 // of oopSize, then 2*sizeof(PcDesc) is)
   361 static int adjust_pcs_size(int pcs_size) {
   362   int nsize = round_to(pcs_size,   oopSize);
   363   if ((nsize % sizeof(PcDesc)) != 0) {
   364     nsize = pcs_size + sizeof(PcDesc);
   365   }
   366   assert((nsize % oopSize) == 0, "correct alignment");
   367   return nsize;
   368 }
   370 //-----------------------------------------------------------------------------
   373 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
   374   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
   375   assert(new_entry != NULL,"Must be non null");
   376   assert(new_entry->next() == NULL, "Must be null");
   378   if (exception_cache() != NULL) {
   379     new_entry->set_next(exception_cache());
   380   }
   381   set_exception_cache(new_entry);
   382 }
   384 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
   385   ExceptionCache* prev = NULL;
   386   ExceptionCache* curr = exception_cache();
   387   assert(curr != NULL, "nothing to remove");
   388   // find the previous and next entry of ec
   389   while (curr != ec) {
   390     prev = curr;
   391     curr = curr->next();
   392     assert(curr != NULL, "ExceptionCache not found");
   393   }
   394   // now: curr == ec
   395   ExceptionCache* next = curr->next();
   396   if (prev == NULL) {
   397     set_exception_cache(next);
   398   } else {
   399     prev->set_next(next);
   400   }
   401   delete curr;
   402 }
   405 // public method for accessing the exception cache
   406 // These are the public access methods.
   407 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
   408   // We never grab a lock to read the exception cache, so we may
   409   // have false negatives. This is okay, as it can only happen during
   410   // the first few exception lookups for a given nmethod.
   411   ExceptionCache* ec = exception_cache();
   412   while (ec != NULL) {
   413     address ret_val;
   414     if ((ret_val = ec->match(exception,pc)) != NULL) {
   415       return ret_val;
   416     }
   417     ec = ec->next();
   418   }
   419   return NULL;
   420 }
   423 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
   424   // There are potential race conditions during exception cache updates, so we
   425   // must own the ExceptionCache_lock before doing ANY modifications. Because
   426   // we don't lock during reads, it is possible to have several threads attempt
   427   // to update the cache with the same data. We need to check for already inserted
   428   // copies of the current data before adding it.
   430   MutexLocker ml(ExceptionCache_lock);
   431   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
   433   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
   434     target_entry = new ExceptionCache(exception,pc,handler);
   435     add_exception_cache_entry(target_entry);
   436   }
   437 }
   440 //-------------end of code for ExceptionCache--------------
   443 int nmethod::total_size() const {
   444   return
   445     consts_size()        +
   446     insts_size()         +
   447     stub_size()          +
   448     scopes_data_size()   +
   449     scopes_pcs_size()    +
   450     handler_table_size() +
   451     nul_chk_table_size();
   452 }
   454 const char* nmethod::compile_kind() const {
   455   if (is_osr_method())     return "osr";
   456   if (method() != NULL && is_native_method())  return "c2n";
   457   return NULL;
   458 }
   460 // Fill in default values for various flag fields
   461 void nmethod::init_defaults() {
   462   _state                      = alive;
   463   _marked_for_reclamation     = 0;
   464   _has_flushed_dependencies   = 0;
   465   _has_unsafe_access          = 0;
   466   _has_method_handle_invokes  = 0;
   467   _lazy_critical_native       = 0;
   468   _has_wide_vectors           = 0;
   469   _marked_for_deoptimization  = 0;
   470   _lock_count                 = 0;
   471   _stack_traversal_mark       = 0;
   472   _unload_reported            = false;           // jvmti state
   474 #ifdef ASSERT
   475   _oops_are_stale             = false;
   476 #endif
   478   _oops_do_mark_link       = NULL;
   479   _jmethod_id              = NULL;
   480   _osr_link                = NULL;
   481   _scavenge_root_link      = NULL;
   482   _scavenge_root_state     = 0;
   483   _compiler                = NULL;
   485 #ifdef HAVE_DTRACE_H
   486   _trap_offset             = 0;
   487 #endif // def HAVE_DTRACE_H
   488 }
   490 nmethod* nmethod::new_native_nmethod(methodHandle method,
   491   int compile_id,
   492   CodeBuffer *code_buffer,
   493   int vep_offset,
   494   int frame_complete,
   495   int frame_size,
   496   ByteSize basic_lock_owner_sp_offset,
   497   ByteSize basic_lock_sp_offset,
   498   OopMapSet* oop_maps) {
   499   code_buffer->finalize_oop_references(method);
   500   // create nmethod
   501   nmethod* nm = NULL;
   502   {
   503     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   504     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   505     CodeOffsets offsets;
   506     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   507     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   508     nm = new (native_nmethod_size) nmethod(method(), native_nmethod_size,
   509                                             compile_id, &offsets,
   510                                             code_buffer, frame_size,
   511                                             basic_lock_owner_sp_offset,
   512                                             basic_lock_sp_offset, oop_maps);
   513     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
   514     if (PrintAssembly && nm != NULL) {
   515       Disassembler::decode(nm);
   516     }
   517   }
   518   // verify nmethod
   519   debug_only(if (nm) nm->verify();) // might block
   521   if (nm != NULL) {
   522     nm->log_new_nmethod();
   523   }
   525   return nm;
   526 }
   528 #ifdef HAVE_DTRACE_H
   529 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
   530                                      CodeBuffer *code_buffer,
   531                                      int vep_offset,
   532                                      int trap_offset,
   533                                      int frame_complete,
   534                                      int frame_size) {
   535   code_buffer->finalize_oop_references(method);
   536   // create nmethod
   537   nmethod* nm = NULL;
   538   {
   539     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   540     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   541     CodeOffsets offsets;
   542     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   543     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
   544     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   546     nm = new (nmethod_size) nmethod(method(), nmethod_size,
   547                                     &offsets, code_buffer, frame_size);
   549     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
   550     if (PrintAssembly && nm != NULL) {
   551       Disassembler::decode(nm);
   552     }
   553   }
   554   // verify nmethod
   555   debug_only(if (nm) nm->verify();) // might block
   557   if (nm != NULL) {
   558     nm->log_new_nmethod();
   559   }
   561   return nm;
   562 }
   564 #endif // def HAVE_DTRACE_H
   566 nmethod* nmethod::new_nmethod(methodHandle method,
   567   int compile_id,
   568   int entry_bci,
   569   CodeOffsets* offsets,
   570   int orig_pc_offset,
   571   DebugInformationRecorder* debug_info,
   572   Dependencies* dependencies,
   573   CodeBuffer* code_buffer, int frame_size,
   574   OopMapSet* oop_maps,
   575   ExceptionHandlerTable* handler_table,
   576   ImplicitExceptionTable* nul_chk_table,
   577   AbstractCompiler* compiler,
   578   int comp_level
   579 )
   580 {
   581   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   582   code_buffer->finalize_oop_references(method);
   583   // create nmethod
   584   nmethod* nm = NULL;
   585   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   586     int nmethod_size =
   587       allocation_size(code_buffer, sizeof(nmethod))
   588       + adjust_pcs_size(debug_info->pcs_size())
   589       + round_to(dependencies->size_in_bytes() , oopSize)
   590       + round_to(handler_table->size_in_bytes(), oopSize)
   591       + round_to(nul_chk_table->size_in_bytes(), oopSize)
   592       + round_to(debug_info->data_size()       , oopSize);
   594     nm = new (nmethod_size)
   595     nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
   596             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
   597             oop_maps,
   598             handler_table,
   599             nul_chk_table,
   600             compiler,
   601             comp_level);
   603     if (nm != NULL) {
   604       // To make dependency checking during class loading fast, record
   605       // the nmethod dependencies in the classes it is dependent on.
   606       // This allows the dependency checking code to simply walk the
   607       // class hierarchy above the loaded class, checking only nmethods
   608       // which are dependent on those classes.  The slow way is to
   609       // check every nmethod for dependencies which makes it linear in
   610       // the number of methods compiled.  For applications with a lot
   611       // classes the slow way is too slow.
   612       for (Dependencies::DepStream deps(nm); deps.next(); ) {
   613         Klass* klass = deps.context_type();
   614         if (klass == NULL) {
   615           continue;  // ignore things like evol_method
   616         }
   618         // record this nmethod as dependent on this klass
   619         InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
   620       }
   621       NOT_PRODUCT(nmethod_stats.note_nmethod(nm));
   622       if (PrintAssembly) {
   623         Disassembler::decode(nm);
   624       }
   625     }
   626   }
   627   // Do verification and logging outside CodeCache_lock.
   628   if (nm != NULL) {
   629     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
   630     DEBUG_ONLY(nm->verify();)
   631     nm->log_new_nmethod();
   632   }
   633   return nm;
   634 }
   637 // For native wrappers
   638 nmethod::nmethod(
   639   Method* method,
   640   int nmethod_size,
   641   int compile_id,
   642   CodeOffsets* offsets,
   643   CodeBuffer* code_buffer,
   644   int frame_size,
   645   ByteSize basic_lock_owner_sp_offset,
   646   ByteSize basic_lock_sp_offset,
   647   OopMapSet* oop_maps )
   648   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
   649              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   650   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
   651   _native_basic_lock_sp_offset(basic_lock_sp_offset)
   652 {
   653   {
   654     debug_only(No_Safepoint_Verifier nsv;)
   655     assert_locked_or_safepoint(CodeCache_lock);
   657     init_defaults();
   658     _method                  = method;
   659     _entry_bci               = InvocationEntryBci;
   660     // We have no exception handler or deopt handler make the
   661     // values something that will never match a pc like the nmethod vtable entry
   662     _exception_offset        = 0;
   663     _deoptimize_offset       = 0;
   664     _deoptimize_mh_offset    = 0;
   665     _orig_pc_offset          = 0;
   667     _consts_offset           = data_offset();
   668     _stub_offset             = data_offset();
   669     _oops_offset             = data_offset();
   670     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
   671     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
   672     _scopes_pcs_offset       = _scopes_data_offset;
   673     _dependencies_offset     = _scopes_pcs_offset;
   674     _handler_table_offset    = _dependencies_offset;
   675     _nul_chk_table_offset    = _handler_table_offset;
   676     _nmethod_end_offset      = _nul_chk_table_offset;
   677     _compile_id              = compile_id;
   678     _comp_level              = CompLevel_none;
   679     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
   680     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
   681     _osr_entry_point         = NULL;
   682     _exception_cache         = NULL;
   683     _pc_desc_cache.reset_to(NULL);
   684     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
   686     code_buffer->copy_values_to(this);
   687     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
   688       CodeCache::add_scavenge_root_nmethod(this);
   689       Universe::heap()->register_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);
   769     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
   771     code_buffer->copy_values_to(this);
   772     debug_only(verify_scavenge_root_oops());
   773     CodeCache::commit(this);
   774   }
   776   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
   777     ttyLocker ttyl;  // keep the following output all in one block
   778     // This output goes directly to the tty, not the compiler log.
