gin/v8_platform.cc - chromium/src - Git at Google

 // Copyright 2014 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/v8_platform.h"

 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/location.h"
 #include "base/sys_info.h"
 #include "base/threading/worker_pool.h"
 #include "base/trace_event/trace_event.h"
 #include "gin/per_isolate_data.h"

 namespace gin {

 namespace {

 base::LazyInstance<V8Platform>::Leaky g_v8_platform = LAZY_INSTANCE_INITIALIZER;

 void RunWithLocker(v8::Isolate* isolate, v8::Task* task) {
   v8::Locker lock(isolate);
   task->Run();
 }

 class IdleTaskWithLocker : public v8::IdleTask {
  public:
   IdleTaskWithLocker(v8::Isolate* isolate, v8::IdleTask* task)
       : isolate_(isolate), task_(task) {}

   ~IdleTaskWithLocker() override = default;

   // v8::IdleTask implementation.
   void Run(double deadline_in_seconds) override {
     v8::Locker lock(isolate_);
     task_->Run(deadline_in_seconds);
   }

  private:
   v8::Isolate* isolate_;
   std::unique_ptr<v8::IdleTask> task_;

   DISALLOW_COPY_AND_ASSIGN(IdleTaskWithLocker);
 };

 void PrintStackTrace() {
   base::debug::StackTrace trace;
   trace.Print();
 }

 }  // namespace

 // static
 V8Platform* V8Platform::Get() { return g_v8_platform.Pointer(); }

 V8Platform::V8Platform() {}

 V8Platform::~V8Platform() {}

 size_t V8Platform::NumberOfAvailableBackgroundThreads() {
   // WorkerPool will currently always create additional threads for posted
   // background tasks, unless there are threads sitting idle (on posix).
   // Indicate that V8 should create no more than the number of cores available,
   // reserving one core for the main thread.
   const size_t available_cores =
     static_cast<size_t>(base::SysInfo::NumberOfProcessors());
   if (available_cores > 1) {
     return available_cores - 1;
   }
   return 1;
 }

 void V8Platform::CallOnBackgroundThread(
     v8::Task* task,
     v8::Platform::ExpectedRuntime expected_runtime) {
   base::WorkerPool::PostTask(
       FROM_HERE,
       base::Bind(&v8::Task::Run, base::Owned(task)),
       expected_runtime == v8::Platform::kLongRunningTask);
 }

 void V8Platform::CallOnForegroundThread(v8::Isolate* isolate, v8::Task* task) {
   PerIsolateData* data = PerIsolateData::From(isolate);
   if (data->access_mode() == IsolateHolder::kUseLocker) {
     data->task_runner()->PostTask(
         FROM_HERE, base::Bind(RunWithLocker, base::Unretained(isolate),
                               base::Owned(task)));
   } else {
     data->task_runner()->PostTask(
         FROM_HERE, base::Bind(&v8::Task::Run, base::Owned(task)));
   }
 }

 void V8Platform::CallDelayedOnForegroundThread(v8::Isolate* isolate,
                                                v8::Task* task,
                                                double delay_in_seconds) {
   PerIsolateData* data = PerIsolateData::From(isolate);
   if (data->access_mode() == IsolateHolder::kUseLocker) {
     data->task_runner()->PostDelayedTask(
         FROM_HERE,
         base::Bind(RunWithLocker, base::Unretained(isolate), base::Owned(task)),
         base::TimeDelta::FromSecondsD(delay_in_seconds));
   } else {
     data->task_runner()->PostDelayedTask(
         FROM_HERE, base::Bind(&v8::Task::Run, base::Owned(task)),
         base::TimeDelta::FromSecondsD(delay_in_seconds));
   }
 }

 void V8Platform::CallIdleOnForegroundThread(v8::Isolate* isolate,
                                             v8::IdleTask* task) {
   PerIsolateData* data = PerIsolateData::From(isolate);
   DCHECK(data->idle_task_runner());
   if (data->access_mode() == IsolateHolder::kUseLocker) {
     data->idle_task_runner()->PostIdleTask(
         new IdleTaskWithLocker(isolate, task));
   } else {
     data->idle_task_runner()->PostIdleTask(task);
   }
 }

 bool V8Platform::IdleTasksEnabled(v8::Isolate* isolate) {
   return PerIsolateData::From(isolate)->idle_task_runner() != nullptr;
 }

 double V8Platform::MonotonicallyIncreasingTime() {
   return base::TimeTicks::Now().ToInternalValue() /
       static_cast<double>(base::Time::kMicrosecondsPerSecond);
 }

 const uint8_t* V8Platform::GetCategoryGroupEnabled(const char* name) {
   return TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(name);
 }

