82 lines
2.8 KiB
Groff
82 lines
2.8 KiB
Groff
.\" Copyright (c) 1983, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)sigsuspend.2 8.2 (Berkeley) 5/16/95
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.\" $FreeBSD$
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.\"
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.Dd May 16, 1995
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.Dt SIGSUSPEND 2
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.Os
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.Sh NAME
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.Nm sigsuspend
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.Nd atomically release blocked signals and wait for interrupt
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In signal.h
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.Ft int
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.Fn sigsuspend "const sigset_t *sigmask"
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.Sh DESCRIPTION
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The
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.Fn sigsuspend
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system call
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temporarily changes the blocked signal mask to the set to which
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.Fa sigmask
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points,
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and then waits for a signal to arrive;
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on return the previous set of masked signals is restored.
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The signal mask set
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is usually empty to indicate that all
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signals are to be unblocked for the duration of the call.
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.Pp
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In normal usage, a signal is blocked using
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.Xr sigprocmask 2
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to begin a critical section, variables modified on the occurrence
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of the signal are examined to determine that there is no work
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to be done, and the process pauses awaiting work by using
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.Fn sigsuspend
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with the previous mask returned by
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.Xr sigprocmask 2 .
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.Sh RETURN VALUES
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The
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.Fn sigsuspend
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system call
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always terminates by being interrupted, returning -1 with
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.Va errno
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set to
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.Er EINTR .
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.Sh SEE ALSO
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.Xr sigaction 2 ,
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.Xr sigpending 2 ,
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.Xr sigprocmask 2 ,
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.Xr sigsetops 3
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.Sh STANDARDS
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The
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.Fn sigsuspend
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system call is expected to conform to
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.St -p1003.1-90 .
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