.\"	$NetBSD: _lwp_kill.2,v 1.5 2022/12/04 16:17:50 uwe Exp $
.\"
.\" Copyright (c) 2003, 2007 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jason R. Thorpe of Wasabi Systems, Inc, and by Andrew Doran.
.\"
.\" 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 January 20, 2007
.Dt _LWP_KILL 2
.Os
.Sh NAME
.Nm _lwp_kill
.Nd send a signal to a light-weight process
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In lwp.h
.Ft int
.Fn _lwp_kill "lwpid_t lwp" "int sig"
.Sh DESCRIPTION
.Fn _lwp_kill
sends the signal specified by
.Fa sig
to the light-weight process specified by
.Fa lwp .
If the
.Fa sig
argument is given as 0 (zero),
.Nm
will test for the existence of the target LWP, but will take no further
action.
.Pp
Job control signals and uncatchable signals can not be directed to a specific
LWP: if posted with
.Nm ,
they will affect all LWPs in the process.
.Pp
Signals will be posted successfully to suspended LWPs, but will not be
handled further until the LWP has been continued.
.Sh RETURN VALUES
.Rv -std _lwp_kill
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
.Fa sig
is not a valid signal number.
.It Bq Er ESRCH
No LWP can be found in the current process corresponding to that
specified by
.Fa lwp .
.El
.Sh SEE ALSO
.Xr _lwp_continue 2 ,
.Xr _lwp_suspend 2 ,
.Xr kill 2 ,
.Xr sigaction 2 ,
.Xr signal 7
.Sh HISTORY
The
.Fn _lwp_kill
system call first appeared in
.Nx 5.0 .