Reland of d8 workers: make sure Shell::Quit is only called once

src/d8.cc

 // Copyright 2012 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.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 198 matching lines @@
 base::Mutex Shell::workers_mutex_;
 bool Shell::allow_new_workers_ = true;
 i::List<Worker*> Shell::workers_;
 i::List<SharedArrayBuffer::Contents> Shell::externalized_shared_contents_;
 #endif  // !V8_SHARED
 
 Persistent<Context> Shell::evaluation_context_;
 ArrayBuffer::Allocator* Shell::array_buffer_allocator;
 ShellOptions Shell::options;
 const char* Shell::kPrompt = "d8> ";
+base::OnceType Shell::quit_once_ = V8_ONCE_INIT;
 
 #ifndef V8_SHARED
 bool CounterMap::Match(void* key1, void* key2) {
   const char* name1 = reinterpret_cast<const char*>(key1);
   const char* name2 = reinterpret_cast<const char*>(key2);
   return strcmp(name1, name2) == 0;
 }
 #endif  // !V8_SHARED
 
 
@@ skipping 573 matching lines @@
     return;
   }
 
   Worker* worker =
       static_cast<Worker*>(Local<External>::Cast(this_value)->Value());
   worker->Terminate();
 }
 #endif  // !V8_SHARED
 
 
-void Shell::Quit(const v8::FunctionCallbackInfo<v8::Value>& args) {
-  int exit_code = args[0]->Int32Value();
+void Shell::QuitOnce(v8::FunctionCallbackInfo<v8::Value>* args) {
+  int exit_code = (*args)[0]->Int32Value();
 #ifndef V8_SHARED
   CleanupWorkers();
 #endif  // !V8_SHARED
-  OnExit(args.GetIsolate());
+  OnExit(args->GetIsolate());
   exit(exit_code);
 }
 
 
+void Shell::Quit(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  base::CallOnce(&quit_once_, &QuitOnce,
+                 const_cast<v8::FunctionCallbackInfo<v8::Value>*>(&args));
+}
+
+
 void Shell::Version(const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetReturnValue().Set(
       String::NewFromUtf8(args.GetIsolate(), V8::GetVersion()));
 }
 
 
 void Shell::ReportException(Isolate* isolate, v8::TryCatch* try_catch) {
   HandleScope handle_scope(isolate);
 #ifndef V8_SHARED
   Handle<Context> utility_context;
@@ skipping 1614 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif