Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)
Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.
BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org
Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}diff --git a/webrtc/rtc_base/asyncinvoker.h b/webrtc/rtc_base/asyncinvoker.h
new file mode 100644
index 0000000..03e5724
--- /dev/null
+++ b/webrtc/rtc_base/asyncinvoker.h
@@ -0,0 +1,221 @@
+/*
+ * 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_RTC_BASE_ASYNCINVOKER_H_
+#define WEBRTC_RTC_BASE_ASYNCINVOKER_H_
+
+#include <memory>
+#include <utility>
+
+#include "webrtc/base/asyncinvoker-inl.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/event.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+// Invokes function objects (aka functors) asynchronously on a Thread, and
+// owns the lifetime of calls (ie, when this object is destroyed, calls in
+// flight are cancelled). AsyncInvoker can optionally execute a user-specified
+// function when the asynchronous call is complete, or operates in
+// fire-and-forget mode otherwise.
+//
+// AsyncInvoker does not own the thread it calls functors on.
+//
+// A note about async calls and object lifetimes: users should
+// be mindful of object lifetimes when calling functions asynchronously and
+// ensure objects used by the function _cannot_ be deleted between the
+// invocation and execution of the functor. AsyncInvoker is designed to
+// help: any calls in flight will be cancelled when the AsyncInvoker used to
+// make the call is destructed, and any calls executing will be allowed to
+// complete before AsyncInvoker destructs.
+//
+// The easiest way to ensure lifetimes are handled correctly is to create a
+// class that owns the Thread and AsyncInvoker objects, and then call its
+// methods asynchronously as needed.
+//
+// Example:
+// class MyClass {
+// public:
+// void FireAsyncTaskWithResult(Thread* thread, int x) {
+// // Specify a callback to get the result upon completion.
+// invoker_.AsyncInvoke<int>(RTC_FROM_HERE,
+// thread, Bind(&MyClass::AsyncTaskWithResult, this, x),
+// &MyClass::OnTaskComplete, this);
+// }
+// void FireAnotherAsyncTask(Thread* thread) {
+// // No callback specified means fire-and-forget.
+// invoker_.AsyncInvoke<void>(RTC_FROM_HERE,
+// thread, Bind(&MyClass::AnotherAsyncTask, this));
+//
+// private:
+// int AsyncTaskWithResult(int x) {
+// // Some long running process...
+// return x * x;
+// }
+// void AnotherAsyncTask() {
+// // Some other long running process...
+// }
+// void OnTaskComplete(int result) { result_ = result; }
+//
+// AsyncInvoker invoker_;
+// int result_;
+// };
+class AsyncInvoker : public MessageHandler {
+ public:
+ AsyncInvoker();
+ ~AsyncInvoker() override;
+
+ // Call |functor| asynchronously on |thread|, with no callback upon
+ // completion. Returns immediately.
+ template <class ReturnT, class FunctorT>
+ void AsyncInvoke(const Location& posted_from,
+ Thread* thread,
+ const FunctorT& functor,
+ uint32_t id = 0) {
+ std::unique_ptr<AsyncClosure> closure(
+ new FireAndForgetAsyncClosure<FunctorT>(this, functor));
+ DoInvoke(posted_from, thread, std::move(closure), id);
+ }
+
+ // Call |functor| asynchronously on |thread| with |delay_ms|, with no callback
+ // upon completion. Returns immediately.
+ template <class ReturnT, class FunctorT>
+ void AsyncInvokeDelayed(const Location& posted_from,
+ Thread* thread,
+ const FunctorT& functor,
+ uint32_t delay_ms,
+ uint32_t id = 0) {
+ std::unique_ptr<AsyncClosure> closure(
+ new FireAndForgetAsyncClosure<FunctorT>(this, functor));
+ DoInvokeDelayed(posted_from, thread, std::move(closure), delay_ms, id);
+ }
+
+ // Synchronously execute on |thread| all outstanding calls we own
+ // that are pending on |thread|, and wait for calls to complete
+ // before returning. Optionally filter by message id.
+ // The destructor will not wait for outstanding calls, so if that
+ // behavior is desired, call Flush() before destroying this object.
