143 lines
4.5 KiB
Groff
143 lines
4.5 KiB
Groff
.\" $NetBSD: psignal.9,v 1.1 1996/06/22 22:57:35 pk Exp $
|
|
.\"
|
|
.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Paul Kranenburg.
|
|
.\"
|
|
.\" 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.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the NetBSD
|
|
.\" Foundation, Inc. and its contributors.
|
|
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
.\" contributors may be used to endorse or promote products derived
|
|
.\" from this software without specific prior written permission.
|
|
.\"
|
|
.\" 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 REGENTS 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 22, 1996
|
|
.Dt PSIGNAL 9
|
|
.Os
|
|
.Sh NAME
|
|
.Fd #include <sys/types.h>
|
|
.Fd #include <sys/signalvar.h>
|
|
.Nm psignal ,
|
|
.Nm pgsignal ,
|
|
.Nm gsignal
|
|
.Nd post signal to a process or process group
|
|
.Sh SYNOPSIS
|
|
.Ft void
|
|
.Fn psignal "struct proc *p" "int signum"
|
|
.Ft void
|
|
.Fn pgsignal "struct pgrp *pgrp" "int signum" "int checkctty"
|
|
.Ft void
|
|
.Fn gsignal "int pgid" "int signum"
|
|
.Sh DESCRIPTION
|
|
These functions post a signal to one or more processes. The argument
|
|
.Fa signum
|
|
common to all three functions should be in the range
|
|
.Bq 1- Ns Dv NSIG .
|
|
.Pp
|
|
The
|
|
.Fn psignal
|
|
function posts signal number
|
|
.Fa signum
|
|
to the process represented by the process structure
|
|
.Fa p .
|
|
With a few exceptions noted below, the target process signal disposition is
|
|
updated and is marked as runnable, so further handling of the signal is done
|
|
in the context of the target process after a context switch. Note that
|
|
.Fn psignal
|
|
does not by itself cause a context switch to happen.
|
|
.Pp
|
|
The target process is not marked as runnable in the following cases:
|
|
.Bl -bullet -offset indent
|
|
.It
|
|
The target process is sleeping uninterruptibly. The signal will be
|
|
noticed when the process returns from the system call or trap.
|
|
.It
|
|
The target process is currently ignoring the signal.
|
|
.It
|
|
If a stop signal is sent to a sleeping process that takes the
|
|
default action
|
|
.Pq see Xr sigaction 2 ,
|
|
the process is stopped without awakening it.
|
|
.It
|
|
.Dv SIGCONT
|
|
restarts a stopped process
|
|
.Pq or puts them back to sleep
|
|
regardless of the signal action
|
|
.Pq e.g., blocked or ignored .
|
|
.El
|
|
.Pp
|
|
If the target process is being traced
|
|
.Fn psignal
|
|
behaves as if the target process were taking the default action for
|
|
.Fa signum .
|
|
This allows the tracing process to be notified of the signal.
|
|
.Pp
|
|
The
|
|
.Fn pgsignal
|
|
function posts signal number
|
|
.Fa signum
|
|
to each member of the process group described by
|
|
.Fa pgrp .
|
|
If
|
|
.Fa checkctty
|
|
is non-zero, the signal will be posted only to processes that have
|
|
a controlling terminal.
|
|
.Fn pgsignal
|
|
is implemented by walking along the process list headed by the field
|
|
.Li pg_members
|
|
of the process group structure
|
|
pointed at by
|
|
.Fa pgrp
|
|
and calling
|
|
.Fn psignal
|
|
as appropriate. If
|
|
.Fa pgrp
|
|
is
|
|
.Dv NULL
|
|
no action is taken.
|
|
.Pp
|
|
The
|
|
.Fn gsignal
|
|
function posts signal number
|
|
.Fa signum
|
|
to each member of the process group identified by the group id
|
|
.Fa pgid .
|
|
.Fn gsignal
|
|
first finds the group structure associated with
|
|
.Fa pgid ,
|
|
then invokes
|
|
.Fn pgsignal
|
|
with the argument
|
|
.Fa checkctty
|
|
set to zero. If
|
|
.Fa pgid
|
|
is zero no action is taken.
|
|
.Sh SEE ALSO
|
|
.Xr sigaction 2 ,
|
|
.Xr tsleep 9
|