1 | /* |
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2 | * Mutex Handler |
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3 | * |
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4 | * DESCRIPTION: |
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5 | * |
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6 | * This package is the implementation of the Mutex Handler. |
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7 | * This handler provides synchronization and mutual exclusion capabilities. |
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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.com/license/LICENSE. |
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15 | * |
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16 | * $Id$ |
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17 | */ |
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18 | |
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19 | #if HAVE_CONFIG_H |
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20 | #include "config.h" |
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21 | #endif |
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22 | |
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23 | #include <rtems/system.h> |
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24 | #include <rtems/score/isr.h> |
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25 | #include <rtems/score/coremutex.h> |
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26 | #include <rtems/score/states.h> |
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27 | #include <rtems/score/thread.h> |
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28 | #include <rtems/score/threadq.h> |
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29 | |
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30 | /*PAGE |
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31 | * |
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32 | * _CORE_mutex_Initialize |
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33 | * |
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34 | * This routine initializes a mutex at create time and set the control |
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35 | * structure according to the values passed. |
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36 | * |
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37 | * Input parameters: |
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38 | * the_mutex - the mutex control block to initialize |
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39 | * the_mutex_attributes - the mutex attributes specified at create time |
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40 | * initial_lock - mutex initial lock or unlocked status |
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41 | * |
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42 | * Output parameters: NONE |
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43 | */ |
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44 | |
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45 | void _CORE_mutex_Initialize( |
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46 | CORE_mutex_Control *the_mutex, |
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47 | CORE_mutex_Attributes *the_mutex_attributes, |
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48 | uint32_t initial_lock |
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49 | ) |
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50 | { |
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51 | |
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52 | /* Add this to the RTEMS environment later ????????? |
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53 | rtems_assert( initial_lock == CORE_MUTEX_LOCKED || |
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54 | initial_lock == CORE_MUTEX_UNLOCKED ); |
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55 | */ |
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56 | |
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57 | the_mutex->Attributes = *the_mutex_attributes; |
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58 | the_mutex->lock = initial_lock; |
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59 | the_mutex->blocked_count = 0; |
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60 | |
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61 | if ( initial_lock == CORE_MUTEX_LOCKED ) { |
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62 | the_mutex->nest_count = 1; |
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63 | the_mutex->holder = _Thread_Executing; |
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64 | the_mutex->holder_id = _Thread_Executing->Object.id; |
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65 | if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) || |
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66 | _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ) |
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67 | |
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68 | #ifdef __RTEMS_STRICT_ORDER_MUTEX__ |
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69 | _Chain_Prepend_unprotected( &executing->lock_mutex, |
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70 | &the_mutex->queue.lock_queue ); |
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71 | the_mutex->queue.priority_before = executing->current_priority; |
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72 | #endif |
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73 | |
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74 | _Thread_Executing->resource_count++; |
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75 | } else { |
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76 | the_mutex->nest_count = 0; |
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77 | the_mutex->holder = NULL; |
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78 | the_mutex->holder_id = 0; |
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79 | } |
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80 | |
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81 | _Thread_queue_Initialize( |
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82 | &the_mutex->Wait_queue, |
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83 | _CORE_mutex_Is_fifo( the_mutex_attributes ) ? |
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84 | THREAD_QUEUE_DISCIPLINE_FIFO : THREAD_QUEUE_DISCIPLINE_PRIORITY, |
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85 | STATES_WAITING_FOR_MUTEX, |
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86 | CORE_MUTEX_TIMEOUT |
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87 | ); |
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88 | } |
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