SIGWAIT(2) System Calls Manual SIGWAIT(2)

sigwaitselect a set of signals

#include <signal.h>

sigwait(const sigset_t *restrict set, int *restrict sig);

The () function selects a set of signals, specified by set. If none of the selected signals are pending, sigwait() waits until one or more of the selected signals has been generated. Then sigwait() atomically clears one of the selected signals from the set of pending signals for the process and sets the location pointed to by sig to the signal number that was cleared.

The signals specified by set should be blocked, but not ignored, at the time of the call to ().

Processes which call () on ignored signals will wait indefinitely. Ignored signals are dropped immediately by the system, before delivery to a waiting process.

If successful, sigwait() returns 0 and sets the location pointed to by sig to the cleared signal number. Otherwise, an error number is returned.

sigwait() will fail if:

set specifies one or more invalid signal numbers.

pthread_sigmask(2), sigaction(2), sigpending(2), sigsuspend(2), pause(3)

sigwait() conforms to ISO/IEC 9945-1:1996 (``POSIX.1'')

April 27, 2000 macOS 14.1