osfmk/man/lock_handoff_accept.html

   1 <h2>lock_handoff_accept</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Accept a lock hand-off.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   lock_handoff_accept</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
  17 lock.
  18 <p>
  19 <dt> <var>lock_id</var>
  20 <dd>
  21 [in scalar] The lock, represented by the lock set, that is the object
  22 of the handoff operation.
  23 </dl>
  24 <h3>DESCRIPTION</h3>
  25 <p>
  26 The <strong>lock_handoff_accept</strong> function accepts a lock
  27 hand-off from an anonymous sending thread. If the sending thread is
  28 not waiting to hand-off the lock, the calling thread will block until
  29 the lock handoff is completed.  Only one thread may be waiting to
  30 accept a lock handoff at any given time.
  31 <h3>RETURN VALUES</h3>
  32 <dl>
  33 <p>
  34 <dt> <strong>KERN_ALREADY_WAITING</strong>
  35 <dd>
  36 Another thread is already waiting for a hand-off of this lock.
  37 <p>
  38 <dt> <strong>KERN_INVALID_ARGUMENT</strong>
  39 <dd>
  40 The specified lock_set is invalid, or the lock_id is out of range.
  41 <p>
  42 <dt> <strong>KERN_SUCCESS</strong>
  43 <dd>
  44 The lock hand-off was successful.
  45 <p>
  46 <dt> <strong>KERN_LOCK_UNSTABLE</strong>
  47 <dd>
  48 The acquired lock has an unstable state.
  49 <p>
  50 <dt> <strong>KERN_LOCK_SET_DESTROYED</strong>
  51 <dd>
  52 The specified lock has been destroyed.
  53 <p>
  54 <dt> <strong>KERN_ABORTED</strong>
  55 <dd>
  56 While blocked to wait for the sending thread to transfer the lock's ownership,
  57      the calling thread was awoken by an unrelated event;
  58      the lock's handoff state is cleared.
  59 </dl>
  60 <h3>RELATED INFORMATION</h3>
  61 <p>
  62 Functions:
  63 <a href="lock_acquire.html"><strong>lock_acquire</strong></a>,
  64 <a href="lock_release.html"><strong>lock_release</strong></a>,
  65 <a href="lock_try.html"><strong>lock_try</strong></a>,
  66 <a href="lock_handoff.html"><strong>lock_handoff</strong></a>.