   779     // To enable tools to match it up with the compilation activity,
   780     // be sure to tag this tty output with the compile ID.
   781     if (xtty != NULL) {
   782       xtty->begin_head("print_dtrace_nmethod");
   783       xtty->method(_method);
   784       xtty->stamp();
   785       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   786     }
   787     // print the header part first
   788     print();
   789     // then print the requested information
   790     if (PrintNMethods) {
   791       print_code();
   792     }
   793     if (PrintRelocations) {
   794       print_relocations();
   795     }
   796     if (xtty != NULL) {
   797       xtty->tail("print_dtrace_nmethod");
   798     }
   799   }
   800 }
   801 #endif // def HAVE_DTRACE_H
   803 void* nmethod::operator new(size_t size, int nmethod_size) throw() {
   804   // Not critical, may return null if there is too little continuous memory
   805   return CodeCache::allocate(nmethod_size);
   806 }
   808 nmethod::nmethod(
   809   Method* method,
   810   int nmethod_size,
   811   int compile_id,
   812   int entry_bci,
   813   CodeOffsets* offsets,
   814   int orig_pc_offset,
   815   DebugInformationRecorder* debug_info,
   816   Dependencies* dependencies,
   817   CodeBuffer *code_buffer,
   818   int frame_size,
   819   OopMapSet* oop_maps,
   820   ExceptionHandlerTable* handler_table,
   821   ImplicitExceptionTable* nul_chk_table,
   822   AbstractCompiler* compiler,
   823   int comp_level
   824   )
   825   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
   826              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   827   _native_receiver_sp_offset(in_ByteSize(-1)),
   828   _native_basic_lock_sp_offset(in_ByteSize(-1))
   829 {
   830   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   831   {
   832     debug_only(No_Safepoint_Verifier nsv;)
   833     assert_locked_or_safepoint(CodeCache_lock);
   835     init_defaults();
   836     _method                  = method;
   837     _entry_bci               = entry_bci;
   838     _compile_id              = compile_id;
   839     _comp_level              = comp_level;
   840     _compiler                = compiler;
   841     _orig_pc_offset          = orig_pc_offset;
   842     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
   844     // Section offsets
   845     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
   846     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
   848     // Exception handler and deopt handler are in the stub section
   849     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
   850     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
   851     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
   852     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
   853     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
   854       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
   855     } else {
   856       _deoptimize_mh_offset  = -1;
   857     }
   858     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
   859       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
   860     } else {
   861       _unwind_handler_offset = -1;
   862     }
   864     _oops_offset             = data_offset();
   865     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
   866     _scopes_data_offset      = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
   868     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
   869     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
   870     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
   871     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
   872     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
   874     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
   875     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
   876     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
   877     _exception_cache         = NULL;
   878     _pc_desc_cache.reset_to(scopes_pcs_begin());
   880     // Copy contents of ScopeDescRecorder to nmethod
   881     code_buffer->copy_values_to(this);
   882     debug_info->copy_to(this);
   883     dependencies->copy_to(this);
   884     if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
   885       CodeCache::add_scavenge_root_nmethod(this);
   886       Universe::heap()->register_nmethod(this);
   887     }
   888     debug_only(verify_scavenge_root_oops());
   890     CodeCache::commit(this);
   892     // Copy contents of ExceptionHandlerTable to nmethod
   893     handler_table->copy_to(this);
   894     nul_chk_table->copy_to(this);
   896     // we use the information of entry points to find out if a method is
   897     // static or non static
   898     assert(compiler->is_c2() ||
   899            _method->is_static() == (entry_point() == _verified_entry_point),
   900            " entry points must be same for static methods and vice versa");
   901   }
   903   bool printnmethods = PrintNMethods
   904     || CompilerOracle::should_print(_method)
   905     || CompilerOracle::has_option_string(_method, "PrintNMethods");
   906   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
   907     print_nmethod(printnmethods);
   908   }
   909 }
   912 // Print a short set of xml attributes to identify this nmethod.  The
   913 // output should be embedded in some other element.
   914 void nmethod::log_identity(xmlStream* log) const {
   915   log->print(" compile_id='%d'", compile_id());
   916   const char* nm_kind = compile_kind();
   917   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
   918   if (compiler() != NULL) {
   919     log->print(" compiler='%s'", compiler()->name());
   920   }
   921   if (TieredCompilation) {
   922     log->print(" level='%d'", comp_level());
   923   }
   924 }
   927 #define LOG_OFFSET(log, name)                    \
   928   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
   929     log->print(" " XSTR(name) "_offset='%d'"    , \
   930                (intptr_t)name##_begin() - (intptr_t)this)
   933 void nmethod::log_new_nmethod() const {
   934   if (LogCompilation && xtty != NULL) {
   935     ttyLocker ttyl;
   936     HandleMark hm;
   937     xtty->begin_elem("nmethod");
   938     log_identity(xtty);
   939     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
   940     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   942     LOG_OFFSET(xtty, relocation);
   943     LOG_OFFSET(xtty, consts);
   944     LOG_OFFSET(xtty, insts);
   945     LOG_OFFSET(xtty, stub);
   946     LOG_OFFSET(xtty, scopes_data);
   947     LOG_OFFSET(xtty, scopes_pcs);
   948     LOG_OFFSET(xtty, dependencies);
   949     LOG_OFFSET(xtty, handler_table);
   950     LOG_OFFSET(xtty, nul_chk_table);
   951     LOG_OFFSET(xtty, oops);
   953     xtty->method(method());
   954     xtty->stamp();
   955     xtty->end_elem();
   956   }
   957 }
   959 #undef LOG_OFFSET
   962 // Print out more verbose output usually for a newly created nmethod.
   963 void nmethod::print_on(outputStream* st, const char* msg) const {
   964   if (st != NULL) {
   965     ttyLocker ttyl;
   966     if (WizardMode) {
   967       CompileTask::print_compilation(st, this, msg, /*short_form:*/ true);
   968       st->print_cr(" (" INTPTR_FORMAT ")", this);
   969     } else {
   970       CompileTask::print_compilation(st, this, msg, /*short_form:*/ false);
   971     }
   972   }
   973 }
   976 void nmethod::print_nmethod(bool printmethod) {
   977   ttyLocker ttyl;  // keep the following output all in one block
   978   if (xtty != NULL) {
   979     xtty->begin_head("print_nmethod");
   980     xtty->stamp();
   981     xtty->end_head();
   982   }
   983   // print the header part first
   984   print();
   985   // then print the requested information
   986   if (printmethod) {
   987     print_code();
   988     print_pcs();
   989     if (oop_maps()) {
   990       oop_maps()->print();
   991     }
   992   }
   993   if (PrintDebugInfo) {
   994     print_scopes();
   995   }
   996   if (PrintRelocations) {
   997     print_relocations();
   998   }
   999   if (PrintDependencies) {
  1000     print_dependencies();
  1002   if (PrintExceptionHandlers) {
  1003     print_handler_table();
  1004     print_nul_chk_table();
  1006   if (xtty != NULL) {
  1007     xtty->tail("print_nmethod");
  1012 // Promote one word from an assembly-time handle to a live embedded oop.
  1013 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
  1014   if (handle == NULL ||
  1015       // As a special case, IC oops are initialized to 1 or -1.
  1016       handle == (jobject) Universe::non_oop_word()) {
  1017     (*dest) = (oop) handle;
  1018   } else {
  1019     (*dest) = JNIHandles::resolve_non_null(handle);
  1024 // Have to have the same name because it's called by a template
  1025 void nmethod::copy_values(GrowableArray<jobject>* array) {
  1026   int length = array->length();
  1027   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
  1028   oop* dest = oops_begin();
  1029   for (int index = 0 ; index < length; index++) {
  1030     initialize_immediate_oop(&dest[index], array->at(index));
  1033   // Now we can fix up all the oops in the code.  We need to do this
  1034   // in the code because the assembler uses jobjects as placeholders.
  1035   // The code and relocations have already been initialized by the
  1036   // CodeBlob constructor, so it is valid even at this early point to
  1037   // iterate over relocations and patch the code.
  1038   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
  1041 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
  1042   int length = array->length();
  1043   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
  1044   Metadata** dest = metadata_begin();
  1045   for (int index = 0 ; index < length; index++) {
  1046     dest[index] = array->at(index);
  1050 bool nmethod::is_at_poll_return(address pc) {
  1051   RelocIterator iter(this, pc, pc+1);
  1052   while (iter.next()) {
  1053     if (iter.type() == relocInfo::poll_return_type)
  1054       return true;
  1056   return false;
  1060 bool nmethod::is_at_poll_or_poll_return(address pc) {
  1061   RelocIterator iter(this, pc, pc+1);
  1062   while (iter.next()) {
  1063     relocInfo::relocType t = iter.type();
  1064     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
  1065       return true;
  1067   return false;
  1071 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
  1072   // re-patch all oop-bearing instructions, just in case some oops moved
  1073   RelocIterator iter(this, begin, end);
  1074   while (iter.next()) {
  1075     if (iter.type() == relocInfo::oop_type) {
  1076       oop_Relocation* reloc = iter.oop_reloc();
  1077       if (initialize_immediates && reloc->oop_is_immediate()) {
  1078         oop* dest = reloc->oop_addr();
  1079         initialize_immediate_oop(dest, (jobject) *dest);
  1081       // Refresh the oop-related bits of this instruction.