 const char* V8Platform::GetCategoryGroupName(
     const uint8_t* category_enabled_flag) {
   return base::trace_event::TraceLog::GetCategoryGroupName(
       category_enabled_flag);
 }

 namespace {

 class ConvertableToTraceFormatWrapper
     : public base::trace_event::ConvertableToTraceFormat {
  public:
   explicit ConvertableToTraceFormatWrapper(
       std::unique_ptr<v8::ConvertableToTraceFormat>& inner)
       : inner_(std::move(inner)) {}
   ~ConvertableToTraceFormatWrapper() override = default;
   void AppendAsTraceFormat(std::string* out) const final {
     inner_->AppendAsTraceFormat(out);
   }

  private:
   std::unique_ptr<v8::ConvertableToTraceFormat> inner_;

   DISALLOW_COPY_AND_ASSIGN(ConvertableToTraceFormatWrapper);
 };

 }  // namespace

 uint64_t V8Platform::AddTraceEvent(
     char phase,
     const uint8_t* category_enabled_flag,
     const char* name,
     const char* scope,
     uint64_t id,
     uint64_t bind_id,
     int32_t num_args,
     const char** arg_names,
     const uint8_t* arg_types,
     const uint64_t* arg_values,
     std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
     unsigned int flags) {
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> convertables[2];
   if (num_args > 0 && arg_types[0] == TRACE_VALUE_TYPE_CONVERTABLE) {
     convertables[0].reset(
         new ConvertableToTraceFormatWrapper(arg_convertables[0]));
   }
   if (num_args > 1 && arg_types[1] == TRACE_VALUE_TYPE_CONVERTABLE) {
     convertables[1].reset(
         new ConvertableToTraceFormatWrapper(arg_convertables[1]));
   }
   DCHECK_LE(num_args, 2);
   base::trace_event::TraceEventHandle handle =
       TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_BIND_ID(
           phase, category_enabled_flag, name, scope, id, bind_id, num_args,
           arg_names, arg_types, (const long long unsigned int*)arg_values,
           convertables, flags);
   uint64_t result;
   memcpy(&result, &handle, sizeof(result));
   return result;
 }

 void V8Platform::UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
                                           const char* name,
                                           uint64_t handle) {
   base::trace_event::TraceEventHandle traceEventHandle;
   memcpy(&traceEventHandle, &handle, sizeof(handle));
   TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_enabled_flag, name,
                                               traceEventHandle);
 }

 namespace {

 class EnabledStateObserverImpl final
     : public base::trace_event::TraceLog::EnabledStateObserver {
  public:
   EnabledStateObserverImpl() = default;

   void OnTraceLogEnabled() final {
     base::AutoLock lock(mutex_);
     for (auto* o : observers_) {
       o->OnTraceEnabled();
     }
   }

   void OnTraceLogDisabled() final {
     base::AutoLock lock(mutex_);
     for (auto* o : observers_) {
       o->OnTraceDisabled();
     }
   }

   void AddObserver(v8::Platform::TraceStateObserver* observer) {
     {
       base::AutoLock lock(mutex_);
       DCHECK(!observers_.count(observer));
       if (observers_.empty()) {
         base::trace_event::TraceLog::GetInstance()->AddEnabledStateObserver(
             this);
       }
       observers_.insert(observer);
     }
     // Fire the observer if recording is already in progress.
     if (base::trace_event::TraceLog::GetInstance()->IsEnabled())
       observer->OnTraceEnabled();
   }

   void RemoveObserver(v8::Platform::TraceStateObserver* observer) {
     base::AutoLock lock(mutex_);
     DCHECK(observers_.count(observer) == 1);
     observers_.erase(observer);
     if (observers_.empty()) {
       base::trace_event::TraceLog::GetInstance()->RemoveEnabledStateObserver(
           this);
     }
   }

  private:
   base::Lock mutex_;
   std::unordered_set<v8::Platform::TraceStateObserver*> observers_;

   DISALLOW_COPY_AND_ASSIGN(EnabledStateObserverImpl);
 };

 base::LazyInstance<EnabledStateObserverImpl>::Leaky g_trace_state_dispatcher =
     LAZY_INSTANCE_INITIALIZER;

 }  // namespace

 void V8Platform::AddTraceStateObserver(
     v8::Platform::TraceStateObserver* observer) {
   g_trace_state_dispatcher.Get().AddObserver(observer);
 }

 void V8Platform::RemoveTraceStateObserver(
     v8::Platform::TraceStateObserver* observer) {
   g_trace_state_dispatcher.Get().RemoveObserver(observer);
 }

 v8::Platform::StackTracePrinter V8Platform::GetStackTracePrinter() {
   return PrintStackTrace;
 }

 }  // namespace gin
	// Copyright 2014 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/v8_platform.h"

