1 | /* |
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2 | * Event Manager |
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3 | * |
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4 | * COPYRIGHT (c) 1989-2008. |
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5 | * On-Line Applications Research Corporation (OAR). |
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6 | * |
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7 | * The license and distribution terms for this file may be |
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8 | * found in the file LICENSE in this distribution or at |
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9 | * http://www.rtems.com/license/LICENSE. |
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10 | * |
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11 | * $Id$ |
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12 | */ |
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13 | |
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14 | #if HAVE_CONFIG_H |
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15 | #include "config.h" |
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16 | #endif |
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17 | |
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18 | #include <rtems/system.h> |
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19 | #include <rtems/rtems/status.h> |
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20 | #include <rtems/rtems/event.h> |
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21 | #include <rtems/score/isr.h> |
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22 | #include <rtems/score/object.h> |
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23 | #include <rtems/rtems/options.h> |
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24 | #include <rtems/score/states.h> |
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25 | #include <rtems/score/thread.h> |
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26 | #include <rtems/rtems/tasks.h> |
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27 | |
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28 | /*PAGE |
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29 | * |
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30 | * _Event_Timeout |
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31 | * |
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32 | * This routine processes a thread which timeouts while waiting to |
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33 | * receive an event_set. It is called by the watchdog handler. |
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34 | * |
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35 | * Input parameters: |
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36 | * id - thread id |
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37 | * |
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38 | * Output parameters: NONE |
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39 | */ |
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40 | |
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41 | void _Event_Timeout( |
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42 | Objects_Id id, |
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43 | void *ignored |
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44 | ) |
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45 | { |
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46 | Thread_Control *the_thread; |
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47 | Objects_Locations location; |
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48 | ISR_Level level; |
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49 | |
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50 | the_thread = _Thread_Get( id, &location ); |
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51 | switch ( location ) { |
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52 | |
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53 | case OBJECTS_LOCAL: |
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54 | |
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55 | /* |
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56 | * If the event manager is not synchronized, then it is either |
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57 | * "nothing happened", "timeout", or "satisfied". If the_thread |
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58 | * is the executing thread, then it is in the process of blocking |
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59 | * and it is the thread which is responsible for the synchronization |
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60 | * process. |
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61 | * |
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62 | * If it is not satisfied, then it is "nothing happened" and |
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63 | * this is the "timeout" transition. After a request is satisfied, |
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64 | * a timeout is not allowed to occur. |
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65 | */ |
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66 | _ISR_Disable( level ); |
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67 | /* |
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68 | * Verify that the thread is still waiting for the event condition. |
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69 | * This test is necessary to avoid state corruption if the timeout |
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70 | * happens after the event condition is satisfied in |
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71 | * _Event_Surrender(). A satisfied event condition is indicated with |
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72 | * count set to zero. |
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73 | */ |
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74 | if ( !the_thread->Wait.count ) { |
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75 | _Thread_Unnest_dispatch(); |
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76 | _ISR_Enable( level ); |
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77 | return; |
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78 | } |
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79 | |
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80 | the_thread->Wait.count = 0; |
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81 | if ( _Thread_Is_executing( the_thread ) ) { |
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82 | if ( _Event_Sync_state == THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED ) |
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83 | _Event_Sync_state = THREAD_BLOCKING_OPERATION_TIMEOUT; |
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84 | } |
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85 | |
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86 | the_thread->Wait.return_code = RTEMS_TIMEOUT; |
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87 | _ISR_Enable( level ); |
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88 | _Thread_Unblock( the_thread ); |
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89 | _Thread_Unnest_dispatch(); |
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90 | break; |
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91 | |
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92 | #if defined(RTEMS_MULTIPROCESSING) |
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93 | case OBJECTS_REMOTE: /* impossible */ |
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94 | #endif |
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95 | case OBJECTS_ERROR: |
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96 | break; |
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97 | } |
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98 | } |
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