  1082       reloc->fix_oop_relocation();
  1083     } else if (iter.type() == relocInfo::metadata_type) {
  1084       metadata_Relocation* reloc = iter.metadata_reloc();
  1085       reloc->fix_metadata_relocation();
  1091 void nmethod::verify_oop_relocations() {
  1092   // Ensure sure that the code matches the current oop values
  1093   RelocIterator iter(this, NULL, NULL);
  1094   while (iter.next()) {
  1095     if (iter.type() == relocInfo::oop_type) {
  1096       oop_Relocation* reloc = iter.oop_reloc();
  1097       if (!reloc->oop_is_immediate()) {
  1098         reloc->verify_oop_relocation();
  1105 ScopeDesc* nmethod::scope_desc_at(address pc) {
  1106   PcDesc* pd = pc_desc_at(pc);
  1107   guarantee(pd != NULL, "scope must be present");
  1108   return new ScopeDesc(this, pd->scope_decode_offset(),
  1109                        pd->obj_decode_offset(), pd->should_reexecute(),
  1110                        pd->return_oop());
  1114 void nmethod::clear_inline_caches() {
  1115   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
  1116   if (is_zombie()) {
  1117     return;
  1120   RelocIterator iter(this);
  1121   while (iter.next()) {
  1122     iter.reloc()->clear_inline_cache();
  1127 void nmethod::cleanup_inline_caches() {
  1129   assert_locked_or_safepoint(CompiledIC_lock);
  1131   // If the method is not entrant or zombie then a JMP is plastered over the
  1132   // first few bytes.  If an oop in the old code was there, that oop
  1133   // should not get GC'd.  Skip the first few bytes of oops on
  1134   // not-entrant methods.
  1135   address low_boundary = verified_entry_point();
  1136   if (!is_in_use()) {
  1137     low_boundary += NativeJump::instruction_size;
  1138     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1139     // This means that the low_boundary is going to be a little too high.
  1140     // This shouldn't matter, since oops of non-entrant methods are never used.
  1141     // In fact, why are we bothering to look at oops in a non-entrant method??
  1144   // Find all calls in an nmethod, and clear the ones that points to zombie methods
  1145   ResourceMark rm;
  1146   RelocIterator iter(this, low_boundary);
  1147   while(iter.next()) {
  1148     switch(iter.type()) {
  1149       case relocInfo::virtual_call_type:
  1150       case relocInfo::opt_virtual_call_type: {
  1151         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1152         // Ok, to lookup references to zombies here
  1153         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
  1154         if( cb != NULL && cb->is_nmethod() ) {
  1155           nmethod* nm = (nmethod*)cb;
  1156           // Clean inline caches pointing to both zombie and not_entrant methods
  1157           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
  1159         break;
  1161       case relocInfo::static_call_type: {
  1162         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
  1163         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
  1164         if( cb != NULL && cb->is_nmethod() ) {
  1165           nmethod* nm = (nmethod*)cb;
  1166           // Clean inline caches pointing to both zombie and not_entrant methods
  1167           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
  1169         break;
  1175 // This is a private interface with the sweeper.
  1176 void nmethod::mark_as_seen_on_stack() {
  1177   assert(is_alive(), "Must be an alive method");
  1178   // Set the traversal mark to ensure that the sweeper does 2
  1179   // cleaning passes before moving to zombie.
  1180   set_stack_traversal_mark(NMethodSweeper::traversal_count());
  1183 // Tell if a non-entrant method can be converted to a zombie (i.e.,
  1184 // there are no activations on the stack, not in use by the VM,
  1185 // and not in use by the ServiceThread)
  1186 bool nmethod::can_not_entrant_be_converted() {
  1187   assert(is_not_entrant(), "must be a non-entrant method");
  1189   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
  1190   // count can be greater than the stack traversal count before it hits the
  1191   // nmethod for the second time.
  1192   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
  1193          !is_locked_by_vm();
  1196 void nmethod::inc_decompile_count() {
  1197   if (!is_compiled_by_c2()) return;
  1198   // Could be gated by ProfileTraps, but do not bother...
  1199   Method* m = method();
  1200   if (m == NULL)  return;
  1201   MethodData* mdo = m->method_data();
  1202   if (mdo == NULL)  return;
  1203   // There is a benign race here.  See comments in methodData.hpp.
  1204   mdo->inc_decompile_count();
  1207 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
  1209   post_compiled_method_unload();
  1211   // Since this nmethod is being unloaded, make sure that dependencies
  1212   // recorded in instanceKlasses get flushed and pass non-NULL closure to
  1213   // indicate that this work is being done during a GC.
  1214   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
  1215   assert(is_alive != NULL, "Should be non-NULL");
  1216   // A non-NULL is_alive closure indicates that this is being called during GC.
  1217   flush_dependencies(is_alive);
  1219   // Break cycle between nmethod & method
  1220   if (TraceClassUnloading && WizardMode) {
  1221     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
  1222                   " unloadable], Method*(" INTPTR_FORMAT
  1223                   "), cause(" INTPTR_FORMAT ")",
  1224                   this, (address)_method, (address)cause);
  1225     if (!Universe::heap()->is_gc_active())
  1226       cause->klass()->print();
  1228   // Unlink the osr method, so we do not look this up again
  1229   if (is_osr_method()) {
  1230     invalidate_osr_method();
  1232   // If _method is already NULL the Method* is about to be unloaded,
  1233   // so we don't have to break the cycle. Note that it is possible to
  1234   // have the Method* live here, in case we unload the nmethod because
  1235   // it is pointing to some oop (other than the Method*) being unloaded.
  1236   if (_method != NULL) {
  1237     // OSR methods point to the Method*, but the Method* does not
  1238     // point back!
  1239     if (_method->code() == this) {
  1240       _method->clear_code(); // Break a cycle
  1242     _method = NULL;            // Clear the method of this dead nmethod
  1244   // Make the class unloaded - i.e., change state and notify sweeper
  1245   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1246   if (is_in_use()) {
  1247     // Transitioning directly from live to unloaded -- so
  1248     // we need to force a cache clean-up; remember this
  1249     // for later on.
  1250     CodeCache::set_needs_cache_clean(true);
  1252   _state = unloaded;
  1254   // Log the unloading.
  1255   log_state_change();
  1257   // The Method* is gone at this point
  1258   assert(_method == NULL, "Tautology");
  1260   set_osr_link(NULL);
  1261   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
  1262   NMethodSweeper::report_state_change(this);
  1265 void nmethod::invalidate_osr_method() {
  1266   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
  1267   // Remove from list of active nmethods
  1268   if (method() != NULL)
  1269     method()->method_holder()->remove_osr_nmethod(this);
  1270   // Set entry as invalid
  1271   _entry_bci = InvalidOSREntryBci;
  1274 void nmethod::log_state_change() const {
  1275   if (LogCompilation) {
  1276     if (xtty != NULL) {
  1277       ttyLocker ttyl;  // keep the following output all in one block
  1278       if (_state == unloaded) {
  1279         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
  1280                          os::current_thread_id());
  1281       } else {
  1282         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
  1283                          os::current_thread_id(),
  1284                          (_state == zombie ? " zombie='1'" : ""));
  1286       log_identity(xtty);
  1287       xtty->stamp();
  1288       xtty->end_elem();
  1291   if (PrintCompilation && _state != unloaded) {
  1292     print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
  1296 /**
  1297  * Common functionality for both make_not_entrant and make_zombie
  1298  */
  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;
  1308   // during patching, depending on the nmethod state we must notify the GC that
  1309   // code has been unloaded, unregistering it. We cannot do this right while
  1310   // holding the Patching_lock because we need to use the CodeCache_lock. This
  1311   // would be prone to deadlocks.
  1312   // This flag is used to remember whether we need to later lock and unregister.
  1313   bool nmethod_needs_unregister = false;
  1316     // invalidate osr nmethod before acquiring the patching lock since
  1317     // they both acquire leaf locks and we don't want a deadlock.
  1318     // This logic is equivalent to the logic below for patching the
  1319     // verified entry point of regular methods.
  1320     if (is_osr_method()) {
  1321       // this effectively makes the osr nmethod not entrant
  1322       invalidate_osr_method();
  1325     // Enter critical section.  Does not block for safepoint.
  1326     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
  1328     if (_state == state) {
  1329       // another thread already performed this transition so nothing
  1330       // to do, but return false to indicate this.
  1331       return false;
  1334     // The caller can be calling the method statically or through an inline
  1335     // cache call.
  1336     if (!is_osr_method() && !is_not_entrant()) {
  1337       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
  1338                   SharedRuntime::get_handle_wrong_method_stub());
  1341     if (is_in_use()) {
  1342       // It's a true state change, so mark the method as decompiled.
  1343       // Do it only for transition from alive.
  1344       inc_decompile_count();
  1347     // If the state is becoming a zombie, signal to unregister the nmethod with
  1348     // the heap.
  1349     // This nmethod may have already been unloaded during a full GC.
  1350     if ((state == zombie) && !is_unloaded()) {
  1351       nmethod_needs_unregister = true;
  1354     // Must happen before state change. Otherwise we have a race condition in
  1355     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
  1356     // transition its state from 'not_entrant' to 'zombie' without having to wait
  1357     // for stack scanning.
  1358     if (state == not_entrant) {
  1359       mark_as_seen_on_stack();
  1360       OrderAccess::storestore();
  1363     // Change state
  1364     _state = state;
  1366     // Log the transition once
  1367     log_state_change();
  1369     // Remove nmethod from method.
  1370     // We need to check if both the _code and _from_compiled_code_entry_point
  1371     // refer to this nmethod because there is a race in setting these two fields
  1372     // in Method* as seen in bugid 4947125.
  1373     // If the vep() points to the zombie nmethod, the memory for the nmethod
  1374     // could be flushed and the compiler and vtable stubs could still call
  1375     // through it.
  1376     if (method() != NULL && (method()->code() == this ||
  1377                              method()->from_compiled_entry() == verified_entry_point())) {
  1378       HandleMark hm;
  1379       method()->clear_code();
  1381   } // leave critical region under Patching_lock
  1383   // When the nmethod becomes zombie it is no longer alive so the
  1384   // dependencies must be flushed.  nmethods in the not_entrant
  1385   // state will be flushed later when the transition to zombie
  1386   // happens or they get unloaded.
