/*
* If act is not NULL, set the action for signum.
* If oact is not NULL. store the old action to oact.
*/
int
sigaction(int signum, const struct sigaction *act, struct sigaction *oact)
{
struct sigaction *sa;
if (signum <= 0 || signum >= NSIG ||
signum == SIGSTOP || signum == SIGKILL) {
errno = EINVAL;
return -1;
}
SIGNAL_LOCK();
sa = &__sig_act[signum];
if (oact != NULL)
*oact = *sa;
if (act != NULL)
*sa = *act;
/* Discard pending signal in some cases */
if (sa->sa_handler == SIG_IGN ||
(sa->sa_handler == SIG_DFL && signum == SIGCHLD))
__sig_pending &= ~sigmask(signum);
SIGNAL_UNLOCK();
/* Process pending signal */
__sig_flush();
return 0;
}
/*
* Exception handler for signal emulation
*/
static void
__exception_handler(int excpt)
{
if (excpt > 0 && excpt <= NSIG) {
SIGNAL_LOCK();
if (__sig_act[excpt].sa_handler != SIG_IGN)
__sig_pending |= sigmask(excpt);
SIGNAL_UNLOCK();
}
__sig_flush();
exception_return();
}
int
pause(void)
{
int sig, wait;
/* Wait signal if no pending singal */
if (__sig_flush()) {
wait = 1;
while (wait) {
exception_wait(&sig);
SIGNAL_LOCK();
/* It is ok if processed signal is not masked and not pending */
if (!(__sig_mask & sigmask(sig)) &&
!(__sig_pending & sigmask(sig)))
wait = 0;
SIGNAL_UNLOCK();
}
}
/* Always returns error */
errno = EINTR;
return -1;
}