122 lines
3.7 KiB
C++
122 lines
3.7 KiB
C++
// Copyright (c) 2012 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.
|
|
|
|
#ifndef BASE_RUN_LOOP_H_
|
|
#define BASE_RUN_LOOP_H_
|
|
|
|
#include "base/base_export.h"
|
|
#include "base/callback.h"
|
|
#include "base/memory/weak_ptr.h"
|
|
#include "base/message_loop/message_loop.h"
|
|
|
|
namespace base {
|
|
#if defined(OS_ANDROID)
|
|
class MessagePumpForUI;
|
|
#endif
|
|
|
|
#if defined(OS_IOS)
|
|
class MessagePumpUIApplication;
|
|
#endif
|
|
|
|
// Helper class to Run a nested MessageLoop. Please do not use nested
|
|
// MessageLoops in production code! If you must, use this class instead of
|
|
// calling MessageLoop::Run/Quit directly. RunLoop::Run can only be called once
|
|
// per RunLoop lifetime. Create a RunLoop on the stack and call Run/Quit to run
|
|
// a nested MessageLoop.
|
|
class BASE_EXPORT RunLoop {
|
|
public:
|
|
RunLoop();
|
|
#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
|
|
explicit RunLoop(MessageLoop::Dispatcher* dispatcher);
|
|
#endif
|
|
~RunLoop();
|
|
|
|
#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
|
|
void set_dispatcher(MessageLoop::Dispatcher* dispatcher) {
|
|
dispatcher_ = dispatcher;
|
|
}
|
|
#endif
|
|
|
|
// Run the current MessageLoop. This blocks until Quit is called. Before
|
|
// calling Run, be sure to grab an AsWeakPtr or the QuitClosure in order to
|
|
// stop the MessageLoop asynchronously. MessageLoop::Quit and QuitNow will
|
|
// also trigger a return from Run, but those are deprecated.
|
|
void Run();
|
|
|
|
// Run the current MessageLoop until it doesn't find any tasks or messages in
|
|
// the queue (it goes idle). WARNING: This may never return! Only use this
|
|
// when repeating tasks such as animated web pages have been shut down.
|
|
void RunUntilIdle();
|
|
|
|
bool running() const { return running_; }
|
|
|
|
// Quit an earlier call to Run(). There can be other nested RunLoops servicing
|
|
// the same task queue (MessageLoop); Quitting one RunLoop has no bearing on
|
|
// the others. Quit can be called before, during or after Run. If called
|
|
// before Run, Run will return immediately when called. Calling Quit after the
|
|
// RunLoop has already finished running has no effect.
|
|
//
|
|
// WARNING: You must NEVER assume that a call to Quit will terminate the
|
|
// targetted message loop. If a nested message loop continues running, the
|
|
// target may NEVER terminate. It is very easy to livelock (run forever) in
|
|
// such a case.
|
|
void Quit();
|
|
|
|
// Convenience method to get a closure that safely calls Quit (has no effect
|
|
// if the RunLoop instance is gone).
|
|
//
|
|
// Example:
|
|
// RunLoop run_loop;
|
|
// PostTask(run_loop.QuitClosure());
|
|
// run_loop.Run();
|
|
base::Closure QuitClosure();
|
|
|
|
private:
|
|
friend class MessageLoop;
|
|
#if defined(OS_ANDROID)
|
|
// Android doesn't support the blocking MessageLoop::Run, so it calls
|
|
// BeforeRun and AfterRun directly.
|
|
friend class base::MessagePumpForUI;
|
|
#endif
|
|
|
|
#if defined(OS_IOS)
|
|
// iOS doesn't support the blocking MessageLoop::Run, so it calls
|
|
// BeforeRun directly.
|
|
friend class base::MessagePumpUIApplication;
|
|
#endif
|
|
|
|
// Return false to abort the Run.
|
|
bool BeforeRun();
|
|
void AfterRun();
|
|
|
|
MessageLoop* loop_;
|
|
|
|
// WeakPtrFactory for QuitClosure safety.
|
|
base::WeakPtrFactory<RunLoop> weak_factory_;
|
|
|
|
// Parent RunLoop or NULL if this is the top-most RunLoop.
|
|
RunLoop* previous_run_loop_;
|
|
|
|
#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
|
|
MessageLoop::Dispatcher* dispatcher_;
|
|
#endif
|
|
|
|
// Used to count how many nested Run() invocations are on the stack.
|
|
int run_depth_;
|
|
|
|
bool run_called_;
|
|
bool quit_called_;
|
|
bool running_;
|
|
|
|
// Used to record that QuitWhenIdle() was called on the MessageLoop, meaning
|
|
// that we should quit Run once it becomes idle.
|
|
bool quit_when_idle_received_;
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(RunLoop);
|
|
};
|
|
|
|
} // namespace base
|
|
|
|
#endif // BASE_RUN_LOOP_H_
|