.\"	$NetBSD: _lwp_suspend.2,v 1.4 2008/04/30 13:10:51 martin Exp $
.\"
.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jason R. Thorpe of Wasabi Systems, Inc.
.\"
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.Dd January 13, 2003
.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
Upon successful completion,
.Fn _lwp_suspend
and
.Fn _lwp_continue
return a value of 0.
Otherwise, an error code is returned to indicate the error.
.Sh ERRORS
.Fn _lwp_suspend
and
.Fn _lwp_continue
will fail if:
.Bl -tag -width [EDEADLK]
.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 [EDEADLK]
.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 .