source: rtems/cpukit/score/src/threadchangepriority.c @ 6a941e3

4.115
Last change on this file since 6a941e3 was 6a941e3, checked in by Sebastian Huber <sebastian.huber@…>, on Mar 17, 2015 at 3:24:44 PM

score: Fix _Thread_Change_priority()

Atomically update the current priority of a thread and the wait queue.
Serialize the scheduler update in a separate critical section with a
generation number.

New test sptests/spintrcritical23.

Close #2310.

  • Property mode set to 100644
File size: 1.4 KB
Line 
1/**
2 * @file
3 *
4 * @brief Changes the Priority of a Thread
5 *
6 * @ingroup ScoreThread
7 */
8
9/*
10 *  COPYRIGHT (c) 1989-2014.
11 *  On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.rtems.org/license/LICENSE.
16 */
17
18#if HAVE_CONFIG_H
19#include "config.h"
20#endif
21
22#include <rtems/score/threadimpl.h>
23#include <rtems/score/schedulerimpl.h>
24#include <rtems/score/threadqimpl.h>
25
26void _Thread_Change_priority(
27  Thread_Control   *the_thread,
28  Priority_Control  new_priority,
29  bool              prepend_it
30)
31{
32  ISR_Level level;
33
34  _ISR_Disable( level );
35
36  /*
37   *  Do not bother recomputing all the priority related information if
38   *  we are not REALLY changing priority.
39   */
40  if ( the_thread->current_priority != new_priority ) {
41    uint32_t my_generation = the_thread->priority_generation + 1;
42
43    the_thread->current_priority = new_priority;
44    the_thread->priority_generation = my_generation;
45
46    _Thread_queue_Requeue( the_thread->Wait.queue, the_thread );
47
48    _ISR_Flash( level );
49
50    if ( the_thread->priority_generation == my_generation ) {
51      if ( _States_Is_ready( the_thread->current_state ) ) {
52        _Scheduler_Change_priority(
53          the_thread,
54          new_priority,
55          prepend_it
56        );
57      } else {
58        _Scheduler_Update_priority( the_thread, new_priority );
59      }
60    }
61  }
62
63  _ISR_Enable( level );
64}
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