  1387   if (state == zombie) {
  1389       // Flushing dependecies must be done before any possible
  1390       // safepoint can sneak in, otherwise the oops used by the
  1391       // dependency logic could have become stale.
  1392       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
  1393       if (nmethod_needs_unregister) {
  1394         Universe::heap()->unregister_nmethod(this);
  1396       flush_dependencies(NULL);
  1399     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
  1400     // event and it hasn't already been reported for this nmethod then
  1401     // report it now. The event may have been reported earilier if the GC
  1402     // marked it for unloading). JvmtiDeferredEventQueue support means
  1403     // we no longer go to a safepoint here.
  1404     post_compiled_method_unload();
  1406 #ifdef ASSERT
  1407     // It's no longer safe to access the oops section since zombie
  1408     // nmethods aren't scanned for GC.
  1409     _oops_are_stale = true;
  1410 #endif
  1411      // the Method may be reclaimed by class unloading now that the
  1412      // nmethod is in zombie state
  1413     set_method(NULL);
  1414   } else {
  1415     assert(state == not_entrant, "other cases may need to be handled differently");
  1418   if (TraceCreateZombies) {
  1419     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
  1422   NMethodSweeper::report_state_change(this);
  1423   return true;
  1426 void nmethod::flush() {
  1427   // Note that there are no valid oops in the nmethod anymore.
  1428   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
  1429   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
  1431   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
  1432   assert_locked_or_safepoint(CodeCache_lock);
  1434   // completely deallocate this method
  1435   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, this);
  1436   if (PrintMethodFlushing) {
  1437     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
  1438         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
  1441   // We need to deallocate any ExceptionCache data.
  1442   // Note that we do not need to grab the nmethod lock for this, it
  1443   // better be thread safe if we're disposing of it!
  1444   ExceptionCache* ec = exception_cache();
  1445   set_exception_cache(NULL);
  1446   while(ec != NULL) {
  1447     ExceptionCache* next = ec->next();
  1448     delete ec;
  1449     ec = next;
  1452   if (on_scavenge_root_list()) {
  1453     CodeCache::drop_scavenge_root_nmethod(this);
  1456 #ifdef SHARK
  1457   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
  1458 #endif // SHARK
  1460   ((CodeBlob*)(this))->flush();
  1462   CodeCache::free(this);
  1466 //
  1467 // Notify all classes this nmethod is dependent on that it is no
  1468 // longer dependent. This should only be called in two situations.
  1469 // First, when a nmethod transitions to a zombie all dependents need
  1470 // to be clear.  Since zombification happens at a safepoint there's no
  1471 // synchronization issues.  The second place is a little more tricky.
  1472 // During phase 1 of mark sweep class unloading may happen and as a
  1473 // result some nmethods may get unloaded.  In this case the flushing
  1474 // of dependencies must happen during phase 1 since after GC any
  1475 // dependencies in the unloaded nmethod won't be updated, so
  1476 // traversing the dependency information in unsafe.  In that case this
  1477 // function is called with a non-NULL argument and this function only
  1478 // notifies instanceKlasses that are reachable
  1480 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
  1481   assert_locked_or_safepoint(CodeCache_lock);
  1482   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
  1483   "is_alive is non-NULL if and only if we are called during GC");
  1484   if (!has_flushed_dependencies()) {
  1485     set_has_flushed_dependencies();
  1486     for (Dependencies::DepStream deps(this); deps.next(); ) {
  1487       Klass* klass = deps.context_type();
  1488       if (klass == NULL)  continue;  // ignore things like evol_method
  1490       // During GC the is_alive closure is non-NULL, and is used to
  1491       // determine liveness of dependees that need to be updated.
  1492       if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
  1493         InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
  1500 // If this oop is not live, the nmethod can be unloaded.
  1501 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
  1502   assert(root != NULL, "just checking");
  1503   oop obj = *root;
  1504   if (obj == NULL || is_alive->do_object_b(obj)) {
  1505       return false;
  1508   // If ScavengeRootsInCode is true, an nmethod might be unloaded
  1509   // simply because one of its constant oops has gone dead.
  1510   // No actual classes need to be unloaded in order for this to occur.
  1511   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
  1512   make_unloaded(is_alive, obj);
  1513   return true;
  1516 // ------------------------------------------------------------------
  1517 // post_compiled_method_load_event
  1518 // new method for install_code() path
  1519 // Transfer information from compilation to jvmti
  1520 void nmethod::post_compiled_method_load_event() {
  1522   Method* moop = method();
  1523 #ifndef USDT2
  1524   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
  1525       moop->klass_name()->bytes(),
  1526       moop->klass_name()->utf8_length(),
  1527       moop->name()->bytes(),
  1528       moop->name()->utf8_length(),
  1529       moop->signature()->bytes(),
  1530       moop->signature()->utf8_length(),
  1531       insts_begin(), insts_size());
  1532 #else /* USDT2 */
  1533   HOTSPOT_COMPILED_METHOD_LOAD(
  1534       (char *) moop->klass_name()->bytes(),
  1535       moop->klass_name()->utf8_length(),
  1536       (char *) moop->name()->bytes(),
  1537       moop->name()->utf8_length(),
  1538       (char *) moop->signature()->bytes(),
  1539       moop->signature()->utf8_length(),
  1540       insts_begin(), insts_size());
  1541 #endif /* USDT2 */
  1543   if (JvmtiExport::should_post_compiled_method_load() ||
  1544       JvmtiExport::should_post_compiled_method_unload()) {
  1545     get_and_cache_jmethod_id();
  1548   if (JvmtiExport::should_post_compiled_method_load()) {
  1549     // Let the Service thread (which is a real Java thread) post the event
  1550     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  1551     JvmtiDeferredEventQueue::enqueue(
  1552       JvmtiDeferredEvent::compiled_method_load_event(this));
  1556 jmethodID nmethod::get_and_cache_jmethod_id() {
  1557   if (_jmethod_id == NULL) {
  1558     // Cache the jmethod_id since it can no longer be looked up once the
  1559     // method itself has been marked for unloading.
  1560     _jmethod_id = method()->jmethod_id();
  1562   return _jmethod_id;
  1565 void nmethod::post_compiled_method_unload() {
  1566   if (unload_reported()) {
  1567     // During unloading we transition to unloaded and then to zombie
  1568     // and the unloading is reported during the first transition.
  1569     return;
  1572   assert(_method != NULL && !is_unloaded(), "just checking");
  1573   DTRACE_METHOD_UNLOAD_PROBE(method());
  1575   // If a JVMTI agent has enabled the CompiledMethodUnload event then
  1576   // post the event. Sometime later this nmethod will be made a zombie
  1577   // by the sweeper but the Method* will not be valid at that point.
  1578   // If the _jmethod_id is null then no load event was ever requested
  1579   // so don't bother posting the unload.  The main reason for this is
  1580   // that the jmethodID is a weak reference to the Method* so if
  1581   // it's being unloaded there's no way to look it up since the weak
  1582   // ref will have been cleared.
  1583   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
  1584     assert(!unload_reported(), "already unloaded");
  1585     JvmtiDeferredEvent event =
  1586       JvmtiDeferredEvent::compiled_method_unload_event(this,
  1587           _jmethod_id, insts_begin());
  1588     if (SafepointSynchronize::is_at_safepoint()) {
  1589       // Don't want to take the queueing lock. Add it as pending and
  1590       // it will get enqueued later.
  1591       JvmtiDeferredEventQueue::add_pending_event(event);
  1592     } else {
  1593       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  1594       JvmtiDeferredEventQueue::enqueue(event);
  1598   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
  1599   // any time. As the nmethod is being unloaded now we mark it has
  1600   // having the unload event reported - this will ensure that we don't
  1601   // attempt to report the event in the unlikely scenario where the
  1602   // event is enabled at the time the nmethod is made a zombie.
  1603   set_unload_reported();
  1606 // This is called at the end of the strong tracing/marking phase of a
  1607 // GC to unload an nmethod if it contains otherwise unreachable
  1608 // oops.
  1610 void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
  1611   // Make sure the oop's ready to receive visitors
  1612   assert(!is_zombie() && !is_unloaded(),
  1613          "should not call follow on zombie or unloaded nmethod");
  1615   // If the method is not entrant then a JMP is plastered over the
  1616   // first few bytes.  If an oop in the old code was there, that oop
  1617   // should not get GC'd.  Skip the first few bytes of oops on
  1618   // not-entrant methods.
  1619   address low_boundary = verified_entry_point();
  1620   if (is_not_entrant()) {
  1621     low_boundary += NativeJump::instruction_size;
  1622     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1623     // (See comment above.)
  1626   // The RedefineClasses() API can cause the class unloading invariant
  1627   // to no longer be true. See jvmtiExport.hpp for details.
  1628   // Also, leave a debugging breadcrumb in local flag.
  1629   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
  1630   if (a_class_was_redefined) {
  1631     // This set of the unloading_occurred flag is done before the
  1632     // call to post_compiled_method_unload() so that the unloading
  1633     // of this nmethod is reported.
  1634     unloading_occurred = true;
  1637   // Exception cache
  1638   ExceptionCache* ec = exception_cache();
  1639   while (ec != NULL) {
  1640     Klass* ex_klass = ec->exception_type();
  1641     ExceptionCache* next_ec = ec->next();
  1642     if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
  1643       remove_from_exception_cache(ec);
  1645     ec = next_ec;
  1648   // If class unloading occurred we first iterate over all inline caches and
  1649   // clear ICs where the cached oop is referring to an unloaded klass or method.
  1650   // The remaining live cached oops will be traversed in the relocInfo::oop_type
  1651   // iteration below.
  1652   if (unloading_occurred) {
  1653     RelocIterator iter(this, low_boundary);
  1654     while(iter.next()) {
  1655       if (iter.type() == relocInfo::virtual_call_type) {
  1656         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1657         if (ic->is_icholder_call()) {
  1658           // The only exception is compiledICHolder oops which may
  1659           // yet be marked below. (We check this further below).
