NAME¶

sigsuspend, rt_sigsuspend - wait for a signal

LIBRARY¶

Standard C library (libc, -lc)

SYNOPSIS¶

#include <signal.h>

int sigsuspend(const sigset_t *mask);

sigsuspend():

    _POSIX_C_SOURCE

DESCRIPTION¶

sigsuspend() temporarily replaces the signal mask of the calling thread with the mask given by mask and then suspends the thread until delivery of a signal whose action is to invoke a signal handler or to terminate a process.

If the signal terminates the process, then sigsuspend() does not return. If the signal is caught, then sigsuspend() returns after the signal handler returns, and the signal mask is restored to the state before the call to sigsuspend().

It is not possible to block SIGKILL or SIGSTOP; specifying these signals in mask, has no effect on the thread's signal mask.

RETURN VALUE¶

sigsuspend() always returns -1, with errno set to indicate the error (normally, EINTR).

ERRORS¶

EFAULT

mask points to memory which is not a valid part of the process address space.

EINTR

The call was interrupted by a signal; signal(7).

STANDARDS¶

POSIX.1-2001, POSIX.1-2008.

NOTES¶

Normally, sigsuspend() is used in conjunction with sigprocmask(2) in order to prevent delivery of a signal during the execution of a critical code section. The caller first blocks the signals with sigprocmask(2). When the critical code has completed, the caller then waits for the signals by calling sigsuspend() with the signal mask that was returned by sigprocmask(2) (in the oldset argument).

See sigsetops(3) for details on manipulating signal sets.

SEE ALSO¶

kill(2), pause(2), sigaction(2), signal(2), sigprocmask(2), sigwaitinfo(2), sigsetops(3), sigwait(3), signal(7)