src/share/vm/oops/methodOop.cpp

Mon, 09 Mar 2009 13:28:46 -0700

author
xdono
date
Mon, 09 Mar 2009 13:28:46 -0700
changeset 1014
0fbdb4381b99
parent 953
0af8b0718fc9
child 1145
e5b0439ef4ae
permissions
-rw-r--r--

6814575: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 03/09
Reviewed-by: katleman, tbell, ohair

     1 /*
     2  * Copyright 1997-2009 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/_methodOop.cpp.incl"
    29 // Implementation of methodOopDesc
    31 address methodOopDesc::get_i2c_entry() {
    32   assert(_adapter != NULL, "must have");
    33   return _adapter->get_i2c_entry();
    34 }
    36 address methodOopDesc::get_c2i_entry() {
    37   assert(_adapter != NULL, "must have");
    38   return _adapter->get_c2i_entry();
    39 }
    41 address methodOopDesc::get_c2i_unverified_entry() {
    42   assert(_adapter != NULL, "must have");
    43   return _adapter->get_c2i_unverified_entry();
    44 }
    46 char* methodOopDesc::name_and_sig_as_C_string() {
    47   return name_and_sig_as_C_string(Klass::cast(constants()->pool_holder()), name(), signature());
    48 }
    50 char* methodOopDesc::name_and_sig_as_C_string(char* buf, int size) {
    51   return name_and_sig_as_C_string(Klass::cast(constants()->pool_holder()), name(), signature(), buf, size);
    52 }
    54 char* methodOopDesc::name_and_sig_as_C_string(Klass* klass, symbolOop method_name, symbolOop signature) {
    55   const char* klass_name = klass->external_name();
    56   int klass_name_len  = (int)strlen(klass_name);
    57   int method_name_len = method_name->utf8_length();
    58   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
    59   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
    60   strcpy(dest, klass_name);
    61   dest[klass_name_len] = '.';
    62   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
    63   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
    64   dest[len] = 0;
    65   return dest;
    66 }
    68 char* methodOopDesc::name_and_sig_as_C_string(Klass* klass, symbolOop method_name, symbolOop signature, char* buf, int size) {
    69   symbolOop klass_name = klass->name();
    70   klass_name->as_klass_external_name(buf, size);
    71   int len = (int)strlen(buf);
    73   if (len < size - 1) {
    74     buf[len++] = '.';
    76     method_name->as_C_string(&(buf[len]), size - len);
    77     len = (int)strlen(buf);
    79     signature->as_C_string(&(buf[len]), size - len);
    80   }
    82   return buf;
    83 }
    85 int  methodOopDesc::fast_exception_handler_bci_for(KlassHandle ex_klass, int throw_bci, TRAPS) {
    86   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
    87   const int beg_bci_offset     = 0;
    88   const int end_bci_offset     = 1;
    89   const int handler_bci_offset = 2;
    90   const int klass_index_offset = 3;
    91   const int entry_size         = 4;
    92   // access exception table
    93   typeArrayHandle table (THREAD, constMethod()->exception_table());
    94   int length = table->length();
    95   assert(length % entry_size == 0, "exception table format has changed");
    96   // iterate through all entries sequentially
    97   constantPoolHandle pool(THREAD, constants());
    98   for (int i = 0; i < length; i += entry_size) {
    99     int beg_bci = table->int_at(i + beg_bci_offset);
   100     int end_bci = table->int_at(i + end_bci_offset);
   101     assert(beg_bci <= end_bci, "inconsistent exception table");
   102     if (beg_bci <= throw_bci && throw_bci < end_bci) {
   103       // exception handler bci range covers throw_bci => investigate further
   104       int handler_bci = table->int_at(i + handler_bci_offset);
   105       int klass_index = table->int_at(i + klass_index_offset);
   106       if (klass_index == 0) {
   107         return handler_bci;
   108       } else if (ex_klass.is_null()) {
   109         return handler_bci;
   110       } else {
   111         // we know the exception class => get the constraint class
   112         // this may require loading of the constraint class; if verification
   113         // fails or some other exception occurs, return handler_bci
   114         klassOop k = pool->klass_at(klass_index, CHECK_(handler_bci));
   115         KlassHandle klass = KlassHandle(THREAD, k);
   116         assert(klass.not_null(), "klass not loaded");
   117         if (ex_klass->is_subtype_of(klass())) {
   118           return handler_bci;
   119         }
   120       }
   121     }
   122   }
   124   return -1;
   125 }
   127 methodOop methodOopDesc::method_from_bcp(address bcp) {
   128   debug_only(static int count = 0; count++);
   129   assert(Universe::heap()->is_in_permanent(bcp), "bcp not in perm_gen");
   130   // TO DO: this may be unsafe in some configurations
   131   HeapWord* p = Universe::heap()->block_start(bcp);
   132   assert(Universe::heap()->block_is_obj(p), "must be obj");
   133   assert(oop(p)->is_constMethod(), "not a method");
   134   return constMethodOop(p)->method();
   135 }
   138 void methodOopDesc::mask_for(int bci, InterpreterOopMap* mask) {
   140   Thread* myThread    = Thread::current();
   141   methodHandle h_this(myThread, this);
   142 #ifdef ASSERT
   143   bool has_capability = myThread->is_VM_thread() ||
   144                         myThread->is_ConcurrentGC_thread() ||
   145                         myThread->is_GC_task_thread();
   147   if (!has_capability) {
   148     if (!VerifyStack && !VerifyLastFrame) {
   149       // verify stack calls this outside VM thread
   150       warning("oopmap should only be accessed by the "
   151               "VM, GC task or CMS threads (or during debugging)");
   152       InterpreterOopMap local_mask;
   153       instanceKlass::cast(method_holder())->mask_for(h_this, bci, &local_mask);
   154       local_mask.print();
   155     }
   156   }
   157 #endif
   158   instanceKlass::cast(method_holder())->mask_for(h_this, bci, mask);
   159   return;
   160 }
   163 int methodOopDesc::bci_from(address bcp) const {
   164   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
   165   return bcp - code_base();
   166 }
   169 // Return (int)bcx if it appears to be a valid BCI.
