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 03/17/15 at 15:24:44

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
RevLine 
[1b475860]1/**
2 * @file
3 *
4 * @brief Changes the Priority of a Thread
[05df0a8]5 *
[1b475860]6 * @ingroup ScoreThread
7 */
8
9/*
[3250664]10 *  COPYRIGHT (c) 1989-2014.
[05df0a8]11 *  On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
[dcf3687]14 *  found in the file LICENSE in this distribution or at
[c499856]15 *  http://www.rtems.org/license/LICENSE.
[05df0a8]16 */
17
[a8eed23]18#if HAVE_CONFIG_H
19#include "config.h"
20#endif
21
[5618c37a]22#include <rtems/score/threadimpl.h>
[c6e21ee1]23#include <rtems/score/schedulerimpl.h>
[a112364]24#include <rtems/score/threadqimpl.h>
[05df0a8]25
26void _Thread_Change_priority(
27  Thread_Control   *the_thread,
28  Priority_Control  new_priority,
[484a769]29  bool              prepend_it
[05df0a8]30)
31{
[6a941e3]32  ISR_Level level;
33
34  _ISR_Disable( level );
35
[96d0b64]36  /*
37   *  Do not bother recomputing all the priority related information if
38   *  we are not REALLY changing priority.
39   */
[f39f667a]40  if ( the_thread->current_priority != new_priority ) {
[6a941e3]41    uint32_t my_generation = the_thread->priority_generation + 1;
[f39f667a]42
43    the_thread->current_priority = new_priority;
[6a941e3]44    the_thread->priority_generation = my_generation;
[f39f667a]45
[6a941e3]46    _Thread_queue_Requeue( the_thread->Wait.queue, the_thread );
[b8a5abf]47
[6a941e3]48    _ISR_Flash( level );
[96d0b64]49
[6a941e3]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    }
[d9aca5f5]61  }
[6a941e3]62
63  _ISR_Enable( level );
[05df0a8]64}
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