src/share/vm/code/nmethod.cpp

Wed, 02 Sep 2009 00:04:29 -0700

author
ysr
date
Wed, 02 Sep 2009 00:04:29 -0700
changeset 1376
8b46c4d82093
parent 1040
98cb887364d3
child 1378
b1606b3c0a8a
permissions
-rw-r--r--

4957990: Perm heap bloat in JVM
Summary: Treat ProfileData in MDO's as a source of weak, not strong, roots. Fixes the bug for stop-world collection -- the case of concurrent collection will be fixed separately.
Reviewed-by: jcoomes, jmasa, kvn, never

     1 /*
     2  * Copyright 1997-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_nmethod.cpp.incl"
    28 #ifdef DTRACE_ENABLED
    30 // Only bother with this argument setup if dtrace is available
    32 HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
    33   const char*, int, const char*, int, const char*, int, void*, size_t);
    35 HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
    36   char*, int, char*, int, char*, int);
    38 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
    39   {                                                                       \
    40     methodOop m = (method);                                               \
    41     if (m != NULL) {                                                      \
    42       symbolOop klass_name = m->klass_name();                             \
    43       symbolOop name = m->name();                                         \
    44       symbolOop signature = m->signature();                               \
    45       HS_DTRACE_PROBE6(hotspot, compiled__method__unload,                 \
    46         klass_name->bytes(), klass_name->utf8_length(),                   \
    47         name->bytes(), name->utf8_length(),                               \
    48         signature->bytes(), signature->utf8_length());                    \
    49     }                                                                     \
    50   }
    52 #else //  ndef DTRACE_ENABLED
    54 #define DTRACE_METHOD_UNLOAD_PROBE(method)
    56 #endif
    58 bool nmethod::is_compiled_by_c1() const {
    59   if (is_native_method()) return false;
    60   assert(compiler() != NULL, "must be");
    61   return compiler()->is_c1();
    62 }
    63 bool nmethod::is_compiled_by_c2() const {
    64   if (is_native_method()) return false;
    65   assert(compiler() != NULL, "must be");
    66   return compiler()->is_c2();
    67 }
    71 //---------------------------------------------------------------------------------
    72 // NMethod statistics
    73 // They are printed under various flags, including:
    74 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
    75 // (In the latter two cases, they like other stats are printed to the log only.)
    77 #ifndef PRODUCT
    78 // These variables are put into one block to reduce relocations
    79 // and make it simpler to print from the debugger.
    80 static
    81 struct nmethod_stats_struct {
    82   int nmethod_count;
    83   int total_size;
    84   int relocation_size;
    85   int code_size;
    86   int stub_size;
    87   int consts_size;
    88   int scopes_data_size;
    89   int scopes_pcs_size;
    90   int dependencies_size;
    91   int handler_table_size;
    92   int nul_chk_table_size;
    93   int oops_size;
    95   void note_nmethod(nmethod* nm) {
    96     nmethod_count += 1;
    97     total_size          += nm->size();
    98     relocation_size     += nm->relocation_size();
    99     code_size           += nm->code_size();
   100     stub_size           += nm->stub_size();
   101     consts_size         += nm->consts_size();
   102     scopes_data_size    += nm->scopes_data_size();
   103     scopes_pcs_size     += nm->scopes_pcs_size();
   104     dependencies_size   += nm->dependencies_size();
   105     handler_table_size  += nm->handler_table_size();
   106     nul_chk_table_size  += nm->nul_chk_table_size();
   107     oops_size += nm->oops_size();
   108   }
   109   void print_nmethod_stats() {
   110     if (nmethod_count == 0)  return;
   111     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
   112     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
   113     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
   114     if (code_size != 0)           tty->print_cr(" main code      = %d", code_size);
   115     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
   116     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
   117     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
   118     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
   119     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
   120     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
   121     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
   122     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
   123   }
   125   int native_nmethod_count;
   126   int native_total_size;
   127   int native_relocation_size;
   128   int native_code_size;
   129   int native_oops_size;
   130   void note_native_nmethod(nmethod* nm) {
   131     native_nmethod_count += 1;
   132     native_total_size       += nm->size();
   133     native_relocation_size  += nm->relocation_size();
   134     native_code_size        += nm->code_size();
   135     native_oops_size        += nm->oops_size();
   136   }
   137   void print_native_nmethod_stats() {
   138     if (native_nmethod_count == 0)  return;
   139     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
   140     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
   141     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
   142     if (native_code_size != 0)        tty->print_cr(" N. main code   = %d", native_code_size);
   143     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
   144   }
   146   int pc_desc_resets;   // number of resets (= number of caches)
   147   int pc_desc_queries;  // queries to nmethod::find_pc_desc
   148   int pc_desc_approx;   // number of those which have approximate true
   149   int pc_desc_repeats;  // number of _last_pc_desc hits
   150   int pc_desc_hits;     // number of LRU cache hits
   151   int pc_desc_tests;    // total number of PcDesc examinations
   152   int pc_desc_searches; // total number of quasi-binary search steps
   153   int pc_desc_adds;     // number of LUR cache insertions
   155   void print_pc_stats() {
   156     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
   157                   pc_desc_queries,
   158                   (double)(pc_desc_tests + pc_desc_searches)
   159                   / pc_desc_queries);
   160     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
   161                   pc_desc_resets,
   162                   pc_desc_queries, pc_desc_approx,
   163                   pc_desc_repeats, pc_desc_hits,
   164                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
   165   }
   166 } nmethod_stats;
   167 #endif //PRODUCT
   169 //---------------------------------------------------------------------------------
   172 // The _unwind_handler is a special marker address, which says that
   173 // for given exception oop and address, the frame should be removed
   174 // as the tuple cannot be caught in the nmethod
   175 address ExceptionCache::_unwind_handler = (address) -1;
   178 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
   179   assert(pc != NULL, "Must be non null");
   180   assert(exception.not_null(), "Must be non null");
   181   assert(handler != NULL, "Must be non null");
   183   _count = 0;
   184   _exception_type = exception->klass();
   185   _next = NULL;
   187   add_address_and_handler(pc,handler);
   188 }
   191 address ExceptionCache::match(Handle exception, address pc) {
   192   assert(pc != NULL,"Must be non null");
   193   assert(exception.not_null(),"Must be non null");
   194   if (exception->klass() == exception_type()) {
   195     return (test_address(pc));
   196   }
   198   return NULL;
   199 }
   202 bool ExceptionCache::match_exception_with_space(Handle exception) {
   203   assert(exception.not_null(),"Must be non null");
   204   if (exception->klass() == exception_type() && count() < cache_size) {
   205     return true;
   206   }
   207   return false;
   208 }
   211 address ExceptionCache::test_address(address addr) {
   212   for (int i=0; i<count(); i++) {
   213     if (pc_at(i) == addr) {
   214       return handler_at(i);
   215     }
   216   }
   217   return NULL;
   218 }
   221 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
   222   if (test_address(addr) == handler) return true;
   223   if (count() < cache_size) {
   224     set_pc_at(count(),addr);
   225     set_handler_at(count(), handler);
   226     increment_count();
   227     return true;
   228   }
   229   return false;
   230 }
   233 // private method for handling exception cache
   234 // These methods are private, and used to manipulate the exception cache
   235 // directly.
   236 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
   237   ExceptionCache* ec = exception_cache();
   238   while (ec != NULL) {
   239     if (ec->match_exception_with_space(exception)) {
   240       return ec;
   241     }
   242     ec = ec->next();
   243   }
   244   return NULL;
   245 }
   248 //-----------------------------------------------------------------------------
   251 // Helper used by both find_pc_desc methods.
   252 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
   253   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
   254   if (!approximate)
   255     return pc->pc_offset() == pc_offset;
   256   else
   257     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
   258 }
   260 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
   261   if (initial_pc_desc == NULL) {
   262     _last_pc_desc = NULL;  // native method
   263     return;
   264   }
   265   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
   266   // reset the cache by filling it with benign (non-null) values
   267   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
   268   _last_pc_desc = initial_pc_desc + 1;  // first valid one is after sentinel
   269   for (int i = 0; i < cache_size; i++)
   270     _pc_descs[i] = initial_pc_desc;
   271 }
   273 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
   274   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
   275   NOT_PRODUCT(if (approximate)  ++nmethod_stats.pc_desc_approx);
   277   // In order to prevent race conditions do not load cache elements
   278   // repeatedly, but use a local copy:
   279   PcDesc* res;
   281   // Step one:  Check the most recently returned value.
   282   res = _last_pc_desc;
   283   if (res == NULL)  return NULL;  // native method; no PcDescs at all
   284   if (match_desc(res, pc_offset, approximate)) {
   285     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
   286     return res;
   287   }
   289   // Step two:  Check the LRU cache.
   290   for (int i = 0; i < cache_size; i++) {
   291     res = _pc_descs[i];
   292     if (res->pc_offset() < 0)  break;  // optimization: skip empty cache
   293     if (match_desc(res, pc_offset, approximate)) {
   294       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
   295       _last_pc_desc = res;  // record this cache hit in case of repeat
   296       return res;
   297     }
   298   }
   300   // Report failure.
   301   return NULL;
   302 }
   304 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
   305   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
   306   // Update the LRU cache by shifting pc_desc forward:
   307   for (int i = 0; i < cache_size; i++)  {
   308     PcDesc* next = _pc_descs[i];
   309     _pc_descs[i] = pc_desc;
   310     pc_desc = next;
   311   }
   312   // Note:  Do not update _last_pc_desc.  It fronts for the LRU cache.
