osfmk/man/lock_set_create.html

   1 <h2>lock_set_create</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Create a new lock set.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   lock_set_create</strong>
   8                 <strong>(task_t</strong>                                    <var>task</var>,
   9                  <strong>lock_set_t</strong>                            <var>lock_set</var>,
  10                  <strong>int</strong>                                      <var>locks</var>,
  11                  <strong>int</strong>                                     <var>policy</var><strong>);</strong>
  12 </pre>
  13 <h3>PARAMETERS</h3>
  14 <dl>
  15 <p>
  16 <dt> <var>task</var>
  17 <dd>
  18 The task receiving the send right to the newly created lock set.
  19 <p>
  20 <dt> <var>lock_set</var>
  21 <dd>
  22 [out send right] The port naming the lock set which represents the lock.
  23 <p>
  24 <dt> <var>locks</var>
  25 <dd>
  26 [in scalar] The number of locks the lock set will represent (must be a positive value).
  27 <p>
  28 <dt> <var>policy</var>
  29 <dd>
  30 [in scalar] The blocked thread wakeup policy for the newly created lock set. Valid policies are:
  31      <dl>
  32 <p>
  33 <dt> SYNC_POLICY_FIFO
  34 <dd>
  35 a first-in-first-out policy for scheduling thread wakeup.
  36 <p>
  37 <dt> SYNC_POLICY_FIXED_PRIORITY
  38 <dd>
  39 a fixed priority policy for scheduling thread wakeup.
  40 </dl>
  41 </dl>
  42 <h3>DESCRIPTION</h3>
  43 <p>
  44 The <strong>lock_set_create</strong> function creates a new lock set representing a
  45 collection of associated locks. The lock set is associated with the
  46 specified task. A send right naming the lock set is returned to the
  47 caller.
  48 <h3>RETURN VALUES</h3>
  49 <dl>
  50 <p>
  51 <dt> <strong>KERN_SUCCESS</strong>
  52 <dd>
  53 The lock set was created.
  54 <p>
  55 <dt> <strong>KERN_INVALID_ARGUMENT</strong>
  56 <dd>
  57 Either the task or policy argument is invalid, or the locks argument
  58 has a value that is less than or equal to zero.
  59 <p>
  60 <dt> <strong>KERN_RESOURCE_SHORTAGE</strong>
  61 <dd>
  62 The kernel could not allocate the lock set.
  63 </dl>
  64 <h3>RELATED INFORMATION</h3>
  65 <p>
  66 Functions:
  67 <a href="lock_acquire.html"><strong>lock_acquire</strong></a>,
  68 <a href="lock_make_stable.html"><strong>lock_make_stable</strong></a>,
  69 <a href="lock_try.html"><strong>lock_try</strong></a>,
  70 <a href="lock_handoff.html"><strong>lock_handoff</strong></a>,
  71 <a href="lock_handoff_accept.html"><strong>lock_handoff_accept</strong></a>,
  72 <a href="lock_try.html"><strong>lock_try</strong></a>,
  73 <a href="lock_set_destroy.html"><strong>lock_set_destroy</strong></a>.