source: rtems/cpukit/score/src/threadtickletimeslice.c @ c25cea9

4.8
Last change on this file since c25cea9 was c25cea9, checked in by Joel Sherrill <joel.sherrill@…>, on Aug 5, 2008 at 1:11:01 PM

2008-08-05 Xudong Guan <xudong.guan@…>

PR 1212/cpukit

  • rtems/src/taskmode.c, score/src/threadtickletimeslice.c: Time slicing will not happen if the task mode is changed from a non-timeslicing mode to timeslicing mode if it is done by the executing thread (e.g. in its task body). This change includes sp44 to demonstrate the problem and verify the correction.
  • 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.rtems.com/license/LICENSE.
11 *
12 *  $Id$
13 */
14
15#if HAVE_CONFIG_H
16#include "config.h"
17#endif
18
19#include <rtems/system.h>
20#include <rtems/score/apiext.h>
21#include <rtems/score/context.h>
22#include <rtems/score/interr.h>
23#include <rtems/score/isr.h>
24#include <rtems/score/object.h>
25#include <rtems/score/priority.h>
26#include <rtems/score/states.h>
27#include <rtems/score/sysstate.h>
28#include <rtems/score/thread.h>
29#include <rtems/score/threadq.h>
30#include <rtems/score/userext.h>
31#include <rtems/score/wkspace.h>
32
33/*PAGE
34 *
35 *  _Thread_Tickle_timeslice
36 *
37 *  This scheduler routine determines if timeslicing is enabled
38 *  for the currently executing thread and, if so, updates the
39 *  timeslice count and checks for timeslice expiration.
40 *
41 *  Input parameters:   NONE
42 *
43 *  Output parameters:  NONE
44 */
45
46void _Thread_Tickle_timeslice( void )
47{
48  Thread_Control *executing;
49
50  executing = _Thread_Executing;
51
52  #ifndef RTEMS_ENABLE_NANOSECOND_CPU_USAGE_STATISTICS
53    /*
54     *  Increment the number of ticks this thread has been executing
55     */
56    executing->ticks_executed++;
57  #endif
58
59  /*
60   *  If the thread is not preemptible or is not ready, then
61   *  just return.
62   */
63
64  if ( !executing->is_preemptible )
65    return;
66
67  if ( !_States_Is_ready( executing->current_state ) )
68    return;
69
70  /*
71   *  The cpu budget algorithm determines what happens next.
72   */
73
74  switch ( executing->budget_algorithm ) {
75    case THREAD_CPU_BUDGET_ALGORITHM_NONE:
76      break;
77
78    case THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE:
79    case THREAD_CPU_BUDGET_ALGORITHM_EXHAUST_TIMESLICE:
80      if ( (int)(--executing->cpu_time_budget) <= 0 ) {
81        _Thread_Reset_timeslice();
82        executing->cpu_time_budget = _Thread_Ticks_per_timeslice;
83      }
84      break;
85
86    case THREAD_CPU_BUDGET_ALGORITHM_CALLOUT:
87      if ( --executing->cpu_time_budget == 0 )
88        (*executing->budget_callout)( executing );
89      break;
90  }
91}
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