sigsuspend(2)

sigsuspend2

Atomically release blocked signals and wait for interrupt

Usage

#include <signal.h>

int

sigsuspend(const sigset_t *sigmask);

Overview

sigsuspend() temporarily changes the blocked signal mask to the set to which sigmask points, and then waits for a signal to arrive; on return the previous set of masked signals is restored. The signal mask set is usually empty to indicate that all signals are to be unblocked for the duration of the call.

In normal usage, a signal is blocked using sigprocmask(2) to begin a critical section, variables modified on the occurrence of the signal are examined to determine that there is no work to be done, and the process pauses awaiting work by using sigsuspend() with the previous mask returned by sigprocmask.

Return values

The sigsuspend() function always terminates by being interrupted, returning -1 with errno set to EINTR.

Releases

155 releases since Mac OS X 10.0; the text changed 2 times.

  1. 10.0–10.4.11
  2. 10.5–10.11.6
  3. 10.12–26.5

Standards

The sigsuspend function call conforms to IEEE Std 1003.1-1988 (“POSIX.1”).

From xnu 12377.121.6 in macOS 26.5. Parsed by carta from the page's mdoc source.