+ void Flush(Thread* thread, uint32_t id = MQID_ANY);
+
+ private:
+ void OnMessage(Message* msg) override;
+ void DoInvoke(const Location& posted_from,
+ Thread* thread,
+ std::unique_ptr<AsyncClosure> closure,
+ uint32_t id);
+ void DoInvokeDelayed(const Location& posted_from,
+ Thread* thread,
+ std::unique_ptr<AsyncClosure> closure,
+ uint32_t delay_ms,
+ uint32_t id);
+ volatile int pending_invocations_ = 0;
+ Event invocation_complete_;
+ bool destroying_ = false;
+ friend class AsyncClosure;
+
+ RTC_DISALLOW_COPY_AND_ASSIGN(AsyncInvoker);
+};
+
+// Similar to AsyncInvoker, but guards against the Thread being destroyed while
+// there are outstanding dangling pointers to it. It will connect to the current
+// thread in the constructor, and will get notified when that thread is
+// destroyed. After GuardedAsyncInvoker is constructed, it can be used from
+// other threads to post functors to the thread it was constructed on. If that
+// thread dies, any further calls to AsyncInvoke() will be safely ignored.
+class GuardedAsyncInvoker : public sigslot::has_slots<> {
+ public:
+ GuardedAsyncInvoker();
+ ~GuardedAsyncInvoker() override;
+
+ // Synchronously execute all outstanding calls we own, and wait for calls to
+ // complete before returning. Optionally filter by message id. The destructor
+ // will not wait for outstanding calls, so if that behavior is desired, call
+ // Flush() first. Returns false if the thread has died.
+ bool Flush(uint32_t id = MQID_ANY);
+
+ // Call |functor| asynchronously with no callback upon completion. Returns
+ // immediately. Returns false if the thread has died.
+ template <class ReturnT, class FunctorT>
+ bool AsyncInvoke(const Location& posted_from,
+ const FunctorT& functor,
+ uint32_t id = 0) {
+ rtc::CritScope cs(&crit_);
+ if (thread_ == nullptr)
+ return false;
+ invoker_.AsyncInvoke<ReturnT, FunctorT>(posted_from, thread_, functor, id);
+ return true;
+ }
+
+ // Call |functor| asynchronously with |delay_ms|, with no callback upon
+ // completion. Returns immediately. Returns false if the thread has died.
+ template <class ReturnT, class FunctorT>
+ bool AsyncInvokeDelayed(const Location& posted_from,
+ const FunctorT& functor,
+ uint32_t delay_ms,
+ uint32_t id = 0) {
+ rtc::CritScope cs(&crit_);
+ if (thread_ == nullptr)
+ return false;
+ invoker_.AsyncInvokeDelayed<ReturnT, FunctorT>(posted_from, thread_,
+ functor, delay_ms, id);
+ return true;
+ }
+
+ // Call |functor| asynchronously, calling |callback| when done. Returns false
+ // if the thread has died.
+ template <class ReturnT, class FunctorT, class HostT>
+ bool AsyncInvoke(const Location& posted_from,
+ const Location& callback_posted_from,
+ const FunctorT& functor,
+ void (HostT::*callback)(ReturnT),
+ HostT* callback_host,
+ uint32_t id = 0) {
+ rtc::CritScope cs(&crit_);
+ if (thread_ == nullptr)
+ return false;
+ invoker_.AsyncInvoke<ReturnT, FunctorT, HostT>(
+ posted_from, callback_posted_from, thread_, functor, callback,
+ callback_host, id);
+ return true;
+ }
+
+ // Call |functor| asynchronously calling |callback| when done. Overloaded for
+ // void return. Returns false if the thread has died.
+ template <class ReturnT, class FunctorT, class HostT>
+ bool AsyncInvoke(const Location& posted_from,
+ const Location& callback_posted_from,
+ const FunctorT& functor,
+ void (HostT::*callback)(),
+ HostT* callback_host,
+ uint32_t id = 0) {
+ rtc::CritScope cs(&crit_);
+ if (thread_ == nullptr)
+ return false;
+ invoker_.AsyncInvoke<ReturnT, FunctorT, HostT>(
+ posted_from, callback_posted_from, thread_, functor, callback,
+ callback_host, id);
+ return true;
+ }
+
+ private:
+ // Callback when |thread_| is destroyed.
+ void ThreadDestroyed();
+
+ CriticalSection crit_;
+ Thread* thread_ GUARDED_BY(crit_);
+ AsyncInvoker invoker_ GUARDED_BY(crit_);
+};
+
+} // namespace rtc
+
+#endif // WEBRTC_RTC_BASE_ASYNCINVOKER_H_