source: rtems/c/src/exec/score/src/threadrotatequeue.c @ df49c60

4.104.114.84.95
Last change on this file since df49c60 was 08311cc3, checked in by Joel Sherrill <joel.sherrill@…>, on 11/17/99 at 17:51:34

Updated copyright notice.

  • Property mode set to 100644
File size: 2.1 KB
Line 
1/*
2 *  Thread Handler
3 *
4 *
5 *  COPYRIGHT (c) 1989-1999.
6 *  On-Line Applications Research Corporation (OAR).
7 *
8 *  The license and distribution terms for this file may be
9 *  found in found in the file LICENSE in this distribution or at
10 *  http://www.OARcorp.com/rtems/license.html.
11 *
12 *  $Id$
13 */
14
15#include <rtems/system.h>
16#include <rtems/score/apiext.h>
17#include <rtems/score/context.h>
18#include <rtems/score/interr.h>
19#include <rtems/score/isr.h>
20#include <rtems/score/object.h>
21#include <rtems/score/priority.h>
22#include <rtems/score/states.h>
23#include <rtems/score/sysstate.h>
24#include <rtems/score/thread.h>
25#include <rtems/score/threadq.h>
26#include <rtems/score/userext.h>
27#include <rtems/score/wkspace.h>
28
29/*PAGE
30 *
31 *  _Thread_Rotate_Ready_Queue
32 *
33 *  This kernel routine will rotate the ready queue.
34 *  remove the running THREAD from the ready chain
35 *  and place it immediatly at the rear of this chain.  Reset timeslice
36 *  and yield the processor functions both use this routine, therefore if
37 *  reset is TRUE and this is the only thread on the chain then the
38 *  timeslice counter is reset.  The heir THREAD will be updated if the
39 *  running is also the currently the heir.
40 *
41 *  Input parameters: 
42 *      Priority of the queue we wish to modify.
43 *
44 *  Output parameters:  NONE
45 *
46 *  INTERRUPT LATENCY:
47 *    ready chain
48 *    select heir
49 */
50
51void _Thread_Rotate_Ready_Queue(
52  Priority_Control  priority
53)
54{
55  ISR_Level       level;
56  Thread_Control *executing;
57  Chain_Control  *ready;
58  Chain_Node     *node;
59
60  ready     = &_Thread_Ready_chain[ priority ];
61  executing = _Thread_Executing;
62
63  if ( ready == executing->ready ) {
64    _Thread_Yield_processor();
65    return;
66  }
67
68  _ISR_Disable( level );
69
70  if ( !_Chain_Is_empty( ready ) ) {
71    if (!_Chain_Has_only_one_node( ready ) ) {
72      node = _Chain_Get_first_unprotected( ready );
73      _Chain_Append_unprotected( ready, node );
74    }
75  }
76
77  _ISR_Flash( level );
78
79  if ( _Thread_Heir->ready == ready )
80    _Thread_Heir = (Thread_Control *) ready->first;
81
82  if ( executing != _Thread_Heir )
83    _Context_Switch_necessary = TRUE;
84
85  _ISR_Enable( level );
86}
87
88
89
90
91
92
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