[PLUG] question about nanosleep() call behavior

[website reader]

During the day, I have programs running which make literally hundreds
of thousands of timestamps.  There were noticeable glitches in the
regular timestamps, in some cases, the stamp was delayed by 0.4 to 0.5
seconds, an enormously long time by computer standards.

I wrote a test program which is the heart of the timestamp loop and
ran it for over 7 hours yesterday evening, and found that I had 76
gaps in time.  One noticeable segment seemed to occur with high system
activity, it had 7 or 8 gaps clustered together in about 3 or 4
seconds.

Apparently this is traceable to the nanosleep() call not returning
from the set interval, but at a later time, apparently held up by
signal handlers.  (my current impression)

As the manual says, "If the call is interrupted by a signal handler,
nanosleep() returns -1, sets errno to EINTR and writes the remaining
time into the structure pointed to by rem unless rem in NULL.  The
value of *rem can then be used to call nanosleep() again and complete
the specified pause."

Unfortunately, nanosleep is coming back live but after a long delay,
in my case, as shown by the timestamps.

Do I interpret the manual to suggest that nanosleep is being suddenly
terminated, and I should call it again?  My initial impression is that
nanosleep is being delayed, not suddenly terminated.

I guess I have to put some more code in that timestamp checking
program to catch the err and see what happened.  It would be very nice
to have an uninterruptable timer call.

Randall