gecko-dev/widget/VsyncDispatcher.h
Matt Woodrow e3453844bf Bug 1510853 - Introduce VsyncId and VsyncEvent for identifying vsyncs without timestamp comparisons. r=jrmuizel
MozReview-Commit-ID: 6TO6hYOdJYo

Differential Revision: https://phabricator.services.mozilla.com/D13757

--HG--
extra : moz-landing-system : lando
2018-12-07 23:27:28 +00:00

102 lines
3.5 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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_widget_VsyncDispatcher_h
#define mozilla_widget_VsyncDispatcher_h
#include "mozilla/Mutex.h"
#include "mozilla/TimeStamp.h"
#include "nsISupportsImpl.h"
#include "nsTArray.h"
#include "mozilla/RefPtr.h"
#include "VsyncSource.h"
namespace mozilla {
class VsyncObserver {
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(VsyncObserver)
public:
// The method called when a vsync occurs. Return true if some work was done.
// In general, this vsync notification will occur on the hardware vsync
// thread from VsyncSource. But it might also be called on PVsync ipc thread
// if this notification is cross process. Thus all observer should check the
// thread model before handling the real task.
virtual bool NotifyVsync(const VsyncEvent& aVsync) = 0;
protected:
VsyncObserver() {}
virtual ~VsyncObserver() {}
}; // VsyncObserver
// Used to dispatch vsync events in the parent process to compositors.
//
// When the compositor is in-process, CompositorWidgets own a
// CompositorVsyncDispatcher, and directly attach the compositor's observer
// to it.
//
// When the compositor is out-of-process, the CompositorWidgetDelegate owns
// the vsync dispatcher instead. The widget receives vsync observer/unobserve
// commands via IPDL, and uses this to attach a CompositorWidgetVsyncObserver.
// This observer forwards vsync notifications (on the vsync thread) to a
// dedicated vsync I/O thread, which then forwards the notification to the
// compositor thread in the compositor process.
class CompositorVsyncDispatcher final {
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorVsyncDispatcher)
public:
CompositorVsyncDispatcher();
// Called on the vsync thread when a hardware vsync occurs
void NotifyVsync(const VsyncEvent& aVsync);
// Compositor vsync observers must be added/removed on the compositor thread
void SetCompositorVsyncObserver(VsyncObserver* aVsyncObserver);
void Shutdown();
private:
virtual ~CompositorVsyncDispatcher();
void ObserveVsync(bool aEnable);
Mutex mCompositorObserverLock;
RefPtr<VsyncObserver> mCompositorVsyncObserver;
bool mDidShutdown;
};
// Dispatch vsync event to ipc actor parent and chrome RefreshTimer.
class RefreshTimerVsyncDispatcher final {
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(RefreshTimerVsyncDispatcher)
public:
RefreshTimerVsyncDispatcher();
// Please check CompositorVsyncDispatcher::NotifyVsync().
void NotifyVsync(const VsyncEvent& aVsync);
// Set chrome process's RefreshTimer to this dispatcher.
// This function can be called from any thread.
void SetParentRefreshTimer(VsyncObserver* aVsyncObserver);
// Add or remove the content process' RefreshTimer to this dispatcher. This
// will be a no-op for AddChildRefreshTimer() if the observer is already
// registered.
// These functions can be called from any thread.
void AddChildRefreshTimer(VsyncObserver* aVsyncObserver);
void RemoveChildRefreshTimer(VsyncObserver* aVsyncObserver);
private:
virtual ~RefreshTimerVsyncDispatcher();
void UpdateVsyncStatus();
bool NeedsVsync();
Mutex mRefreshTimersLock;
RefPtr<VsyncObserver> mParentRefreshTimer;
nsTArray<RefPtr<VsyncObserver>> mChildRefreshTimers;
};
} // namespace mozilla
#endif // mozilla_widget_VsyncDispatcher_h