SIGSUSPEND(2) System Calls SIGSUSPEND(2)
NAME
sigsuspend - install a signal mask and suspend caller until signal
SYNOPSIS
#include <signal.h>
int sigsuspend(
const sigset_t *set);
DESCRIPTION
The
sigsuspend() function replaces the caller's signal mask with the
set of signals pointed to by the
set argument and suspends the
caller until delivery of a signal whose action is either to execute a
signal catching function or to terminate the process. If the
set argument points to an invalid address, the behavior is undefined and
errno may be set to
EFAULT.
If the action is to terminate the process,
sigsuspend() does not
return. If the action is to execute a signal catching function,
sigsuspend() returns after the signal catching function returns. On
return, the signal mask is restored to the set that existed before
the call to
sigsuspend().
It is not possible to block signals that cannot be ignored (see
signal.h(3HEAD)). This restriction is silently imposed by the system.
RETURN VALUES
Since
sigsuspend() suspends the caller's execution indefinitely,
there is no successful completion return value. On failure, it
returns
-1 and sets
errno to indicate the error.
ERRORS
The
sigsuspend() function will fail if:
EINTR A signal was caught by the caller and control was returned
from the signal catching function.
The
sigsuspend() function may fail if:
EFAULT The
set argument points to an illegal address.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Standard |
+--------------------+-------------------+
|MT-Level | Async-Signal-Safe |
+--------------------+-------------------+
SEE ALSO
sigaction(2),
sigprocmask(2),
sigwait(2),
signal(3C),
sigsetops(3C),
signal.h(3HEAD),
attributes(7)NOTES
If the caller specifies more than one unblocked signal in the mask to
sigsuspend(), more than one signal might be processed before the call
to
sigsuspend() returns.
While the caller is executing the signal handler that interrupted its
call to
sigsuspend(), its signal mask is the one passed to
sigsuspend(), modified as usual by the signal mask specification in
the signal's
sigaction(2) parameters. The caller's signal mask is
not restored to its previous value until the caller returns from all
the signal handlers that interrupted
sigsuspend().
June 24, 2001 SIGSUSPEND(2)