  1660           CompiledICHolder* cichk_oop = ic->cached_icholder();
  1661           if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
  1662               cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
  1663               continue;
  1665         } else {
  1666           Metadata* ic_oop = ic->cached_metadata();
  1667           if (ic_oop != NULL) {
  1668             if (ic_oop->is_klass()) {
  1669               if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
  1670                 continue;
  1672             } else if (ic_oop->is_method()) {
  1673               if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
  1674                 continue;
  1676             } else {
  1677               ShouldNotReachHere();
  1681           ic->set_to_clean();
  1686   // Compiled code
  1688   RelocIterator iter(this, low_boundary);
  1689   while (iter.next()) {
  1690     if (iter.type() == relocInfo::oop_type) {
  1691       oop_Relocation* r = iter.oop_reloc();
  1692       // In this loop, we must only traverse those oops directly embedded in
  1693       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1694       assert(1 == (r->oop_is_immediate()) +
  1695                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1696              "oop must be found in exactly one place");
  1697       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1698         if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
  1699           return;
  1707   // Scopes
  1708   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1709     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1710     if (can_unload(is_alive, p, unloading_occurred)) {
  1711       return;
  1715   // Ensure that all metadata is still alive
  1716   verify_metadata_loaders(low_boundary, is_alive);
  1719 #ifdef ASSERT
  1721 class CheckClass : AllStatic {
  1722   static BoolObjectClosure* _is_alive;
  1724   // Check class_loader is alive for this bit of metadata.
  1725   static void check_class(Metadata* md) {
  1726     Klass* klass = NULL;
  1727     if (md->is_klass()) {
  1728       klass = ((Klass*)md);
  1729     } else if (md->is_method()) {
  1730       klass = ((Method*)md)->method_holder();
  1731     } else if (md->is_methodData()) {
  1732       klass = ((MethodData*)md)->method()->method_holder();
  1733     } else {
  1734       md->print();
  1735       ShouldNotReachHere();
  1737     assert(klass->is_loader_alive(_is_alive), "must be alive");
  1739  public:
  1740   static void do_check_class(BoolObjectClosure* is_alive, nmethod* nm) {
  1741     assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
  1742     _is_alive = is_alive;
  1743     nm->metadata_do(check_class);
  1745 };
  1747 // This is called during a safepoint so can use static data
  1748 BoolObjectClosure* CheckClass::_is_alive = NULL;
  1749 #endif // ASSERT
  1752 // Processing of oop references should have been sufficient to keep
  1753 // all strong references alive.  Any weak references should have been
  1754 // cleared as well.  Visit all the metadata and ensure that it's
  1755 // really alive.
  1756 void nmethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
  1757 #ifdef ASSERT
  1758     RelocIterator iter(this, low_boundary);
  1759     while (iter.next()) {
  1760     // static_stub_Relocations may have dangling references to
  1761     // Method*s so trim them out here.  Otherwise it looks like
  1762     // compiled code is maintaining a link to dead metadata.
  1763     address static_call_addr = NULL;
  1764     if (iter.type() == relocInfo::opt_virtual_call_type) {
  1765       CompiledIC* cic = CompiledIC_at(iter.reloc());
  1766       if (!cic->is_call_to_interpreted()) {
  1767         static_call_addr = iter.addr();
  1769     } else if (iter.type() == relocInfo::static_call_type) {
  1770       CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
  1771       if (!csc->is_call_to_interpreted()) {
  1772         static_call_addr = iter.addr();
  1775     if (static_call_addr != NULL) {
  1776       RelocIterator sciter(this, low_boundary);
  1777       while (sciter.next()) {
  1778         if (sciter.type() == relocInfo::static_stub_type &&
  1779             sciter.static_stub_reloc()->static_call() == static_call_addr) {
  1780           sciter.static_stub_reloc()->clear_inline_cache();
  1785   // Check that the metadata embedded in the nmethod is alive
  1786   CheckClass::do_check_class(is_alive, this);
  1787 #endif
  1791 // Iterate over metadata calling this function.   Used by RedefineClasses
  1792 void nmethod::metadata_do(void f(Metadata*)) {
  1793   address low_boundary = verified_entry_point();
  1794   if (is_not_entrant()) {
  1795     low_boundary += NativeJump::instruction_size;
  1796     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1797     // (See comment above.)
  1800     // Visit all immediate references that are embedded in the instruction stream.
  1801     RelocIterator iter(this, low_boundary);
  1802     while (iter.next()) {
  1803       if (iter.type() == relocInfo::metadata_type ) {
  1804         metadata_Relocation* r = iter.metadata_reloc();
  1805         // In this lmetadata, we must only follow those metadatas directly embedded in
  1806         // the code.  Other metadatas (oop_index>0) are seen as part of
  1807         // the metadata section below.
  1808         assert(1 == (r->metadata_is_immediate()) +
  1809                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
  1810                "metadata must be found in exactly one place");
  1811         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
  1812           Metadata* md = r->metadata_value();
  1813           f(md);
  1815       } else if (iter.type() == relocInfo::virtual_call_type) {
  1816         // Check compiledIC holders associated with this nmethod
  1817         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1818         if (ic->is_icholder_call()) {
  1819           CompiledICHolder* cichk = ic->cached_icholder();
  1820           f(cichk->holder_method());
  1821           f(cichk->holder_klass());
  1822         } else {
  1823           Metadata* ic_oop = ic->cached_metadata();
  1824           if (ic_oop != NULL) {
  1825             f(ic_oop);
  1832   // Visit the metadata section
  1833   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
  1834     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
  1835     Metadata* md = *p;
  1836     f(md);
  1839   // Call function Method*, not embedded in these other places.
  1840   if (_method != NULL) f(_method);
  1843 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
  1844   // make sure the oops ready to receive visitors
  1845   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
  1846   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
  1848   // If the method is not entrant or zombie then a JMP is plastered over the
  1849   // first few bytes.  If an oop in the old code was there, that oop
  1850   // should not get GC'd.  Skip the first few bytes of oops on
  1851   // not-entrant methods.
  1852   address low_boundary = verified_entry_point();
  1853   if (is_not_entrant()) {
  1854     low_boundary += NativeJump::instruction_size;
  1855     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1856     // (See comment above.)
  1859   RelocIterator iter(this, low_boundary);
  1861   while (iter.next()) {
  1862     if (iter.type() == relocInfo::oop_type ) {
  1863       oop_Relocation* r = iter.oop_reloc();
  1864       // In this loop, we must only follow those oops directly embedded in
  1865       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1866       assert(1 == (r->oop_is_immediate()) +
  1867                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1868              "oop must be found in exactly one place");
  1869       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1870         f->do_oop(r->oop_addr());
  1875   // Scopes
  1876   // This includes oop constants not inlined in the code stream.
  1877   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1878     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1879     f->do_oop(p);
  1883 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
  1885 nmethod* volatile nmethod::_oops_do_mark_nmethods;
  1887 // An nmethod is "marked" if its _mark_link is set non-null.
  1888 // Even if it is the end of the linked list, it will have a non-null link value,
  1889 // as long as it is on the list.
  1890 // This code must be MP safe, because it is used from parallel GC passes.
  1891 bool nmethod::test_set_oops_do_mark() {
  1892   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
  1893   nmethod* observed_mark_link = _oops_do_mark_link;
  1894   if (observed_mark_link == NULL) {
  1895     // Claim this nmethod for this thread to mark.
  1896     observed_mark_link = (nmethod*)
  1897       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
  1898     if (observed_mark_link == NULL) {
  1900       // Atomically append this nmethod (now claimed) to the head of the list:
  1901       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
  1902       for (;;) {
  1903         nmethod* required_mark_nmethods = observed_mark_nmethods;
  1904         _oops_do_mark_link = required_mark_nmethods;
  1905         observed_mark_nmethods = (nmethod*)
  1906           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
  1907         if (observed_mark_nmethods == required_mark_nmethods)
  1908           break;
  1910       // Mark was clear when we first saw this guy.
  1911       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark"));
  1912       return false;
  1915   // On fall through, another racing thread marked this nmethod before we did.
  1916   return true;
  1919 void nmethod::oops_do_marking_prologue() {
  1920   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
  1921   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
  1922   // We use cmpxchg_ptr instead of regular assignment here because the user
  1923   // may fork a bunch of threads, and we need them all to see the same state.
  1924   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
  1925   guarantee(observed == NULL, "no races in this sequential code");
  1928 void nmethod::oops_do_marking_epilogue() {
  1929   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
  1930   nmethod* cur = _oops_do_mark_nmethods;
  1931   while (cur != NMETHOD_SENTINEL) {
  1932     assert(cur != NULL, "not NULL-terminated");
  1933     nmethod* next = cur->_oops_do_mark_link;
  1934     cur->_oops_do_mark_link = NULL;
  1935     cur->fix_oop_relocations();
  1936     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
  1937     cur = next;
  1939   void* required = _oops_do_mark_nmethods;
  1940   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
  1941   guarantee(observed == required, "no races in this sequential code");
  1942   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
  1945 class DetectScavengeRoot: public OopClosure {
  1946   bool     _detected_scavenge_root;
  1947 public:
  1948   DetectScavengeRoot() : _detected_scavenge_root(false)
  1949   { NOT_PRODUCT(_print_nm = NULL); }
  1950   bool detected_scavenge_root() { return _detected_scavenge_root; }
  1951   virtual void do_oop(oop* p) {
  1952     if ((*p) != NULL && (*p)->is_scavengable()) {
  1953       NOT_PRODUCT(maybe_print(p));
  1954       _detected_scavenge_root = true;
  1957   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  1959 #ifndef PRODUCT
  1960   nmethod* _print_nm;
  1961   void maybe_print(oop* p) {
  1962     if (_print_nm == NULL)  return;
  1963     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
  1964     tty->print_cr(""PTR_FORMAT"[offset=%d] detected scavengable oop "PTR_FORMAT" (found at "PTR_FORMAT")",
  1965                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
  1966                   (void *)(*p), (intptr_t)p);
  1967     (*p)->print();
  1969 #endif //PRODUCT
  1970 };
  1972 bool nmethod::detect_scavenge_root_oops() {
  1973   DetectScavengeRoot detect_scavenge_root;
  1974   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
  1975   oops_do(&detect_scavenge_root);
  1976   return detect_scavenge_root.detected_scavenge_root();
  1979 // Method that knows how to preserve outgoing arguments at call. This method must be
  1980 // called with a frame corresponding to a Java invoke
  1981 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
  1982 #ifndef SHARK
  1983   if (!method()->is_native()) {
  1984     SimpleScopeDesc ssd(this, fr.pc());
  1985     Bytecode_invoke call(ssd.method(), ssd.bci());
  1986     bool has_receiver = call.has_receiver();
  1987     bool has_appendix = call.has_appendix();
  1988     Symbol* signature = call.signature();
  1989     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
  1991 #endif // !SHARK
  1995 oop nmethod::embeddedOop_at(u_char* p) {
  1996   RelocIterator iter(this, p, p + 1);
  1997   while (iter.next())
  1998     if (iter.type() == relocInfo::oop_type) {
  1999       return iter.oop_reloc()->oop_value();
  2001   return NULL;
  2005 inline bool includes(void* p, void* from, void* to) {
  2006   return from <= p && p < to;
  2010 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
  2011   assert(count >= 2, "must be sentinel values, at least");
  2013 #ifdef ASSERT
  2014   // must be sorted and unique; we do a binary search in find_pc_desc()
  2015   int prev_offset = pcs[0].pc_offset();
  2016   assert(prev_offset == PcDesc::lower_offset_limit,
  2017          "must start with a sentinel");
  2018   for (int i = 1; i < count; i++) {
  2019     int this_offset = pcs[i].pc_offset();
  2020     assert(this_offset > prev_offset, "offsets must be sorted");
  2021     prev_offset = this_offset;
  2023   assert(prev_offset == PcDesc::upper_offset_limit,
  2024          "must end with a sentinel");
  2025 #endif //ASSERT
  2027   // Search for MethodHandle invokes and tag the nmethod.
