Description

   The sigtimedwait function behaves the same as the sigwaitinfo
   function except that if none of the signals specified by set are
   pending, sigtimedwait waits for the time interval specified in
   the timespec structure referenced by timeout. If the timespec
   structure pointed to by timeout is zero-valued and if none of the
   signals specified by set are pending, then sigtimedwait returns
   immediately with an error.

   See also sigwait and sigwaitinfo.

   See the "Error and Signal Handling" chapter of the VSI C RTL
   Reference Manual for more information on signal handling.