gecko-dev/widget/gtk/WaylandVsyncSource.h

108 lines
3.4 KiB
C++

/* -*- Mode: C++; tab-width: 20; 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 _WaylandVsyncSource_h_
#define _WaylandVsyncSource_h_
#include "mozilla/RefPtr.h"
#include "mozilla/Mutex.h"
#include "mozilla/Monitor.h"
#include "MozContainer.h"
#include "VsyncSource.h"
#include "base/thread.h"
#include "nsWaylandDisplay.h"
namespace mozilla {
/*
* WaylandVsyncSource
*
* This class provides a per-widget VsyncSource under Wayland, emulated using
* frame callbacks on the widget surface with empty surface commits.
*
* Wayland does not expose vsync/vblank, as it considers that an implementation
* detail the clients should not concern themselves with. Instead, frame
* callbacks are provided whenever the compositor believes it is a good time to
* start drawing the next frame for a particular surface, giving us as much
* time as possible to do so.
*
* Note that the compositor sends frame callbacks only when it sees fit, and
* when that may be is entirely up to the compositor. One cannot expect a
* certain rate of callbacks, or any callbacks at all. Examples of common
* variations would be surfaces moved between outputs with different refresh
* rates, and surfaces that are hidden and therefore do not receieve any
* callbacks at all. Other hypothetical scenarios of variation could be
* throttling to conserve power, or because a user has requested it.
*
*/
class WaylandVsyncSource final : public gfx::VsyncSource {
public:
explicit WaylandVsyncSource(MozContainer* container) {
MOZ_ASSERT(NS_IsMainThread());
mGlobalDisplay = new WaylandDisplay(container);
}
virtual ~WaylandVsyncSource() { MOZ_ASSERT(NS_IsMainThread()); }
virtual Display& GetGlobalDisplay() override { return *mGlobalDisplay; }
struct WaylandFrameCallbackContext;
class WaylandDisplay final : public mozilla::gfx::VsyncSource::Display {
public:
explicit WaylandDisplay(MozContainer* container);
bool Setup();
void EnableMonitor();
void DisableMonitor();
void FrameCallback();
void Notify();
virtual void EnableVsync() override;
virtual void DisableVsync() override;
virtual bool IsVsyncEnabled() override;
virtual void Shutdown() override;
private:
virtual ~WaylandDisplay() = default;
void Loop();
void SetupFrameCallback();
void ClearFrameCallback();
base::Thread mThread;
RefPtr<Runnable> mTask;
WaylandFrameCallbackContext* mCallbackContext;
Monitor mNotifyThreadMonitor;
Mutex mEnabledLock;
bool mVsyncEnabled;
bool mMonitorEnabled;
bool mShutdown;
struct wl_display* mDisplay;
MozContainer* mContainer;
};
// The WaylandFrameCallbackContext is a context owned by the frame callbacks.
// It is created by the display, but deleted by the frame callbacks on the
// next callback after being disabled.
struct WaylandFrameCallbackContext {
explicit WaylandFrameCallbackContext(
WaylandVsyncSource::WaylandDisplay* aDisplay)
: mEnabled(true), mDisplay(aDisplay) {}
bool mEnabled;
WaylandVsyncSource::WaylandDisplay* mDisplay;
};
private:
// We need a refcounted VsyncSource::Display to use chromium IPC runnables.
RefPtr<WaylandDisplay> mGlobalDisplay;
};
} // namespace mozilla
#endif // _WaylandVsyncSource_h_