   313 }
   315 // adjust pcs_size so that it is a multiple of both oopSize and
   316 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
   317 // of oopSize, then 2*sizeof(PcDesc) is)
   318 static int  adjust_pcs_size(int pcs_size) {
   319   int nsize = round_to(pcs_size,   oopSize);
   320   if ((nsize % sizeof(PcDesc)) != 0) {
   321     nsize = pcs_size + sizeof(PcDesc);
   322   }
   323   assert((nsize %  oopSize) == 0, "correct alignment");
   324   return nsize;
   325 }
   327 //-----------------------------------------------------------------------------
   330 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
   331   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
   332   assert(new_entry != NULL,"Must be non null");
   333   assert(new_entry->next() == NULL, "Must be null");
   335   if (exception_cache() != NULL) {
   336     new_entry->set_next(exception_cache());
   337   }
   338   set_exception_cache(new_entry);
   339 }
   341 void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
   342   ExceptionCache* prev = NULL;
   343   ExceptionCache* curr = exception_cache();
   344   assert(curr != NULL, "nothing to remove");
   345   // find the previous and next entry of ec
   346   while (curr != ec) {
   347     prev = curr;
   348     curr = curr->next();
   349     assert(curr != NULL, "ExceptionCache not found");
   350   }
   351   // now: curr == ec
   352   ExceptionCache* next = curr->next();
   353   if (prev == NULL) {
   354     set_exception_cache(next);
   355   } else {
   356     prev->set_next(next);
   357   }
   358   delete curr;
   359 }
   362 // public method for accessing the exception cache
   363 // These are the public access methods.
   364 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
   365   // We never grab a lock to read the exception cache, so we may
   366   // have false negatives. This is okay, as it can only happen during
   367   // the first few exception lookups for a given nmethod.
   368   ExceptionCache* ec = exception_cache();
   369   while (ec != NULL) {
   370     address ret_val;
   371     if ((ret_val = ec->match(exception,pc)) != NULL) {
   372       return ret_val;
   373     }
   374     ec = ec->next();
   375   }
   376   return NULL;
   377 }
   380 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
   381   // There are potential race conditions during exception cache updates, so we
   382   // must own the ExceptionCache_lock before doing ANY modifications. Because
   383   // we don't lock during reads, it is possible to have several threads attempt
   384   // to update the cache with the same data. We need to check for already inserted
   385   // copies of the current data before adding it.
   387   MutexLocker ml(ExceptionCache_lock);
   388   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
   390   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
   391     target_entry = new ExceptionCache(exception,pc,handler);
   392     add_exception_cache_entry(target_entry);
   393   }
   394 }
   397 //-------------end of code for ExceptionCache--------------
   400 void nmFlags::clear() {
   401   assert(sizeof(nmFlags) == sizeof(int), "using more than one word for nmFlags");
   402   *(jint*)this = 0;
   403 }
   405 int nmethod::total_size() const {
   406   return
   407     code_size()          +
   408     stub_size()          +
   409     consts_size()        +
   410     scopes_data_size()   +
   411     scopes_pcs_size()    +
   412     handler_table_size() +
   413     nul_chk_table_size();
   414 }
   416 const char* nmethod::compile_kind() const {
   417   if (method() == NULL)    return "unloaded";
   418   if (is_native_method())  return "c2n";
   419   if (is_osr_method())     return "osr";
   420   return NULL;
   421 }
   423 // %%% This variable is no longer used?
   424 int nmethod::_zombie_instruction_size = NativeJump::instruction_size;
   427 nmethod* nmethod::new_native_nmethod(methodHandle method,
   428   CodeBuffer *code_buffer,
   429   int vep_offset,
   430   int frame_complete,
   431   int frame_size,
   432   ByteSize basic_lock_owner_sp_offset,
   433   ByteSize basic_lock_sp_offset,
   434   OopMapSet* oop_maps) {
   435   // create nmethod
   436   nmethod* nm = NULL;
   437   {
   438     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   439     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   440     CodeOffsets offsets;
   441     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   442     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   443     nm = new (native_nmethod_size)
   444       nmethod(method(), native_nmethod_size, &offsets,
   445               code_buffer, frame_size,
   446               basic_lock_owner_sp_offset, basic_lock_sp_offset,
   447               oop_maps);
   448     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
   449     if (PrintAssembly && nm != NULL)
   450       Disassembler::decode(nm);
   451   }
   452   // verify nmethod
   453   debug_only(if (nm) nm->verify();) // might block
   455   if (nm != NULL) {
   456     nm->log_new_nmethod();
   457   }
   459   return nm;
   460 }
   462 #ifdef HAVE_DTRACE_H
   463 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
   464                                      CodeBuffer *code_buffer,
   465                                      int vep_offset,
   466                                      int trap_offset,
   467                                      int frame_complete,
   468                                      int frame_size) {
   469   // create nmethod
   470   nmethod* nm = NULL;
   471   {
   472     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   473     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
   474     CodeOffsets offsets;
   475     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
   476     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
   477     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
   479     nm = new (nmethod_size) nmethod(method(), nmethod_size, &offsets, code_buffer, frame_size);
   481     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
   482     if (PrintAssembly && nm != NULL)
   483       Disassembler::decode(nm);
   484   }
   485   // verify nmethod
   486   debug_only(if (nm) nm->verify();) // might block
   488   if (nm != NULL) {
   489     nm->log_new_nmethod();
   490   }
   492   return nm;
   493 }
   495 #endif // def HAVE_DTRACE_H
   497 nmethod* nmethod::new_nmethod(methodHandle method,
   498   int compile_id,
   499   int entry_bci,
   500   CodeOffsets* offsets,
   501   int orig_pc_offset,
   502   DebugInformationRecorder* debug_info,
   503   Dependencies* dependencies,
   504   CodeBuffer* code_buffer, int frame_size,
   505   OopMapSet* oop_maps,
   506   ExceptionHandlerTable* handler_table,
   507   ImplicitExceptionTable* nul_chk_table,
   508   AbstractCompiler* compiler,
   509   int comp_level
   510 )
   511 {
   512   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   513   // create nmethod
   514   nmethod* nm = NULL;
   515   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   516     int nmethod_size =
   517       allocation_size(code_buffer, sizeof(nmethod))
   518       + adjust_pcs_size(debug_info->pcs_size())
   519       + round_to(dependencies->size_in_bytes() , oopSize)
   520       + round_to(handler_table->size_in_bytes(), oopSize)
   521       + round_to(nul_chk_table->size_in_bytes(), oopSize)
   522       + round_to(debug_info->data_size()       , oopSize);
   523     nm = new (nmethod_size)
   524       nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
   525               orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
   526               oop_maps,
   527               handler_table,
   528               nul_chk_table,
   529               compiler,
   530               comp_level);
   531     if (nm != NULL) {
   532       // To make dependency checking during class loading fast, record
   533       // the nmethod dependencies in the classes it is dependent on.
   534       // This allows the dependency checking code to simply walk the
   535       // class hierarchy above the loaded class, checking only nmethods
   536       // which are dependent on those classes.  The slow way is to
   537       // check every nmethod for dependencies which makes it linear in
   538       // the number of methods compiled.  For applications with a lot
   539       // classes the slow way is too slow.
   540       for (Dependencies::DepStream deps(nm); deps.next(); ) {
   541         klassOop klass = deps.context_type();
   542         if (klass == NULL)  continue;  // ignore things like evol_method
   544         // record this nmethod as dependent on this klass
   545         instanceKlass::cast(klass)->add_dependent_nmethod(nm);
   546       }
   547     }
   548     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
   549     if (PrintAssembly && nm != NULL)
   550       Disassembler::decode(nm);
   551   }
   553   // verify nmethod
   554   debug_only(if (nm) nm->verify();) // might block
   556   if (nm != NULL) {
   557     nm->log_new_nmethod();
   558   }
   560   // done
   561   return nm;
   562 }
   565 // For native wrappers
   566 nmethod::nmethod(
   567   methodOop method,
   568   int nmethod_size,
   569   CodeOffsets* offsets,
   570   CodeBuffer* code_buffer,
   571   int frame_size,
   572   ByteSize basic_lock_owner_sp_offset,
   573   ByteSize basic_lock_sp_offset,
   574   OopMapSet* oop_maps )
   575   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
   576              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   577   _compiled_synchronized_native_basic_lock_owner_sp_offset(basic_lock_owner_sp_offset),
   578   _compiled_synchronized_native_basic_lock_sp_offset(basic_lock_sp_offset)
   579 {
   580   {
   581     debug_only(No_Safepoint_Verifier nsv;)
   582     assert_locked_or_safepoint(CodeCache_lock);
   584     NOT_PRODUCT(_has_debug_info = false; )
   585     _method                  = method;
   586     _entry_bci               = InvocationEntryBci;
   587     _link                    = NULL;
   588     _compiler                = NULL;
   589     // We have no exception handler or deopt handler make the
   590     // values something that will never match a pc like the nmethod vtable entry
   591     _exception_offset        = 0;
   592     _deoptimize_offset       = 0;
   593     _orig_pc_offset          = 0;
   594 #ifdef HAVE_DTRACE_H
   595     _trap_offset             = 0;
   596 #endif // def HAVE_DTRACE_H
   597     _stub_offset             = data_offset();
   598     _consts_offset           = data_offset();
   599     _scopes_data_offset      = data_offset();
   600     _scopes_pcs_offset       = _scopes_data_offset;
   601     _dependencies_offset     = _scopes_pcs_offset;
   602     _handler_table_offset    = _dependencies_offset;
   603     _nul_chk_table_offset    = _handler_table_offset;
   604     _nmethod_end_offset      = _nul_chk_table_offset;
   605     _compile_id              = 0;  // default
   606     _comp_level              = CompLevel_none;
   607     _entry_point             = instructions_begin();
   608     _verified_entry_point    = instructions_begin() + offsets->value(CodeOffsets::Verified_Entry);
   609     _osr_entry_point         = NULL;
   610     _exception_cache         = NULL;
   611     _pc_desc_cache.reset_to(NULL);
   613     flags.clear();
   614     flags.state              = alive;
   615     _markedForDeoptimization = 0;
   617     _lock_count = 0;
   618     _stack_traversal_mark    = 0;
   620     code_buffer->copy_oops_to(this);
   621     debug_only(check_store();)
   622     CodeCache::commit(this);
   623     VTune::create_nmethod(this);
   624   }
   626   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
   627     ttyLocker ttyl;  // keep the following output all in one block
   628     // This output goes directly to the tty, not the compiler log.
   629     // To enable tools to match it up with the compilation activity,
   630     // be sure to tag this tty output with the compile ID.
