1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup ScoreWatchdog |
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5 | * @brief Watchdog Tickle |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-1999. |
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10 | * On-Line Applications Research Corporation (OAR). |
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11 | * |
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12 | * The license and distribution terms for this file may be |
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13 | * found in the file LICENSE in this distribution or at |
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14 | * http://www.rtems.org/license/LICENSE. |
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15 | */ |
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16 | |
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17 | #if HAVE_CONFIG_H |
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18 | #include "config.h" |
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19 | #endif |
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20 | |
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21 | #include <rtems/score/watchdogimpl.h> |
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22 | |
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23 | void _Watchdog_Tickle( |
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24 | Watchdog_Header *header |
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25 | ) |
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26 | { |
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27 | ISR_lock_Context lock_context; |
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28 | |
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29 | _Watchdog_Acquire( header, &lock_context ); |
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30 | |
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31 | if ( !_Watchdog_Is_empty( header ) ) { |
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32 | Watchdog_Control *first; |
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33 | Watchdog_Interval delta; |
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34 | |
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35 | first = _Watchdog_First( header ); |
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36 | delta = first->delta_interval; |
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37 | |
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38 | /* |
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39 | * Although it is forbidden to insert watchdogs with a delta interval of |
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40 | * zero it is possible to observe watchdogs with a delta interval of zero |
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41 | * at this point. For example lets have a watchdog chain of one watchdog |
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42 | * with a delta interval of one and insert a new one with an initial value |
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43 | * of one. At the start of the insert procedure it will advance one step |
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44 | * and reduce its delta interval by one yielding zero. Now a tick happens. |
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45 | * This will remove the watchdog on the chain and update the insert |
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46 | * iterator. Now the insert operation continues and will insert the new |
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47 | * watchdog with a delta interval of zero. |
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48 | */ |
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49 | if ( delta > 0 ) { |
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50 | --delta; |
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51 | first->delta_interval = delta; |
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52 | } |
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53 | |
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54 | while ( delta == 0 ) { |
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55 | bool run; |
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56 | Watchdog_Service_routine_entry routine; |
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57 | Objects_Id id; |
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58 | void *user_data; |
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59 | |
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60 | run = ( first->state == WATCHDOG_ACTIVE ); |
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61 | |
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62 | _Watchdog_Remove_it( header, first ); |
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63 | |
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64 | routine = first->routine; |
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65 | id = first->id; |
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66 | user_data = first->user_data; |
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67 | |
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68 | _Watchdog_Release( header, &lock_context ); |
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69 | |
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70 | if ( run ) { |
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71 | (*routine)( id, user_data ); |
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72 | } |
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73 | |
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74 | _Watchdog_Acquire( header, &lock_context ); |
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75 | |
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76 | if ( _Watchdog_Is_empty( header ) ) { |
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77 | break; |
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78 | } |
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79 | |
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80 | first = _Watchdog_First( header ); |
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81 | delta = first->delta_interval; |
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82 | } |
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83 | } |
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84 | |
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85 | _Watchdog_Release( header, &lock_context ); |
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86 | } |
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