	#include "base/bind.h"
	#include "base/debug/stack_trace.h"
	#include "base/location.h"
	#include "base/sys_info.h"
	#include "base/threading/worker_pool.h"
	#include "base/trace_event/trace_event.h"
	#include "gin/per_isolate_data.h"

	namespace gin {

	namespace {

	base::LazyInstance<V8Platform>::Leaky g_v8_platform = LAZY_INSTANCE_INITIALIZER;

	void RunWithLocker(v8::Isolate* isolate, v8::Task* task) {
	v8::Locker lock(isolate);
	task->Run();
	}

	class IdleTaskWithLocker : public v8::IdleTask {
	public:
	IdleTaskWithLocker(v8::Isolate* isolate, v8::IdleTask* task)
	: isolate_(isolate), task_(task) {}

	~IdleTaskWithLocker() override = default;

	// v8::IdleTask implementation.
	void Run(double deadline_in_seconds) override {
	v8::Locker lock(isolate_);
	task_->Run(deadline_in_seconds);
	}

	private:
	v8::Isolate* isolate_;
	std::unique_ptr<v8::IdleTask> task_;

	DISALLOW_COPY_AND_ASSIGN(IdleTaskWithLocker);
	};

	void PrintStackTrace() {
	base::debug::StackTrace trace;
	trace.Print();
	}

	} // namespace

	// static
	V8Platform* V8Platform::Get() { return g_v8_platform.Pointer(); }

	V8Platform::V8Platform() {}

	V8Platform::~V8Platform() {}

	size_t V8Platform::NumberOfAvailableBackgroundThreads() {
	// WorkerPool will currently always create additional threads for posted
	// background tasks, unless there are threads sitting idle (on posix).
	// Indicate that V8 should create no more than the number of cores available,
	// reserving one core for the main thread.
	const size_t available_cores =
	static_cast<size_t>(base::SysInfo::NumberOfProcessors());
	if (available_cores > 1) {
	return available_cores - 1;
	}
	return 1;
	}

	void V8Platform::CallOnBackgroundThread(
	v8::Task* task,
	v8::Platform::ExpectedRuntime expected_runtime) {
	base::WorkerPool::PostTask(
	FROM_HERE,
	base::Bind(&v8::Task::Run, base::Owned(task)),
	expected_runtime == v8::Platform::kLongRunningTask);
	}

	void V8Platform::CallOnForegroundThread(v8::Isolate* isolate, v8::Task* task) {
	PerIsolateData* data = PerIsolateData::From(isolate);
	if (data->access_mode() == IsolateHolder::kUseLocker) {
	data->task_runner()->PostTask(
	FROM_HERE, base::Bind(RunWithLocker, base::Unretained(isolate),
	base::Owned(task)));
	} else {
	data->task_runner()->PostTask(
	FROM_HERE, base::Bind(&v8::Task::Run, base::Owned(task)));
	}
	}

	void V8Platform::CallDelayedOnForegroundThread(v8::Isolate* isolate,
	v8::Task* task,
	double delay_in_seconds) {
	PerIsolateData* data = PerIsolateData::From(isolate);
	if (data->access_mode() == IsolateHolder::kUseLocker) {
	data->task_runner()->PostDelayedTask(
	FROM_HERE,
	base::Bind(RunWithLocker, base::Unretained(isolate), base::Owned(task)),
	base::TimeDelta::FromSecondsD(delay_in_seconds));
	} else {
	data->task_runner()->PostDelayedTask(
	FROM_HERE, base::Bind(&v8::Task::Run, base::Owned(task)),
	base::TimeDelta::FromSecondsD(delay_in_seconds));
	}
	}

	void V8Platform::CallIdleOnForegroundThread(v8::Isolate* isolate,
	v8::IdleTask* task) {
	PerIsolateData* data = PerIsolateData::From(isolate);
	DCHECK(data->idle_task_runner());
	if (data->access_mode() == IsolateHolder::kUseLocker) {
	data->idle_task_runner()->PostIdleTask(
	new IdleTaskWithLocker(isolate, task));
	} else {
	data->idle_task_runner()->PostIdleTask(task);
	}
	}

	bool V8Platform::IdleTasksEnabled(v8::Isolate* isolate) {
	return PerIsolateData::From(isolate)->idle_task_runner() != nullptr;
	}

	double V8Platform::MonotonicallyIncreasingTime() {
	return base::TimeTicks::Now().ToInternalValue() /
	static_cast<double>(base::Time::kMicrosecondsPerSecond);
	}

	const uint8_t* V8Platform::GetCategoryGroupEnabled(const char* name) {
	return TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(name);
	}