   170 // Return bci_from((address)bcx) if it appears to be a valid BCP.
   171 // Return -1 otherwise.
   172 // Used by profiling code, when invalid data is a possibility.
   173 // The caller is responsible for validating the methodOop itself.
   174 int methodOopDesc::validate_bci_from_bcx(intptr_t bcx) const {
   175   // keep bci as -1 if not a valid bci
   176   int bci = -1;
   177   if (bcx == 0 || (address)bcx == code_base()) {
   178     // code_size() may return 0 and we allow 0 here
   179     // the method may be native
   180     bci = 0;
   181   } else if (frame::is_bci(bcx)) {
   182     if (bcx < code_size()) {
   183       bci = (int)bcx;
   184     }
   185   } else if (contains((address)bcx)) {
   186     bci = (address)bcx - code_base();
   187   }
   188   // Assert that if we have dodged any asserts, bci is negative.
   189   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
   190   return bci;
   191 }
   193 address methodOopDesc::bcp_from(int bci) const {
   194   assert((is_native() && bci == 0)  || (!is_native() && 0 <= bci && bci < code_size()), "illegal bci");
   195   address bcp = code_base() + bci;
   196   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
   197   return bcp;
   198 }
   201 int methodOopDesc::object_size(bool is_native) {
   202   // If native, then include pointers for native_function and signature_handler
   203   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
   204   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
   205   return align_object_size(header_size() + extra_words);
   206 }
   209 symbolOop methodOopDesc::klass_name() const {
   210   klassOop k = method_holder();
   211   assert(k->is_klass(), "must be klass");
   212   instanceKlass* ik = (instanceKlass*) k->klass_part();
   213   return ik->name();
   214 }
   217 void methodOopDesc::set_interpreter_kind() {
   218   int kind = Interpreter::method_kind(methodOop(this));
   219   assert(kind != Interpreter::invalid,
   220          "interpreter entry must be valid");
   221   set_interpreter_kind(kind);
   222 }
   225 // Attempt to return method oop to original state.  Clear any pointers
   226 // (to objects outside the shared spaces).  We won't be able to predict
   227 // where they should point in a new JVM.  Further initialize some
   228 // entries now in order allow them to be write protected later.
   230 void methodOopDesc::remove_unshareable_info() {
   231   unlink_method();
   232   set_interpreter_kind();
   233 }
   236 bool methodOopDesc::was_executed_more_than(int n) const {
   237   // Invocation counter is reset when the methodOop is compiled.
   238   // If the method has compiled code we therefore assume it has
   239   // be excuted more than n times.
   240   if (is_accessor() || is_empty_method() || (code() != NULL)) {
   241     // interpreter doesn't bump invocation counter of trivial methods
   242     // compiler does not bump invocation counter of compiled methods
   243     return true;
   244   } else if (_invocation_counter.carry()) {
   245     // The carry bit is set when the counter overflows and causes
   246     // a compilation to occur.  We don't know how many times
   247     // the counter has been reset, so we simply assume it has
   248     // been executed more than n times.
   249     return true;
   250   } else {
   251     return invocation_count() > n;
   252   }
   253 }
   255 #ifndef PRODUCT
   256 void methodOopDesc::print_invocation_count() const {
   257   if (is_static()) tty->print("static ");
   258   if (is_final()) tty->print("final ");
   259   if (is_synchronized()) tty->print("synchronized ");
   260   if (is_native()) tty->print("native ");
   261   method_holder()->klass_part()->name()->print_symbol_on(tty);
   262   tty->print(".");
   263   name()->print_symbol_on(tty);
   264   signature()->print_symbol_on(tty);
   266   if (WizardMode) {
   267     // dump the size of the byte codes
   268     tty->print(" {%d}", code_size());
   269   }
   270   tty->cr();
   272   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
   273   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
   274   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
   275   if (CountCompiledCalls) {
   276     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
   277   }
   279 }
   280 #endif
   282 // Build a methodDataOop object to hold information about this method
   283 // collected in the interpreter.
   284 void methodOopDesc::build_interpreter_method_data(methodHandle method, TRAPS) {
   285   // Grab a lock here to prevent multiple
   286   // methodDataOops from being created.
   287   MutexLocker ml(MethodData_lock, THREAD);
   288   if (method->method_data() == NULL) {
   289     methodDataOop method_data = oopFactory::new_methodData(method, CHECK);
   290     method->set_method_data(method_data);
   291     if (PrintMethodData && (Verbose || WizardMode)) {
   292       ResourceMark rm(THREAD);
   293       tty->print("build_interpreter_method_data for ");
   294       method->print_name(tty);
   295       tty->cr();
   296       // At the end of the run, the MDO, full of data, will be dumped.