   631     if (xtty != NULL) {
   632       xtty->begin_head("print_native_nmethod");
   633       xtty->method(_method);
   634       xtty->stamp();
   635       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   636     }
   637     // print the header part first
   638     print();
   639     // then print the requested information
   640     if (PrintNativeNMethods) {
   641       print_code();
   642       oop_maps->print();
   643     }
   644     if (PrintRelocations) {
   645       print_relocations();
   646     }
   647     if (xtty != NULL) {
   648       xtty->tail("print_native_nmethod");
   649     }
   650   }
   651   Events::log("Create nmethod " INTPTR_FORMAT, this);
   652 }
   654 // For dtrace wrappers
   655 #ifdef HAVE_DTRACE_H
   656 nmethod::nmethod(
   657   methodOop method,
   658   int nmethod_size,
   659   CodeOffsets* offsets,
   660   CodeBuffer* code_buffer,
   661   int frame_size)
   662   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
   663              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
   664   _compiled_synchronized_native_basic_lock_owner_sp_offset(in_ByteSize(-1)),
   665   _compiled_synchronized_native_basic_lock_sp_offset(in_ByteSize(-1))
   666 {
   667   {
   668     debug_only(No_Safepoint_Verifier nsv;)
   669     assert_locked_or_safepoint(CodeCache_lock);
   671     NOT_PRODUCT(_has_debug_info = false; )
   672     _method                  = method;
   673     _entry_bci               = InvocationEntryBci;
   674     _link                    = NULL;
   675     _compiler                = NULL;
   676     // We have no exception handler or deopt handler make the
   677     // values something that will never match a pc like the nmethod vtable entry
   678     _exception_offset        = 0;
   679     _deoptimize_offset       = 0;
   680     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
   681     _orig_pc_offset          = 0;
   682     _stub_offset             = data_offset();
   683     _consts_offset           = data_offset();
   684     _scopes_data_offset      = data_offset();
   685     _scopes_pcs_offset       = _scopes_data_offset;
   686     _dependencies_offset     = _scopes_pcs_offset;
   687     _handler_table_offset    = _dependencies_offset;
   688     _nul_chk_table_offset    = _handler_table_offset;
   689     _nmethod_end_offset      = _nul_chk_table_offset;
   690     _compile_id              = 0;  // default
   691     _comp_level              = CompLevel_none;
   692     _entry_point             = instructions_begin();
   693     _verified_entry_point    = instructions_begin() + offsets->value(CodeOffsets::Verified_Entry);
   694     _osr_entry_point         = NULL;
   695     _exception_cache         = NULL;
   696     _pc_desc_cache.reset_to(NULL);
   698     flags.clear();
   699     flags.state              = alive;
   700     _markedForDeoptimization = 0;
   702     _lock_count = 0;
   703     _stack_traversal_mark    = 0;
   705     code_buffer->copy_oops_to(this);
   706     debug_only(check_store();)
   707     CodeCache::commit(this);
   708     VTune::create_nmethod(this);
   709   }
   711   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
   712     ttyLocker ttyl;  // keep the following output all in one block
   713     // This output goes directly to the tty, not the compiler log.
   714     // To enable tools to match it up with the compilation activity,
   715     // be sure to tag this tty output with the compile ID.
   716     if (xtty != NULL) {
   717       xtty->begin_head("print_dtrace_nmethod");
   718       xtty->method(_method);
   719       xtty->stamp();
   720       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   721     }
   722     // print the header part first
   723     print();
   724     // then print the requested information
   725     if (PrintNMethods) {
   726       print_code();
   727     }
   728     if (PrintRelocations) {
   729       print_relocations();
   730     }
   731     if (xtty != NULL) {
   732       xtty->tail("print_dtrace_nmethod");
   733     }
   734   }
   735   Events::log("Create nmethod " INTPTR_FORMAT, this);
   736 }
   737 #endif // def HAVE_DTRACE_H
   739 void* nmethod::operator new(size_t size, int nmethod_size) {
   740   // Always leave some room in the CodeCache for I2C/C2I adapters
   741   if (CodeCache::unallocated_capacity() < CodeCacheMinimumFreeSpace) return NULL;
   742   return CodeCache::allocate(nmethod_size);
   743 }
   746 nmethod::nmethod(
   747   methodOop method,
   748   int nmethod_size,
   749   int compile_id,
   750   int entry_bci,
   751   CodeOffsets* offsets,
   752   int orig_pc_offset,
   753   DebugInformationRecorder* debug_info,
   754   Dependencies* dependencies,
   755   CodeBuffer *code_buffer,
   756   int frame_size,
   757   OopMapSet* oop_maps,
   758   ExceptionHandlerTable* handler_table,
   759   ImplicitExceptionTable* nul_chk_table,
   760   AbstractCompiler* compiler,
   761   int comp_level
   762   )
   763   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
   764              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   765   _compiled_synchronized_native_basic_lock_owner_sp_offset(in_ByteSize(-1)),
   766   _compiled_synchronized_native_basic_lock_sp_offset(in_ByteSize(-1))
   767 {
   768   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   769   {
   770     debug_only(No_Safepoint_Verifier nsv;)
   771     assert_locked_or_safepoint(CodeCache_lock);
   773     NOT_PRODUCT(_has_debug_info = false; )
   774     _method                  = method;
   775     _compile_id              = compile_id;
   776     _comp_level              = comp_level;
   777     _entry_bci               = entry_bci;
   778     _link                    = NULL;
   779     _compiler                = compiler;
   780     _orig_pc_offset          = orig_pc_offset;
   781 #ifdef HAVE_DTRACE_H
   782     _trap_offset             = 0;
   783 #endif // def HAVE_DTRACE_H
   784     _stub_offset             = instructions_offset() + code_buffer->total_offset_of(code_buffer->stubs()->start());
   786     // Exception handler and deopt handler are in the stub section
   787     _exception_offset        = _stub_offset + offsets->value(CodeOffsets::Exceptions);
   788     _deoptimize_offset       = _stub_offset + offsets->value(CodeOffsets::Deopt);
   789     _consts_offset           = instructions_offset() + code_buffer->total_offset_of(code_buffer->consts()->start());
   790     _scopes_data_offset      = data_offset();
   791     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size         (), oopSize);
   792     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
   793     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
   794     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
   795     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
   797     _entry_point             = instructions_begin();
   798     _verified_entry_point    = instructions_begin() + offsets->value(CodeOffsets::Verified_Entry);
   799     _osr_entry_point         = instructions_begin() + offsets->value(CodeOffsets::OSR_Entry);
   800     _exception_cache         = NULL;
   801     _pc_desc_cache.reset_to(scopes_pcs_begin());
   803     flags.clear();
   804     flags.state              = alive;
   805     _markedForDeoptimization = 0;
   807     _unload_reported         = false;           // jvmti state
   809     _lock_count = 0;
   810     _stack_traversal_mark    = 0;
   812     // Copy contents of ScopeDescRecorder to nmethod
   813     code_buffer->copy_oops_to(this);
   814     debug_info->copy_to(this);
   815     dependencies->copy_to(this);
   816     debug_only(check_store();)
   818     CodeCache::commit(this);
   820     VTune::create_nmethod(this);
   822     // Copy contents of ExceptionHandlerTable to nmethod
   823     handler_table->copy_to(this);
   824     nul_chk_table->copy_to(this);
   826     // we use the information of entry points to find out if a method is
   827     // static or non static
   828     assert(compiler->is_c2() ||
   829            _method->is_static() == (entry_point() == _verified_entry_point),
   830            " entry points must be same for static methods and vice versa");
   831   }
   833   bool printnmethods = PrintNMethods
   834     || CompilerOracle::should_print(_method)
   835     || CompilerOracle::has_option_string(_method, "PrintNMethods");
   836   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
   837     print_nmethod(printnmethods);
   838   }
   840   // Note: Do not verify in here as the CodeCache_lock is
   841   //       taken which would conflict with the CompiledIC_lock
   842   //       which taken during the verification of call sites.
   843   //       (was bug - gri 10/25/99)
   845   Events::log("Create nmethod " INTPTR_FORMAT, this);
   846 }
   849 // Print a short set of xml attributes to identify this nmethod.  The
   850 // output should be embedded in some other element.
   851 void nmethod::log_identity(xmlStream* log) const {
   852   log->print(" compile_id='%d'", compile_id());
   853   const char* nm_kind = compile_kind();
   854   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
   855   if (compiler() != NULL) {
   856     log->print(" compiler='%s'", compiler()->name());
   857   }
   858 #ifdef TIERED
   859   log->print(" level='%d'", comp_level());
   860 #endif // TIERED
   861 }
   864 #define LOG_OFFSET(log, name)                    \
   865   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
   866     log->print(" " XSTR(name) "_offset='%d'"    , \
   867                (intptr_t)name##_begin() - (intptr_t)this)
   870 void nmethod::log_new_nmethod() const {
   871   if (LogCompilation && xtty != NULL) {
   872     ttyLocker ttyl;
   873     HandleMark hm;
   874     xtty->begin_elem("nmethod");
   875     log_identity(xtty);
   876     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'",
   877                 instructions_begin(), size());
   878     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
   880     LOG_OFFSET(xtty, relocation);
   881     LOG_OFFSET(xtty, code);
   882     LOG_OFFSET(xtty, stub);
   883     LOG_OFFSET(xtty, consts);
   884     LOG_OFFSET(xtty, scopes_data);
   885     LOG_OFFSET(xtty, scopes_pcs);
   886     LOG_OFFSET(xtty, dependencies);
   887     LOG_OFFSET(xtty, handler_table);
   888     LOG_OFFSET(xtty, nul_chk_table);
   889     LOG_OFFSET(xtty, oops);
   891     xtty->method(method());
   892     xtty->stamp();
   893     xtty->end_elem();
   894   }
   895 }
   897 #undef LOG_OFFSET
   900 // Print out more verbose output usually for a newly created nmethod.
