SIGSUSPEND(2)

NAME
sigsuspend - wait for a signal

SYNOPSIS
#include <signal.h>

int sigsuspend(const sigset_t *mask);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

sigsuspend(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE

DESCRIPTION
sigsuspend() temporarily replaces the signal mask of the calling process with the mask given by mask and then suspends the process 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 process'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.

CONFORMING TO
POSIX.1-2001.

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)

COLOPHON
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