   297     }
   298   }
   299 }
   301 void methodOopDesc::cleanup_inline_caches() {
   302   // The current system doesn't use inline caches in the interpreter
   303   // => nothing to do (keep this method around for future use)
   304 }
   307 void methodOopDesc::compute_size_of_parameters(Thread *thread) {
   308   symbolHandle h_signature(thread, signature());
   309   ArgumentSizeComputer asc(h_signature);
   310   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
   311 }
   313 #ifdef CC_INTERP
   314 void methodOopDesc::set_result_index(BasicType type)          {
   315   _result_index = Interpreter::BasicType_as_index(type);
   316 }
   317 #endif
   319 BasicType methodOopDesc::result_type() const {
   320   ResultTypeFinder rtf(signature());
   321   return rtf.type();
   322 }
   325 bool methodOopDesc::is_empty_method() const {
   326   return  code_size() == 1
   327       && *code_base() == Bytecodes::_return;
   328 }
   331 bool methodOopDesc::is_vanilla_constructor() const {
   332   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
   333   // which only calls the superclass vanilla constructor and possibly does stores of
   334   // zero constants to local fields:
   335   //
   336   //   aload_0
   337   //   invokespecial
   338   //   indexbyte1
   339   //   indexbyte2
   340   //
   341   // followed by an (optional) sequence of:
   342   //
   343   //   aload_0
   344   //   aconst_null / iconst_0 / fconst_0 / dconst_0
   345   //   putfield
   346   //   indexbyte1
   347   //   indexbyte2
   348   //
   349   // followed by:
   350   //
   351   //   return
   353   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
   354   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
   355   int size = code_size();
   356   // Check if size match
   357   if (size == 0 || size % 5 != 0) return false;
   358   address cb = code_base();
   359   int last = size - 1;
   360   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
   361     // Does not call superclass default constructor
   362     return false;
   363   }
   364   // Check optional sequence
   365   for (int i = 4; i < last; i += 5) {
   366     if (cb[i] != Bytecodes::_aload_0) return false;
   367     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
   368     if (cb[i+2] != Bytecodes::_putfield) return false;
   369   }
   370   return true;
   371 }
   374 bool methodOopDesc::compute_has_loops_flag() {
   375   BytecodeStream bcs(methodOop(this));
   376   Bytecodes::Code bc;
   378   while ((bc = bcs.next()) >= 0) {
   379     switch( bc ) {
   380       case Bytecodes::_ifeq:
   381       case Bytecodes::_ifnull:
   382       case Bytecodes::_iflt:
   383       case Bytecodes::_ifle:
   384       case Bytecodes::_ifne:
   385       case Bytecodes::_ifnonnull:
   386       case Bytecodes::_ifgt:
   387       case Bytecodes::_ifge:
   388       case Bytecodes::_if_icmpeq:
   389       case Bytecodes::_if_icmpne:
   390       case Bytecodes::_if_icmplt:
   391       case Bytecodes::_if_icmpgt:
   392       case Bytecodes::_if_icmple:
   393       case Bytecodes::_if_icmpge:
   394       case Bytecodes::_if_acmpeq:
   395       case Bytecodes::_if_acmpne:
   396       case Bytecodes::_goto:
   397       case Bytecodes::_jsr:
   398         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
   399         break;
   401       case Bytecodes::_goto_w:
   402       case Bytecodes::_jsr_w:
   403         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
   404         break;
   405     }
   406   }
   407   _access_flags.set_loops_flag_init();
   408   return _access_flags.has_loops();
   409 }
   412 bool methodOopDesc::is_final_method() const {
   413   // %%% Should return true for private methods also,
   414   // since there is no way to override them.
   415   return is_final() || Klass::cast(method_holder())->is_final();
   416 }
   419 bool methodOopDesc::is_strict_method() const {
   420   return is_strict();
   421 }
   424 bool methodOopDesc::can_be_statically_bound() const {
   425   if (is_final_method())  return true;
   426   return vtable_index() == nonvirtual_vtable_index;
   427 }
   430 bool methodOopDesc::is_accessor() const {
   431   if (code_size() != 5) return false;
   432   if (size_of_parameters() != 1) return false;
   433   methodOop m = (methodOop)this;  // pass to code_at() to avoid method_from_bcp
   434   if (Bytecodes::java_code_at(code_base()+0, m) != Bytecodes::_aload_0 ) return false;
   435   if (Bytecodes::java_code_at(code_base()+1, m) != Bytecodes::_getfield) return false;
   436   if (Bytecodes::java_code_at(code_base()+4, m) != Bytecodes::_areturn &&
   437       Bytecodes::java_code_at(code_base()+4, m) != Bytecodes::_ireturn ) return false;
   438   return true;
   439 }
   442 bool methodOopDesc::is_initializer() const {
   443   return name() == vmSymbols::object_initializer_name() || name() == vmSymbols::class_initializer_name();
   444 }
   447 objArrayHandle methodOopDesc::resolved_checked_exceptions_impl(methodOop this_oop, TRAPS) {
   448   int length = this_oop->checked_exceptions_length();
   449   if (length == 0) {  // common case
   450     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
   451   } else {
   452     methodHandle h_this(THREAD, this_oop);
   453     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::class_klass(), length, CHECK_(objArrayHandle()));
   454     objArrayHandle mirrors (THREAD, m_oop);
   455     for (int i = 0; i < length; i++) {
   456       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
   457       klassOop k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
   458       assert(Klass::cast(k)->is_subclass_of(SystemDictionary::throwable_klass()), "invalid exception class");
   459       mirrors->obj_at_put(i, Klass::cast(k)->java_mirror());
   460     }
   461     return mirrors;
   462   }
   463 };
   466 int methodOopDesc::line_number_from_bci(int bci) const {
   467   if (bci == SynchronizationEntryBCI) bci = 0;
   468   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
   469   int best_bci  =  0;
   470   int best_line = -1;
   472   if (has_linenumber_table()) {
   473     // The line numbers are a short array of 2-tuples [start_pc, line_number].
   474     // Not necessarily sorted and not necessarily one-to-one.
   475     CompressedLineNumberReadStream stream(compressed_linenumber_table());
   476     while (stream.read_pair()) {
   477       if (stream.bci() == bci) {
   478         // perfect match
   479         return stream.line();
   480       } else {
   481         // update best_bci/line
   482         if (stream.bci() < bci && stream.bci() >= best_bci) {
   483           best_bci  = stream.bci();
   484           best_line = stream.line();
   485         }
   486       }
   487     }
   488   }
   489   return best_line;
   490 }
   493 bool methodOopDesc::is_klass_loaded_by_klass_index(int klass_index) const {
   494   if( _constants->tag_at(klass_index).is_unresolved_klass() ) {
   495     Thread *thread = Thread::current();
   496     symbolHandle klass_name(thread, _constants->klass_name_at(klass_index));
   497     Handle loader(thread, instanceKlass::cast(method_holder())->class_loader());
   498     Handle prot  (thread, Klass::cast(method_holder())->protection_domain());
   499     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
   500   } else {
   501     return true;
   502   }
   503 }
   506 bool methodOopDesc::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
   507   int klass_index = _constants->klass_ref_index_at(refinfo_index);
   508   if (must_be_resolved) {
   509     // Make sure klass is resolved in constantpool.
