xnu-1504.3.12.tar.gz

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<h2>lock_try</h2>
<hr>
<p>
<strong>Function</strong> - Attempt to acquire access rights to a lock.
<h3>SYNOPSIS</h3>
<pre>
<strong>kern_return_t   lock_try</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, to be acquired.
</dl>
<h3>DESCRIPTION</h3>
<p>
The <strong>lock_try</strong> function attempts to acquire the specified lock without
blocking. The return value indicates whether the lock was acquired.
<h3>RETURN VALUES</h3>
<dl>
<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 was acquired.
<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_LOCK_OWNED</strong>
<dd>
Another thread currently owns the requested lock.
<p>
<dt> <strong>KERN_LOCK_OWNED_SELF</strong>
<dd>
The calling thread already owns the lock.
</dl>
<h3>RELATED INFORMATION</h3>
<p>
Functions:
<a href="lock_acquire.html"><strong>lock_acquire</strong></a>,
<a href="lock_make_stable.html"><strong>lock_make_stable</strong></a>,
<a href="lock_release.html"><strong>lock_release</strong></a>,
<a href="lock_handoff.html"><strong>lock_handoff</strong></a>,
<a href="lock_handoff_accept.html"><strong>lock_handoff_accept</strong></a>,
<a href="lock_set_create.html"><strong>lock_set_create</strong></a>,
<a href="lock_set_destroy.html"><strong>lock_set_destroy</strong></a>.