.\"	$NetBSD: _lwp_kill.2,v 1.4 2009/06/24 22:19:14 zafer Exp $
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.\" by Jason R. Thorpe of Wasabi Systems, Inc, and by Andrew Doran.
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.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
A 0 value indicates that the call succeeded.
A \-1 return value indicates an error occurred and
.Va errno
is set to indicate the reason.
.Sh ERRORS
.Bl -tag -width [EINVAL]
.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 .