   901 void nmethod::print_on(outputStream* st, const char* title) const {
   902   if (st != NULL) {
   903     ttyLocker ttyl;
   904     // Print a little tag line that looks like +PrintCompilation output:
   905     st->print("%3d%c  %s",
   906               compile_id(),
   907               is_osr_method() ? '%' :
   908               method() != NULL &&
   909               is_native_method() ? 'n' : ' ',
   910               title);
   911 #ifdef TIERED
   912     st->print(" (%d) ", comp_level());
   913 #endif // TIERED
   914     if (WizardMode) st->print(" (" INTPTR_FORMAT ")", this);
   915     if (method() != NULL) {
   916       method()->print_short_name(st);
   917       if (is_osr_method())
   918         st->print(" @ %d", osr_entry_bci());
   919       if (method()->code_size() > 0)
   920         st->print(" (%d bytes)", method()->code_size());
   921     }
   922   }
   923 }
   926 void nmethod::print_nmethod(bool printmethod) {
   927   ttyLocker ttyl;  // keep the following output all in one block
   928   if (xtty != NULL) {
   929     xtty->begin_head("print_nmethod");
   930     xtty->stamp();
   931     xtty->end_head();
   932   }
   933   // print the header part first
   934   print();
   935   // then print the requested information
   936   if (printmethod) {
   937     print_code();
   938     print_pcs();
   939     oop_maps()->print();
   940   }
   941   if (PrintDebugInfo) {
   942     print_scopes();
   943   }
   944   if (PrintRelocations) {
   945     print_relocations();
   946   }
   947   if (PrintDependencies) {
   948     print_dependencies();
   949   }
   950   if (PrintExceptionHandlers) {
   951     print_handler_table();
   952     print_nul_chk_table();
   953   }
   954   if (xtty != NULL) {
   955     xtty->tail("print_nmethod");
   956   }
   957 }
   960 void nmethod::set_version(int v) {
   961   flags.version = v;
   962 }
   965 ScopeDesc* nmethod::scope_desc_at(address pc) {
   966   PcDesc* pd = pc_desc_at(pc);
   967   guarantee(pd != NULL, "scope must be present");
   968   return new ScopeDesc(this, pd->scope_decode_offset(),
   969                        pd->obj_decode_offset());
   970 }
   973 void nmethod::clear_inline_caches() {
   974   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
   975   if (is_zombie()) {
   976     return;
   977   }
   979   RelocIterator iter(this);
   980   while (iter.next()) {
   981     iter.reloc()->clear_inline_cache();
   982   }
   983 }
   986 void nmethod::cleanup_inline_caches() {
   988   assert(SafepointSynchronize::is_at_safepoint() &&
   989         !CompiledIC_lock->is_locked() &&
   990         !Patching_lock->is_locked(), "no threads must be updating the inline caches by them selfs");
   992   // If the method is not entrant or zombie then a JMP is plastered over the
   993   // first few bytes.  If an oop in the old code was there, that oop
   994   // should not get GC'd.  Skip the first few bytes of oops on
   995   // not-entrant methods.
   996   address low_boundary = verified_entry_point();
   997   if (!is_in_use()) {
   998     low_boundary += NativeJump::instruction_size;
   999     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1000     // This means that the low_boundary is going to be a little too high.
  1001     // This shouldn't matter, since oops of non-entrant methods are never used.
  1002     // In fact, why are we bothering to look at oops in a non-entrant method??
  1005   // Find all calls in an nmethod, and clear the ones that points to zombie methods
  1006   ResourceMark rm;
  1007   RelocIterator iter(this, low_boundary);
  1008   while(iter.next()) {
  1009     switch(iter.type()) {
  1010       case relocInfo::virtual_call_type:
  1011       case relocInfo::opt_virtual_call_type: {
  1012         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1013         // Ok, to lookup references to zombies here
  1014         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
  1015         if( cb != NULL && cb->is_nmethod() ) {
  1016           nmethod* nm = (nmethod*)cb;
  1017           // Clean inline caches pointing to both zombie and not_entrant methods
  1018           if (!nm->is_in_use()) ic->set_to_clean();
  1020         break;
  1022       case relocInfo::static_call_type: {
  1023         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
  1024         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
  1025         if( cb != NULL && cb->is_nmethod() ) {
  1026           nmethod* nm = (nmethod*)cb;
  1027           // Clean inline caches pointing to both zombie and not_entrant methods
  1028           if (!nm->is_in_use()) csc->set_to_clean();
  1030         break;
  1036 void nmethod::mark_as_seen_on_stack() {
  1037   assert(is_not_entrant(), "must be a non-entrant method");
  1038   set_stack_traversal_mark(NMethodSweeper::traversal_count());
  1041 // Tell if a non-entrant method can be converted to a zombie (i.e., there is no activations on the stack)
  1042 bool nmethod::can_not_entrant_be_converted() {
  1043   assert(is_not_entrant(), "must be a non-entrant method");
  1044   assert(SafepointSynchronize::is_at_safepoint(), "must be called during a safepoint");
  1046   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
  1047   // count can be greater than the stack traversal count before it hits the
  1048   // nmethod for the second time.
  1049   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count();
  1052 void nmethod::inc_decompile_count() {
  1053   // Could be gated by ProfileTraps, but do not bother...
  1054   methodOop m = method();
  1055   if (m == NULL)  return;
  1056   methodDataOop mdo = m->method_data();
  1057   if (mdo == NULL)  return;
  1058   // There is a benign race here.  See comments in methodDataOop.hpp.
  1059   mdo->inc_decompile_count();
  1062 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
  1064   post_compiled_method_unload();
  1066   // Since this nmethod is being unloaded, make sure that dependencies
  1067   // recorded in instanceKlasses get flushed and pass non-NULL closure to
  1068   // indicate that this work is being done during a GC.
  1069   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
  1070   assert(is_alive != NULL, "Should be non-NULL");
  1071   // A non-NULL is_alive closure indicates that this is being called during GC.
  1072   flush_dependencies(is_alive);
  1074   // Break cycle between nmethod & method
  1075   if (TraceClassUnloading && WizardMode) {
  1076     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
  1077                   " unloadable], methodOop(" INTPTR_FORMAT
  1078                   "), cause(" INTPTR_FORMAT ")",
  1079                   this, (address)_method, (address)cause);
  1080     cause->klass()->print();
  1082   // Unlink the osr method, so we do not look this up again
  1083   if (is_osr_method()) {
  1084     invalidate_osr_method();
  1086   // If _method is already NULL the methodOop is about to be unloaded,
  1087   // so we don't have to break the cycle. Note that it is possible to
  1088   // have the methodOop live here, in case we unload the nmethod because
  1089   // it is pointing to some oop (other than the methodOop) being unloaded.
  1090   if (_method != NULL) {
  1091     // OSR methods point to the methodOop, but the methodOop does not
  1092     // point back!
  1093     if (_method->code() == this) {
  1094       _method->clear_code(); // Break a cycle
  1096     inc_decompile_count();     // Last chance to make a mark on the MDO
  1097     _method = NULL;            // Clear the method of this dead nmethod
  1099   // Make the class unloaded - i.e., change state and notify sweeper
  1100   check_safepoint();
  1101   if (is_in_use()) {
  1102     // Transitioning directly from live to unloaded -- so
  1103     // we need to force a cache clean-up; remember this
  1104     // for later on.
  1105     CodeCache::set_needs_cache_clean(true);
  1107   flags.state = unloaded;
  1109   // The methodOop is gone at this point
  1110   assert(_method == NULL, "Tautology");
  1112   set_link(NULL);
  1113   NMethodSweeper::notify(this);
  1116 void nmethod::invalidate_osr_method() {
  1117   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
  1118   if (_entry_bci != InvalidOSREntryBci)
  1119     inc_decompile_count();
  1120   // Remove from list of active nmethods
  1121   if (method() != NULL)
  1122     instanceKlass::cast(method()->method_holder())->remove_osr_nmethod(this);
  1123   // Set entry as invalid
  1124   _entry_bci = InvalidOSREntryBci;
  1127 void nmethod::log_state_change(int state) const {
  1128   if (LogCompilation) {
  1129     if (xtty != NULL) {
  1130       ttyLocker ttyl;  // keep the following output all in one block
  1131       xtty->begin_elem("make_not_entrant %sthread='" UINTX_FORMAT "'",
  1132                        (state == zombie ? "zombie='1' " : ""),
  1133                        os::current_thread_id());
  1134       log_identity(xtty);
  1135       xtty->stamp();
  1136       xtty->end_elem();
  1139   if (PrintCompilation) {
  1140     print_on(tty, state == zombie ? "made zombie " : "made not entrant ");
  1141     tty->cr();
  1145 // Common functionality for both make_not_entrant and make_zombie
  1146 void nmethod::make_not_entrant_or_zombie(int state) {
  1147   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
  1149   // Code for an on-stack-replacement nmethod is removed when a class gets unloaded.
  1150   // They never become zombie/non-entrant, so the nmethod sweeper will never remove
  1151   // them. Instead the entry_bci is set to InvalidOSREntryBci, so the osr nmethod
  1152   // will never be used anymore. That the nmethods only gets removed when class unloading
  1153   // happens, make life much simpler, since the nmethods are not just going to disappear
  1154   // out of the blue.
  1155   if (is_osr_method()) {
  1156     if (osr_entry_bci() != InvalidOSREntryBci) {
  1157       // only log this once
  1158       log_state_change(state);
  1160     invalidate_osr_method();
  1161     return;
  1164   // If the method is already zombie or set to the state we want, nothing to do
  1165   if (is_zombie() || (state == not_entrant && is_not_entrant())) {
  1166     return;
  1169   log_state_change(state);
  1171   // Make sure the nmethod is not flushed in case of a safepoint in code below.
  1172   nmethodLocker nml(this);
  1175     // Enter critical section.  Does not block for safepoint.
  1176     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
  1177     // The caller can be calling the method statically or through an inline
  1178     // cache call.
