93b5e13308
This changes how we synchronize through vsync. We use a mutex and a wait condition to synchronize the threads. When presenting the frame our main gui thread blocks and will be woken up by the vsync event (or a timeout of max 1 frame time slot). In order to minimize the blocked time we use the blocksForRetrace functionality from the GLX compositor. Given this change we no longer need to tell the compositor that we are swapping the frame, it's blocked anyway. Also we don't need the failsafe QTimer anymore. With this change applied on a Nexus 5 it's succeeding the "Martin tortures phone test". It doesn't tear anymore and has a smooth experience. I'm rather disappointed by the fact that we need to block in order to get vsync. This means Android/hwcomposer is as bad as GLX. So much for the "Android stack is so awesome", in fact it's not. Anybody thinking it's awesome should compare to DRM/KMS and especially atomic modesetting. Yes it's possible to present frames without tearing and without having to block the rendering thread. Reviewed-By: Marco Martin and Bhushan Shah
102 lines
2.8 KiB
C++
102 lines
2.8 KiB
C++
/********************************************************************
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KWin - the KDE window manager
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This file is part of the KDE project.
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Copyright (C) 2015 Martin Gräßlin <mgraesslin@kde.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*********************************************************************/
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#ifndef KWIN_HWCOMPOSER_BACKEND_H
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#define KWIN_HWCOMPOSER_BACKEND_H
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#include "abstract_backend.h"
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#include <QMutex>
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#include <QWaitCondition>
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// libhybris
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#include <hwcomposer_window.h>
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// needed as hwcomposer_window.h includes EGL which on non-arm includes Xlib
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#include <fixx11h.h>
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typedef struct hwc_display_contents_1 hwc_display_contents_1_t;
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typedef struct hwc_layer_1 hwc_layer_1_t;
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typedef struct hwc_composer_device_1 hwc_composer_device_1_t;
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class HWComposerNativeWindowBuffer;
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namespace KWin
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{
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class HwcomposerWindow;
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class HwcomposerBackend : public AbstractBackend
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{
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Q_OBJECT
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Q_INTERFACES(KWin::AbstractBackend)
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Q_PLUGIN_METADATA(IID "org.kde.kwin.AbstractBackend" FILE "hwcomposer.json")
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public:
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explicit HwcomposerBackend(QObject *parent = nullptr);
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virtual ~HwcomposerBackend();
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void init() override;
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Screens *createScreens(QObject *parent = nullptr) override;
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OpenGLBackend *createOpenGLBackend() override;
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HwcomposerWindow *createSurface();
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QSize size() const {
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return m_displaySize;
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}
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hwc_composer_device_1_t *device() const {
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return m_device;
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}
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int refreshRate() const {
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return m_refreshRate;
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}
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void enableVSync(bool enable);
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void waitVSync();
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void wakeVSync();
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private Q_SLOTS:
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void toggleBlankOutput();
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private:
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QSize m_displaySize;
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hwc_composer_device_1_t *m_device = nullptr;
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bool m_outputBlank = true;
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int m_refreshRate = 60000;
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int m_vsyncInterval = 16;
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bool m_hasVsync = false;
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QMutex m_vsyncMutex;
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QWaitCondition m_vsyncWaitCondition;
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};
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class HwcomposerWindow : public HWComposerNativeWindow
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{
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public:
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virtual ~HwcomposerWindow();
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void present(HWComposerNativeWindowBuffer *buffer);
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private:
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friend HwcomposerBackend;
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HwcomposerWindow(HwcomposerBackend *backend);
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HwcomposerBackend *m_backend;
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hwc_display_contents_1_t **m_list;
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};
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}
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#endif
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