   510     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
   511   }
   512   return is_klass_loaded_by_klass_index(klass_index);
   513 }
   516 void methodOopDesc::set_native_function(address function, bool post_event_flag) {
   517   assert(function != NULL, "use clear_native_function to unregister natives");
   518   address* native_function = native_function_addr();
   520   // We can see racers trying to place the same native function into place. Once
   521   // is plenty.
   522   address current = *native_function;
   523   if (current == function) return;
   524   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
   525       function != NULL) {
   526     // native_method_throw_unsatisfied_link_error_entry() should only
   527     // be passed when post_event_flag is false.
   528     assert(function !=
   529       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
   530       "post_event_flag mis-match");
   532     // post the bind event, and possible change the bind function
   533     JvmtiExport::post_native_method_bind(this, &function);
   534   }
   535   *native_function = function;
   536   // This function can be called more than once. We must make sure that we always
   537   // use the latest registered method -> check if a stub already has been generated.
   538   // If so, we have to make it not_entrant.
   539   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
   540   if (nm != NULL) {
   541     nm->make_not_entrant();
   542   }
   543 }
   546 bool methodOopDesc::has_native_function() const {
   547   address func = native_function();
   548   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
   549 }
   552 void methodOopDesc::clear_native_function() {
   553   set_native_function(
   554     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
   555     !native_bind_event_is_interesting);
   556   clear_code();
   557 }
   560 void methodOopDesc::set_signature_handler(address handler) {
   561   address* signature_handler =  signature_handler_addr();
   562   *signature_handler = handler;
   563 }
   566 bool methodOopDesc::is_not_compilable(int comp_level) const {
   567   methodDataOop mdo = method_data();
   568   if (mdo != NULL
   569       && (uint)mdo->decompile_count() > (uint)PerMethodRecompilationCutoff) {
   570     // Since (uint)-1 is large, -1 really means 'no cutoff'.
   571     return true;
   572   }
   573 #ifdef COMPILER2
   574   if (is_tier1_compile(comp_level)) {
   575     if (is_not_tier1_compilable()) {
   576       return true;
   577     }
   578   }
   579 #endif // COMPILER2
   580   return (_invocation_counter.state() == InvocationCounter::wait_for_nothing)
   581           || (number_of_breakpoints() > 0);
   582 }
   584 // call this when compiler finds that this method is not compilable
   585 void methodOopDesc::set_not_compilable(int comp_level) {
   586   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
   587     ttyLocker ttyl;
   588     xtty->begin_elem("make_not_compilable thread='%d'", (int) os::current_thread_id());
   589     xtty->method(methodOop(this));
   590     xtty->stamp();
   591     xtty->end_elem();
   592   }
   593 #ifdef COMPILER2
   594   if (is_tier1_compile(comp_level)) {
   595     set_not_tier1_compilable();
   596     return;
   597   }
   598 #endif /* COMPILER2 */
   599   assert(comp_level == CompLevel_highest_tier, "unexpected compilation level");
   600   invocation_counter()->set_state(InvocationCounter::wait_for_nothing);
   601   backedge_counter()->set_state(InvocationCounter::wait_for_nothing);
   602 }
   604 // Revert to using the interpreter and clear out the nmethod
   605 void methodOopDesc::clear_code() {
   607   // this may be NULL if c2i adapters have not been made yet
   608   // Only should happen at allocate time.
   609   if (_adapter == NULL) {
   610     _from_compiled_entry    = NULL;
   611   } else {
   612     _from_compiled_entry    = _adapter->get_c2i_entry();
   613   }
   614   OrderAccess::storestore();
   615   _from_interpreted_entry = _i2i_entry;
   616   OrderAccess::storestore();
   617   _code = NULL;
   618 }
   620 // Called by class data sharing to remove any entry points (which are not shared)
   621 void methodOopDesc::unlink_method() {
   622   _code = NULL;
   623   _i2i_entry = NULL;
   624   _from_interpreted_entry = NULL;
   625   if (is_native()) {
   626     *native_function_addr() = NULL;
   627     set_signature_handler(NULL);
   628   }
   629   NOT_PRODUCT(set_compiled_invocation_count(0);)
   630   invocation_counter()->reset();
   631   backedge_counter()->reset();
   632   _adapter = NULL;
   633   _from_compiled_entry = NULL;
   634   assert(_method_data == NULL, "unexpected method data?");
   635   set_method_data(NULL);
   636   set_interpreter_throwout_count(0);
   637   set_interpreter_invocation_count(0);
   638   _highest_tier_compile = CompLevel_none;
   639 }
   641 // Called when the method_holder is getting linked. Setup entrypoints so the method
   642 // is ready to be called from interpreter, compiler, and vtables.
   643 void methodOopDesc::link_method(methodHandle h_method, TRAPS) {
   644   assert(_i2i_entry == NULL, "should only be called once");
   645   assert(_adapter == NULL, "init'd to NULL" );
   646   assert( _code == NULL, "nothing compiled yet" );
   648   // Setup interpreter entrypoint
   649   assert(this == h_method(), "wrong h_method()" );
   650   address entry = Interpreter::entry_for_method(h_method);
   651   assert(entry != NULL, "interpreter entry must be non-null");
   652   // Sets both _i2i_entry and _from_interpreted_entry
   653   set_interpreter_entry(entry);
   654   if (is_native()) {
   655     set_native_function(
   656       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
   657       !native_bind_event_is_interesting);
   658   }
   660   // Setup compiler entrypoint.  This is made eagerly, so we do not need
   661   // special handling of vtables.  An alternative is to make adapters more
   662   // lazily by calling make_adapter() from from_compiled_entry() for the
   663   // normal calls.  For vtable calls life gets more complicated.  When a
   664   // call-site goes mega-morphic we need adapters in all methods which can be
   665   // called from the vtable.  We need adapters on such methods that get loaded
   666   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
   667   // problem we'll make these lazily later.
