osfmk/man/lock_try.html

   1 <h2>lock_try</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Attempt to acquire access rights to a lock.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   lock_try</strong>
   8                 <strong>(lock_set_t</strong>                            <var>lock_set</var>,
   9                  <strong>int</strong>                                    <var>lock_id</var><strong>);</strong>
  10 </pre>
  11 <h3>PARAMETERS</h3>
  12 <dl>
  13 <p>
  14 <dt> <var>lock_set</var>
  15 <dd>
  16 [in send right] The port naming the lock set which represents the lock.
  17 <p>
  18 <dt> <var>lock_id</var>
  19 <dd>
  20 [in scalar] The lock, represented by the lock set, to be acquired.
  21 </dl>
  22 <h3>DESCRIPTION</h3>
  23 <p>
  24 The <strong>lock_try</strong> function attempts to acquire the specified lock without
  25 blocking. The return value indicates whether the lock was acquired.
  26 <h3>RETURN VALUES</h3>
  27 <dl>
  28 <p>
  29 <dt> <strong>KERN_INVALID_ARGUMENT</strong>
  30 <dd>
  31 The specified lock_set is invalid, or the lock_id is out of range.
  32 <p>
  33 <dt> <strong>KERN_SUCCESS</strong>
  34 <dd>
  35 The lock was acquired.
  36 <p>
  37 <dt> <strong>KERN_LOCK_UNSTABLE</strong>
  38 <dd>
  39 The acquired lock has an unstable state.
  40 <p>
  41 <dt> <strong>KERN_LOCK_SET_DESTROYED</strong>
  42 <dd>
  43 The specified lock has been destroyed.
  44 <p>
  45 <dt> <strong>KERN_LOCK_OWNED</strong>
  46 <dd>
  47 Another thread currently owns the requested lock.
  48 <p>
  49 <dt> <strong>KERN_LOCK_OWNED_SELF</strong>
  50 <dd>
  51 The calling thread already owns the lock.
  52 </dl>
  53 <h3>RELATED INFORMATION</h3>
  54 <p>
  55 Functions:
  56 <a href="lock_acquire.html"><strong>lock_acquire</strong></a>,
  57 <a href="lock_make_stable.html"><strong>lock_make_stable</strong></a>,
  58 <a href="lock_release.html"><strong>lock_release</strong></a>,
  59 <a href="lock_handoff.html"><strong>lock_handoff</strong></a>,
  60 <a href="lock_handoff_accept.html"><strong>lock_handoff_accept</strong></a>,
  61 <a href="lock_set_create.html"><strong>lock_set_create</strong></a>,
  62 <a href="lock_set_destroy.html"><strong>lock_set_destroy</strong></a>.