source: rtems/cpukit/rtems/src/ratemongetstatus.c @ ee0e4135

5
Last change on this file since ee0e4135 was ee0e4135, checked in by Sebastian Huber <sebastian.huber@…>, on 08/04/16 at 08:20:29

score: Fix a release/cancel job race condition

Split up the potential thread priority change in the scheduler
release/cancel job operation. Protect the rate monotonic period state
with a dedicated SMP lock. This avoids a race condition during
_Rate_monotonic_Timeout() while _Rate_monotonic_Cancel() is called on
another processor.

  • Property mode set to 100644
File size: 2.1 KB
Line 
1/**
2 *  @file
3 *
4 *  @brief RTEMS Rate Monotonic Get Status
5 *  @ingroup ClassicRateMon
6 */
7
8/*
9 *  COPYRIGHT (c) 1989-2009.
10 *  On-Line Applications Research Corporation (OAR).
11 *  Copyright (c) 2016 embedded brains GmbH.
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/rtems/ratemonimpl.h>
23
24rtems_status_code rtems_rate_monotonic_get_status(
25  rtems_id                            id,
26  rtems_rate_monotonic_period_status *period_status
27)
28{
29  Rate_monotonic_Control *the_period;
30  ISR_lock_Context        lock_context;
31  rtems_status_code       status;
32
33  if ( period_status == NULL ) {
34    return RTEMS_INVALID_ADDRESS;
35  }
36
37  the_period = _Rate_monotonic_Get( id, &lock_context );
38  if ( the_period == NULL ) {
39    return RTEMS_INVALID_ID;
40  }
41
42  _Rate_monotonic_Acquire_critical( the_period, &lock_context );
43
44  period_status->owner = the_period->owner->Object.id;
45  period_status->state = the_period->state;
46
47  if ( the_period->state == RATE_MONOTONIC_INACTIVE ) {
48    /*
49     *  If the period is inactive, there is no information.
50     */
51    _Timespec_Set_to_zero( &period_status->since_last_period );
52    _Timespec_Set_to_zero( &period_status->executed_since_last_period );
53    status = RTEMS_SUCCESSFUL;
54  } else {
55    Timestamp_Control wall_since_last_period;
56    Timestamp_Control cpu_since_last_period;
57    bool              valid_status;
58
59    /*
60     *  Grab the current status.
61     */
62    valid_status = _Rate_monotonic_Get_status(
63      the_period,
64      &wall_since_last_period,
65      &cpu_since_last_period
66    );
67    if ( valid_status ) {
68      _Timestamp_To_timespec(
69        &wall_since_last_period,
70        &period_status->since_last_period
71      );
72      _Timestamp_To_timespec(
73        &cpu_since_last_period,
74        &period_status->executed_since_last_period
75      );
76      status = RTEMS_SUCCESSFUL;
77    } else {
78      status = RTEMS_NOT_DEFINED;
79    }
80  }
81
82  _Rate_monotonic_Release( the_period, &lock_context );
83  return status;
84}
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