   668   (void) make_adapters(h_method, CHECK);
   670   // ONLY USE the h_method now as make_adapter may have blocked
   672 }
   674 address methodOopDesc::make_adapters(methodHandle mh, TRAPS) {
   675   // Adapters for compiled code are made eagerly here.  They are fairly
   676   // small (generally < 100 bytes) and quick to make (and cached and shared)
   677   // so making them eagerly shouldn't be too expensive.
   678   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
   679   if (adapter == NULL ) {
   680     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
   681   }
   683   mh->set_adapter_entry(adapter);
   684   mh->_from_compiled_entry = adapter->get_c2i_entry();
   685   return adapter->get_c2i_entry();
   686 }
   688 // The verified_code_entry() must be called when a invoke is resolved
   689 // on this method.
   691 // It returns the compiled code entry point, after asserting not null.
   692 // This function is called after potential safepoints so that nmethod
   693 // or adapter that it points to is still live and valid.
   694 // This function must not hit a safepoint!
   695 address methodOopDesc::verified_code_entry() {
   696   debug_only(No_Safepoint_Verifier nsv;)
   697   assert(_from_compiled_entry != NULL, "must be set");
   698   return _from_compiled_entry;
   699 }
   701 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
   702 // (could be racing a deopt).
   703 // Not inline to avoid circular ref.
   704 bool methodOopDesc::check_code() const {
   705   // cached in a register or local.  There's a race on the value of the field.
   706   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
   707   return code == NULL || (code->method() == NULL) || (code->method() == (methodOop)this && !code->is_osr_method());
   708 }
   710 // Install compiled code.  Instantly it can execute.
   711 void methodOopDesc::set_code(methodHandle mh, nmethod *code) {
   712   assert( code, "use clear_code to remove code" );
   713   assert( mh->check_code(), "" );
   715   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
   717   // These writes must happen in this order, because the interpreter will
   718   // directly jump to from_interpreted_entry which jumps to an i2c adapter
   719   // which jumps to _from_compiled_entry.
   720   mh->_code = code;             // Assign before allowing compiled code to exec
   722   int comp_level = code->comp_level();
   723   // In theory there could be a race here. In practice it is unlikely
   724   // and not worth worrying about.
   725   if (comp_level > highest_tier_compile()) {
   726     set_highest_tier_compile(comp_level);
   727   }
   729   OrderAccess::storestore();
   730   mh->_from_compiled_entry = code->verified_entry_point();
   731   OrderAccess::storestore();
   732   // Instantly compiled code can execute.
   733   mh->_from_interpreted_entry = mh->get_i2c_entry();
   735 }
   738 bool methodOopDesc::is_overridden_in(klassOop k) const {
   739   instanceKlass* ik = instanceKlass::cast(k);
   741   if (ik->is_interface()) return false;
   743   // If method is an interface, we skip it - except if it
   744   // is a miranda method
   745   if (instanceKlass::cast(method_holder())->is_interface()) {
   746     // Check that method is not a miranda method
   747     if (ik->lookup_method(name(), signature()) == NULL) {
   748       // No implementation exist - so miranda method
   749       return false;
   750     }
   751     return true;
   752   }
   754   assert(ik->is_subclass_of(method_holder()), "should be subklass");
   755   assert(ik->vtable() != NULL, "vtable should exist");
   756   if (vtable_index() == nonvirtual_vtable_index) {
   757     return false;
   758   } else {
   759     methodOop vt_m = ik->method_at_vtable(vtable_index());
   760     return vt_m != methodOop(this);
   761   }
   762 }
   765 // give advice about whether this methodOop should be cached or not
   766 bool methodOopDesc::should_not_be_cached() const {
   767   if (is_old()) {
   768     // This method has been redefined. It is either EMCP or obsolete
   769     // and we don't want to cache it because that would pin the method
   770     // down and prevent it from being collectible if and when it
   771     // finishes executing.
   772     return true;
   773   }
   775   if (mark()->should_not_be_cached()) {
   776     // It is either not safe or not a good idea to cache this
   777     // method at this time because of the state of the embedded
   778     // markOop. See markOop.cpp for the gory details.
   779     return true;
   780   }
   782   // caching this method should be just fine
   783   return false;
   784 }
   787 methodHandle methodOopDesc:: clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
   788                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
   789   // Code below does not work for native methods - they should never get rewritten anyway
   790   assert(!m->is_native(), "cannot rewrite native methods");
   791   // Allocate new methodOop
   792   AccessFlags flags = m->access_flags();
   793   int checked_exceptions_len = m->checked_exceptions_length();
   794   int localvariable_len = m->localvariable_table_length();
   795   // Allocate newm_oop with the is_conc_safe parameter set
   796   // to IsUnsafeConc to indicate that newm_oop is not yet
   797   // safe for concurrent processing by a GC.
   798   methodOop newm_oop = oopFactory::new_method(new_code_length,
   799                                               flags,
   800                                               new_compressed_linenumber_size,
   801                                               localvariable_len,
   802                                               checked_exceptions_len,
   803                                               IsUnsafeConc,
   804                                               CHECK_(methodHandle()));
   805   methodHandle newm (THREAD, newm_oop);
   806   int new_method_size = newm->method_size();
   807   // Create a shallow copy of methodOopDesc part, but be careful to preserve the new constMethodOop
   808   constMethodOop newcm = newm->constMethod();
   809   int new_const_method_size = newm->constMethod()->object_size();
   811   memcpy(newm(), m(), sizeof(methodOopDesc));
   812   // Create shallow copy of constMethodOopDesc, but be careful to preserve the methodOop
   813   // is_conc_safe is set to false because that is the value of
   814   // is_conc_safe initialzied into newcm and the copy should
   815   // not overwrite that value.  During the window during which it is
   816   // tagged as unsafe, some extra work could be needed during precleaning
   817   // or concurrent marking but those phases will be correct.  Setting and
   818   // resetting is done in preference to a careful copying into newcm to
   819   // avoid having to know the precise layout of a constMethodOop.
