On Friday, January 9, 2009 2:32 am Daniel Stone wrote: > On Fri, Jan 09, 2009 at 09:27:25AM +0100, Michel Dänzer wrote: > > On Thu, 2009-01-08 at 11:13 -0800, Jesse Barnes wrote: > > > On Thursday, January 8, 2009 2:13 am Daniel Stone wrote: > > > > You probably want to get the entire clock_gettime awesomeness, to > > > > avoid the pathological worst case of rewinding the clock during a > > > > wait which is destined to time out: rewind the clock 11h, 0.5sec into > > > > the wait, and you'll be blocked for 11h and 0.5sec. CLOCK_MONOTONIC > > > > ftw. > > > > > > CLOCK_MONOTONIC isn't supposed to go backwards though; it can't be set > > > (at least according to spec). So I must be missing something here... > > > > I interpreted Daniel's words such that while the monotonic clock can't > > go backwards, it may 'stand still' indefinitely. Right, Daniel? > > > > If so, maybe it would be better to simply use gettimeofday() and time > > out if the absolute delta is >= 1^6 us. That'll result in the timeout > > being slightly early or late if the clock jumps, but that's probably a > > better failure mode than a hang. > > Sorry, I didn't realise you'd also taken the CLOCK_MONOTONIC stuff. > Clearly more Sudafed required. MONOTONIC will always go forward (cf. > jiffies), so you don't have to worry about anything, as long as you're > not trying to correlate the result of clock_gettime(CLOCK_MONOTONIC, ...) > and gettimeofday().
Oh right, that would be a recipe for lolz. I think CLOCK_MONOTONIC is safe enough for now... Thanks, -- Jesse Barnes, Intel Open Source Technology Center ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
