155 lines
4.2 KiB
Groff
155 lines
4.2 KiB
Groff
.\" $NetBSD: sigtimedwait.2,v 1.7 2010/05/31 11:02:24 drochner Exp $
|
|
.\"
|
|
.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Jaromir Dolecek.
|
|
.\"
|
|
.\" 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, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``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 FOUNDATION OR CONTRIBUTORS
|
|
.\" 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.
|
|
.\"
|
|
.Dd May 30, 2010
|
|
.Dt SIGTIMEDWAIT 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm sigtimedwait ,
|
|
.Nm sigwaitinfo ,
|
|
.Nm sigwait
|
|
.Nd wait for queued signals
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In 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"
|
|
.Ft int
|
|
.Fn sigwait "const sigset_t * restrict set" "int * restrict sig"
|
|
.Sh DESCRIPTION
|
|
.Fn sigwaitinfo
|
|
and
|
|
.Fn sigwait
|
|
return the first pending signal from the set specified by
|
|
.Fa set .
|
|
Should multiple signals from
|
|
.Fa 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
|
|
.Ar set
|
|
pending at the time of the call, the calling thread
|
|
is suspended until one of the specified signals is generated.
|
|
.Pp
|
|
.Fn sigtimedwait
|
|
is exactly equal to
|
|
.Fn sigwaitinfo ,
|
|
except
|
|
.Fa timeout
|
|
specifies the maximum time interval for which the calling thread will
|
|
be suspended.
|
|
If
|
|
.Fa timeout
|
|
is zero (tv_sec == tv_nsec == 0),
|
|
.Fn sigtimedwait
|
|
only checks the currently pending signals and returns immediately.
|
|
If
|
|
.Dv NULL
|
|
is used for
|
|
.Fa timeout ,
|
|
.Fn sigtimedwait
|
|
behaves exactly like
|
|
.Fn sigwaitinfo
|
|
in all regards.
|
|
.Pp
|
|
If several threads are waiting for a given signal, exactly one of them
|
|
returns from the signal wait when the signal is generated.
|
|
.Pp
|
|
Behaviour of these functions is unspecified if any of the signals in
|
|
.Fa set
|
|
are unblocked at the time these functions are called.
|
|
.Sh RETURN VALUES
|
|
Upon successful completion of
|
|
.Fn sigtimedwait
|
|
or
|
|
.Fn sigwaitinfo
|
|
.Fa info
|
|
is updated with signal information, and the function returns the signal number.
|
|
Otherwise, \-1 is returned and the global variable
|
|
.Va errno
|
|
indicates the error.
|
|
Upon successful completion of
|
|
.Fn sigwait
|
|
.Fa sig
|
|
is updated with ihe signal number, and the function returns 0.
|
|
Otherwise, a non-zero error code is returned,
|
|
.Sh ERRORS
|
|
.Fn sigwaitinfo
|
|
and
|
|
.Fn sigwait
|
|
always succeed.
|
|
.Pp
|
|
.Fn sigtimedwait
|
|
will fail and the
|
|
.Fa info
|
|
pointer will remain unchanged if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EAGAIN
|
|
No signal specified in
|
|
.Fa set
|
|
was generated in the specified
|
|
.Fa timeout .
|
|
.El
|
|
.Pp
|
|
.Fn sigtimedwait
|
|
may also fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The specified
|
|
.Fa timeout
|
|
was invalid.
|
|
.El
|
|
.Pp
|
|
This error is only checked if no signal from
|
|
.Fa set
|
|
is pending and it would be necessary to wait.
|
|
.Sh SEE ALSO
|
|
.Xr sigaction 2 ,
|
|
.Xr sigprocmask 2 ,
|
|
.Xr signal 7
|
|
.Sh STANDARDS
|
|
The functions
|
|
.Fn sigtimedwait ,
|
|
.Fn sigwaitinfo ,
|
|
and
|
|
.Fn sigwait
|
|
conform to
|
|
.St -p1003.1-2001 .
|
|
.Sh HISTORY
|
|
The
|
|
.Fn sigtimedwait ,
|
|
.Fn sigwaitinfo ,
|
|
and
|
|
.Fn sigwait
|
|
functions appeared in
|
|
.Nx 2.0 .
|