sigwaitinfo(2) [netbsd man page]

SIGTIMEDWAIT(2) 					      BSD System Calls Manual						   SIGTIMEDWAIT(2)

NAME

     sigtimedwait, sigwaitinfo, sigwait -- wait for queued signals

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <signal.h>

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

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

     int
     sigwait(const sigset_t * restrict set, int * restrict sig);

DESCRIPTION

     sigwaitinfo() and sigwait() return the first pending signal from the set specified by set.  Should multiple signals from set be pending, the
     lowest numbered one is returned.  The selection order between realtime and non-realtime signals is unspecified.  If there is no signal from
     set pending at the time of the call, the calling thread is suspended until one of the specified signals is generated.

     sigtimedwait() is exactly equal to sigwaitinfo(), except timeout specifies the maximum time interval for which the calling thread will be
     suspended.  If timeout is zero (tv_sec == tv_nsec == 0), sigtimedwait() only checks the currently pending signals and returns immediately.
     If NULL is used for timeout, sigtimedwait() behaves exactly like sigwaitinfo() in all regards.

     If several threads are waiting for a given signal, exactly one of them returns from the signal wait when the signal is generated.

     Behaviour of these functions is unspecified if any of the signals in set are unblocked at the time these functions are called.

RETURN VALUES

     Upon successful completion of sigtimedwait() or sigwaitinfo() info is updated with signal information, and the function returns the signal
     number.  Otherwise, -1 is returned and the global variable errno indicates the error.  Upon successful completion of sigwait() sig is updated
     with ihe signal number, and the function returns 0.  Otherwise, a non-zero error code is returned,

ERRORS

     sigwaitinfo() and sigwait() always succeed.

     sigtimedwait() will fail and the info pointer will remain unchanged if:

     [EAGAIN]		No signal specified in set was generated in the specified timeout.

     sigtimedwait() may also fail if:

     [EINVAL]		The specified timeout was invalid.

     This error is only checked if no signal from set is pending and it would be necessary to wait.

SEE ALSO

     sigaction(2), sigprocmask(2), signal(7)

STANDARDS

     The functions sigtimedwait(), sigwaitinfo(), and sigwait() conform to IEEE Std 1003.1-2001 (``POSIX.1'').

HISTORY

     The sigtimedwait(), sigwaitinfo(), and sigwait() functions appeared in NetBSD 2.0.

BSD
								   May 30, 2010 							       BSD

sigwaitinfo(3C) 					   Standard C Library Functions 					   sigwaitinfo(3C)

NAME

       sigwaitinfo, sigtimedwait - wait for queued signals

SYNOPSIS

       #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 fail if:

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

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

       EFAULT	 The set, info, or timeout argument points to an invalid address.

       The sigtimedwait() function may 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	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Safe		   |
       +-----------------------------+-----------------------------+
       |Standard		     |See standards(5). 	   |
       +-----------------------------+-----------------------------+

SEE ALSO

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

SunOS 5.11							    5 Feb 2008							   sigwaitinfo(3C)