  1179     if (!is_not_entrant()) {
  1180       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
  1181                   SharedRuntime::get_handle_wrong_method_stub());
  1182       assert (NativeJump::instruction_size == nmethod::_zombie_instruction_size, "");
  1185     // When the nmethod becomes zombie it is no longer alive so the
  1186     // dependencies must be flushed.  nmethods in the not_entrant
  1187     // state will be flushed later when the transition to zombie
  1188     // happens or they get unloaded.
  1189     if (state == zombie) {
  1190       assert(SafepointSynchronize::is_at_safepoint(), "must be done at safepoint");
  1191       flush_dependencies(NULL);
  1192     } else {
  1193       assert(state == not_entrant, "other cases may need to be handled differently");
  1196     // Change state
  1197     flags.state = state;
  1198   } // leave critical region under Patching_lock
  1200   if (state == not_entrant) {
  1201     Events::log("Make nmethod not entrant " INTPTR_FORMAT, this);
  1202   } else {
  1203     Events::log("Make nmethod zombie " INTPTR_FORMAT, this);
  1206   if (TraceCreateZombies) {
  1207     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
  1210   // Make sweeper aware that there is a zombie method that needs to be removed
  1211   NMethodSweeper::notify(this);
  1213   // not_entrant only stuff
  1214   if (state == not_entrant) {
  1215     mark_as_seen_on_stack();
  1218   // It's a true state change, so mark the method as decompiled.
  1219   inc_decompile_count();
  1222   // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload event
  1223   // and it hasn't already been reported for this nmethod then report it now.
  1224   // (the event may have been reported earilier if the GC marked it for unloading).
  1225   if (state == zombie) {
  1227     DTRACE_METHOD_UNLOAD_PROBE(method());
  1229     if (JvmtiExport::should_post_compiled_method_unload() &&
  1230         !unload_reported()) {
  1231       assert(method() != NULL, "checking");
  1233         HandleMark hm;
  1234         JvmtiExport::post_compiled_method_unload_at_safepoint(
  1235             method()->jmethod_id(), code_begin());
  1237       set_unload_reported();
  1242   // Zombie only stuff
  1243   if (state == zombie) {
  1244     VTune::delete_nmethod(this);
  1247   // Check whether method got unloaded at a safepoint before this,
  1248   // if so we can skip the flushing steps below
  1249   if (method() == NULL) return;
  1251   // Remove nmethod from method.
  1252   // We need to check if both the _code and _from_compiled_code_entry_point
  1253   // refer to this nmethod because there is a race in setting these two fields
  1254   // in methodOop as seen in bugid 4947125.
  1255   // If the vep() points to the zombie nmethod, the memory for the nmethod
  1256   // could be flushed and the compiler and vtable stubs could still call
  1257   // through it.
  1258   if (method()->code() == this ||
  1259       method()->from_compiled_entry() == verified_entry_point()) {
  1260     HandleMark hm;
  1261     method()->clear_code();
  1266 #ifndef PRODUCT
  1267 void nmethod::check_safepoint() {
  1268   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1270 #endif
  1273 void nmethod::flush() {
  1274   // Note that there are no valid oops in the nmethod anymore.
  1275   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
  1276   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
  1278   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
  1279   check_safepoint();
  1281   // completely deallocate this method
  1282   EventMark m("flushing nmethod " INTPTR_FORMAT " %s", this, "");
  1283   if (PrintMethodFlushing) {
  1284     tty->print_cr("*flushing nmethod " INTPTR_FORMAT ". Live blobs: %d", this, CodeCache::nof_blobs());
  1287   // We need to deallocate any ExceptionCache data.
  1288   // Note that we do not need to grab the nmethod lock for this, it
  1289   // better be thread safe if we're disposing of it!
  1290   ExceptionCache* ec = exception_cache();
  1291   set_exception_cache(NULL);
  1292   while(ec != NULL) {
  1293     ExceptionCache* next = ec->next();
  1294     delete ec;
  1295     ec = next;
  1298   ((CodeBlob*)(this))->flush();
  1300   CodeCache::free(this);
  1304 //
  1305 // Notify all classes this nmethod is dependent on that it is no
  1306 // longer dependent. This should only be called in two situations.
  1307 // First, when a nmethod transitions to a zombie all dependents need
  1308 // to be clear.  Since zombification happens at a safepoint there's no
  1309 // synchronization issues.  The second place is a little more tricky.
  1310 // During phase 1 of mark sweep class unloading may happen and as a
  1311 // result some nmethods may get unloaded.  In this case the flushing
  1312 // of dependencies must happen during phase 1 since after GC any
  1313 // dependencies in the unloaded nmethod won't be updated, so
  1314 // traversing the dependency information in unsafe.  In that case this
  1315 // function is called with a non-NULL argument and this function only
  1316 // notifies instanceKlasses that are reachable
  1318 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
  1319   assert(SafepointSynchronize::is_at_safepoint(), "must be done at safepoint");
  1320   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
  1321   "is_alive is non-NULL if and only if we are called during GC");
  1322   if (!has_flushed_dependencies()) {
  1323     set_has_flushed_dependencies();
  1324     for (Dependencies::DepStream deps(this); deps.next(); ) {
  1325       klassOop klass = deps.context_type();
  1326       if (klass == NULL)  continue;  // ignore things like evol_method
  1328       // During GC the is_alive closure is non-NULL, and is used to
  1329       // determine liveness of dependees that need to be updated.
  1330       if (is_alive == NULL || is_alive->do_object_b(klass)) {
  1331         instanceKlass::cast(klass)->remove_dependent_nmethod(this);
  1338 // If this oop is not live, the nmethod can be unloaded.
  1339 bool nmethod::can_unload(BoolObjectClosure* is_alive,
  1340                          OopClosure* keep_alive,
  1341                          oop* root, bool unloading_occurred) {
  1342   assert(root != NULL, "just checking");
  1343   oop obj = *root;
  1344   if (obj == NULL || is_alive->do_object_b(obj)) {
  1345       return false;
  1347   if (obj->is_compiledICHolder()) {
  1348     compiledICHolderOop cichk_oop = compiledICHolderOop(obj);
  1349     if (is_alive->do_object_b(
  1350           cichk_oop->holder_method()->method_holder()) &&
  1351         is_alive->do_object_b(cichk_oop->holder_klass())) {
  1352       // The oop should be kept alive
  1353       keep_alive->do_oop(root);
  1354       return false;
  1357   assert(unloading_occurred, "Inconsistency in unloading");
  1358   make_unloaded(is_alive, obj);
  1359   return true;
  1362 // ------------------------------------------------------------------
  1363 // post_compiled_method_load_event
  1364 // new method for install_code() path
  1365 // Transfer information from compilation to jvmti
  1366 void nmethod::post_compiled_method_load_event() {
  1368   methodOop moop = method();
  1369   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
  1370       moop->klass_name()->bytes(),
  1371       moop->klass_name()->utf8_length(),
  1372       moop->name()->bytes(),
  1373       moop->name()->utf8_length(),
  1374       moop->signature()->bytes(),
  1375       moop->signature()->utf8_length(),
  1376       code_begin(), code_size());
  1378   if (JvmtiExport::should_post_compiled_method_load()) {
  1379     JvmtiExport::post_compiled_method_load(this);
  1383 void nmethod::post_compiled_method_unload() {
  1384   assert(_method != NULL && !is_unloaded(), "just checking");
  1385   DTRACE_METHOD_UNLOAD_PROBE(method());
  1387   // If a JVMTI agent has enabled the CompiledMethodUnload event then
  1388   // post the event. Sometime later this nmethod will be made a zombie by
  1389   // the sweeper but the methodOop will not be valid at that point.
  1390   if (JvmtiExport::should_post_compiled_method_unload()) {
  1391     assert(!unload_reported(), "already unloaded");
  1392     HandleMark hm;
  1393     JvmtiExport::post_compiled_method_unload_at_safepoint(
  1394                       method()->jmethod_id(), code_begin());
  1397   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
  1398   // any time. As the nmethod is being unloaded now we mark it has
  1399   // having the unload event reported - this will ensure that we don't
  1400   // attempt to report the event in the unlikely scenario where the
  1401   // event is enabled at the time the nmethod is made a zombie.
  1402   set_unload_reported();
  1405 // This is called at the end of the strong tracing/marking phase of a
  1406 // GC to unload an nmethod if it contains otherwise unreachable
  1407 // oops.
  1409 void nmethod::do_unloading(BoolObjectClosure* is_alive,
  1410                            OopClosure* keep_alive, bool unloading_occurred) {
  1411   // Make sure the oop's ready to receive visitors
  1412   assert(!is_zombie() && !is_unloaded(),
  1413          "should not call follow on zombie or unloaded nmethod");
  1415   // If the method is not entrant then a JMP is plastered over the
  1416   // first few bytes.  If an oop in the old code was there, that oop
  1417   // should not get GC'd.  Skip the first few bytes of oops on
  1418   // not-entrant methods.
  1419   address low_boundary = verified_entry_point();
  1420   if (is_not_entrant()) {
  1421     low_boundary += NativeJump::instruction_size;
  1422     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1423     // (See comment above.)
  1426   // The RedefineClasses() API can cause the class unloading invariant
  1427   // to no longer be true. See jvmtiExport.hpp for details.
  1428   // Also, leave a debugging breadcrumb in local flag.
  1429   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
  1430   if (a_class_was_redefined) {
  1431     // This set of the unloading_occurred flag is done before the
  1432     // call to post_compiled_method_unload() so that the unloading
  1433     // of this nmethod is reported.
  1434     unloading_occurred = true;
  1437   // Follow methodOop
  1438   if (can_unload(is_alive, keep_alive, (oop*)&_method, unloading_occurred)) {
  1439     return;
  1442   // Exception cache
  1443   ExceptionCache* ec = exception_cache();
  1444   while (ec != NULL) {
  1445     oop* ex_addr = (oop*)ec->exception_type_addr();
  1446     oop ex = *ex_addr;
  1447     ExceptionCache* next_ec = ec->next();
  1448     if (ex != NULL && !is_alive->do_object_b(ex)) {
  1449       assert(!ex->is_compiledICHolder(), "Possible error here");
  1450       remove_from_exception_cache(ec);
  1452     ec = next_ec;
  1455   // If class unloading occurred we first iterate over all inline caches and
  1456   // clear ICs where the cached oop is referring to an unloaded klass or method.
