On 9/26/12 3:23 PM, Craig Ruff wrote: > Earlier in the week, we were seeing immediate failures when starting the > server with the timeout value set for 3 days in the future. For what > ever reason, while troubleshooting it on Monday, the value seemed to be > related to a specific value of absolute time, and as wall clock time > passed I could reduce the timeout value accordingly to a smaller value > (still more than 1 day), and still see the failure. I was able to > recreate this on both multiple RHEL 6.2 and OpenSUSE 12.1 systems > and multiple users saw the issue. > > Today, strangely, things are working again. Since it was so repeatable, > I assume there was/is an issue with the X server's timeout code and a > 2s compliment overflow causing the timeout call back to be called > immediately when the idle timeout timer is set. There might be a > range of values that triggers the problem.
OK, I think I see the issue now. All of the X timer stuff uses unsigned 32-bit values to store the number of milliseconds since the epoch, but since these values are milliseconds and not seconds, they're going to wrap around to 0 every 49 days. If the server was started near the end of one of these 49-day cycles but the idle timeout was set far enough into the future that it occurred in a new cycle, then the expiration time for the timer would wrap around and actually be a lower value than the current time, thus causing the server to exit. Oddly, newer X server code bases don't fix this issue as much as they work around it by checking for a wrap-around and resetting all of the timers if one is detected. Rather than do that, I just made the timers all 64-bit. Patch has been checked into trunk. I'm relying on you to test it, since I don't personally use the idle timeout feature. ------------------------------------------------------------------------------ How fast is your code? 3 out of 4 devs don\\\'t know how their code performs in production. Find out how slow your code is with AppDynamics Lite. http://ad.doubleclick.net/clk;262219672;13503038;z? http://info.appdynamics.com/FreeJavaPerformanceDownload.html _______________________________________________ VirtualGL-Users mailing list VirtualGL-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtualgl-users
