Date: Wed, 27 Feb 2008 10:32:10 +0100 From: Thomas Mueller <tmueller@sysgo.com> To: John Hein <jhein@timing.com> Cc: freebsd-x11@freebsd.org, d@delphij.net Subject: Re: Xorg vs gettimeofday() and clock_gettime() Message-ID: <20080227103210.694787ec@tom.ulm.sysgo.com> In-Reply-To: <18371.11144.568407.26227@gromit.timing.com> References: <47C320DB.70004@delphij.net> <18371.11144.568407.26227@gromit.timing.com>
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On Mon, 25 Feb 2008 13:56:40 -0700, John Hein wrote: > Xin LI wrote at 12:11 -0800 on Feb 25, 2008: > > Shall we make some source-level change to Xorg (either upstream under > > ifdef FreeBSD or our own port, _FAST clocks are not available on some > > other operating systems) so that we can override the gettimeofday() > > direct calls and X_GETTIMEOFDAY's to use clock_gettime with a faster clock? > > Sounds good to me. > I vote for putting in a patch in the x11-servers/xorg-server port so > it gets some quick exposure and then feeding it back upstream where > it can be added on their schedule. FWIW, xorg already has support for clock_gettime(CLOCK_MONOTONIC) in xorg-server-1.4/os/utils.c: _X_EXPORT CARD32 GetTimeInMillis(void) { struct timeval tv; #ifdef MONOTONIC_CLOCK struct timespec tp; if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) return (tp.tv_sec * 1000) + (tp.tv_nsec / 1000000L); #endif X_GETTIMEOFDAY(&tv); return(tv.tv_sec * 1000) + (tv.tv_usec / 1000); } Apparently the autoconf check for presence of CLOCK_MONOTONIC fails on FreeBSD: #define _POSIX_C_SOURCE 199309L #include <time.h> int main(int argc, char *argv[]) { struct timespec tp; if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) return 0; else return 1; } /usr/include/time.h: #if !defined(CLOCK_REALTIME) && __POSIX_VISIBLE >= 200112 #define CLOCK_REALTIME 0 [...] #define CLOCK_MONOTONIC 4 Was CLOCK_MONOTONIC already defined for _POSIX_C_SOURCE 199309? -- Thomas Mueller
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