Minimize malloc heap allocation on process startup.

src/debug.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1947 matching lines @@
 
 void Debug::AfterGarbageCollection() {
   // Generate events for collected scripts.
   if (script_cache_ != NULL) {
     script_cache_->ProcessCollectedScripts();
   }
 }
 
 
 Debugger::Debugger(Isolate* isolate)
-    : debugger_access_(OS::CreateMutex()),
+    : debugger_access_(isolate->debugger_access()),
       event_listener_(Handle<Object>()),
       event_listener_data_(Handle<Object>()),
       compiling_natives_(false),
       is_loading_debugger_(false),
       never_unload_debugger_(false),
       message_handler_(NULL),
       debugger_unload_pending_(false),
       host_dispatch_handler_(NULL),
       dispatch_handler_access_(OS::CreateMutex()),
       debug_message_dispatch_handler_(NULL),
       message_dispatch_helper_thread_(NULL),
       host_dispatch_micros_(100 * 1000),
       agent_(NULL),
       command_queue_(isolate->logger(), kQueueInitialSize),
       command_received_(OS::CreateSemaphore(0)),
       event_command_queue_(isolate->logger(), kQueueInitialSize),
       isolate_(isolate) {
 }
 
 
 Debugger::~Debugger() {
-  delete debugger_access_;
-  debugger_access_ = 0;
   delete dispatch_handler_access_;
   dispatch_handler_access_ = 0;
   delete command_received_;
   command_received_ = 0;
 }
 
 
 Handle<Object> Debugger::MakeJSObject(Vector<const char> constructor_name,
                                       int argc, Object*** argv,
                                       bool* caught_exception) {
@@ skipping 1126 matching lines @@
     {
       Locker locker;
       Isolate::Current()->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal