sigwait - wait for a signal
Standard C library (libc
, -lc
)
#include <signal.h>
int sigwait(const sigset_t *restrict set, int *restrict sig);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
sigwait():
Since glibc 2.26:
_POSIX_C_SOURCE >= 199506L
glibc 2.25 and earlier:
_POSIX_C_SOURCE
The sigwait() function suspends execution of the
calling thread until one of the signals specified in the signal set
set
becomes pending. The function accepts the signal (removes
it from the pending list of signals), and returns the signal number in
sig
.
The operation of sigwait() is the same as sigwaitinfo(2), except that:
sigwait() returns only the signal number, rather
than a siginfo_t
structure describing the signal.
The return values of the two functions are different.
On success, sigwait() returns 0. On error, it returns a positive error number (listed in ERRORS).
See pthread_sigmask(3).
set
contains an invalid signal number.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
sigwait() |
Thread safety | MT-Safe |
sigwait() is implemented using sigtimedwait(2).
The glibc implementation of sigwait() silently ignores attempts to wait for the two real-time signals that are used internally by the NPTL threading implementation. See nptl(7) for details.
POSIX.1-2008.
POSIX.1-2001.
sigaction(2), signalfd(2), sigpending(2), sigsuspend(2), sigwaitinfo(2), sigsetops(3), signal(7)