	const char* V8Platform::GetCategoryGroupName(
	const uint8_t* category_enabled_flag) {
	return base::trace_event::TraceLog::GetCategoryGroupName(
	category_enabled_flag);
	}

	namespace {

	class ConvertableToTraceFormatWrapper
	: public base::trace_event::ConvertableToTraceFormat {
	public:
	explicit ConvertableToTraceFormatWrapper(
	std::unique_ptr<v8::ConvertableToTraceFormat>& inner)
	: inner_(std::move(inner)) {}
	~ConvertableToTraceFormatWrapper() override = default;
	void AppendAsTraceFormat(std::string* out) const final {
	inner_->AppendAsTraceFormat(out);
	}

	private:
	std::unique_ptr<v8::ConvertableToTraceFormat> inner_;

	DISALLOW_COPY_AND_ASSIGN(ConvertableToTraceFormatWrapper);
	};

	} // namespace

	uint64_t V8Platform::AddTraceEvent(
	char phase,
	const uint8_t* category_enabled_flag,
	const char* name,
	const char* scope,
	uint64_t id,
	uint64_t bind_id,
	int32_t num_args,
	const char** arg_names,
	const uint8_t* arg_types,
	const uint64_t* arg_values,
	std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
	unsigned int flags) {
	std::unique_ptr<base::trace_event::ConvertableToTraceFormat> convertables[2];
	if (num_args > 0 && arg_types[0] == TRACE_VALUE_TYPE_CONVERTABLE) {
	convertables[0].reset(
	new ConvertableToTraceFormatWrapper(arg_convertables[0]));
	}
	if (num_args > 1 && arg_types[1] == TRACE_VALUE_TYPE_CONVERTABLE) {
	convertables[1].reset(
	new ConvertableToTraceFormatWrapper(arg_convertables[1]));
	}
	DCHECK_LE(num_args, 2);
	base::trace_event::TraceEventHandle handle =
	TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_BIND_ID(
	phase, category_enabled_flag, name, scope, id, bind_id, num_args,
	arg_names, arg_types, (const long long unsigned int*)arg_values,
	convertables, flags);
	uint64_t result;
	memcpy(&result, &handle, sizeof(result));
	return result;
	}

	void V8Platform::UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
	const char* name,
	uint64_t handle) {
	base::trace_event::TraceEventHandle traceEventHandle;
	memcpy(&traceEventHandle, &handle, sizeof(handle));
	TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_enabled_flag, name,
	traceEventHandle);
	}

	namespace {

	class EnabledStateObserverImpl final
	: public base::trace_event::TraceLog::EnabledStateObserver {
	public:
	EnabledStateObserverImpl() = default;

	void OnTraceLogEnabled() final {
	base::AutoLock lock(mutex_);
	for (auto* o : observers_) {
	o->OnTraceEnabled();
	}
	}

	void OnTraceLogDisabled() final {
	base::AutoLock lock(mutex_);
	for (auto* o : observers_) {
	o->OnTraceDisabled();
	}
	}

	void AddObserver(v8::Platform::TraceStateObserver* observer) {
	{
	base::AutoLock lock(mutex_);
	DCHECK(!observers_.count(observer));
	if (observers_.empty()) {
	base::trace_event::TraceLog::GetInstance()->AddEnabledStateObserver(
	this);
	}
	observers_.insert(observer);
	}
	// Fire the observer if recording is already in progress.
	if (base::trace_event::TraceLog::GetInstance()->IsEnabled())
	observer->OnTraceEnabled();
	}

	void RemoveObserver(v8::Platform::TraceStateObserver* observer) {
	base::AutoLock lock(mutex_);
	DCHECK(observers_.count(observer) == 1);
	observers_.erase(observer);
	if (observers_.empty()) {
	base::trace_event::TraceLog::GetInstance()->RemoveEnabledStateObserver(
	this);
	}
	}

	private:
	base::Lock mutex_;
	std::unordered_set<v8::Platform::TraceStateObserver*> observers_;

	DISALLOW_COPY_AND_ASSIGN(EnabledStateObserverImpl);
	};

	base::LazyInstance<EnabledStateObserverImpl>::Leaky g_trace_state_dispatcher =
	LAZY_INSTANCE_INITIALIZER;

	} // namespace

	void V8Platform::AddTraceStateObserver(
	v8::Platform::TraceStateObserver* observer) {
	g_trace_state_dispatcher.Get().AddObserver(observer);
	}

	void V8Platform::RemoveTraceStateObserver(
	v8::Platform::TraceStateObserver* observer) {
	g_trace_state_dispatcher.Get().RemoveObserver(observer);
	}

	v8::Platform::StackTracePrinter V8Platform::GetStackTracePrinter() {
	return PrintStackTrace;
	}

	} // namespace gin