  2028   for (int i = 0; i < count; i++) {
  2029     if (pcs[i].is_method_handle_invoke()) {
  2030       set_has_method_handle_invokes(true);
  2031       break;
  2034   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
  2036   int size = count * sizeof(PcDesc);
  2037   assert(scopes_pcs_size() >= size, "oob");
  2038   memcpy(scopes_pcs_begin(), pcs, size);
  2040   // Adjust the final sentinel downward.
  2041   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
  2042   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
  2043   last_pc->set_pc_offset(content_size() + 1);
  2044   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
  2045     // Fill any rounding gaps with copies of the last record.
  2046     last_pc[1] = last_pc[0];
  2048   // The following assert could fail if sizeof(PcDesc) is not
  2049   // an integral multiple of oopSize (the rounding term).
  2050   // If it fails, change the logic to always allocate a multiple
  2051   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
  2052   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
  2055 void nmethod::copy_scopes_data(u_char* buffer, int size) {
  2056   assert(scopes_data_size() >= size, "oob");
  2057   memcpy(scopes_data_begin(), buffer, size);
  2061 #ifdef ASSERT
  2062 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
  2063   PcDesc* lower = nm->scopes_pcs_begin();
  2064   PcDesc* upper = nm->scopes_pcs_end();
  2065   lower += 1; // exclude initial sentinel
  2066   PcDesc* res = NULL;
  2067   for (PcDesc* p = lower; p < upper; p++) {
  2068     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
  2069     if (match_desc(p, pc_offset, approximate)) {
  2070       if (res == NULL)
  2071         res = p;
  2072       else
  2073         res = (PcDesc*) badAddress;
  2076   return res;
  2078 #endif
  2081 // Finds a PcDesc with real-pc equal to "pc"
  2082 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
  2083   address base_address = code_begin();
  2084   if ((pc < base_address) ||
  2085       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
  2086     return NULL;  // PC is wildly out of range
  2088   int pc_offset = (int) (pc - base_address);
  2090   // Check the PcDesc cache if it contains the desired PcDesc
  2091   // (This as an almost 100% hit rate.)
  2092   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
  2093   if (res != NULL) {
  2094     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
  2095     return res;
  2098   // Fallback algorithm: quasi-linear search for the PcDesc
  2099   // Find the last pc_offset less than the given offset.
  2100   // The successor must be the required match, if there is a match at all.
  2101   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
  2102   PcDesc* lower = scopes_pcs_begin();
  2103   PcDesc* upper = scopes_pcs_end();
  2104   upper -= 1; // exclude final sentinel
  2105   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
  2107 #define assert_LU_OK \
  2108   /* invariant on lower..upper during the following search: */ \
  2109   assert(lower->pc_offset() <  pc_offset, "sanity"); \
  2110   assert(upper->pc_offset() >= pc_offset, "sanity")
  2111   assert_LU_OK;
  2113   // Use the last successful return as a split point.
  2114   PcDesc* mid = _pc_desc_cache.last_pc_desc();
  2115   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2116   if (mid->pc_offset() < pc_offset) {
  2117     lower = mid;
  2118   } else {
  2119     upper = mid;
  2122   // Take giant steps at first (4096, then 256, then 16, then 1)
  2123   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
  2124   const int RADIX = (1 << LOG2_RADIX);
  2125   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
  2126     while ((mid = lower + step) < upper) {
  2127       assert_LU_OK;
  2128       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2129       if (mid->pc_offset() < pc_offset) {
  2130         lower = mid;
  2131       } else {
  2132         upper = mid;
  2133         break;
  2136     assert_LU_OK;
  2139   // Sneak up on the value with a linear search of length ~16.
  2140   while (true) {
  2141     assert_LU_OK;
  2142     mid = lower + 1;
  2143     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  2144     if (mid->pc_offset() < pc_offset) {
  2145       lower = mid;
  2146     } else {
  2147       upper = mid;
  2148       break;
  2151 #undef assert_LU_OK
  2153   if (match_desc(upper, pc_offset, approximate)) {
  2154     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
  2155     _pc_desc_cache.add_pc_desc(upper);
  2156     return upper;
  2157   } else {
  2158     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
  2159     return NULL;
  2164 bool nmethod::check_all_dependencies() {
  2165   bool found_check = false;
  2166   // wholesale check of all dependencies
  2167   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2168     if (deps.check_dependency() != NULL) {
  2169       found_check = true;
  2170       NOT_DEBUG(break);
  2173   return found_check;  // tell caller if we found anything
  2176 bool nmethod::check_dependency_on(DepChange& changes) {
  2177   // What has happened:
  2178   // 1) a new class dependee has been added
  2179   // 2) dependee and all its super classes have been marked
  2180   bool found_check = false;  // set true if we are upset
  2181   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2182     // Evaluate only relevant dependencies.
  2183     if (deps.spot_check_dependency_at(changes) != NULL) {
  2184       found_check = true;
  2185       NOT_DEBUG(break);
  2188   return found_check;
  2191 bool nmethod::is_evol_dependent_on(Klass* dependee) {
  2192   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
  2193   Array<Method*>* dependee_methods = dependee_ik->methods();
  2194   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2195     if (deps.type() == Dependencies::evol_method) {
  2196       Method* method = deps.method_argument(0);
  2197       for (int j = 0; j < dependee_methods->length(); j++) {
  2198         if (dependee_methods->at(j) == method) {
  2199           // RC_TRACE macro has an embedded ResourceMark
  2200           RC_TRACE(0x01000000,
  2201             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
  2202             _method->method_holder()->external_name(),
  2203             _method->name()->as_C_string(),
  2204             _method->signature()->as_C_string(), compile_id(),
  2205             method->method_holder()->external_name(),
  2206             method->name()->as_C_string(),
  2207             method->signature()->as_C_string()));
  2208           if (TraceDependencies || LogCompilation)
  2209             deps.log_dependency(dependee);
  2210           return true;
  2215   return false;
  2218 // Called from mark_for_deoptimization, when dependee is invalidated.
  2219 bool nmethod::is_dependent_on_method(Method* dependee) {
  2220   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2221     if (deps.type() != Dependencies::evol_method)
  2222       continue;
  2223     Method* method = deps.method_argument(0);
  2224     if (method == dependee) return true;
  2226   return false;
  2230 bool nmethod::is_patchable_at(address instr_addr) {
  2231   assert(insts_contains(instr_addr), "wrong nmethod used");
  2232   if (is_zombie()) {
  2233     // a zombie may never be patched
  2234     return false;
  2236   return true;
  2240 address nmethod::continuation_for_implicit_exception(address pc) {
  2241   // Exception happened outside inline-cache check code => we are inside
  2242   // an active nmethod => use cpc to determine a return address
  2243   int exception_offset = pc - code_begin();
  2244   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
  2245 #ifdef ASSERT
  2246   if (cont_offset == 0) {
  2247     Thread* thread = ThreadLocalStorage::get_thread_slow();
  2248     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
  2249     HandleMark hm(thread);
  2250     ResourceMark rm(thread);
  2251     CodeBlob* cb = CodeCache::find_blob(pc);
  2252     assert(cb != NULL && cb == this, "");
  2253     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
  2254     print();
  2255     method()->print_codes();
  2256     print_code();
  2257     print_pcs();
  2259 #endif
  2260   if (cont_offset == 0) {
  2261     // Let the normal error handling report the exception
  2262     return NULL;
  2264   return code_begin() + cont_offset;
  2269 void nmethod_init() {
  2270   // make sure you didn't forget to adjust the filler fields
  2271   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
  2275 //-------------------------------------------------------------------------------------------
  2278 // QQQ might we make this work from a frame??
  2279 nmethodLocker::nmethodLocker(address pc) {
  2280   CodeBlob* cb = CodeCache::find_blob(pc);
  2281   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
  2282   _nm = (nmethod*)cb;
  2283   lock_nmethod(_nm);
  2286 // Only JvmtiDeferredEvent::compiled_method_unload_event()
  2287 // should pass zombie_ok == true.