  1457   // The remaining live cached oops will be traversed in the relocInfo::oop_type
  1458   // iteration below.
  1459   if (unloading_occurred) {
  1460     RelocIterator iter(this, low_boundary);
  1461     while(iter.next()) {
  1462       if (iter.type() == relocInfo::virtual_call_type) {
  1463         CompiledIC *ic = CompiledIC_at(iter.reloc());
  1464         oop ic_oop = ic->cached_oop();
  1465         if (ic_oop != NULL && !is_alive->do_object_b(ic_oop)) {
  1466           // The only exception is compiledICHolder oops which may
  1467           // yet be marked below. (We check this further below).
  1468           if (ic_oop->is_compiledICHolder()) {
  1469             compiledICHolderOop cichk_oop = compiledICHolderOop(ic_oop);
  1470             if (is_alive->do_object_b(
  1471                   cichk_oop->holder_method()->method_holder()) &&
  1472                 is_alive->do_object_b(cichk_oop->holder_klass())) {
  1473               continue;
  1476           ic->set_to_clean();
  1477           assert(ic->cached_oop() == NULL, "cached oop in IC should be cleared")
  1483   // Compiled code
  1484   RelocIterator iter(this, low_boundary);
  1485   while (iter.next()) {
  1486     if (iter.type() == relocInfo::oop_type) {
  1487       oop_Relocation* r = iter.oop_reloc();
  1488       // In this loop, we must only traverse those oops directly embedded in
  1489       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1490       assert(1 == (r->oop_is_immediate()) +
  1491                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1492              "oop must be found in exactly one place");
  1493       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1494         if (can_unload(is_alive, keep_alive, r->oop_addr(), unloading_occurred)) {
  1495           return;
  1502   // Scopes
  1503   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1504     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1505     if (can_unload(is_alive, keep_alive, p, unloading_occurred)) {
  1506       return;
  1510 #ifndef PRODUCT
  1511   // This nmethod was not unloaded; check below that all CompiledICs
  1512   // refer to marked oops.
  1514     RelocIterator iter(this, low_boundary);
  1515     while (iter.next()) {
  1516       if (iter.type() == relocInfo::virtual_call_type) {
  1517          CompiledIC *ic = CompiledIC_at(iter.reloc());
  1518          oop ic_oop = ic->cached_oop();
  1519          assert(ic_oop == NULL || is_alive->do_object_b(ic_oop),
  1520                 "Found unmarked ic_oop in reachable nmethod");
  1524 #endif // !PRODUCT
  1527 // This method is called twice during GC -- once while
  1528 // tracing the "active" nmethods on thread stacks during
  1529 // the (strong) marking phase, and then again when walking
  1530 // the code cache contents during the weak roots processing
  1531 // phase. The two uses are distinguished by means of the
  1532 // do_nmethods() method in the closure "f" below -- which
  1533 // answers "yes" in the first case, and "no" in the second
  1534 // case. We want to walk the weak roots in the nmethod
  1535 // only in the second case. The weak roots in the nmethod
  1536 // are the oops in the ExceptionCache and the InlineCache
  1537 // oops.
  1538 void nmethod::oops_do(OopClosure* f) {
  1539   // make sure the oops ready to receive visitors
  1540   assert(!is_zombie() && !is_unloaded(),
  1541          "should not call follow on zombie or unloaded nmethod");
  1543   // If the method is not entrant or zombie then a JMP is plastered over the
  1544   // first few bytes.  If an oop in the old code was there, that oop
  1545   // should not get GC'd.  Skip the first few bytes of oops on
  1546   // not-entrant methods.
  1547   address low_boundary = verified_entry_point();
  1548   if (is_not_entrant()) {
  1549     low_boundary += NativeJump::instruction_size;
  1550     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
  1551     // (See comment above.)
  1554   // Compiled code
  1555   f->do_oop((oop*) &_method);
  1556   if (!f->do_nmethods()) {
  1557     // weak roots processing phase -- update ExceptionCache oops
  1558     ExceptionCache* ec = exception_cache();
  1559     while(ec != NULL) {
  1560       f->do_oop((oop*)ec->exception_type_addr());
  1561       ec = ec->next();
  1563   } // Else strong roots phase -- skip oops in ExceptionCache
  1565   RelocIterator iter(this, low_boundary);
  1567   while (iter.next()) {
  1568     if (iter.type() == relocInfo::oop_type ) {
  1569       oop_Relocation* r = iter.oop_reloc();
  1570       // In this loop, we must only follow those oops directly embedded in
  1571       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
  1572       assert(1 == (r->oop_is_immediate()) +
  1573                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
  1574              "oop must be found in exactly one place");
  1575       if (r->oop_is_immediate() && r->oop_value() != NULL) {
  1576         f->do_oop(r->oop_addr());
  1581   // Scopes
  1582   for (oop* p = oops_begin(); p < oops_end(); p++) {
  1583     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
  1584     f->do_oop(p);
  1588 // Method that knows how to preserve outgoing arguments at call. This method must be
  1589 // called with a frame corresponding to a Java invoke
  1590 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
  1591   if (!method()->is_native()) {
  1592     SimpleScopeDesc ssd(this, fr.pc());
  1593     Bytecode_invoke* call = Bytecode_invoke_at(ssd.method(), ssd.bci());
  1594     bool is_static = call->is_invokestatic();
  1595     symbolOop signature = call->signature();
  1596     fr.oops_compiled_arguments_do(signature, is_static, reg_map, f);
  1601 oop nmethod::embeddedOop_at(u_char* p) {
  1602   RelocIterator iter(this, p, p + oopSize);
  1603   while (iter.next())
  1604     if (iter.type() == relocInfo::oop_type) {
  1605       return iter.oop_reloc()->oop_value();
  1607   return NULL;
  1611 inline bool includes(void* p, void* from, void* to) {
  1612   return from <= p && p < to;
  1616 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
  1617   assert(count >= 2, "must be sentinel values, at least");
  1619 #ifdef ASSERT
  1620   // must be sorted and unique; we do a binary search in find_pc_desc()
  1621   int prev_offset = pcs[0].pc_offset();
  1622   assert(prev_offset == PcDesc::lower_offset_limit,
  1623          "must start with a sentinel");
  1624   for (int i = 1; i < count; i++) {
  1625     int this_offset = pcs[i].pc_offset();
  1626     assert(this_offset > prev_offset, "offsets must be sorted");
  1627     prev_offset = this_offset;
  1629   assert(prev_offset == PcDesc::upper_offset_limit,
  1630          "must end with a sentinel");
  1631 #endif //ASSERT
  1633   int size = count * sizeof(PcDesc);
  1634   assert(scopes_pcs_size() >= size, "oob");
  1635   memcpy(scopes_pcs_begin(), pcs, size);
  1637   // Adjust the final sentinel downward.
  1638   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
  1639   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
  1640   last_pc->set_pc_offset(instructions_size() + 1);
  1641   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
  1642     // Fill any rounding gaps with copies of the last record.
  1643     last_pc[1] = last_pc[0];
  1645   // The following assert could fail if sizeof(PcDesc) is not
  1646   // an integral multiple of oopSize (the rounding term).
  1647   // If it fails, change the logic to always allocate a multiple
  1648   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
  1649   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
  1652 void nmethod::copy_scopes_data(u_char* buffer, int size) {
  1653   assert(scopes_data_size() >= size, "oob");
  1654   memcpy(scopes_data_begin(), buffer, size);
  1658 #ifdef ASSERT
  1659 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
  1660   PcDesc* lower = nm->scopes_pcs_begin();
  1661   PcDesc* upper = nm->scopes_pcs_end();
  1662   lower += 1; // exclude initial sentinel
  1663   PcDesc* res = NULL;
  1664   for (PcDesc* p = lower; p < upper; p++) {
  1665     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
  1666     if (match_desc(p, pc_offset, approximate)) {
  1667       if (res == NULL)
  1668         res = p;
  1669       else
  1670         res = (PcDesc*) badAddress;
  1673   return res;
  1675 #endif
  1678 // Finds a PcDesc with real-pc equal to "pc"
  1679 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
  1680   address base_address = instructions_begin();
  1681   if ((pc < base_address) ||
  1682       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
  1683     return NULL;  // PC is wildly out of range
  1685   int pc_offset = (int) (pc - base_address);
  1687   // Check the PcDesc cache if it contains the desired PcDesc
  1688   // (This as an almost 100% hit rate.)
  1689   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
  1690   if (res != NULL) {
  1691     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
  1692     return res;
  1695   // Fallback algorithm: quasi-linear search for the PcDesc
  1696   // Find the last pc_offset less than the given offset.
  1697   // The successor must be the required match, if there is a match at all.
  1698   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
  1699   PcDesc* lower = scopes_pcs_begin();
  1700   PcDesc* upper = scopes_pcs_end();
  1701   upper -= 1; // exclude final sentinel
  1702   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
  1704 #define assert_LU_OK \
  1705   /* invariant on lower..upper during the following search: */ \
  1706   assert(lower->pc_offset() <  pc_offset, "sanity"); \
  1707   assert(upper->pc_offset() >= pc_offset, "sanity")
  1708   assert_LU_OK;
  1710   // Use the last successful return as a split point.
  1711   PcDesc* mid = _pc_desc_cache.last_pc_desc();
  1712   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  1713   if (mid->pc_offset() < pc_offset) {
  1714     lower = mid;
  1715   } else {
  1716     upper = mid;
  1719   // Take giant steps at first (4096, then 256, then 16, then 1)
  1720   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
  1721   const int RADIX = (1 << LOG2_RADIX);
  1722   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
  1723     while ((mid = lower + step) < upper) {
  1724       assert_LU_OK;
  1725       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  1726       if (mid->pc_offset() < pc_offset) {
  1727         lower = mid;
  1728       } else {
  1729         upper = mid;
  1730         break;
  1733     assert_LU_OK;
  1736   // Sneak up on the value with a linear search of length ~16.
