source: rtems/c/src/exec/rtems/src/event.c @ 107ce47b

4.104.114.84.95
Last change on this file since 107ce47b was 107ce47b, checked in by Joel Sherrill <joel.sherrill@…>, on Feb 9, 1996 at 2:30:42 PM

new isr synchronization algorithm using a single enumerated set of states.

  • Property mode set to 100644
File size: 8.6 KB
Line 
1/*
2 *  Event Manager
3 *
4 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
5 *  On-Line Applications Research Corporation (OAR).
6 *  All rights assigned to U.S. Government, 1994.
7 *
8 *  This material may be reproduced by or for the U.S. Government pursuant
9 *  to the copyright license under the clause at DFARS 252.227-7013.  This
10 *  notice must appear in all copies of this file and its derivatives.
11 *
12 *  $Id$
13 */
14
15#include <rtems/system.h>
16#include <rtems/rtems/status.h>
17#include <rtems/rtems/event.h>
18#include <rtems/score/isr.h>
19#include <rtems/score/object.h>
20#include <rtems/rtems/options.h>
21#include <rtems/score/states.h>
22#include <rtems/score/thread.h>
23#include <rtems/rtems/tasks.h>
24
25/*PAGE
26 *
27 *  rtems_event_send
28 *
29 *  This directive allows a thread send an event set to another thread.
30 *
31 *  Input parameters:
32 *    id    - thread id
33 *    event - event set
34 *
35 *  Output parameters:
36 *    RTEMS_SUCCESSFUL - if successful
37 *    error code - if unsuccessful
38 */
39
40rtems_status_code rtems_event_send(
41  Objects_Id         id,
42  rtems_event_set event_in
43)
44{
45  register Thread_Control *the_thread;
46  Objects_Locations        location;
47  RTEMS_API_Control       *api;
48
49  the_thread = _Thread_Get( id, &location );
50  switch ( location ) {
51    case OBJECTS_ERROR:
52      return RTEMS_INVALID_ID;
53    case OBJECTS_REMOTE:
54      return(
55        _Event_MP_Send_request_packet(
56          EVENT_MP_SEND_REQUEST,
57          id,
58          event_in
59        )
60      );
61    case OBJECTS_LOCAL:
62      api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
63      _Event_sets_Post( event_in, &api->pending_events );
64      _Event_Surrender( the_thread );
65      _Thread_Enable_dispatch();
66      return RTEMS_SUCCESSFUL;
67  }
68
69  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */
70}
71
72/*PAGE
73 *
74 *  rtems_event_receive
75 *
76 *  This directive allows a thread to receive a set of events.
77 *
78 *  Input parameters:
79 *    event_in   - input event condition
80 *    option_set - options
81 *    ticks      - number of ticks to wait (0 means wait forever)
82 *    event_out  - pointer to output event set
83 *
84 *  Output parameters:
85 *    event out         - event set
86 *    RTEMS_SUCCESSFUL - if successful
87 *    error code        - if unsuccessful
88 */
89
90rtems_status_code rtems_event_receive(
91  rtems_event_set  event_in,
92  rtems_option     option_set,
93  rtems_interval   ticks,
94  rtems_event_set *event_out
95)
96{
97  RTEMS_API_Control       *api;
98
99  api = _Thread_Executing->API_Extensions[ THREAD_API_RTEMS ];
100
101  if ( _Event_sets_Is_empty( event_in ) ) {
102    *event_out = api->pending_events;
103    return RTEMS_SUCCESSFUL;
104  }
105
106  _Thread_Disable_dispatch();
107  _Event_Seize( event_in, option_set, ticks, event_out );
108  _Thread_Enable_dispatch();
109  return( _Thread_Executing->Wait.return_code );
110}
111
112
113/*PAGE
114 *
115 *  _Event_Seize
116 *
117 *  This routine attempts to satisfy the requested event condition
118 *  for the running thread.
119 *
120 *  Input parameters:
121 *    event_in   - the event condition to satisfy
122 *    option_set - acquire event options
123 *    ticks      - interval to wait
124 *    event_out  - pointer to event set output area
125 *
126 *  Output parameters: NONE
127 *    *event_out - event set output area filled in
128 *
129 *  INTERRUPT LATENCY:
130 *    available
131 *    wait
132 *    check sync
133 */
134
135void _Event_Seize(
136  rtems_event_set  event_in,
137  rtems_option     option_set,
138  rtems_interval   ticks,
139  rtems_event_set *event_out
140)
141{
142  Thread_Control    *executing;
143  rtems_event_set    seized_events;
144  rtems_event_set    pending_events;
145  ISR_Level          level;
146  RTEMS_API_Control  *api;
147  Event_Sync_states   sync_state;
148
149  executing = _Thread_Executing;
150  executing->Wait.return_code = RTEMS_SUCCESSFUL;
151
152  api = executing->API_Extensions[ THREAD_API_RTEMS ];
153
154  _ISR_Disable( level );
155  pending_events = api->pending_events;
156  seized_events  = _Event_sets_Get( pending_events, event_in );
157
158  if ( !_Event_sets_Is_empty( seized_events ) &&
159       (seized_events == event_in || _Options_Is_any( option_set )) ) {
160    api->pending_events =
161      _Event_sets_Clear( pending_events, seized_events );
162    _ISR_Enable( level );
163    *event_out = seized_events;
164    return;
165  }
166
167  if ( _Options_Is_no_wait( option_set ) ) {
168    _ISR_Enable( level );
169    executing->Wait.return_code = RTEMS_UNSATISFIED;
170    *event_out = seized_events;
