gecko-dev/dom/plugins/ipc/TaskFactory.h

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2.8 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_plugins_TaskFactory_h
#define mozilla_plugins_TaskFactory_h
#include <base/task.h>
#include "mozilla/Move.h"
/*
* This is based on the ScopedRunnableMethodFactory from ipc/chromium/src/base/task.h
* Chromium's factories assert if tasks are created and run on different threads,
* which is something we need to do in PluginModuleParent (hang UI vs. main thread).
* TaskFactory just provides cancellable tasks that don't assert this.
* This version also allows both ScopedMethod and regular Tasks to be generated
* by the same Factory object.
*/
namespace mozilla {
namespace plugins {
template<class T>
class TaskFactory : public RevocableStore
{
private:
template<class TaskType>
class TaskWrapper : public TaskType
{
public:
template<typename... Args>
explicit TaskWrapper(RevocableStore* store, Args&&... args)
: TaskType(mozilla::Forward<Args>(args)...)
, revocable_(store)
{
}
NS_IMETHOD Run() override {
if (!revocable_.revoked())
TaskType::Run();
return NS_OK;
}
private:
Revocable revocable_;
};
public:
explicit TaskFactory(T* object) : object_(object) { }
template <typename TaskParamType, typename... Args>
inline already_AddRefed<TaskParamType> NewTask(Args&&... args)
{
typedef TaskWrapper<TaskParamType> TaskWrapper;
RefPtr<TaskWrapper> task =
new TaskWrapper(this, mozilla::Forward<Args>(args)...);
return task.forget();
}
template <class Method>
inline already_AddRefed<Runnable> NewRunnableMethod(Method method) {
typedef TaskWrapper<RunnableMethod<Method, Tuple0> > TaskWrapper;
RefPtr<TaskWrapper> task = new TaskWrapper(this);
task->Init(object_, method, base::MakeTuple());
return task.forget();
}
template <class Method, class A>
inline already_AddRefed<Runnable> NewRunnableMethod(Method method, const A& a) {
typedef TaskWrapper<RunnableMethod<Method, Tuple1<A> > > TaskWrapper;
RefPtr<TaskWrapper> task = new TaskWrapper(this);
task->Init(object_, method, base::MakeTuple(a));
return task.forget();
}
protected:
template <class Method, class Params>
class RunnableMethod : public Runnable {
public:
RunnableMethod() { }
void Init(T* obj, Method meth, const Params& params) {
obj_ = obj;
meth_ = meth;
params_ = params;
}
NS_IMETHOD Run() override {
DispatchToMethod(obj_, meth_, params_);
return NS_OK;
}
private:
T* obj_;
Method meth_;
Params params_;
};
private:
T* object_;
};
} // namespace plugins
} // namespace mozilla
#endif // mozilla_plugins_TaskFactory_h