int sigsuspend(const sigset_t *sigmask);
IEEE Std 1003.1-2017
sigsuspend() function shall replace the current signal mask of the calling thread with the set of signals pointed to
by sigmask and then suspend the thread until delivery of a signal whose action is either to execute a signal-catching
function or to terminate the process. This shall not cause any other signals that may have been pending on the process to become
pending on the thread.
If the action is to terminate the process then
sigsuspend() shall never return. If the action is to execute a
signal-catching function, then
sigsuspend() shall return after the signal-catching function returns, with the signal mask
restored to the set that existed prior to the
It is not possible to block signals that cannot be ignored. This is enforced by the system without causing an error to be
sigsuspend() suspends thread execution indefinitely, there is no successful completion return value. If a return
-1 shall be returned and
errno set to indicate the error.
sigsuspend() function shall fail if:
EINTR- A signal is caught by the calling process and control is returned from the signal-catching function.
The following sections are informative.