I've been running OSG1.0 on dual-core HT Pentium D Windows XP machine, without that problem. (looks like 4 procs). Although, it looks like I updated to OpenThreads 1.1 (OSG_OP_OT1.1 version of OpenThreads) to fix some lock up problems. Maybe at the time I was experiencing the same problem? It is too long ago for me to remember, though, and my CM logs don't tell me the reason. Is it possible you are not compiling the correct OpenThreads version?
Zach _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Glenn Waldron Sent: Wednesday, March 07, 2007 14:56 To: osg users Subject: Re: [osg-users] Problems using QueryPerformanceCounter()?? Anders, There is a previous discussion on this topic here: http://openscenegraph.org/archiver/osg-users/2006-March/0252.html I'm running OSG 1.2 and I still see this problem on dual-core or HT machines. -gw On 3/7/07, Anders Backman <[EMAIL PROTECTED] > wrote: Is there anyone out there experiencing strange hang and timing problems on dual CPU/Core/HT windows XP machines? except for the ordinary laptop-timing problems of course ;-) Im currently debugging something that gives me gray hair, and someone suggested that it could be a potential problem coming from the fact that QueryPerformanceCounter() is used (osg::Timer) I have an app that runs just fine for a while (can be 1 minute, sometimes 30) and then it hangs, and it never occurs in debug-mode (of course!) so its quite tricky find the cause for it. I have already found one reason for the hangs, and that was in Producer where a OpenGL timer query never returned....But that is fixed (by skipping after 1000 iterations). It seems to be quite a few developers with this problem when I searched the web. For example: http://www.virtualdub.org/blog/pivot/entry.php?id=106 <http://www.virtualdub.org/blog/pivot/entry.php?id=106> It seems that when a thread is moved in and out between different execution cores/CPU:s it can drop timing or even get negative timing results.... It also talks about hangs (which I guess could be a second order problem that comes from the timing problem). Right now Im looking at something that looks like a hang inside osg::Timer::tick() So is there anyone else experiencing this? There is a bunch of recommendations from MS: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/directx9_c/ Game_Timing_and_Multicore_Processors.asp - using QueryPerformanceCounter from only one thread - setting SetThreadAffinityMask so that the timing thread runs on only one CPU/Core - clamping the subtraction result so you never get a negative one: inline double delta_s( Timer_t t1, Timer_t t2 ) const { return (double)(t2 - t1)*_secsPerTick; } Should be: inline double delta_s( Timer_t t1, Timer_t t2 ) const { return (double)osg::clampAbove((t2 - t1), 0)*_secsPerTick; } -- ________________________________________________________________ Anders Backman Email: [EMAIL PROTECTED] HPC2N/VRlab Phone: +46 (0)90-786 9936 Umea university Cellular: +46 (0)70-392 64 67 S-901 87 UMEA SWEDEN Fax: +46 90-786 6126 http://www.cs.umu.se/~andersb <http://www.cs.umu.se/%7Eandersb> _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/ -- Glenn Waldron : Pelican Mapping : 703-652-4791
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