  2288 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
  2289   if (nm == NULL)  return;
  2290   Atomic::inc(&nm->_lock_count);
  2291   guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
  2294 void nmethodLocker::unlock_nmethod(nmethod* nm) {
  2295   if (nm == NULL)  return;
  2296   Atomic::dec(&nm->_lock_count);
  2297   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
  2301 // -----------------------------------------------------------------------------
  2302 // nmethod::get_deopt_original_pc
  2303 //
  2304 // Return the original PC for the given PC if:
  2305 // (a) the given PC belongs to a nmethod and
  2306 // (b) it is a deopt PC
  2307 address nmethod::get_deopt_original_pc(const frame* fr) {
  2308   if (fr->cb() == NULL)  return NULL;
  2310   nmethod* nm = fr->cb()->as_nmethod_or_null();
  2311   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
  2312     return nm->get_original_pc(fr);
  2314   return NULL;
  2318 // -----------------------------------------------------------------------------
  2319 // MethodHandle
  2321 bool nmethod::is_method_handle_return(address return_pc) {
  2322   if (!has_method_handle_invokes())  return false;
  2323   PcDesc* pd = pc_desc_at(return_pc);
  2324   if (pd == NULL)
  2325     return false;
  2326   return pd->is_method_handle_invoke();
  2330 // -----------------------------------------------------------------------------
  2331 // Verification
  2333 class VerifyOopsClosure: public OopClosure {
  2334   nmethod* _nm;
  2335   bool     _ok;
  2336 public:
  2337   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
  2338   bool ok() { return _ok; }
  2339   virtual void do_oop(oop* p) {
  2340     if ((*p) == NULL || (*p)->is_oop())  return;
  2341     if (_ok) {
  2342       _nm->print_nmethod(true);
  2343       _ok = false;
  2345     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
  2346                   (void *)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
  2348   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  2349 };
  2351 void nmethod::verify() {
  2353   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
  2354   // seems odd.
  2356   if( is_zombie() || is_not_entrant() )
  2357     return;
  2359   // Make sure all the entry points are correctly aligned for patching.
  2360   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
  2362   // assert(method()->is_oop(), "must be valid");
  2364   ResourceMark rm;
  2366   if (!CodeCache::contains(this)) {
  2367     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
  2370   if(is_native_method() )
  2371     return;
  2373   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
  2374   if (nm != this) {
  2375     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
  2376                   this));
  2379   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2380     if (! p->verify(this)) {
  2381       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
  2385   VerifyOopsClosure voc(this);
  2386   oops_do(&voc);
  2387   assert(voc.ok(), "embedded oops must be OK");
  2388   verify_scavenge_root_oops();
  2390   verify_scopes();
  2394 void nmethod::verify_interrupt_point(address call_site) {
  2395   // Verify IC only when nmethod installation is finished.
  2396   bool is_installed = (method()->code() == this) // nmethod is in state 'alive' and installed
  2397                       || !this->is_in_use();     // nmethod is installed, but not in 'alive' state
  2398   if (is_installed) {
  2399     Thread *cur = Thread::current();
  2400     if (CompiledIC_lock->owner() == cur ||
  2401         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
  2402          SafepointSynchronize::is_at_safepoint())) {
  2403       CompiledIC_at(this, call_site);
  2404       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  2405     } else {
  2406       MutexLocker ml_verify (CompiledIC_lock);
  2407       CompiledIC_at(this, call_site);
  2411   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
  2412   assert(pd != NULL, "PcDesc must exist");
  2413   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
  2414                                      pd->obj_decode_offset(), pd->should_reexecute(),
  2415                                      pd->return_oop());
  2416        !sd->is_top(); sd = sd->sender()) {
  2417     sd->verify();
  2421 void nmethod::verify_scopes() {
  2422   if( !method() ) return;       // Runtime stubs have no scope
  2423   if (method()->is_native()) return; // Ignore stub methods.
  2424   // iterate through all interrupt point
  2425   // and verify the debug information is valid.
  2426   RelocIterator iter((nmethod*)this);
  2427   while (iter.next()) {
  2428     address stub = NULL;
  2429     switch (iter.type()) {
  2430       case relocInfo::virtual_call_type:
  2431         verify_interrupt_point(iter.addr());
  2432         break;
  2433       case relocInfo::opt_virtual_call_type:
  2434         stub = iter.opt_virtual_call_reloc()->static_stub();
  2435         verify_interrupt_point(iter.addr());
  2436         break;
  2437       case relocInfo::static_call_type:
  2438         stub = iter.static_call_reloc()->static_stub();
  2439         //verify_interrupt_point(iter.addr());
  2440         break;
  2441       case relocInfo::runtime_call_type:
  2442         address destination = iter.reloc()->value();
  2443         // Right now there is no way to find out which entries support
  2444         // an interrupt point.  It would be nice if we had this
  2445         // information in a table.
  2446         break;
  2448     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
  2453 // -----------------------------------------------------------------------------
  2454 // Non-product code
  2455 #ifndef PRODUCT
  2457 class DebugScavengeRoot: public OopClosure {
  2458   nmethod* _nm;
  2459   bool     _ok;
  2460 public:
  2461   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
  2462   bool ok() { return _ok; }
  2463   virtual void do_oop(oop* p) {
  2464     if ((*p) == NULL || !(*p)->is_scavengable())  return;
  2465     if (_ok) {
  2466       _nm->print_nmethod(true);
  2467       _ok = false;
  2469     tty->print_cr("*** scavengable oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
  2470                   (void *)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
  2471     (*p)->print();
  2473   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  2474 };
  2476 void nmethod::verify_scavenge_root_oops() {
  2477   if (!on_scavenge_root_list()) {
  2478     // Actually look inside, to verify the claim that it's clean.
  2479     DebugScavengeRoot debug_scavenge_root(this);
  2480     oops_do(&debug_scavenge_root);
  2481     if (!debug_scavenge_root.ok())
  2482       fatal("found an unadvertised bad scavengable oop in the code cache");
  2484   assert(scavenge_root_not_marked(), "");
  2487 #endif // PRODUCT
  2489 // Printing operations
  2491 void nmethod::print() const {
  2492   ResourceMark rm;
  2493   ttyLocker ttyl;   // keep the following output all in one block
  2495   tty->print("Compiled method ");
  2497   if (is_compiled_by_c1()) {
  2498     tty->print("(c1) ");
  2499   } else if (is_compiled_by_c2()) {
  2500     tty->print("(c2) ");
  2501   } else if (is_compiled_by_shark()) {
  2502     tty->print("(shark) ");
  2503   } else {
  2504     tty->print("(nm) ");
  2507   print_on(tty, NULL);
  2509   if (WizardMode) {
  2510     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
  2511     tty->print(" for method " INTPTR_FORMAT , (address)method());
  2512     tty->print(" { ");
  2513     if (is_in_use())      tty->print("in_use ");
  2514     if (is_not_entrant()) tty->print("not_entrant ");
  2515     if (is_zombie())      tty->print("zombie ");
  2516     if (is_unloaded())    tty->print("unloaded ");
  2517     if (on_scavenge_root_list())  tty->print("scavenge_root ");
  2518     tty->print_cr("}:");
  2520   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2521                                               (address)this,
  2522                                               (address)this + size(),
  2523                                               size());
  2524   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2525                                               relocation_begin(),
  2526                                               relocation_end(),
  2527                                               relocation_size());
  2528   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2529                                               consts_begin(),
  2530                                               consts_end(),
  2531                                               consts_size());
  2532   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2533                                               insts_begin(),
  2534                                               insts_end(),
  2535                                               insts_size());
  2536   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2537                                               stub_begin(),
  2538                                               stub_end(),
  2539                                               stub_size());
  2540   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2541                                               oops_begin(),
  2542                                               oops_end(),
  2543                                               oops_size());
  2544   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2545                                               metadata_begin(),
  2546                                               metadata_end(),
  2547                                               metadata_size());
  2548   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2549                                               scopes_data_begin(),
  2550                                               scopes_data_end(),
  2551                                               scopes_data_size());
  2552   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2553                                               scopes_pcs_begin(),
  2554                                               scopes_pcs_end(),
  2555                                               scopes_pcs_size());
  2556   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2557                                               dependencies_begin(),
  2558                                               dependencies_end(),
  2559                                               dependencies_size());
  2560   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2561                                               handler_table_begin(),
  2562                                               handler_table_end(),
  2563                                               handler_table_size());
  2564   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2565                                               nul_chk_table_begin(),
  2566                                               nul_chk_table_end(),
  2567                                               nul_chk_table_size());
  2570 void nmethod::print_code() {
  2571   HandleMark hm;
  2572   ResourceMark m;
  2573   Disassembler::decode(this);
  2577 #ifndef PRODUCT
  2579 void nmethod::print_scopes() {
  2580   // Find the first pc desc for all scopes in the code and print it.
