Mojo JS bindings: draining a DataPipe

gin/isolate_holder.cc

 // Copyright 2013 The Chromium 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 "gin/public/isolate_holder.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "base/logging.h"
+#include "base/message_loop/message_loop.h"
 #include "base/rand_util.h"
 #include "base/sys_info.h"
 #include "gin/array_buffer.h"
 #include "gin/debug_impl.h"
 #include "gin/function_template.h"
 #include "gin/per_isolate_data.h"
 #include "gin/public/v8_platform.h"
+#include "gin/run_microtasks_observer.h"
 
 namespace gin {
 
 namespace {
 
 v8::ArrayBuffer::Allocator* g_array_buffer_allocator = NULL;
 
 bool GenerateEntropy(unsigned char* buffer, size_t amount) {
   base::RandBytes(buffer, amount);
   return true;
 }
 
 }  // namespace
 
 IsolateHolder::IsolateHolder() {
   CHECK(g_array_buffer_allocator)
       << "You need to invoke gin::IsolateHolder::Initialize first";
   v8::Isolate::CreateParams params;
   params.entry_hook = DebugImpl::GetFunctionEntryHook();
   params.code_event_handler = DebugImpl::GetJitCodeEventHandler();
   params.constraints.ConfigureDefaults(base::SysInfo::AmountOfPhysicalMemory(),
                                        base::SysInfo::AmountOfVirtualMemory(),
                                        base::SysInfo::NumberOfProcessors());
   isolate_ = v8::Isolate::New(params);
   isolate_data_.reset(new PerIsolateData(isolate_, g_array_buffer_allocator));
 }
 
 IsolateHolder::~IsolateHolder() {
+  if (task_observer_.get())
+    base::MessageLoop::current()->RemoveTaskObserver(task_observer_.get());

[abarth-chromium, 2014/09/25 00:01:42]

Should this call RemoveRunMicrotasksObserver() ?

[hansmuller, 2014/09/25 14:36:35]

The Add,RemoveRunMicrotasksObserver() use DCHECK to warn about likely mistakes
(adding twice say). In ~IsolateHolder() the DCHECK would just get in the way.

   isolate_data_.reset();
   isolate_->Dispose();
 }
 
 // static
 void IsolateHolder::Initialize(ScriptMode mode,
                                v8::ArrayBuffer::Allocator* allocator) {
   CHECK(allocator);
   static bool v8_is_initialized = false;
   if (v8_is_initialized)
     return;
   v8::V8::InitializePlatform(V8Platform::Get());
   v8::V8::SetArrayBufferAllocator(allocator);
   g_array_buffer_allocator = allocator;
   if (mode == gin::IsolateHolder::kStrictMode) {
     static const char v8_flags[] = "--use_strict";
     v8::V8::SetFlagsFromString(v8_flags, sizeof(v8_flags) - 1);
   }
   v8::V8::SetEntropySource(&GenerateEntropy);
   v8::V8::Initialize();
   v8_is_initialized = true;
 }
 
+void IsolateHolder::AddRunMicrotasksObserver() {
+  DCHECK(!task_observer_.get());
+  task_observer_.reset(new RunMicrotasksObserver(isolate_));;
+  base::MessageLoop::current()->AddTaskObserver(task_observer_.get());
+}
+
+void IsolateHolder::RemoveRunMicrotasksObserver() {
+  DCHECK(task_observer_.get());
+  base::MessageLoop::current()->RemoveTaskObserver(task_observer_.get());
+  task_observer_.reset();
+}
+
 }  // namespace gin