kwin/plugins/platforms/drm/egl_gbm_backend.h
Martin Flöser 47343fb8f7 [platforms/drm] Use a shared pointer for gbm_surface
Summary:
The gbm_surface is owned by the EglGbmBackend, but it's not the only one
using it. The DrmSurfaceBuffer is also using it and needs it to destroy
the gbm_bo. Now this can become a problem in the following situation:

* a page flip is still pending
* the EglGbmBackend destroys the gbm_surface

-> when the page flip happens the DrmSurfaceBuffer will try to destroy
the gbm_bo and crash as the gbm_surface is no longer valid. This
situation can happen when switching screens or when switching compositing
backend (OpenGL 2 -> OpenGL 3).

To address this problem a class GbmSurface is added which wrapps the
gbm_surface pointer. The EglGbmBackend creates and holds a shared pointer
to the GbmSurface and passes that one to the DrmSurfaceBuffer. So when
cleaning up the gbm_surface only the shared pointer is reset and in case
the DrmSurfaceBuffer still needs it, it can access it without problems.

BUG: 385372
FIXED-IN: 5.11.0

Test Plan: Not yet

Reviewers: #kwin, #plasma, subdiff

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D8152
2017-10-05 21:32:46 +02:00

98 lines
2.9 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2015 Martin Gräßlin <mgraesslin@kde.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#ifndef KWIN_EGL_GBM_BACKEND_H
#define KWIN_EGL_GBM_BACKEND_H
#include "abstract_egl_backend.h"
#include "scene_opengl.h"
#include <memory>
struct gbm_surface;
namespace KWin
{
class DrmBackend;
class DrmBuffer;
class DrmOutput;
class GbmSurface;
/**
* @brief OpenGL Backend using Egl on a GBM surface.
**/
class EglGbmBackend : public AbstractEglBackend
{
Q_OBJECT
public:
EglGbmBackend(DrmBackend *b);
virtual ~EglGbmBackend();
void screenGeometryChanged(const QSize &size) override;
SceneOpenGL::TexturePrivate *createBackendTexture(SceneOpenGL::Texture *texture) override;
QRegion prepareRenderingFrame() override;
void endRenderingFrame(const QRegion &renderedRegion, const QRegion &damagedRegion) override;
void endRenderingFrameForScreen(int screenId, const QRegion &damage, const QRegion &damagedRegion) override;
bool usesOverlayWindow() const override;
bool perScreenRendering() const override;
QRegion prepareRenderingForScreen(int screenId) override;
void init() override;
protected:
void present() override;
void cleanupSurfaces() override;
private:
bool initializeEgl();
bool initBufferConfigs();
bool initRenderingContext();
struct Output {
DrmOutput *output = nullptr;
DrmBuffer *buffer = nullptr;
std::shared_ptr<GbmSurface> gbmSurface;
EGLSurface eglSurface = EGL_NO_SURFACE;
int bufferAge = 0;
/**
* @brief The damage history for the past 10 frames.
*/
QList<QRegion> damageHistory;
};
bool makeContextCurrent(const Output &output);
void presentOnOutput(Output &output);
void cleanupOutput(const Output &output);
void createOutput(DrmOutput *output);
DrmBackend *m_backend;
QVector<Output> m_outputs;
friend class EglGbmTexture;
};
/**
* @brief Texture using an EGLImageKHR.
**/
class EglGbmTexture : public AbstractEglTexture
{
public:
virtual ~EglGbmTexture();
private:
friend class EglGbmBackend;
EglGbmTexture(SceneOpenGL::Texture *texture, EglGbmBackend *backend);
};
} // namespace
#endif