sigsuspend(2)							 sigsuspend(2)

NAME
       sigsuspend - wait for a signal

SYNOPSIS
DESCRIPTION
       The  function  replaces	the  current signal mask of the calling thread
       with the set of signals pointed to by  and  then	 suspends  the	thread
       until  delivery of a signal whose action is either to execute a signal-
       catching function or to terminate the process.  This will not cause any
       other signals that may have been pending on the process to become pend‐
       ing on the thread.

       If the action is to terminate the process then will  never  return.  If
       the  action  is	to  execute   a	  signal-catching  function, then will
       return after the signal-catching function returns, with the signal mask
       restored to the set that existed prior to the call.

       It  is  not  possible  to block signals that cannot be ignored. This is
       enforced by the system without causing an error to be indicated.

RETURN VALUE
       Since suspends thread execution indefinitely, there  is	no  successful
       completion  return value. If a return occurs, −1 is returned and is set
       to indicate the error.

ERRORS
       The function will fail if:

	      A signal is  caught  by  the  calling  process  and  control  is
	      returned from
			     the signal-catching function.

	      sigmask	     points  to	 an  invalid  address.	 The  reliable
			     detection of this error is	 implementation-depen‐
			     dent.

APPLICATION USAGE
   Threads Considerations
       Since blocked signal masks are maintained at the thread level, modifies
       only the calling thread's blocked signal mask.  suspends only the call‐
       ing thread until it receives a signal.

       If other threads in the process do not block the signal, the signal may
       be delivered to another thread in the process and  the  thread  in  may
       continue	 waiting.   For	 this  reason, the use of sigwait(2) is recom‐
       mended instead of for multi-threaded applications.

       For more information regarding signals and threads, refer to signal(5).

   LWP (Lightweight Processes) Considerations
       modifies only the calling LWP's signal mask and suspends only the call‐
       ing LWP until receipt of a signal.

AUTHOR
       was derived from the IEEE POSIX 1003.1-1988 Standard.

SEE ALSO
       pause(2),  sigaction(2),	 sigpending(2), sigprocmask(2), sigsetops(3C),
       sigwait(2), signal(5).

CHANGE HISTORY
       First released in Issue 3.

       Entry included for alignment with the POSIX.1-1988 standard.

STANDARDS CONFORMANCE
								 sigsuspend(2)

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