sigwaitinfo(3RT)					    Realtime Library Functions						  sigwaitinfo(3RT)

NAME

       sigwaitinfo, sigtimedwait - wait for queued signals

SYNOPSIS

       cc [ flag... ] file... -lrt [ library... ]
       #include <signal.h>

       int sigwaitinfo(const sigset_t *restrict set, siginfo_t *restrict info);

       int sigtimedwait(const sigset_t *restrict set, siginfo_t *restrict info, const struct timespec *restrict timeout);

DESCRIPTION

       The   sigwaitinfo()  function selects the pending signal from the set specified by set. Should any of multiple pending signals in the range
       SIGRTMIN to SIGRTMAX be selected, it will be the lowest numbered one. The selection order between realtime  and	non-realtime  signals,	or
       between	multiple  pending non-realtime signals, is unspecified. If no signal in set is pending at the time of the call, the calling thread
       is suspended until one or more signals in set become pending or until it is interrupted by an unblocked, caught signal.

       The  sigwaitinfo() function behaves the same as the sigwait(2) function if the info argument is NULL. If the info argument is non-NULL, the
       sigwaitinfo()  function	behaves  the  same as sigwait(2), except that the selected signal number is stored in the si_signo member, and the
       cause of the signal is stored in the si_code member. If any value is queued to the selected signal, the first such queued value is dequeued
       and,  if  the  info  argument is non-NULL, the value is stored in the si_value member of info. The system resource used to queue the signal
       will be released and made available to queue other signals.  If no value is queued, the content of the si_value member is undefined. If	no
       further	signals are queued for the selected signal, the pending indication for that signal will be reset. If the value of the si_code mem-
       ber is SI_NOINFO, only the si_signo member of siginfo_t is meaningful, and the value of all other members is unspecified.

       The  sigtimedwait() function behaves the same as sigwaitinfo() except that if none of the signals specified by set are  pending,  sigtimed-
       wait() waits for the time interval specified in the timespec structure referenced by timeout. If the timespec structure pointed to by time-
       out is zero-valued and if none of the signals specified by set are pending, then sigtimedwait() returns immediately with an error. If time-
       out is the NULL pointer, the behavior is unspecified.

       If,  while  sigwaitinfo() or sigtimedwait() is waiting, a signal occurs which is eligible for delivery (that is, not blocked by the process
       signal mask), that signal is handled asynchronously and the wait is interrupted.

RETURN VALUES

       Upon successful completion (that is, one of the signals specified by set is pending or is generated) sigwaitinfo() and sigtimedwait()  will
       return the selected signal number. Otherwise, the function returns -1 and sets errno to indicate the error.

ERRORS

       The sigwaitinfo() and sigtimedwait() functions will fail if:

       EINTR	       The wait was interrupted by an unblocked, caught signal.

       ENOSYS	       The sigwaitinfo() and sigtimedwait() functions are not supported.

       The sigtimedwait() function will also fail if:

       EAGAIN	       No signal specified by set was generated within the specified timeout period.

       The sigtimedwait() function may also fail if:

       EINVAL	       The  timeout  argument  specified  a tv_nsec value less than zero or greater than or equal to 1000 million. The system only
		       checks for this error if no signal is pending in set and it is necessary to wait.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Safe		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       time(2), sigqueue(3RT), siginfo.h(3HEAD), signal.h(3HEAD), time.h(3HEAD), attributes(5), standards(5)

SunOS 5.10							    1 Nov 2003							  sigwaitinfo(3RT)