.\"	$NetBSD: _lwp_suspend.2,v 1.6 2022/12/04 16:21:54 uwe Exp $
.\"
.\" Copyright (c) 2003 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.
.\"
.\" 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 December 4, 2022
.Dt _LWP_SUSPEND 2
.Os
.Sh NAME
.Nm _lwp_suspend ,
.Nm _lwp_continue
.Nd suspend or continue a light-weight process
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In lwp.h
.Ft int
.Fn _lwp_suspend "lwpid_t lwp"
.Ft int
.Fn _lwp_continue "lwpid_t lwp"
.Sh DESCRIPTION
.Fn _lwp_suspend
suspends execution of the LWP specified by
.Fa lwp .
Once an LWP is suspended, subsequent calls to
.Fn _lwp_suspend
have no effect.
The only way to resume execution of a suspended LWP is via
.Fn _lwp_continue .
.Pp
.Fn _lwp_continue
resumes execution of the LWP specified by
.Fa lwp .
Once an LWP is resumed, subsequent calls to
.Fn _lwp_continue
have no effect.
.Sh RETURN VALUES
.Rv -std _lwp_continue _lwp_suspend
.Sh ERRORS
.Fn _lwp_suspend
and
.Fn _lwp_continue
will fail if:
.Bl -tag -width Er
.It Bq Er ESRCH
No LWP can be found in the current process corresponding to that
specified by
.Fa lwp .
.El
.Pp
.Fn _lwp_suspend
will fail if:
.Bl -tag -width Er
.It Bq Er EDEADLK
The LWP specified by
.Fa lwp
is the only LWP in the process.
.El
.Sh SEE ALSO
.Xr _lwp_create 2
.Sh HISTORY
The
.Fn _lwp_create
system call first appeared in
.Nx 2.0 .