171    return;
172  }
173
174  _Event_Sync_state = EVENT_SYNC_NOTHING_HAPPENED;
175
176  executing->Wait.option            = (unsigned32) option_set;
177  executing->Wait.count             = (unsigned32) event_in;
178  executing->Wait.return_argument   = event_out;
179
180  _ISR_Enable( level );
181
182  if ( ticks ) {
183    _Watchdog_Initialize(
184      &executing->Timer,
185      _Event_Timeout,
186      executing->Object.id,
187      NULL
188    );
189    _Watchdog_Insert_ticks( &executing->Timer, ticks );
190  }
191
192  _Thread_Set_state( executing, STATES_WAITING_FOR_EVENT );
193
194  _ISR_Disable( level );
195
196  sync_state = _Event_Sync_state;
197  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
198
199  switch ( sync_state ) {
200    case EVENT_SYNC_SYNCHRONIZED:
201    case EVENT_SYNC_NOTHING_HAPPENED:
202      _ISR_Enable( level );
203      return;
204    case EVENT_SYNC_TIMEOUT:
205      executing->Wait.return_code = RTEMS_TIMEOUT;
206      _ISR_Enable( level );
207      _Thread_Unblock( executing );
208      return;
209    case EVENT_SYNC_SATISFIED:
210      if ( _Watchdog_Is_active( &executing->Timer ) ) {
211        _Watchdog_Deactivate( &executing->Timer );
212        _ISR_Enable( level );
213        (void) _Watchdog_Remove( &executing->Timer );
214      } else
215        _ISR_Enable( level );
216      _Thread_Unblock( executing );
217      return;
218  }
219}
220
221/*PAGE
222 *
223 *  _Event_Surrender
224 *
225 *  This routines remove a thread from the specified threadq.
226 *
227 *  Input parameters:
228 *    the_thread - pointer to thread to be dequeued
229 *
230 *  Output parameters: NONE
231 *
232 *  INTERRUPT LATENCY:
233 *    before flash
234 *    after flash
235 *    check sync
236 */
237
238void _Event_Surrender(
239  Thread_Control *the_thread
240)
241{
242  ISR_Level           level;
243  rtems_event_set     pending_events;
244  rtems_event_set     event_condition;
245  rtems_event_set     seized_events;
246  rtems_option        option_set;
247  RTEMS_API_Control  *api;
248
249  api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
250
251  option_set = (rtems_option) the_thread->Wait.option;
252
253  _ISR_Disable( level );
254  pending_events  = api->pending_events;
255  event_condition = (rtems_event_set) the_thread->Wait.count;
256
257  seized_events = _Event_sets_Get( pending_events, event_condition );
258
259  if ( !_Event_sets_Is_empty( seized_events ) ) {
260    if ( _States_Is_waiting_for_event( the_thread->current_state ) ) {
261      if ( seized_events == event_condition || _Options_Is_any( option_set ) ) {
262        api->pending_events =
263           _Event_sets_Clear( pending_events, seized_events );
264        *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
265
266        _ISR_Flash( level );
267
268        if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
269          _ISR_Enable( level );
270          _Thread_Unblock( the_thread );
271        }
272        else {
273          _Watchdog_Deactivate( &the_thread->Timer );
274          _ISR_Enable( level );
275          (void) _Watchdog_Remove( &the_thread->Timer );
276          _Thread_Unblock( the_thread );
277        }
278        return;
279      }
280    }
281
282    switch ( _Event_Sync_state ) {
283      case EVENT_SYNC_SYNCHRONIZED:
284      case EVENT_SYNC_SATISFIED:
285        break;
286 
287      case EVENT_SYNC_NOTHING_HAPPENED:
288      case EVENT_SYNC_TIMEOUT:
289        if ( !_Thread_Is_executing( the_thread ) )
290          break;
291
292        if ( seized_events == event_condition || _Options_Is_any(option_set) ) {
293          api->pending_events = 
294               _Event_sets_Clear( pending_events,seized_events );
295          *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
296          _Event_Sync_state = EVENT_SYNC_SATISFIED;
297        }
298        break;
299    }
300  }
301  _ISR_Enable( level );
302}
303
304/*PAGE
305 *
306 *  _Event_Timeout
307 *
308 *  This routine processes a thread which timeouts while waiting to
309 *  receive an event_set. It is called by the watchdog handler.
310 *
311 *  Input parameters:
312 *    id - thread id
313 *
314 *  Output parameters: NONE
315 */
316
317void _Event_Timeout(
318  Objects_Id  id,
319  void       *ignored
320)
321{
322  Thread_Control *the_thread;
323  Objects_Locations      location;
324
325  the_thread = _Thread_Get( id, &location );
326  switch ( location ) {
327    case OBJECTS_ERROR:
328    case OBJECTS_REMOTE:  /* impossible */
329      break;
330    case OBJECTS_LOCAL:
331      if ( _Event_Sync_state != EVENT_SYNC_SYNCHRONIZED && 
332           _Thread_Is_executing( the_thread ) ) {
333        if ( _Event_Sync_state != EVENT_SYNC_SATISFIED )
334          _Event_Sync_state = EVENT_SYNC_TIMEOUT;
335      } else {
336        the_thread->Wait.return_code = RTEMS_TIMEOUT;
337        _Thread_Unblock( the_thread );
338      }
339      _Thread_Unnest_dispatch();
340      break;
341  }
342}
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