sigwait

SIGWAIT(3)                  Linux Programmer's Manual                 SIGWAIT(3)



NAME
       sigwait - wait for a signal

SYNOPSIS
       #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

DESCRIPTION
       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.

RETURN VALUE
       On success, sigwait() returns 0.  On error, it returns a positive error
       number (listed in ERRORS).

ERRORS
       EINVAL set contains an invalid signal number.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                     Attribute     Value   │
       ├──────────────────────────────────────────────┼───────────────┼─────────┤
       │sigwait()                                     │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

NOTES
       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.

EXAMPLES
       See pthread_sigmask(3).

SEE ALSO
       sigaction(2), signalfd(2), sigpending(2), sigsuspend(2), sigwaitinfo(2),
       sigsetops(3), signal(7)

COLOPHON
       This page is part of release 5.11 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux                              2021-03-22                         SIGWAIT(3)