On Tue, 2012-07-10 at 15:12 +0100, John Horne wrote:
Printing out what 'now' is gives 0 all the time. 'gettimer' comes from
lib/timefunc.c line 49:
======================================
time_t gettimer(void)
{
int res;
struct timespec t;
#if (_POSIX_TIMERS > 0) && defined(_POSIX_MONOTONIC_CLOCK)
res = clock_gettime(CLOCK_MONOTONIC, &t);
return (time_t) t.tv_sec;
#else
return time(NULL);
#endif
}
======================================
However printing out 'res' shows that 'clock_gettime' is always
returning an error (-1).
Sorry, should have added that errno is showing as 22 (EINVAL). The man
page for clock_gettime states:
EINVAL The clk_id specified is not supported on this system.
However, it seems that although _POSIX_MONOTONIC_CLOCK may seem to be
available, at runtime it is not.
This link (for the 'curl' program) has more discussion about it:
http://curl.haxx.se/mail/tracker-2008-07/0003.html
Checking the RHEL3 system using a small program calling 'sysconf' shows
that _POSIX_MONOTONIC_CLOCK is available if checked, but is not
available at runtime (using sysconf):
===========
monotonic clock: _POSIX_TIMERS: 200112 _POSIX_MONOTONIC_CLOCK: 0
Err found: -1
Err found: -1, errno = 22, string = Invalid argument
Sysconf value for _POSIX_MONOTONIC_CLOCK: -1
===========
So the clock seems to be available, but checking at runtime with sysconf
says that it is not.
Whereas on an RHEL6 system it shows:
===========
monotonic clock: _POSIX_TIMERS: 200809 _POSIX_MONOTONIC_CLOCK: 0
Sysconf value for _POSIX_MONOTONIC_CLOCK: 200809
===========
Again it seems that the clock is available, and the runtime/sysconf
check confirms that.
John.
--
John Horne Tel: +XX (X)XXXX XXXXXX
Plymouth University, UK Fax: +XX (X)XXXX XXXXXX