Public bug reported:
I'm not sure what's the root of the problem. But when I write SDL
programs and forget SwapBuffers I only get a black window, and the
system locks up: mouse remains responsive but keyboard dies (pressing
lock keys does not cause the led switch). The only way to resume work is
a hard reset.
Of course forgetting swapBuffers is obviously my mistake, but the
consequences are quite annoying.
Minimal source code the reproduce it:
#include <stdio.h>
#include <SDL/SDL.h>
#include <GL/gl.h>
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
void drawStuff()
{
glClearColor(0, 0, 1, 0);
glClear(GL_COLOR_BUFFER_BIT);
/* Without this the system locks up. */
/* SDL_GL_SwapBuffers(); */
}
int main()
{
SDL_Surface *screen;
SDL_Event event;
SDL_Init(SDL_INIT_EVERYTHING);
atexit(SDL_Quit);
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 32, SDL_OPENGL);
for(;;)
{
drawStuff();
while (SDL_PollEvent(&event))
{
switch (event.type)
{
case SDL_QUIT:
goto exitLoop;
}
}
}
exitLoop:
SDL_FreeSurface(screen);
return 0;
}
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xorg 1:7.6+12ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-57.87-generic 3.2.52
Uname: Linux 3.2.0-57-generic x86_64
.tmp.unity.support.test.0:
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
CompizPlugins:
[core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: None
Date: Wed Dec 4 09:11:01 2013
DistUpgraded: 2013-05-12 13:21:09,910 DEBUG enabling apt cron job
DistroCodename: precise
DistroVariant: ubuntu
DkmsStatus:
vboxhost, 4.3.4, 3.2.0-56-generic, x86_64: installed
vboxhost, 4.3.4, 3.2.0-57-generic, x86_64: installed
ExtraDebuggingInterest: Yes, if not too technical
GpuHangFrequency: This is the first time
GpuHangReproducibility: Yes, I can easily reproduce it
GpuHangStarted: Today
GraphicsCard:
Intel Corporation 4 Series Chipset Integrated Graphics Controller [8086:2e12]
(rev 03) (prog-if 00 [VGA controller])
Subsystem: Hewlett-Packard Company Device [103c:3034]
Subsystem: Hewlett-Packard Company Device [103c:3034]
InstallationMedia: Ubuntu 10.04.4 LTS "Lucid Lynx" - Release amd64 (20120214.2)
MachineType: Hewlett-Packard HP Compaq dc7900 Small Form Factor
MarkForUpload: True
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=hu_HU.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-57-generic
root=UUID=be6a77fe-88c7-4689-a680-51684e19672d ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
UpgradeStatus: Upgraded to precise on 2013-05-12 (205 days ago)
dmi.bios.date: 03/05/2009
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 786G1 v01.16
dmi.board.asset.tag: CZC9331R6C
dmi.board.name: 3031h
dmi.board.vendor: Hewlett-Packard
dmi.chassis.asset.tag: CZC9331R6C
dmi.chassis.type: 4
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias:
dmi:bvnHewlett-Packard:bvr786G1v01.16:bd03/05/2009:svnHewlett-Packard:pnHPCompaqdc7900SmallFormFactor:pvr:rvnHewlett-Packard:rn3031h:rvr:cvnHewlett-Packard:ct4:cvr:
dmi.product.name: HP Compaq dc7900 Small Form Factor
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.7.12-0ubuntu3
version.ia32-libs: ia32-libs 20090808ubuntu36
version.libdrm2: libdrm2 2.4.43-0ubuntu0.0.3
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.4-0ubuntu0.6
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.4-0ubuntu0.6
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu10.14
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu1.2
version.xserver-xorg-video-ati: xserver-xorg-video-ati
1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4.4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau
1:0.0.16+git20111201+b5534a1-1build3
** Affects: xorg (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug freeze precise ubuntu
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https://bugs.launchpad.net/bugs/1257632
Title:
A forgotten SDL_GL_SwapBuffers can cause system freeze
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