SIGSUSPEND

Section: Linux Programmer's Manual (2)
Updated: 2008-08-29
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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, normally with the error 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.

COLOPHON

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