xnu-7195.101.1.tar.gz

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<h2>lock_handoff_accept</h2>
<hr>
<p>
<strong>Function</strong> - Accept a lock hand-off.
<h3>SYNOPSIS</h3>
<pre>
<strong>kern_return_t   lock_handoff_accept</strong>
                <strong>(lock_set_t</strong>                            <var>lock_set</var>,
                 <strong>int</strong>                                    <var>lock_id</var><strong>);</strong>
</pre>
<h3>PARAMETERS</h3>
<dl>
<p>
<dt> <var>lock_set</var>
<dd>
[in send right] The port naming the lock set which represents the
lock.
<p>
<dt> <var>lock_id</var>
<dd>
[in scalar] The lock, represented by the lock set, that is the object
of the handoff operation.
</dl>
<h3>DESCRIPTION</h3>
<p>
The <strong>lock_handoff_accept</strong> function accepts a lock
hand-off from an anonymous sending thread. If the sending thread is
not waiting to hand-off the lock, the calling thread will block until
the lock handoff is completed.  Only one thread may be waiting to
accept a lock handoff at any given time.
<h3>RETURN VALUES</h3>
<dl>
<p>
<dt> <strong>KERN_ALREADY_WAITING</strong>
<dd>
Another thread is already waiting for a hand-off of this lock.
<p>
<dt> <strong>KERN_INVALID_ARGUMENT</strong>
<dd>
The specified lock_set is invalid, or the lock_id is out of range.
<p>
<dt> <strong>KERN_SUCCESS</strong>
<dd>
The lock hand-off was successful.
<p>
<dt> <strong>KERN_LOCK_UNSTABLE</strong>
<dd>
The acquired lock has an unstable state.
<p>
<dt> <strong>KERN_LOCK_SET_DESTROYED</strong>
<dd>
The specified lock has been destroyed.
<p>
<dt> <strong>KERN_ABORTED</strong>
<dd>
While blocked to wait for the sending thread to transfer the lock's ownership,
     the calling thread was awoken by an unrelated event;
     the lock's handoff state is cleared.
</dl>
<h3>RELATED INFORMATION</h3>
<p>
Functions:
<a href="lock_acquire.html"><strong>lock_acquire</strong></a>,
<a href="lock_release.html"><strong>lock_release</strong></a>,
<a href="lock_try.html"><strong>lock_try</strong></a>,
<a href="lock_handoff.html"><strong>lock_handoff</strong></a>.