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/*
* Copyright 2014 The WebRTC 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 in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_BASE_ASYNCINVOKER_INL_H_
#define WEBRTC_BASE_ASYNCINVOKER_INL_H_
#include "webrtc/base/bind.h"
#include "webrtc/base/callback.h"
#include "webrtc/base/criticalsection.h"
#include "webrtc/base/messagehandler.h"
#include "webrtc/base/refcount.h"
#include "webrtc/base/scoped_ref_ptr.h"
#include "webrtc/base/sigslot.h"
#include "webrtc/base/thread.h"
namespace rtc {
class AsyncInvoker;
// Helper class for AsyncInvoker. Runs a task and triggers a callback
// on the calling thread if necessary. Instances are ref-counted so their
// lifetime can be independent of AsyncInvoker.
class AsyncClosure : public RefCountInterface {
public:
// Runs the asynchronous task, and triggers a callback to the calling
// thread if needed. Should be called from the target thread.
virtual void Execute() = 0;
protected:
~AsyncClosure() override {}
};
// Simple closure that doesn't trigger a callback for the calling thread.
template <class FunctorT>
class FireAndForgetAsyncClosure : public AsyncClosure {
public:
explicit FireAndForgetAsyncClosure(const FunctorT& functor)
: functor_(functor) {}
virtual void Execute() {
functor_();
}
private:
FunctorT functor_;
};
// Base class for closures that may trigger a callback for the calling thread.
// Listens for the "destroyed" signals from the calling thread and the invoker,
// and cancels the callback to the calling thread if either is destroyed.
class NotifyingAsyncClosureBase : public AsyncClosure,
public sigslot::has_slots<> {
public:
~NotifyingAsyncClosureBase() override;
protected:
NotifyingAsyncClosureBase(AsyncInvoker* invoker, Thread* calling_thread);
void TriggerCallback();
void SetCallback(const Callback0<void>& callback) {
CritScope cs(&crit_);
callback_ = callback;
}
bool CallbackCanceled() const { return calling_thread_ == NULL; }
private:
Callback0<void> callback_;
CriticalSection crit_;
AsyncInvoker* invoker_;
Thread* calling_thread_;
void CancelCallback();
};
// Closures that have a non-void return value and require a callback.
template <class ReturnT, class FunctorT, class HostT>
class NotifyingAsyncClosure : public NotifyingAsyncClosureBase {
public:
NotifyingAsyncClosure(AsyncInvoker* invoker,
Thread* calling_thread,
const FunctorT& functor,
void (HostT::*callback)(ReturnT),
HostT* callback_host)
: NotifyingAsyncClosureBase(invoker, calling_thread),
functor_(functor),
callback_(callback),
callback_host_(callback_host) {}
virtual void Execute() {
ReturnT result = functor_();
if (!CallbackCanceled()) {
SetCallback(Callback0<void>(Bind(callback_, callback_host_, result)));
TriggerCallback();
}
}
private:
FunctorT functor_;
void (HostT::*callback_)(ReturnT);
HostT* callback_host_;
};
// Closures that have a void return value and require a callback.
template <class FunctorT, class HostT>
class NotifyingAsyncClosure<void, FunctorT, HostT>
: public NotifyingAsyncClosureBase {
public:
NotifyingAsyncClosure(AsyncInvoker* invoker,
Thread* calling_thread,
const FunctorT& functor,
void (HostT::*callback)(),
HostT* callback_host)
: NotifyingAsyncClosureBase(invoker, calling_thread),
functor_(functor) {
SetCallback(Callback0<void>(Bind(callback, callback_host)));
}
virtual void Execute() {
functor_();
TriggerCallback();
}
private:
FunctorT functor_;
};
} // namespace rtc
#endif // WEBRTC_BASE_ASYNCINVOKER_INL_H_
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