  1737   while (true) {
  1738     assert_LU_OK;
  1739     mid = lower + 1;
  1740     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
  1741     if (mid->pc_offset() < pc_offset) {
  1742       lower = mid;
  1743     } else {
  1744       upper = mid;
  1745       break;
  1748 #undef assert_LU_OK
  1750   if (match_desc(upper, pc_offset, approximate)) {
  1751     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
  1752     _pc_desc_cache.add_pc_desc(upper);
  1753     return upper;
  1754   } else {
  1755     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
  1756     return NULL;
  1761 bool nmethod::check_all_dependencies() {
  1762   bool found_check = false;
  1763   // wholesale check of all dependencies
  1764   for (Dependencies::DepStream deps(this); deps.next(); ) {
  1765     if (deps.check_dependency() != NULL) {
  1766       found_check = true;
  1767       NOT_DEBUG(break);
  1770   return found_check;  // tell caller if we found anything
  1773 bool nmethod::check_dependency_on(DepChange& changes) {
  1774   // What has happened:
  1775   // 1) a new class dependee has been added
  1776   // 2) dependee and all its super classes have been marked
  1777   bool found_check = false;  // set true if we are upset
  1778   for (Dependencies::DepStream deps(this); deps.next(); ) {
  1779     // Evaluate only relevant dependencies.
  1780     if (deps.spot_check_dependency_at(changes) != NULL) {
  1781       found_check = true;
  1782       NOT_DEBUG(break);
  1785   return found_check;
  1788 bool nmethod::is_evol_dependent_on(klassOop dependee) {
  1789   instanceKlass *dependee_ik = instanceKlass::cast(dependee);
  1790   objArrayOop dependee_methods = dependee_ik->methods();
  1791   for (Dependencies::DepStream deps(this); deps.next(); ) {
  1792     if (deps.type() == Dependencies::evol_method) {
  1793       methodOop method = deps.method_argument(0);
  1794       for (int j = 0; j < dependee_methods->length(); j++) {
  1795         if ((methodOop) dependee_methods->obj_at(j) == method) {
  1796           // RC_TRACE macro has an embedded ResourceMark
  1797           RC_TRACE(0x01000000,
  1798             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
  1799             _method->method_holder()->klass_part()->external_name(),
  1800             _method->name()->as_C_string(),
  1801             _method->signature()->as_C_string(), compile_id(),
  1802             method->method_holder()->klass_part()->external_name(),
  1803             method->name()->as_C_string(),
  1804             method->signature()->as_C_string()));
  1805           if (TraceDependencies || LogCompilation)
  1806             deps.log_dependency(dependee);
  1807           return true;
  1812   return false;
  1815 // Called from mark_for_deoptimization, when dependee is invalidated.
  1816 bool nmethod::is_dependent_on_method(methodOop dependee) {
  1817   for (Dependencies::DepStream deps(this); deps.next(); ) {
  1818     if (deps.type() != Dependencies::evol_method)
  1819       continue;
  1820     methodOop method = deps.method_argument(0);
  1821     if (method == dependee) return true;
  1823   return false;
  1827 bool nmethod::is_patchable_at(address instr_addr) {
  1828   assert (code_contains(instr_addr), "wrong nmethod used");
  1829   if (is_zombie()) {
  1830     // a zombie may never be patched
  1831     return false;
  1833   return true;
  1837 address nmethod::continuation_for_implicit_exception(address pc) {
  1838   // Exception happened outside inline-cache check code => we are inside
  1839   // an active nmethod => use cpc to determine a return address
  1840   int exception_offset = pc - instructions_begin();
  1841   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
  1842 #ifdef ASSERT
  1843   if (cont_offset == 0) {
  1844     Thread* thread = ThreadLocalStorage::get_thread_slow();
  1845     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
  1846     HandleMark hm(thread);
  1847     ResourceMark rm(thread);
  1848     CodeBlob* cb = CodeCache::find_blob(pc);
  1849     assert(cb != NULL && cb == this, "");
  1850     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
  1851     print();
  1852     method()->print_codes();
  1853     print_code();
  1854     print_pcs();
  1856 #endif
  1857   guarantee(cont_offset != 0, "unhandled implicit exception in compiled code");
  1858   return instructions_begin() + cont_offset;
  1863 void nmethod_init() {
  1864   // make sure you didn't forget to adjust the filler fields
  1865   assert(sizeof(nmFlags) <= 4,           "nmFlags occupies more than a word");
  1866   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
  1870 //-------------------------------------------------------------------------------------------
  1873 // QQQ might we make this work from a frame??
  1874 nmethodLocker::nmethodLocker(address pc) {
  1875   CodeBlob* cb = CodeCache::find_blob(pc);
  1876   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
  1877   _nm = (nmethod*)cb;
  1878   lock_nmethod(_nm);
  1881 void nmethodLocker::lock_nmethod(nmethod* nm) {
  1882   if (nm == NULL)  return;
  1883   Atomic::inc(&nm->_lock_count);
  1884   guarantee(!nm->is_zombie(), "cannot lock a zombie method");
  1887 void nmethodLocker::unlock_nmethod(nmethod* nm) {
  1888   if (nm == NULL)  return;
  1889   Atomic::dec(&nm->_lock_count);
  1890   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
  1893 bool nmethod::is_deopt_pc(address pc) {
  1894   bool ret =  pc == deopt_handler_begin();
  1895   return ret;
  1899 // -----------------------------------------------------------------------------
  1900 // Verification
  1902 void nmethod::verify() {
  1904   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
  1905   // seems odd.
  1907   if( is_zombie() || is_not_entrant() )
  1908     return;
  1910   // Make sure all the entry points are correctly aligned for patching.
  1911   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
  1913   assert(method()->is_oop(), "must be valid");
  1915   ResourceMark rm;
  1917   if (!CodeCache::contains(this)) {
  1918     fatal1("nmethod at " INTPTR_FORMAT " not in zone", this);
  1921   if(is_native_method() )
  1922     return;
  1924   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
  1925   if (nm != this) {
  1926     fatal1("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", this);
  1929   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  1930     if (! p->verify(this)) {
  1931       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
  1935   verify_scopes();
  1939 void nmethod::verify_interrupt_point(address call_site) {
  1940   // This code does not work in release mode since
  1941   // owns_lock only is available in debug mode.
  1942   CompiledIC* ic = NULL;
  1943   Thread *cur = Thread::current();
  1944   if (CompiledIC_lock->owner() == cur ||
  1945       ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
  1946        SafepointSynchronize::is_at_safepoint())) {
  1947     ic = CompiledIC_at(call_site);
  1948     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  1949   } else {
  1950     MutexLocker ml_verify (CompiledIC_lock);
  1951     ic = CompiledIC_at(call_site);
  1953   PcDesc* pd = pc_desc_at(ic->end_of_call());
  1954   assert(pd != NULL, "PcDesc must exist");
  1955   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
  1956                                      pd->obj_decode_offset());
  1957        !sd->is_top(); sd = sd->sender()) {
  1958     sd->verify();
  1962 void nmethod::verify_scopes() {
  1963   if( !method() ) return;       // Runtime stubs have no scope
  1964   if (method()->is_native()) return; // Ignore stub methods.
  1965   // iterate through all interrupt point
  1966   // and verify the debug information is valid.
  1967   RelocIterator iter((nmethod*)this);
  1968   while (iter.next()) {
  1969     address stub = NULL;
  1970     switch (iter.type()) {
  1971       case relocInfo::virtual_call_type:
  1972         verify_interrupt_point(iter.addr());
  1973         break;
  1974       case relocInfo::opt_virtual_call_type:
  1975         stub = iter.opt_virtual_call_reloc()->static_stub();
  1976         verify_interrupt_point(iter.addr());
  1977         break;
  1978       case relocInfo::static_call_type:
  1979         stub = iter.static_call_reloc()->static_stub();
  1980         //verify_interrupt_point(iter.addr());
  1981         break;
  1982       case relocInfo::runtime_call_type:
  1983         address destination = iter.reloc()->value();
  1984         // Right now there is no way to find out which entries support
  1985         // an interrupt point.  It would be nice if we had this
  1986         // information in a table.
  1987         break;
  1989     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
  1994 // -----------------------------------------------------------------------------
  1995 // Non-product code
  1996 #ifndef PRODUCT
  1998 void nmethod::check_store() {
  1999   // Make sure all oops in the compiled code are tenured
  2001   RelocIterator iter(this);
  2002   while (iter.next()) {
  2003     if (iter.type() == relocInfo::oop_type) {
  2004       oop_Relocation* reloc = iter.oop_reloc();
  2005       oop obj = reloc->oop_value();
  2006       if (obj != NULL && !obj->is_perm()) {
  2007         fatal("must be permanent oop in compiled code");
  2013 #endif // PRODUCT
  2015 // Printing operations
  2017 void nmethod::print() const {
  2018   ResourceMark rm;
  2019   ttyLocker ttyl;   // keep the following output all in one block
  2021   tty->print("Compiled ");
  2023   if (is_compiled_by_c1()) {
  2024     tty->print("(c1) ");
  2025   } else if (is_compiled_by_c2()) {
  2026     tty->print("(c2) ");
  2027   } else {
  2028     tty->print("(nm) ");
  2031   print_on(tty, "nmethod");
  2032   tty->cr();
  2033   if (WizardMode) {
  2034     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
  2035     tty->print(" for method " INTPTR_FORMAT , (address)method());
  2036     tty->print(" { ");
  2037     if (version())        tty->print("v%d ", version());
  2038     if (level())          tty->print("l%d ", level());
  2039     if (is_in_use())      tty->print("in_use ");
  2040     if (is_not_entrant()) tty->print("not_entrant ");
  2041     if (is_zombie())      tty->print("zombie ");
  2042     if (is_unloaded())    tty->print("unloaded ");
  2043     tty->print_cr("}:");
  2045   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2046                                               (address)this,
  2047                                               (address)this + size(),
  2048                                               size());
  2049   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2050                                               relocation_begin(),
  2051                                               relocation_end(),
  2052                                               relocation_size());
  2053   if (code_size         () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2054                                               code_begin(),
  2055                                               code_end(),
  2056                                               code_size());
  2057   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2058                                               stub_begin(),
  2059                                               stub_end(),
  2060                                               stub_size());
  2061   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2062                                               consts_begin(),
  2063                                               consts_end(),
  2064                                               consts_size());
  2065   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2066                                               scopes_data_begin(),
  2067                                               scopes_data_end(),
  2068                                               scopes_data_size());
  2069   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2070                                               scopes_pcs_begin(),
  2071                                               scopes_pcs_end(),
  2072                                               scopes_pcs_size());
  2073   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2074                                               dependencies_begin(),
  2075                                               dependencies_end(),
  2076                                               dependencies_size());
  2077   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2078                                               handler_table_begin(),
  2079                                               handler_table_end(),
  2080                                               handler_table_size());
  2081   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2082                                               nul_chk_table_begin(),
  2083                                               nul_chk_table_end(),
  2084                                               nul_chk_table_size());
  2085   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
  2086                                               oops_begin(),
  2087                                               oops_end(),
  2088                                               oops_size());
  2091 void nmethod::print_code() {
  2092   HandleMark hm;
  2093   ResourceMark m;
  2094   Disassembler::decode(this);
  2098 #ifndef PRODUCT
  2100 void nmethod::print_scopes() {
  2101   // Find the first pc desc for all scopes in the code and print it.
