pthread_sigmask(3T)													       pthread_sigmask(3T)

NAME

       pthread_sigmask() - examine/change signal mask of calling thread

SYNOPSIS

PARAMETERS

	      how	This parameter defines how the signal mask of the calling thread will be changed.

	      set	Pointer to the set of signals that will be used to change the currently blocked signal set.

	      oset	Pointer to where the previous signal mask will be returned.

DESCRIPTION

       allows the calling thread to examine and/or change its signal mask.

       Unless it is a null pointer, the argument set points to a set of signals which are to be used to change the currently blocked signal set.

       The argument how indicates how the set is changed.  The legal values are:

	      The resulting set is the union of the current set and the signal
				set pointed to by set.

	      The resulting set is the intersection of the current set
				and the complement of the signal set pointed to by set.

	      The resulting set is the signal set pointed to by
				set.

       If the argument oset is not a null pointer, the previous signal mask is returned in oset.  If set is a null pointer, the value of the argu-
       ment how is insignificant and the thread's signal mask is unchanged; thus, the call can be used to inquire about currently blocked signals.

       If there any pending unblocked signals after the call to at least one of those signals is delivered before the call to returns.

       It is impossible to block the or signal.  This is enforced by the system without causing an error to be indicated.

       The thread's signal mask is not changed if fails for any reason.

RETURN VALUE

       Upon successful completion, returns zero.  Otherwise, an error number is returned to indicate the error (the variable is not set).

ERRORS

       If any of the following occur, the function returns the corresponding error number:

	      how	     contains an invalid value.

	      set	     or oset points to an invalid address.  The reliable detection of this error is implementation dependent.

AUTHOR

       was derived from the IEEE POSIX P1003.1c standard.

SEE ALSO

       sigprocmask(2).

STANDARDS CONFORMANCE

								  Pthread Library					       pthread_sigmask(3T)