The X server frequently deals with SIGIO and SIGALRM interruptions.
If process execution is inside certain blocking system calls
when these signals arrive, e.g. with the kernel blocked on
a contended semaphore, the system calls will be interrupted.
Some system calls are automatically restartable (the kernel re-executes
them with the same parameters once the signal handler returns) but
only if the signal handler allows it.
Set SA_RESTART on the signal handlers to enable this convenient
behaviour.
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
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