osfmk/man/thread_policy.html

   1 <h2>thread_policy</h2>
<hr>
<p>
<strong>Function</strong> - Set target thread's scheduling policy state.
<h3>SYNOPSIS</h3>
<pre>
<strong>kern_return_t   thread_policy</strong>
                <strong>(thread_act_t</strong>                            <var>thread</var>,
                 <strong>policy_t</strong>                                <var>policy</var>,
                 <strong>policy_base_t</strong>                             <var>base</var>,
                 <strong>base</strong>                                <var>base_count</var>,
                 <strong>boolean_t</strong>                            <var>set_limit</var><strong>);</strong>
</pre>
<h3>PARAMETERS</h3>
<dl>
<p>
<dt> <var>thread</var> 
<dd>
[in thread send right]
The thread scheduling policy is to be set.
<p>
<dt> <var>policy</var> 
<dd>
[in scalar]
Policy to be set.  The values currently defined are <strong>POLICY_TIMESHARE</strong>, 
<strong>POLICY_RR</strong> (round robin) and <strong>POLICY_FIFO</strong> (firstin, first-out).
<p>
<dt> <var>base</var> 
<dd>
[pointer to in structure]
Base scheduling policy specific data,
<strong>policy_fifo_base</strong>, <strong>policy_rr_base</strong> or <strong>policy_timeshare_base</strong>.
<p>
<dt> <var>base_count</var> 
<dd>
[in scalar]
The size of the buffer (in natural-sized units).
<p>
<dt> <var>set_limit</var> 
<dd>
[in scalar]
True if the thread's scheduling limits should be restricted to 
allow no more service than specified by <var>base</var>.
</dl>
<h3>DESCRIPTION</h3>
<p>
The <strong>thread_policy</strong> function sets the scheduling policy
to be applied to thread.  <var>policy</var> must be a scheduling policy 
currently "enabled" for the thread's assigned processor set.
<h3>RETURN VALUES</h3>
<dl>
<p>
<dt> <strong>KERN_INVALID_POLICY</strong>
<dd>
The processor set to which <var>thread</var> is currently assigned does
not currently enable <var>policy</var>.
<p>
<dt> <strong>KERN_POLICY_LIMIT</strong>
<dd>
The specified scheduling attributes exceeds the thread's limits.
</dl>
<h3>RELATED INFORMATION</h3>
<p>
Functions:
<a href="P_set_policy_control.html"><strong>processor_set_policy_control</strong></a>,
<a href="thread_set_policy.html"><strong>thread_set_policy</strong></a>,
<a href="task_policy.html"><strong>task_policy</strong></a>,
<a href="task_set_policy.html"><strong>task_set_policy</strong></a>.
<p>
Data Structures:
<a href="policy_fifo_info.html"><strong>policy_fifo_info</strong></a>,
<a href="policy_rr_info.html"><strong>policy_rr_info</strong></a>,
<a href="policy_timeshare_info.html"><strong>policy_timeshare_info</strong></a>.