1<h2>task_policy</h2>
2<hr>
3<p>
4<strong>Function</strong> - Set target task's default scheduling policy state.
5<h3>SYNOPSIS</h3>
6<pre>
7<strong>kern_return_t   task_policy</strong>
8                <strong>(task_t</strong>                                    <var>task</var>,
9                 <strong>policy_t</strong>                                <var>policy</var>,
10                 <strong>policy_base_t</strong>                             <var>base</var>,
11                 <strong>base</strong>                                <var>base_count</var>,
12                 <strong>boolean_t</strong>                            <var>set_limit</var>,
13                 <strong>boolean_t</strong>                       <var>change_threads</var><strong>);</strong>
14</pre>
15<h3>PARAMETERS</h3>
16<dl>
17<dt> <var>task</var> 
18<dd>
19[in task send right]
20The port for the task whose scheduling attributes 
21are to be set.
22<dt> <var>policy</var> 
23<dd>
24[in scalar]
25Default policy.  The values currently defined are <strong>POLICY_TIMESHARE</strong>, 
26<strong>POLICY_RR</strong> (round robin) and <strong>POLICY_FIFO</strong> (firstin, first-out).
27<dt> <var>base</var> 
28<dd>
29[pointer to in structure]
30Base scheduling policy data, <strong>policy_fifo_base</strong>, 
31<strong>policy_rr_base</strong> or <strong>policy_timeshare_base</strong>.
32<dt> <var>base_count</var> 
33<dd>
34[in scalar]
35The size of the buffer (in natural-sized units).
36<dt> <var>set_limit</var> 
37<dd>
38[in scalar]
39True if the scheduling limits for the task should be restricted 
40to allow no more service than specified by <var>base</var>.
41<dt> <var>change_threads</var> 
42<dd>
43[in scalar]
44True if the attributes (and limits, if <var>set_limit</var> is true) of
45existing threads within the task should also be changed.
46</dl>
47<h3>DESCRIPTION</h3>
48<p>
49The <strong>task_policy</strong> function sets the default scheduling
50attributes for <var>task</var>.  These 
51attributes are used when creating new threads.  Changing the default attributes 
52for a task does not affect the attributes of the contained threads unless 
53<var>change_threads</var> is <strong>TRUE</strong>.  At no time will a thread ever have 
54scheduling attributes that exceed the thread's limits.
55<h3>RETURN VALUES</h3>
56<dl>
57<dt> <strong>KERN_INVALID_POLICY</strong>
58<dd>
59The processor set does not currently enable <var>policy</var>.
60<dt> <strong>KERN_POLICY_LIMIT</strong>
61<dd>
62The specified scheduling attributes exceeds the thread's limits.
63</dl>
64<h3>RELATED INFORMATION</h3>
65<p>
66Functions:
67<a href="thread_policy.html"><strong>thread_policy</strong></a>,
68<a href="thread_set_policy.html"><strong>thread_set_policy</strong></a>,
69<a href="task_set_policy.html"><strong>task_set_policy</strong></a>,
70<a href="P_set_policy_control.html"><strong>processor_set_policy_control</strong></a>.
71<p>
72Data Structures:
73<a href="policy_fifo_info.html"><strong>policy_fifo_info</strong></a>,
74<a href="policy_rr_info.html"><strong>policy_rr_info</strong></a>,
75<a href="policy_timeshare_info.html"><strong>policy_timeshare_info</strong></a>.
76