   820   m->constMethod()->set_is_conc_safe(false);
   821   memcpy(newcm, m->constMethod(), sizeof(constMethodOopDesc));
   822   m->constMethod()->set_is_conc_safe(true);
   823   // Reset correct method/const method, method size, and parameter info
   824   newcm->set_method(newm());
   825   newm->set_constMethod(newcm);
   826   assert(newcm->method() == newm(), "check");
   827   newm->constMethod()->set_code_size(new_code_length);
   828   newm->constMethod()->set_constMethod_size(new_const_method_size);
   829   newm->set_method_size(new_method_size);
   830   assert(newm->code_size() == new_code_length, "check");
   831   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
   832   assert(newm->localvariable_table_length() == localvariable_len, "check");
   833   // Copy new byte codes
   834   memcpy(newm->code_base(), new_code, new_code_length);
   835   // Copy line number table
   836   if (new_compressed_linenumber_size > 0) {
   837     memcpy(newm->compressed_linenumber_table(),
   838            new_compressed_linenumber_table,
   839            new_compressed_linenumber_size);
   840   }
   841   // Copy checked_exceptions
   842   if (checked_exceptions_len > 0) {
   843     memcpy(newm->checked_exceptions_start(),
   844            m->checked_exceptions_start(),
   845            checked_exceptions_len * sizeof(CheckedExceptionElement));
   846   }
   847   // Copy local variable number table
   848   if (localvariable_len > 0) {
   849     memcpy(newm->localvariable_table_start(),
   850            m->localvariable_table_start(),
   851            localvariable_len * sizeof(LocalVariableTableElement));
   852   }
   854   // Only set is_conc_safe to true when changes to newcm are
   855   // complete.
   856   newcm->set_is_conc_safe(true);
   857   return newm;
   858 }
   860 vmIntrinsics::ID methodOopDesc::compute_intrinsic_id() const {
   861   assert(vmIntrinsics::_none == 0, "correct coding of default case");
   862   const uintptr_t max_cache_uint = right_n_bits((int)(sizeof(_intrinsic_id_cache) * BitsPerByte));
   863   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_cache_uint, "else fix cache size");
   864   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
   865   // because we are not loading from core libraries
   866   if (instanceKlass::cast(method_holder())->class_loader() != NULL) return vmIntrinsics::_none;
   868   // see if the klass name is well-known:
   869   symbolOop klass_name    = instanceKlass::cast(method_holder())->name();
   870   vmSymbols::SID klass_id = vmSymbols::find_sid(klass_name);
   871   if (klass_id == vmSymbols::NO_SID)  return vmIntrinsics::_none;
   873   // ditto for method and signature:
   874   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
   875   if (name_id  == vmSymbols::NO_SID)  return vmIntrinsics::_none;
   876   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
   877   if (sig_id   == vmSymbols::NO_SID)  return vmIntrinsics::_none;
   878   jshort flags = access_flags().as_short();
   880   // A few slightly irregular cases:
   881   switch (klass_id) {
   882   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
   883     // Second chance: check in regular Math.
   884     switch (name_id) {
   885     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
   886     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
   887     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
   888       // pretend it is the corresponding method in the non-strict class:
   889       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
   890       break;
   891     }
   892   }
   894   // return intrinsic id if any
   895   return vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
   896 }
   899 // These two methods are static since a GC may move the methodOopDesc
   900 bool methodOopDesc::load_signature_classes(methodHandle m, TRAPS) {
   901   bool sig_is_loaded = true;
   902   Handle class_loader(THREAD, instanceKlass::cast(m->method_holder())->class_loader());
   903   Handle protection_domain(THREAD, Klass::cast(m->method_holder())->protection_domain());
   904   symbolHandle signature(THREAD, m->signature());
   905   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
   906     if (ss.is_object()) {
   907       symbolOop sym = ss.as_symbol(CHECK_(false));
   908       symbolHandle name (THREAD, sym);
   909       klassOop klass = SystemDictionary::resolve_or_null(name, class_loader,
   910                                              protection_domain, THREAD);
   911       // We are loading classes eagerly. If a ClassNotFoundException or
   912       // a LinkageError was generated, be sure to ignore it.
   913       if (HAS_PENDING_EXCEPTION) {
   914         if (PENDING_EXCEPTION->is_a(SystemDictionary::classNotFoundException_klass()) ||
   915             PENDING_EXCEPTION->is_a(SystemDictionary::linkageError_klass())) {
   916           CLEAR_PENDING_EXCEPTION;
   917         } else {
   918           return false;
   919         }
   920       }
   921       if( klass == NULL) { sig_is_loaded = false; }
   922     }
   923   }
   924   return sig_is_loaded;
   925 }
   927 bool methodOopDesc::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
   928   Handle class_loader(THREAD, instanceKlass::cast(m->method_holder())->class_loader());
   929   Handle protection_domain(THREAD, Klass::cast(m->method_holder())->protection_domain());
   930   symbolHandle signature(THREAD, m->signature());
   931   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
   932     if (ss.type() == T_OBJECT) {
   933       symbolHandle name(THREAD, ss.as_symbol_or_null());
   934       if (name() == NULL) return true;
   935       klassOop klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
   936       if (klass == NULL) return true;
   937     }
   938   }
   939   return false;
   940 }
   942 // Exposed so field engineers can debug VM
   943 void methodOopDesc::print_short_name(outputStream* st) {
   944   ResourceMark rm;
   945 #ifdef PRODUCT
   946   st->print(" %s::", method_holder()->klass_part()->external_name());
   947 #else
   948   st->print(" %s::", method_holder()->klass_part()->internal_name());
   949 #endif
   950   name()->print_symbol_on(st);
   951   if (WizardMode) signature()->print_symbol_on(st);
   952 }
   955 extern "C" {
   956   static int method_compare(methodOop* a, methodOop* b) {
   957     return (*a)->name()->fast_compare((*b)->name());
   958   }
   960   // Prevent qsort from reordering a previous valid sort by
   961   // considering the address of the methodOops if two methods
   962   // would otherwise compare as equal.  Required to preserve
   963   // optimal access order in the shared archive.  Slower than
   964   // method_compare, only used for shared archive creation.