  2102   ResourceMark rm;
  2103   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2104     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
  2105       continue;
  2107     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
  2108     sd->print_on(tty, p);
  2112 void nmethod::print_dependencies() {
  2113   ResourceMark rm;
  2114   ttyLocker ttyl;   // keep the following output all in one block
  2115   tty->print_cr("Dependencies:");
  2116   for (Dependencies::DepStream deps(this); deps.next(); ) {
  2117     deps.print_dependency();
  2118     klassOop ctxk = deps.context_type();
  2119     if (ctxk != NULL) {
  2120       Klass* k = Klass::cast(ctxk);
  2121       if (k->oop_is_instance() && ((instanceKlass*)k)->is_dependent_nmethod(this)) {
  2122         tty->print_cr("   [nmethod<=klass]%s", k->external_name());
  2125     deps.log_dependency();  // put it into the xml log also
  2130 void nmethod::print_relocations() {
  2131   ResourceMark m;       // in case methods get printed via the debugger
  2132   tty->print_cr("relocations:");
  2133   RelocIterator iter(this);
  2134   iter.print();
  2135   if (UseRelocIndex) {
  2136     jint* index_end   = (jint*)relocation_end() - 1;
  2137     jint  index_size  = *index_end;
  2138     jint* index_start = (jint*)( (address)index_end - index_size );
  2139     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
  2140     if (index_size > 0) {
  2141       jint* ip;
  2142       for (ip = index_start; ip+2 <= index_end; ip += 2)
  2143         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
  2144                       ip[0],
  2145                       ip[1],
  2146                       header_end()+ip[0],
  2147                       relocation_begin()-1+ip[1]);
  2148       for (; ip < index_end; ip++)
  2149         tty->print_cr("  (%d ?)", ip[0]);
  2150       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip++);
  2151       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
  2157 void nmethod::print_pcs() {
  2158   ResourceMark m;       // in case methods get printed via debugger
  2159   tty->print_cr("pc-bytecode offsets:");
  2160   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
  2161     p->print(this);
  2165 #endif // PRODUCT
  2167 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
  2168   RelocIterator iter(this, begin, end);
  2169   bool have_one = false;
  2170   while (iter.next()) {
  2171     have_one = true;
  2172     switch (iter.type()) {
  2173         case relocInfo::none:                  return "no_reloc";
  2174         case relocInfo::oop_type: {
  2175           stringStream st;
  2176           oop_Relocation* r = iter.oop_reloc();
  2177           oop obj = r->oop_value();
  2178           st.print("oop(");
  2179           if (obj == NULL) st.print("NULL");
  2180           else obj->print_value_on(&st);
  2181           st.print(")");
  2182           return st.as_string();
  2184         case relocInfo::virtual_call_type:     return "virtual_call";
  2185         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
  2186         case relocInfo::static_call_type:      return "static_call";
  2187         case relocInfo::static_stub_type:      return "static_stub";
  2188         case relocInfo::runtime_call_type:     return "runtime_call";
  2189         case relocInfo::external_word_type:    return "external_word";
  2190         case relocInfo::internal_word_type:    return "internal_word";
  2191         case relocInfo::section_word_type:     return "section_word";
  2192         case relocInfo::poll_type:             return "poll";
  2193         case relocInfo::poll_return_type:      return "poll_return";
  2194         case relocInfo::type_mask:             return "type_bit_mask";
  2197   return have_one ? "other" : NULL;
  2200 // Return a the last scope in (begin..end]
  2201 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
  2202   PcDesc* p = pc_desc_near(begin+1);
  2203   if (p != NULL && p->real_pc(this) <= end) {
  2204     return new ScopeDesc(this, p->scope_decode_offset(),
  2205                          p->obj_decode_offset());
  2207   return NULL;
  2210 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
  2211   // First, find an oopmap in (begin, end].
  2212   // We use the odd half-closed interval so that oop maps and scope descs
  2213   // which are tied to the byte after a call are printed with the call itself.
  2214   address base = instructions_begin();
  2215   OopMapSet* oms = oop_maps();
  2216   if (oms != NULL) {
  2217     for (int i = 0, imax = oms->size(); i < imax; i++) {
  2218       OopMap* om = oms->at(i);
  2219       address pc = base + om->offset();
  2220       if (pc > begin) {
  2221         if (pc <= end) {
  2222           st->move_to(column);
  2223           st->print("; ");
  2224           om->print_on(st);
  2226         break;
  2231   // Print any debug info present at this pc.
  2232   ScopeDesc* sd  = scope_desc_in(begin, end);
  2233   if (sd != NULL) {
  2234     st->move_to(column);
  2235     if (sd->bci() == SynchronizationEntryBCI) {
  2236       st->print(";*synchronization entry");
  2237     } else {
  2238       if (sd->method().is_null()) {
  2239         st->print("method is NULL");
  2240       } else if (sd->method()->is_native()) {
  2241         st->print("method is native");
  2242       } else {
  2243         address bcp  = sd->method()->bcp_from(sd->bci());
  2244         Bytecodes::Code bc = Bytecodes::java_code_at(bcp);
  2245         st->print(";*%s", Bytecodes::name(bc));
  2246         switch (bc) {
  2247         case Bytecodes::_invokevirtual:
  2248         case Bytecodes::_invokespecial:
  2249         case Bytecodes::_invokestatic:
  2250         case Bytecodes::_invokeinterface:
  2252             Bytecode_invoke* invoke = Bytecode_invoke_at(sd->method(), sd->bci());
  2253             st->print(" ");
  2254             if (invoke->name() != NULL)
  2255               invoke->name()->print_symbol_on(st);
  2256             else
  2257               st->print("<UNKNOWN>");
  2258             break;
  2260         case Bytecodes::_getfield:
  2261         case Bytecodes::_putfield:
  2262         case Bytecodes::_getstatic:
  2263         case Bytecodes::_putstatic:
  2265             methodHandle sdm = sd->method();
  2266             Bytecode_field* field = Bytecode_field_at(sdm(), sdm->bcp_from(sd->bci()));
  2267             constantPoolOop sdmc = sdm->constants();
  2268             symbolOop name = sdmc->name_ref_at(field->index());
  2269             st->print(" ");
  2270             if (name != NULL)
  2271               name->print_symbol_on(st);
  2272             else
  2273               st->print("<UNKNOWN>");
  2279     // Print all scopes
  2280     for (;sd != NULL; sd = sd->sender()) {
  2281       st->move_to(column);
  2282       st->print("; -");
  2283       if (sd->method().is_null()) {
  2284         st->print("method is NULL");
  2285       } else {
  2286         sd->method()->print_short_name(st);
  2288       int lineno = sd->method()->line_number_from_bci(sd->bci());
  2289       if (lineno != -1) {
  2290         st->print("@%d (line %d)", sd->bci(), lineno);
  2291       } else {
  2292         st->print("@%d", sd->bci());
  2294       st->cr();
  2298   // Print relocation information
  2299   const char* str = reloc_string_for(begin, end);
  2300   if (str != NULL) {
  2301     if (sd != NULL) st->cr();
  2302     st->move_to(column);
  2303     st->print(";   {%s}", str);
  2305   int cont_offset = ImplicitExceptionTable(this).at(begin - instructions_begin());
  2306   if (cont_offset != 0) {
  2307     st->move_to(column);
  2308     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, instructions_begin() + cont_offset);
  2313 #ifndef PRODUCT
  2315 void nmethod::print_value_on(outputStream* st) const {
  2316   print_on(st, "nmethod");
  2319 void nmethod::print_calls(outputStream* st) {
  2320   RelocIterator iter(this);
  2321   while (iter.next()) {
  2322     switch (iter.type()) {
  2323     case relocInfo::virtual_call_type:
  2324     case relocInfo::opt_virtual_call_type: {
  2325       VerifyMutexLocker mc(CompiledIC_lock);
  2326       CompiledIC_at(iter.reloc())->print();
  2327       break;
  2329     case relocInfo::static_call_type:
  2330       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
  2331       compiledStaticCall_at(iter.reloc())->print();
  2332       break;
  2337 void nmethod::print_handler_table() {
  2338   ExceptionHandlerTable(this).print();
  2341 void nmethod::print_nul_chk_table() {
  2342   ImplicitExceptionTable(this).print(instructions_begin());
  2345 void nmethod::print_statistics() {
  2346   ttyLocker ttyl;
  2347   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
  2348   nmethod_stats.print_native_nmethod_stats();
  2349   nmethod_stats.print_nmethod_stats();
  2350   DebugInformationRecorder::print_statistics();
  2351   nmethod_stats.print_pc_stats();
  2352   Dependencies::print_statistics();
  2353   if (xtty != NULL)  xtty->tail("statistics");
  2356 #endif // PRODUCT

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