NetBSD/lib/libc/sys/_lwp_unpark.2

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.\" $NetBSD: _lwp_unpark.2,v 1.4 2010/11/02 20:49:47 skrll Exp $
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jason R. Thorpe of Wasabi Systems, Inc, and by Andrew Doran.
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.Dd January 20, 2007
.Dt _LWP_UNPARK 2
.Os
.Sh NAME
.Nm _lwp_unpark
.Nd resume execution of a waiting LWP
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In lwp.h
.Ft int
.Fn _lwp_unpark "lwpid_t lwp" "const void *hint"
.Sh DESCRIPTION
.Fn _lwp_unpark
resumes execution of the light-weight process
.Fa lwp .
.Pp
The target LWP is assumed to be waiting in the kernel as a result of a
call to
.Fn _lwp_park .
If the target LWP is not currently waiting, it will return immediately
upon the next call to
.Fn _lwp_park .
.Pp
See
.Xr _lwp_park 2
for a description of the
.Fa hint
argument.
.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 ESRCH
No LWP can be found in the current process corresponding to that
specified by
.Fa lwp .
.El
.Sh SEE ALSO
.Xr _lwp_park 2 ,
.Xr _lwp_unpark_all 2 ,
.Xr _lwp_wakeup 2
.Sh HISTORY
The
.Fn _lwp_unpark
system call first appeared in
.Nx 5.0 .