source: rtems/c/src/exec/rtems/src/ratemonperiod.c @ 08311cc3

4.104.114.84.95
Last change on this file since 08311cc3 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: 4.6 KB
Line 
1/*
2 *  Rate Monotonic Manager
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 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/rtems/status.h>
17#include <rtems/rtems/support.h>
18#include <rtems/score/isr.h>
19#include <rtems/score/object.h>
20#include <rtems/rtems/ratemon.h>
21#include <rtems/score/thread.h>
22
23/*PAGE
24 *
25 *  rtems_rate_monotonic_period
26 *
27 *  This directive allows a thread to manipulate a rate monotonic timer.
28 *
29 *  Input parameters:
30 *    id     - rate monotonic id
31 *    length - length of period (in ticks)
32 *
33 *  Output parameters:
34 *    RTEMS_SUCCESSFUL - if successful
35 *    error code        - if unsuccessful
36 */
37
38rtems_status_code rtems_rate_monotonic_period(
39  Objects_Id        id,
40  rtems_interval    length
41)
42{
43  Rate_monotonic_Control              *the_period;
44  Objects_Locations                    location;
45  rtems_status_code                    return_value;
46  rtems_rate_monotonic_period_states   local_state;
47  ISR_Level                            level;
48
49  the_period = _Rate_monotonic_Get( id, &location );
50  switch ( location ) {
51    case OBJECTS_REMOTE:            /* should never return this */
52      return RTEMS_INTERNAL_ERROR;
53
54    case OBJECTS_ERROR:
55      return RTEMS_INVALID_ID;
56
57    case OBJECTS_LOCAL:
58      if ( !_Thread_Is_executing( the_period->owner ) ) {
59        _Thread_Enable_dispatch();
60        return RTEMS_NOT_OWNER_OF_RESOURCE;
61      }
62
63      if ( length == RTEMS_PERIOD_STATUS ) {
64        switch ( the_period->state ) {
65          case RATE_MONOTONIC_INACTIVE:
66            return_value = RTEMS_NOT_DEFINED;
67            break;
68          case RATE_MONOTONIC_ACTIVE:
69            return_value = RTEMS_SUCCESSFUL;
70            break;
71          case RATE_MONOTONIC_EXPIRED:
72            return_value = RTEMS_TIMEOUT;
73            break;
74          default:              /* unreached -- only to remove warnings */
75            return_value = RTEMS_INTERNAL_ERROR;
76            break;
77        }
78        _Thread_Enable_dispatch();
79        return( return_value );
80      }
81
82      _ISR_Disable( level );
83      switch ( the_period->state ) {
84        case RATE_MONOTONIC_INACTIVE:
85          _ISR_Enable( level );
86          the_period->state = RATE_MONOTONIC_ACTIVE;
87          _Watchdog_Initialize(
88            &the_period->Timer,
89            _Rate_monotonic_Timeout,
90            id,
91            NULL
92          );
93
94          the_period->owner_ticks_executed_at_period =
95            _Thread_Executing->ticks_executed;
96
97          the_period->time_at_period = _Watchdog_Ticks_since_boot;
98
99          _Watchdog_Insert_ticks( &the_period->Timer, length );
100          _Thread_Enable_dispatch();
101          return RTEMS_SUCCESSFUL;
102
103        case RATE_MONOTONIC_ACTIVE:
104          /*
105           *  This tells the _Rate_monotonic_Timeout that this task is
106           *  in the process of blocking on the period.
107           */
108
109          the_period->state = RATE_MONOTONIC_OWNER_IS_BLOCKING;
110          _ISR_Enable( level );
111
112          _Thread_Executing->Wait.id = the_period->Object.id;
113          _Thread_Set_state( _Thread_Executing, STATES_WAITING_FOR_PERIOD );
114         
115          /*
116           *  Did the watchdog timer expire while we were actually blocking
117           *  on it?
118           */
119
120          _ISR_Disable( level );
121            local_state = the_period->state;
122            the_period->state = RATE_MONOTONIC_ACTIVE;
123          _ISR_Enable( level );
124
125          /*
126           *  If it did, then we want to unblock ourself and continue as
127           *  if nothing happen.  The period was reset in the timeout routine.
128           */
129
130          if ( local_state == RATE_MONOTONIC_EXPIRED_WHILE_BLOCKING )
131            _Thread_Clear_state( _Thread_Executing, STATES_WAITING_FOR_PERIOD );
132
133          _Thread_Enable_dispatch();
134          return RTEMS_SUCCESSFUL;
135          break;
136
137        case RATE_MONOTONIC_EXPIRED:
138          _ISR_Enable( level );
139          the_period->state = RATE_MONOTONIC_ACTIVE;
140          the_period->owner_ticks_executed_at_period =
141            _Thread_Executing->ticks_executed;
142          the_period->time_at_period = _Watchdog_Ticks_since_boot;
143
144          _Watchdog_Insert_ticks( &the_period->Timer, length );
145          _Thread_Enable_dispatch();
146          return RTEMS_TIMEOUT;
147
148        case RATE_MONOTONIC_OWNER_IS_BLOCKING:
149        case RATE_MONOTONIC_EXPIRED_WHILE_BLOCKING:
150          /*
151           *  These should never happen.
152           */
153          break;
154      }
155  }
156
157  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */
158}
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