sigwaitinfo(3) [osf1 man page]

sigwait(3)						     Library Functions Manual							sigwait(3)

NAME

       sigwait, sigwaitinfo, sigtimedwait - Suspends a calling thread until a signal arrives.

LIBRARY

       Threads Library (libpthread.so):  sigwait()
       Realtime Library (librt.a, librt.so): sigwaitinfo(), sigtimedwait()

SYNOPSIS

       #include <signal.h>

       int sigwait(
	       const sigset_t *set,
		int *signal);

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

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

PARAMETERS

       Specifies  the set of signals to wait for.  Returns the signal number of the selected signal.  (See the DESCRIPTION section for information
       about the selected signal.)  Specifies a pointer to a siginfo structure that is receiving data describing the signal, including any  appli-
       cation-defined data specified when the signal was posted.  Specifies a timeout for the wait. If timeout is null, the argument is ignored.

DESCRIPTION

       The  sigwait  functions suspend the calling thread until at least one of the signals in the set parameter is in the caller's set of pending
       signals. When this happens, one of those signals is automatically selected and removed from the set of pending signals.	The signal  number
       identifying that signal is then returned.

       For the sigwait() function, the signal number is stored in the signal argument.	For the sigwaitinfo() and sigtimedwait() functions, if the
       info argument is specified, the selected signal number is stored in the si_signo member of siginfo structure, and the cause of  the  signal
       is  stored  in  the  si_code  member.  If  any value is queued to the selected signal, the first queued value is dequeued and stored in the
       si_value member of info.  If no value is queued, the content of the si_value member is undefined.

       For sigtimedwait(), if the timeout parameter is specified, the function waits for the specified time interval.  If the  timespec  structure
       specified  contains a timeout value of zero (0), and if none of the signals specified by set are pending, then sigtimedwait() returns imme-
       diately with an error.

       The effect is unspecified if any signals in the set parameter are not blocked when the sigwait functions are called.

       The set parameter is created using the set manipulation functions sigemptyset(), sigfillset(), sigaddset(), and sigdelset().

       If, while the sigwait functions are waiting, a signal occurs that is eligible for delivery (that is, not blocked by the signal mask),  that
       signal is handled asynchronously and the wait is interrupted.

RETURN VALUES

       Upon successful completion, the sigwait() function returns 0 (zero).  The other functions return the number of the selected signal.

       On failure, sigwait() returns the errno value for the failure. The other functions return -1 and set errno to indicate the error.

ERRORS

       If the sigwait functions fail, errno is set to one of the following values:

       [EINVAL]       The value of the set parameter contains an invalid or unsupported signal number.

       [EINVAL]       The timeout argument specified a tv_nsec value that is less than 0 or greater than or equal to 1,000,000,000.

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

       [EAGAIN]       No signal specified by set was delivered within the specified timeout period.

RELATED INFORMATION

       Headers: siginfo(5)

       Functions: sigaction(2), sigpending(2), sigsuspend(2)

       Routines: sigaddset(3), sigdelset(3), sigemptyset(3), sigfillset(3) delim off

																	sigwait(3)

Check Out this Related 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

Linux and UNIX Man Pages

sigwaitinfo(3) [osf1 man page]

Check Out this Related Man Page