rt_sigprocmask(2) -- Linux man page
NAMErt_sigprocmask - Change the list of currently blocked signals
- long sys_rt_sigprocmask (sigset_t *set, sigset_t *oset, size_t sigsetsize);
rt_sigprocmask changes the list of currently blocked signals. The set value stores the signal mask of the pending signals. The previous action on the signal is saved in oact. The value of how indicates how the call should behave; its values are as follows:
- The set of blocked signals is the union of the current set and the set argument.
- The signals in set are removed from the current set of blocked signals. It is okay to unblock a signal that is not blocked.
The set of blocked signals is set to the set argument. sigsetsize should indicate the size of a sigset_t type.
- sigsetsize was not equivalent to the size of a sigset_t type.
- An invalid set, act, or oact was specified.