source: rtems/cpukit/score/src/watchdog.c @ 3652ad35

4.104.114.84.95
Last change on this file since 3652ad35 was 3a4ae6c, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 11, 1995 at 7:35:39 PM

The word "RTEMS" almost completely removed from the core.

Configuration Table Template file added and all tests
modified to use this. All gvar.h and conftbl.h files
removed from test directories.

Configuration parameter maximum_devices added.

Core semaphore and mutex handlers added and RTEMS API Semaphore
Manager updated to reflect this.

Initialization sequence changed to invoke API specific initialization
routines. Initialization tasks table now owned by RTEMS Tasks Manager.

Added user extension for post-switch.

Utilized user extensions to implement API specific functionality
like signal dispatching.

Added extensions to the System Initialization Thread so that an
API can register a function to be invoked while the system
is being initialized. These are largely equivalent to the
pre-driver and post-driver hooks.

Added the Modules file oar-go32_p5, modified oar-go32, and modified
the file make/custom/go32.cfg to look at an environment varable which
determines what CPU model is being used.

All BSPs updated to reflect named devices and clock driver's IOCTL
used by the Shared Memory Driver. Also merged clock isr into
main file and removed ckisr.c where possible.

Updated spsize to reflect new and moved variables.

Makefiles for the executive source and include files updated to show
break down of files into Core, RTEMS API, and Neither.

Header and inline files installed into subdirectory based on whether
logically in the Core or a part of the RTEMS API.