   965   static int method_compare_idempotent(methodOop* a, methodOop* b) {
   966     int i = method_compare(a, b);
   967     if (i != 0) return i;
   968     return ( a < b ? -1 : (a == b ? 0 : 1));
   969   }
   971   typedef int (*compareFn)(const void*, const void*);
   972 }
   975 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
   976 static void reorder_based_on_method_index(objArrayOop methods,
   977                                           objArrayOop annotations,
   978                                           GrowableArray<oop>* temp_array) {
   979   if (annotations == NULL) {
   980     return;
   981   }
   983   int length = methods->length();
   984   int i;
   985   // Copy to temp array
   986   temp_array->clear();
   987   for (i = 0; i < length; i++) {
   988     temp_array->append(annotations->obj_at(i));
   989   }
   991   // Copy back using old method indices
   992   for (i = 0; i < length; i++) {
   993     methodOop m = (methodOop) methods->obj_at(i);
   994     annotations->obj_at_put(i, temp_array->at(m->method_idnum()));
   995   }
   996 }
   999 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
  1000 void methodOopDesc::sort_methods(objArrayOop methods,
  1001                                  objArrayOop methods_annotations,
  1002                                  objArrayOop methods_parameter_annotations,
  1003                                  objArrayOop methods_default_annotations,
  1004                                  bool idempotent) {
  1005   int length = methods->length();
  1006   if (length > 1) {
  1007     bool do_annotations = false;
  1008     if (methods_annotations != NULL ||
  1009         methods_parameter_annotations != NULL ||
  1010         methods_default_annotations != NULL) {
  1011       do_annotations = true;
  1013     if (do_annotations) {
  1014       // Remember current method ordering so we can reorder annotations
  1015       for (int i = 0; i < length; i++) {
  1016         methodOop m = (methodOop) methods->obj_at(i);
  1017         m->set_method_idnum(i);
  1021     // Use a simple bubble sort for small number of methods since
  1022     // qsort requires a functional pointer call for each comparison.
  1023     if (UseCompressedOops || length < 8) {
  1024       bool sorted = true;
  1025       for (int i=length-1; i>0; i--) {
  1026         for (int j=0; j<i; j++) {
  1027           methodOop m1 = (methodOop)methods->obj_at(j);
  1028           methodOop m2 = (methodOop)methods->obj_at(j+1);
  1029           if ((uintptr_t)m1->name() > (uintptr_t)m2->name()) {
  1030             methods->obj_at_put(j, m2);
  1031             methods->obj_at_put(j+1, m1);
  1032             sorted = false;
  1035         if (sorted) break;
  1036           sorted = true;
  1038     } else {
  1039       // XXX This doesn't work for UseCompressedOops because the compare fn
  1040       // will have to decode the methodOop anyway making it not much faster
  1041       // than above.
  1042       compareFn compare = (compareFn) (idempotent ? method_compare_idempotent : method_compare);
  1043       qsort(methods->base(), length, heapOopSize, compare);
  1046     // Sort annotations if necessary
  1047     assert(methods_annotations == NULL           || methods_annotations->length() == methods->length(), "");
  1048     assert(methods_parameter_annotations == NULL || methods_parameter_annotations->length() == methods->length(), "");
  1049     assert(methods_default_annotations == NULL   || methods_default_annotations->length() == methods->length(), "");
  1050     if (do_annotations) {
  1051       ResourceMark rm;
  1052       // Allocate temporary storage
  1053       GrowableArray<oop>* temp_array = new GrowableArray<oop>(length);
  1054       reorder_based_on_method_index(methods, methods_annotations, temp_array);
  1055       reorder_based_on_method_index(methods, methods_parameter_annotations, temp_array);
  1056       reorder_based_on_method_index(methods, methods_default_annotations, temp_array);
  1059     // Reset method ordering
  1060     for (int i = 0; i < length; i++) {
  1061       methodOop m = (methodOop) methods->obj_at(i);
  1062       m->set_method_idnum(i);
  1068 //-----------------------------------------------------------------------------------
  1069 // Non-product code
  1071 #ifndef PRODUCT
  1072 class SignatureTypePrinter : public SignatureTypeNames {
  1073  private:
  1074   outputStream* _st;
  1075   bool _use_separator;
  1077   void type_name(const char* name) {
  1078     if (_use_separator) _st->print(", ");
  1079     _st->print(name);
  1080     _use_separator = true;
  1083  public:
  1084   SignatureTypePrinter(symbolHandle signature, outputStream* st) : SignatureTypeNames(signature) {
  1085     _st = st;
  1086     _use_separator = false;
  1089   void print_parameters()              { _use_separator = false; iterate_parameters(); }
  1090   void print_returntype()              { _use_separator = false; iterate_returntype(); }
  1091 };
  1094 void methodOopDesc::print_name(outputStream* st) {
  1095   Thread *thread = Thread::current();
  1096   ResourceMark rm(thread);
  1097   SignatureTypePrinter sig(signature(), st);
  1098   st->print("%s ", is_static() ? "static" : "virtual");
  1099   sig.print_returntype();
  1100   st->print(" %s.", method_holder()->klass_part()->internal_name());
  1101   name()->print_symbol_on(st);
  1102   st->print("(");
  1103   sig.print_parameters();
  1104   st->print(")");
  1108 void methodOopDesc::print_codes_on(outputStream* st) const {
  1109   print_codes_on(0, code_size(), st);
  1112 void methodOopDesc::print_codes_on(int from, int to, outputStream* st) const {
  1113   Thread *thread = Thread::current();
  1114   ResourceMark rm(thread);
  1115   methodHandle mh (thread, (methodOop)this);
  1116   BytecodeStream s(mh);
  1117   s.set_interval(from, to);
  1118   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
  1119   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
  1121 #endif // not PRODUCT
  1124 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
  1125 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
  1126 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
  1127 // as end-of-stream terminator.
