[platforms/drm] Use a shared pointer for gbm_surface
47343fb8f759
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Authored by graesslin on Oct 5 2017, 4:58 PM.

Description

[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the gbm_bo and crash as the gbm_surface is no longer valid.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

Details

Committed

graesslin

Oct 5 2017, 7:32 PM

Differential Revision

D8152: [platforms/drm] Use a shared pointer for gbm_surface

Parents

R108:31b5b7f9f981: Ensure internal Wayland connection is properly setup before creating LockScreen…

Branches

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Tags

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graesslin committed R108:47343fb8f759: [platforms/drm] Use a shared pointer for gbm_surface (authored by graesslin).Oct 5 2017, 7:32 PM

davidedmundson mentioned this in D8251: Fix DRM EGL crash regression.Oct 11 2017, 6:04 PM

davidedmundson mentioned this in R108:3d619c995b88: Fix DRM EGL crash regression.Oct 12 2017, 9:16 AM

davidedmundson mentioned this in R108:5bca05882624: Fix DRM EGL crash regression.

Changes (11)

				Path	Packages
	M			autotests/CMakeLists.txt
	A			autotests/test_gbm_surface.cpp
	M			plugins/platforms/drm/CMakeLists.txt
	M			plugins/platforms/drm/drm_backend.cpp
	M			plugins/platforms/drm/drm_backend.h
	M			plugins/platforms/drm/drm_buffer_gbm.cpp
	M			plugins/platforms/drm/drm_buffer_gbm.h
	M			plugins/platforms/drm/egl_gbm_backend.cpp
	M			plugins/platforms/drm/egl_gbm_backend.h
	P			plugins/platforms/drm/gbm_surface.cpp Copied from tabbox/x11_filter.h
	P			plugins/platforms/drm/gbm_surface.h Copied from tabbox/x11_filter.h