[loggers] Guard object/code move events using mutexes.

src/log.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/log.h"
 
 #include <cstdarg>
 #include <sstream>
 
 #include "src/bailout-reason.h"
@@ skipping 483 matching lines @@
   void* StartCodePosInfoEvent();
   void EndCodePosInfoEvent(Code* code, void* jit_handler_data);
 
  private:
   virtual void LogRecordedBuffer(Code* code,
                                  SharedFunctionInfo* shared,
                                  const char* name,
                                  int length);
 
   JitCodeEventHandler code_event_handler_;
+  base::Mutex logger_mutex_;
 };
 
 
 JitLogger::JitLogger(JitCodeEventHandler code_event_handler)
     : code_event_handler_(code_event_handler) {
 }
 
 
 void JitLogger::LogRecordedBuffer(Code* code,
                                   SharedFunctionInfo* shared,
                                   const char* name,
                                   int length) {
   JitCodeEvent event;
   memset(&event, 0, sizeof(event));
   event.type = JitCodeEvent::CODE_ADDED;
   event.code_start = code->instruction_start();
   event.code_len = code->instruction_size();
   Handle<SharedFunctionInfo> shared_function_handle;
   if (shared && shared->script()->IsScript()) {
     shared_function_handle = Handle<SharedFunctionInfo>(shared);
   }
   event.script = ToApiHandle<v8::UnboundScript>(shared_function_handle);
   event.name.str = name;
   event.name.len = length;
   code_event_handler_(&event);
 }
 
 
 void JitLogger::CodeMoveEvent(Address from, Address to) {
+  base::LockGuard<base::Mutex> guard(&logger_mutex_);
   Code* from_code = Code::cast(HeapObject::FromAddress(from));
 
   JitCodeEvent event;
   event.type = JitCodeEvent::CODE_MOVED;
   event.code_start = from_code->instruction_start();
   event.code_len = from_code->instruction_size();
 
   // Calculate the header size.
   const size_t header_size =
       from_code->instruction_start() - reinterpret_cast<byte*>(from_code);
@@ skipping 1362 matching lines @@
     removeCodeEventListener(jit_logger_);
     delete jit_logger_;
     jit_logger_ = NULL;
   }
 
   return log_->Close();
 }
 
 }  // namespace internal
 }  // namespace v8