  2581   ResourceMark rm;
  2582   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2583     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
  2584       continue;
  2586     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
  2587     sd->print_on(tty, p);
  2591 void nmethod::print_dependencies() {
  2592   ResourceMark rm;
  2593   ttyLocker ttyl;   // keep the following output all in one block
  2594   tty->print_cr("Dependencies:");
  2595   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2596     deps.print_dependency();
  2597     Klass* ctxk = deps.context_type();
  2598     if (ctxk != NULL) {
  2599       if (ctxk->oop_is_instance() && ((InstanceKlass*)ctxk)->is_dependent_nmethod(this)) {
  2600         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
  2603     deps.log_dependency();  // put it into the xml log also
  2608 void nmethod::print_relocations() {
  2609   ResourceMark m;       // in case methods get printed via the debugger
  2610   tty->print_cr("relocations:");
  2611   RelocIterator iter(this);
  2612   iter.print();
  2613   if (UseRelocIndex) {
  2614     jint* index_end   = (jint*)relocation_end() - 1;
  2615     jint  index_size  = *index_end;
  2616     jint* index_start = (jint*)( (address)index_end - index_size );
  2617     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
  2618     if (index_size > 0) {
  2619       jint* ip;
  2620       for (ip = index_start; ip+2 <= index_end; ip += 2)
  2621         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
  2622                       ip[0],
  2623                       ip[1],
  2624                       header_end()+ip[0],
  2625                       relocation_begin()-1+ip[1]);
  2626       for (; ip < index_end; ip++)
  2627         tty->print_cr("  (%d ?)", ip[0]);
  2628       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip);
  2629       ip++;
  2630       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
  2636 void nmethod::print_pcs() {
  2637   ResourceMark m;       // in case methods get printed via debugger
  2638   tty->print_cr("pc-bytecode offsets:");
  2639   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2640     p->print(this);
  2644 #endif // PRODUCT
  2646 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
  2647   RelocIterator iter(this, begin, end);
  2648   bool have_one = false;
  2649   while (iter.next()) {
  2650     have_one = true;
  2651     switch (iter.type()) {
  2652         case relocInfo::none:                  return "no_reloc";
  2653         case relocInfo::oop_type: {
  2654           stringStream st;
  2655           oop_Relocation* r = iter.oop_reloc();
  2656           oop obj = r->oop_value();
  2657           st.print("oop(");
  2658           if (obj == NULL) st.print("NULL");
  2659           else obj->print_value_on(&st);
  2660           st.print(")");
  2661           return st.as_string();
  2663         case relocInfo::metadata_type: {
  2664           stringStream st;
  2665           metadata_Relocation* r = iter.metadata_reloc();
  2666           Metadata* obj = r->metadata_value();
  2667           st.print("metadata(");
  2668           if (obj == NULL) st.print("NULL");
  2669           else obj->print_value_on(&st);
  2670           st.print(")");
  2671           return st.as_string();
  2673         case relocInfo::virtual_call_type:     return "virtual_call";
  2674         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
  2675         case relocInfo::static_call_type:      return "static_call";
  2676         case relocInfo::static_stub_type:      return "static_stub";
  2677         case relocInfo::runtime_call_type:     return "runtime_call";
  2678         case relocInfo::external_word_type:    return "external_word";
  2679         case relocInfo::internal_word_type:    return "internal_word";
  2680         case relocInfo::section_word_type:     return "section_word";
  2681         case relocInfo::poll_type:             return "poll";
  2682         case relocInfo::poll_return_type:      return "poll_return";
  2683         case relocInfo::type_mask:             return "type_bit_mask";
  2686   return have_one ? "other" : NULL;
  2689 // Return a the last scope in (begin..end]
  2690 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
  2691   PcDesc* p = pc_desc_near(begin+1);
  2692   if (p != NULL && p->real_pc(this) <= end) {
  2693     return new ScopeDesc(this, p->scope_decode_offset(),
  2694                          p->obj_decode_offset(), p->should_reexecute(),
  2695                          p->return_oop());
  2697   return NULL;
  2700 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
  2701   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
  2702   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
  2703   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
  2704   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
  2705   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
  2707   if (has_method_handle_invokes())
  2708     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
  2710   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
  2712   if (block_begin == entry_point()) {
  2713     methodHandle m = method();
  2714     if (m.not_null()) {
  2715       stream->print("  # ");
  2716       m->print_value_on(stream);
  2717       stream->cr();
  2719     if (m.not_null() && !is_osr_method()) {
  2720       ResourceMark rm;
  2721       int sizeargs = m->size_of_parameters();
  2722       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
  2723       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
  2725         int sig_index = 0;
  2726         if (!m->is_static())
  2727           sig_bt[sig_index++] = T_OBJECT; // 'this'
  2728         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
  2729           BasicType t = ss.type();
  2730           sig_bt[sig_index++] = t;
  2731           if (type2size[t] == 2) {
  2732             sig_bt[sig_index++] = T_VOID;
  2733           } else {
  2734             assert(type2size[t] == 1, "size is 1 or 2");
  2737         assert(sig_index == sizeargs, "");
  2739       const char* spname = "sp"; // make arch-specific?
  2740       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
  2741       int stack_slot_offset = this->frame_size() * wordSize;
  2742       int tab1 = 14, tab2 = 24;
  2743       int sig_index = 0;
  2744       int arg_index = (m->is_static() ? 0 : -1);
  2745       bool did_old_sp = false;
  2746       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
  2747         bool at_this = (arg_index == -1);
  2748         bool at_old_sp = false;
  2749         BasicType t = (at_this ? T_OBJECT : ss.type());
  2750         assert(t == sig_bt[sig_index], "sigs in sync");
  2751         if (at_this)
  2752           stream->print("  # this: ");
  2753         else
  2754           stream->print("  # parm%d: ", arg_index);
  2755         stream->move_to(tab1);
  2756         VMReg fst = regs[sig_index].first();
  2757         VMReg snd = regs[sig_index].second();
  2758         if (fst->is_reg()) {
  2759           stream->print("%s", fst->name());
  2760           if (snd->is_valid())  {
  2761             stream->print(":%s", snd->name());
  2763         } else if (fst->is_stack()) {
  2764           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
  2765           if (offset == stack_slot_offset)  at_old_sp = true;
  2766           stream->print("[%s+0x%x]", spname, offset);
  2767         } else {
  2768           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
  2770         stream->print(" ");
  2771         stream->move_to(tab2);
  2772         stream->print("= ");
  2773         if (at_this) {
  2774           m->method_holder()->print_value_on(stream);
  2775         } else {
  2776           bool did_name = false;
  2777           if (!at_this && ss.is_object()) {
  2778             Symbol* name = ss.as_symbol_or_null();
  2779             if (name != NULL) {
  2780               name->print_value_on(stream);
  2781               did_name = true;
  2784           if (!did_name)
  2785             stream->print("%s", type2name(t));
  2787         if (at_old_sp) {
  2788           stream->print("  (%s of caller)", spname);
  2789           did_old_sp = true;
  2791         stream->cr();
  2792         sig_index += type2size[t];
  2793         arg_index += 1;
  2794         if (!at_this)  ss.next();
  2796       if (!did_old_sp) {
  2797         stream->print("  # ");
  2798         stream->move_to(tab1);
  2799         stream->print("[%s+0x%x]", spname, stack_slot_offset);
  2800         stream->print("  (%s of caller)", spname);
  2801         stream->cr();
  2807 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
  2808   // First, find an oopmap in (begin, end].
  2809   // We use the odd half-closed interval so that oop maps and scope descs
  2810   // which are tied to the byte after a call are printed with the call itself.
  2811   address base = code_begin();
  2812   OopMapSet* oms = oop_maps();
  2813   if (oms != NULL) {
  2814     for (int i = 0, imax = oms->size(); i < imax; i++) {
  2815       OopMap* om = oms->at(i);
  2816       address pc = base + om->offset();
  2817       if (pc > begin) {
  2818         if (pc <= end) {
  2819           st->move_to(column);
  2820           st->print("; ");
  2821           om->print_on(st);
  2823         break;
  2828   // Print any debug info present at this pc.
  2829   ScopeDesc* sd  = scope_desc_in(begin, end);
  2830   if (sd != NULL) {
  2831     st->move_to(column);
  2832     if (sd->bci() == SynchronizationEntryBCI) {
  2833       st->print(";*synchronization entry");
  2834     } else {
  2835       if (sd->method() == NULL) {
  2836         st->print("method is NULL");
  2837       } else if (sd->method()->is_native()) {
  2838         st->print("method is native");
  2839       } else {
  2840         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
  2841         st->print(";*%s", Bytecodes::name(bc));
  2842         switch (bc) {
  2843         case Bytecodes::_invokevirtual:
  2844         case Bytecodes::_invokespecial:
  2845         case Bytecodes::_invokestatic:
  2846         case Bytecodes::_invokeinterface:
  2848             Bytecode_invoke invoke(sd->method(), sd->bci());
  2849             st->print(" ");
  2850             if (invoke.name() != NULL)
  2851               invoke.name()->print_symbol_on(st);
  2852             else
  2853               st->print("<UNKNOWN>");
  2854             break;
  2856         case Bytecodes::_getfield:
  2857         case Bytecodes::_putfield:
  2858         case Bytecodes::_getstatic:
  2859         case Bytecodes::_putstatic:
  2861             Bytecode_field field(sd->method(), sd->bci());
  2862             st->print(" ");
  2863             if (field.name() != NULL)
  2864               field.name()->print_symbol_on(st);
  2865             else
  2866               st->print("<UNKNOWN>");
  2872     // Print all scopes
  2873     for (;sd != NULL; sd = sd->sender()) {
  2874       st->move_to(column);
  2875       st->print("; -");
  2876       if (sd->method() == NULL) {
  2877         st->print("method is NULL");
  2878       } else {
  2879         sd->method()->print_short_name(st);
  2881       int lineno = sd->method()->line_number_from_bci(sd->bci());
  2882       if (lineno != -1) {
  2883         st->print("@%d (line %d)", sd->bci(), lineno);
  2884       } else {
  2885         st->print("@%d", sd->bci());
  2887       st->cr();
  2891   // Print relocation information
  2892   const char* str = reloc_string_for(begin, end);
  2893   if (str != NULL) {
  2894     if (sd != NULL) st->cr();
  2895     st->move_to(column);
  2896     st->print(";   {%s}", str);
  2898   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
  2899   if (cont_offset != 0) {
  2900     st->move_to(column);
  2901     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
  2906 #ifndef PRODUCT
  2908 void nmethod::print_value_on(outputStream* st) const {
  2909   st->print("nmethod");
  2910   print_on(st, NULL);
  2913 void nmethod::print_calls(outputStream* st) {
  2914   RelocIterator iter(this);
  2915   while (iter.next()) {
  2916     switch (iter.type()) {
  2917     case relocInfo::virtual_call_type:
  2918     case relocInfo::opt_virtual_call_type: {
  2919       VerifyMutexLocker mc(CompiledIC_lock);
  2920       CompiledIC_at(iter.reloc())->print();
  2921       break;
  2923     case relocInfo::static_call_type:
  2924       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
  2925       compiledStaticCall_at(iter.reloc())->print();
  2926       break;
  2931 void nmethod::print_handler_table() {
  2932   ExceptionHandlerTable(this).print();
  2935 void nmethod::print_nul_chk_table() {
  2936   ImplicitExceptionTable(this).print(code_begin());
  2939 void nmethod::print_statistics() {
  2940   ttyLocker ttyl;
  2941   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
  2942   nmethod_stats.print_native_nmethod_stats();
  2943   nmethod_stats.print_nmethod_stats();
  2944   DebugInformationRecorder::print_statistics();
  2945   nmethod_stats.print_pc_stats();
  2946   Dependencies::print_statistics();
  2947   if (xtty != NULL)  xtty->tail("statistics");
  2950 #endif // PRODUCT

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