  • Property mode set to 100644
File size: 6.3 KB
Line 
1/*
2 *  Watchdog Handler
3 *
4 *
5 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
6 *  On-Line Applications Research Corporation (OAR).
7 *  All rights assigned to U.S. Government, 1994.
8 *
9 *  This material may be reproduced by or for the U.S. Government pursuant
10 *  to the copyright license under the clause at DFARS 252.227-7013.  This
11 *  notice must appear in all copies of this file and its derivatives.
12 *
13 *  $Id$
14 */
15
16#include <rtems/system.h>
17#include <rtems/core/isr.h>
18#include <rtems/core/watchdog.h>
19
20/*PAGE
21 *
22 *  _Watchdog_Handler_initialization
23 *
24 *  This routine initializes the watchdog handler.
25 *
26 *  Input parameters:  NONE
27 *
28 *  Output parameters: NONE
29 */
30
31void _Watchdog_Handler_initialization( void )
32{
33  _Watchdog_Sync_count = 0;
34  _Watchdog_Sync_level = 0;
35  _Chain_Initialize_empty( &_Watchdog_Ticks_chain );
36  _Chain_Initialize_empty( &_Watchdog_Seconds_chain );
37}
38
39/*PAGE
40 *
41 *  _Watchdog_Remove
42 *
43 *  The routine removes a watchdog from a delta chain and updates
44 *  the delta counters of the remaining watchdogs.
45 */
46
47Watchdog_States _Watchdog_Remove(
48  Watchdog_Control *the_watchdog
49)
50{
51  ISR_Level                level;
52  Watchdog_States          previous_state;
53  Watchdog_Control *next_watchdog;
54
55  _ISR_Disable( level );
56  previous_state = the_watchdog->state;
57  switch ( previous_state ) {
58    case WATCHDOG_INACTIVE:
59      break;
60
61    case WATCHDOG_REINSERT: 
62   
63      /*
64       *  It is not actually on the chain so just change the state and
65       *  the Insert operation we interrupted will be aborted.
66       */
67      the_watchdog->state = WATCHDOG_INACTIVE;
68      break;
69
70    case WATCHDOG_ACTIVE:
71    case WATCHDOG_REMOVE_IT:
72
73      the_watchdog->state = WATCHDOG_INACTIVE;
74      next_watchdog = _Watchdog_Next( the_watchdog );
75
76      if ( _Watchdog_Next(next_watchdog) )
77        next_watchdog->delta_interval += the_watchdog->delta_interval;
78
79      if ( _Watchdog_Sync_count )
80        _Watchdog_Sync_level = _ISR_Nest_level;
81
82      _Chain_Extract_unprotected( &the_watchdog->Node );
83      break;
84  }
85  _ISR_Enable( level );
86  return( previous_state );
87}
88
89/*PAGE
90 *
91 *  _Watchdog_Adjust
92 *
93 *  This routine adjusts the delta chain backward or forward in response
94 *  to a time change.
95 *
96 *  Input parameters:
97 *    header    - pointer to the delta chain to be adjusted
98 *    direction - forward or backward adjustment to delta chain
99 *    units     - units to adjust
100 *
101 *  Output parameters:
102 */
103
104void _Watchdog_Adjust(
105  Chain_Control               *header,
106  Watchdog_Adjust_directions   direction,
107  Watchdog_Interval            units
108)
109{
110  if ( !_Chain_Is_empty( header ) ) {
111    switch ( direction ) {
112      case WATCHDOG_BACKWARD:
113        _Watchdog_First( header )->delta_interval += units;
114        break;
115      case WATCHDOG_FORWARD:
116        while ( units ) {
117          if ( units < _Watchdog_First( header )->delta_interval ) {
118            _Watchdog_First( header )->delta_interval -= units;
119            break;
120          } else {
121            units -= _Watchdog_First( header )->delta_interval;
122            _Watchdog_First( header )->delta_interval = 1;
123            _Watchdog_Tickle( header );
124            if ( _Chain_Is_empty( header ) )
125              break;
126          }
127        }
128        break;
129    }
130  }
131}
132
133/*PAGE
134 *
135 *  _Watchdog_Insert
136 *
137 *  This routine inserts a watchdog timer on to the appropriate delta
138 *  chain while updating the delta interval counters.
139 */
140
141void _Watchdog_Insert(
142  Chain_Control         *header,
143  Watchdog_Control      *the_watchdog,
144  Watchdog_Insert_modes  insert_mode
145)
146{
147  ISR_Level          level;
148  Watchdog_Control  *after;
149  unsigned32         insert_isr_nest_level;
150  Watchdog_Interval  delta_interval;
151 
152
153  insert_isr_nest_level   = _ISR_Nest_level;
154  the_watchdog->state = WATCHDOG_REINSERT;
155
156  _Watchdog_Sync_count++;
157restart:
158  delta_interval = the_watchdog->initial;
159
160  _ISR_Disable( level );
161
162  for ( after = _Watchdog_First( header ) ;
163        ;
164        after = _Watchdog_Next( after ) ) {
165
166     if ( delta_interval == 0 || !_Watchdog_Next( after ) )
167       break;
168
169     if ( delta_interval < after->delta_interval ) {
170       after->delta_interval -= delta_interval;
171       break;
172     }
173
174     delta_interval -= after->delta_interval;
175
176     /*
177      *  If you experience problems comment out the _ISR_Flash line.  This
178      *  (3.2.0) is the first release with this critical section redesigned.
179      *  Under certain circumstances, the PREVIOUS critical section algorithm
180      *  used around this flash point allows interrupts to execute
181      *  which violated the design assumptions.  The critical section
182      *  mechanism used here WAS redesigned to address this.
183      */
184
185     _ISR_Flash( level );
186
187     if ( the_watchdog->state != WATCHDOG_REINSERT ) {
188       goto exit_insert;
189     }
190
191     if ( _Watchdog_Sync_level > insert_isr_nest_level ) {
192       _Watchdog_Sync_level = insert_isr_nest_level;
193       _ISR_Enable( level );
194       goto restart;
195     }
196  }
197
198  if ( insert_mode == WATCHDOG_ACTIVATE_NOW )
199    _Watchdog_Activate( the_watchdog );
200
201  the_watchdog->delta_interval = delta_interval;
202
203  _Chain_Insert_unprotected( after->Node.previous, &the_watchdog->Node );
204
205exit_insert:
206  _Watchdog_Sync_level = insert_isr_nest_level;
207  _Watchdog_Sync_count--;
208  _ISR_Enable( level );
209}
210
211/*PAGE
212 *
213 *  _Watchdog_Tickle
214 *
215 *  This routine decrements the delta counter in response to a tick.  The
216 *  delta chain is updated accordingly.
217 *
218 *  Input parameters:
219 *    header - pointer to the delta chain to be tickled
220 *
221 *  Output parameters: NONE
222 */
223
224void _Watchdog_Tickle(
225  Chain_Control *header
226)
227{
228  Watchdog_Control *the_watchdog;
229
230  if ( _Chain_Is_empty( header ) )
231    return;
232
233  the_watchdog = _Watchdog_First( header );
234  the_watchdog->delta_interval--;
235  if ( the_watchdog->delta_interval != 0 )
236    return;
237
238  do {
239     switch( _Watchdog_Remove( the_watchdog ) ) {
240       case WATCHDOG_ACTIVE:
241         (*the_watchdog->routine)(
242           the_watchdog->id,
243           the_watchdog->user_data
244         );
245         break;
246       case WATCHDOG_REINSERT:
247         _Watchdog_Insert( header, the_watchdog, WATCHDOG_ACTIVATE_NOW );
248         break;
249       case WATCHDOG_INACTIVE:
250       case WATCHDOG_REMOVE_IT:
251         break;
252     }
253     the_watchdog = _Watchdog_First( header );
254   } while ( !_Chain_Is_empty( header ) &&
255             (the_watchdog->delta_interval == 0) );
256}
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