  1129 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
  1130   // bci and line number does not compress into single byte.
  1131   // Write out escape character and use regular compression for bci and line number.
  1132   write_byte((jubyte)0xFF);
  1133   write_signed_int(bci_delta);
  1134   write_signed_int(line_delta);
  1137 // See comment in methodOop.hpp which explains why this exists.
  1138 #if defined(_M_AMD64) && MSC_VER >= 1400
  1139 #pragma optimize("", off)
  1140 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
  1141   write_pair_inline(bci, line);
  1143 #pragma optimize("", on)
  1144 #endif
  1146 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
  1147   _bci = 0;
  1148   _line = 0;
  1149 };
  1152 bool CompressedLineNumberReadStream::read_pair() {
  1153   jubyte next = read_byte();
  1154   // Check for terminator
  1155   if (next == 0) return false;
  1156   if (next == 0xFF) {
  1157     // Escape character, regular compression used
  1158     _bci  += read_signed_int();
  1159     _line += read_signed_int();
  1160   } else {
  1161     // Single byte compression used
  1162     _bci  += next >> 3;
  1163     _line += next & 0x7;
  1165   return true;
  1169 Bytecodes::Code methodOopDesc::orig_bytecode_at(int bci) {
  1170   BreakpointInfo* bp = instanceKlass::cast(method_holder())->breakpoints();
  1171   for (; bp != NULL; bp = bp->next()) {
  1172     if (bp->match(this, bci)) {
  1173       return bp->orig_bytecode();
  1176   ShouldNotReachHere();
  1177   return Bytecodes::_shouldnotreachhere;
  1180 void methodOopDesc::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
  1181   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
  1182   BreakpointInfo* bp = instanceKlass::cast(method_holder())->breakpoints();
  1183   for (; bp != NULL; bp = bp->next()) {
  1184     if (bp->match(this, bci)) {
  1185       bp->set_orig_bytecode(code);
  1186       // and continue, in case there is more than one
  1191 void methodOopDesc::set_breakpoint(int bci) {
  1192   instanceKlass* ik = instanceKlass::cast(method_holder());
  1193   BreakpointInfo *bp = new BreakpointInfo(this, bci);
  1194   bp->set_next(ik->breakpoints());
  1195   ik->set_breakpoints(bp);
  1196   // do this last:
  1197   bp->set(this);
  1200 static void clear_matches(methodOop m, int bci) {
  1201   instanceKlass* ik = instanceKlass::cast(m->method_holder());
  1202   BreakpointInfo* prev_bp = NULL;
  1203   BreakpointInfo* next_bp;
  1204   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
  1205     next_bp = bp->next();
  1206     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
  1207     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
  1208       // do this first:
  1209       bp->clear(m);
  1210       // unhook it
  1211       if (prev_bp != NULL)
  1212         prev_bp->set_next(next_bp);
  1213       else
  1214         ik->set_breakpoints(next_bp);
  1215       delete bp;
  1216       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
  1217       // at same location. So we have multiple matching (method_index and bci)
  1218       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
  1219       // breakpoint for clear_breakpoint request and keep all other method versions
  1220       // BreakpointInfo for future clear_breakpoint request.
  1221       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
  1222       // which is being called when class is unloaded. We delete all the Breakpoint
  1223       // information for all versions of method. We may not correctly restore the original
  1224       // bytecode in all method versions, but that is ok. Because the class is being unloaded
  1225       // so these methods won't be used anymore.
  1226       if (bci >= 0) {
  1227         break;
  1229     } else {
  1230       // This one is a keeper.
  1231       prev_bp = bp;
  1236 void methodOopDesc::clear_breakpoint(int bci) {
  1237   assert(bci >= 0, "");
  1238   clear_matches(this, bci);
  1241 void methodOopDesc::clear_all_breakpoints() {
  1242   clear_matches(this, -1);
  1246 BreakpointInfo::BreakpointInfo(methodOop m, int bci) {
  1247   _bci = bci;
  1248   _name_index = m->name_index();
  1249   _signature_index = m->signature_index();
  1250   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
  1251   if (_orig_bytecode == Bytecodes::_breakpoint)
  1252     _orig_bytecode = m->orig_bytecode_at(_bci);
  1253   _next = NULL;
  1256 void BreakpointInfo::set(methodOop method) {
  1257 #ifdef ASSERT
  1259     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
  1260     if (code == Bytecodes::_breakpoint)
  1261       code = method->orig_bytecode_at(_bci);
  1262     assert(orig_bytecode() == code, "original bytecode must be the same");
  1264 #endif
  1265   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
  1266   method->incr_number_of_breakpoints();
  1267   SystemDictionary::notice_modification();
  1269     // Deoptimize all dependents on this method
  1270     Thread *thread = Thread::current();
  1271     HandleMark hm(thread);
  1272     methodHandle mh(thread, method);
  1273     Universe::flush_dependents_on_method(mh);
  1277 void BreakpointInfo::clear(methodOop method) {
  1278   *method->bcp_from(_bci) = orig_bytecode();
  1279   assert(method->number_of_breakpoints() > 0, "must not go negative");
  1280   method->decr_number_of_breakpoints();

mercurial