Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice(s), this list of conditions and the following disclaimer as
the first lines of this file unmodified other than the possible
addition of one or more copyright notices.
2. Redistributions in binary form must reproduce the above copyright
notice(s), this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
$FreeBSD: head/lib/libc/sys/sigwaitinfo.2 152299 2005-11-11 07:50:51Z davidxu $
.Dd Nov 11, 2005 .Dt SIGTIMEDWAIT 2 .Os .Sh NAME .Nm sigtimedwait, .Nm sigwaitinfo .Nd wait for queued signals (REALTIME) .Sh LIBRARY .Lb libc .Sh SYNOPSIS n signal.h .Ft int .Fn sigtimedwait "const sigset_t *restrict set" "siginfo_t *restrict info" "const struct timespec *restrict timeout" .Ft int .Fn sigwaitinfo "const sigset_t * restrict set" "siginfo_t * restrict info" .Sh DESCRIPTION The .Fn sigtimedwait function is equivalent to .Fn sigwaitinfo except that if none of the signals specified by .Fa set are pending, .Fn sigtimedwait waits for the time interval specified in the .Sy timespec structure referenced by .Fa timeout . If the .Sy timespec structure pointed to by .Fa timeout is zero-valued and if none of the signals specified by .Fa set are pending, then .Fn sigtimedwait returns immediately with an error. If .Fa timeout is the NULL pointer, the behavior is unspecified. CLOCK_MONOTONIC clock is used to measure the time interval specified by the .Fa timeout argument.
p The .Fn sigwaitinfo function selects the pending signal from the set specified by .Fa set . Should any of multiple pending signals in the range SIGRTMIN to SIGRTMAX be selected, it shall 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 .Fa set is pending at the time of the call, the calling thread is suspended until one or more signals in .Fa set become pending or until it is interrupted by an unblocked, caught signal.
p The .Fn sigwaitinfo function is equivalent to the .Fn sigwait function if the .Fa info argument is NULL. If the .Fa info argument is non-NULL, the .Fn sigwaitinfo function is equivalent to .Fn sigwait , except that the selected signal number shall be stored in the si_signo member, and the cause of the signal shall be 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 is released and returned to the system for other use. If no value is queued, the content of the si_value member is zero-valued. If no further signals are queued for the selected signal, the pending indication for that signal is reset. .Sh RETURN VALUES Upon successful completion (that is, one of the signals specified by .Fa set is pending or is generated) .Fn sigwaitinfo and .Fn sigtimedwait return the selected signal number. Otherwise, the function return a value of -1 and set errno to indicate the error. .Sh ERRORS The .Fn sigtimedwait will fail if: l -tag -width Er t Bq Er EAGAIN No signal specified by set was generated within the specified timeout period. .El
p The .Fn sigtimedwait and .Fn sigwaitinfo functions fail if: l -tag -width Er t Bq Er EINTR The wait was interrupted by an unblocked, caught signal. t Bq Er EFAULT Any arguments point outside the allocated address space or there is a memory protection fault.
p .El The .Fn sigtimedwait function may also fail if: l -tag -width Er t Bq Er EINVAL The .Fa timeout argument specified a tv_nsec value less than zero or greater than or equal to 1000 million. Kernel only checks for this error if no signal is pending in set and it is necessary to wait. .El .Sh SEE ALSO .Xr sigwait 2 , .Xr sigqueue 2 , .Xr sigaction 2 , .Xr sigpending 2 , .Xr sigsuspend 2 , .Xr pause 3 , .Xr pthread_sigmask 3 .Sh STANDARDS The .Fn sigtimedwait and .Fn sigwaitinfo function conform to .St -p1003.1-96 .