1 | /* |
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2 | * CORE Message Queue 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 CORE Message Queue Handler. |
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7 | * This core object provides task synchronization and communication functions |
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8 | * via messages passed to queue objects. |
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9 | * |
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10 | * COPYRIGHT (c) 1989-1999. |
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11 | * On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * The license and distribution terms for this file may be |
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14 | * found in the file LICENSE in this distribution or at |
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15 | * http://www.OARcorp.com/rtems/license.html. |
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16 | * |
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17 | * $Id$ |
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18 | */ |
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19 | |
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20 | #include <rtems/system.h> |
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21 | #include <rtems/score/chain.h> |
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22 | #include <rtems/score/isr.h> |
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23 | #include <rtems/score/object.h> |
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24 | #include <rtems/score/coremsg.h> |
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25 | #include <rtems/score/states.h> |
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26 | #include <rtems/score/thread.h> |
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27 | #include <rtems/score/wkspace.h> |
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28 | #if defined(RTEMS_MULTIPROCESSING) |
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29 | #include <rtems/score/mpci.h> |
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30 | #endif |
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31 | |
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32 | /*PAGE |
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33 | * |
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34 | * _CORE_message_queue_Broadcast |
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35 | * |
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36 | * This function sends a message for every thread waiting on the queue and |
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37 | * returns the number of threads made ready by the message. |
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38 | * |
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39 | * Input parameters: |
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40 | * the_message_queue - message is submitted to this message queue |
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41 | * buffer - pointer to message buffer |
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42 | * size - size in bytes of message to send |
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43 | * id - id of message queue |
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44 | * api_message_queue_mp_support - api specific mp support callout |
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45 | * count - area to store number of threads made ready |
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46 | * |
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47 | * Output parameters: |
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48 | * count - number of threads made ready |
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49 | * CORE_MESSAGE_QUEUE_SUCCESSFUL - if successful |
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50 | * error code - if unsuccessful |
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51 | */ |
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52 | |
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53 | CORE_message_queue_Status _CORE_message_queue_Broadcast( |
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54 | CORE_message_queue_Control *the_message_queue, |
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55 | void *buffer, |
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56 | unsigned32 size, |
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57 | Objects_Id id, |
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58 | CORE_message_queue_API_mp_support_callout api_message_queue_mp_support, |
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59 | unsigned32 *count |
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60 | ) |
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61 | { |
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62 | Thread_Control *the_thread; |
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63 | unsigned32 number_broadcasted; |
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64 | Thread_Wait_information *waitp; |
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65 | unsigned32 constrained_size; |
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66 | |
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67 | /* |
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68 | * If there are pending messages, then there can't be threads |
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69 | * waiting for us to send them a message. |
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70 | * |
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71 | * NOTE: This check is critical because threads can block on |
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72 | * send and receive and this ensures that we are broadcasting |
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73 | * the message to threads waiting to receive -- not to send. |
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74 | */ |
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75 | |
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76 | if ( the_message_queue->number_of_pending_messages != 0 ) { |
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77 | *count = 0; |
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78 | return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL; |
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79 | } |
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80 | |
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81 | /* |
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82 | * There must be no pending messages if there is a thread waiting to |
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83 | * receive a message. |
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84 | */ |
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85 | |
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86 | number_broadcasted = 0; |
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87 | while ((the_thread = _Thread_queue_Dequeue(&the_message_queue->Wait_queue))) { |
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88 | waitp = &the_thread->Wait; |
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89 | number_broadcasted += 1; |
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90 | |
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91 | constrained_size = size; |
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92 | if ( size > the_message_queue->maximum_message_size ) |
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93 | constrained_size = the_message_queue->maximum_message_size; |
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94 | |
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95 | _CORE_message_queue_Copy_buffer( |
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96 | buffer, |
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97 | waitp->return_argument, |
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98 | constrained_size |
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99 | ); |
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100 | |
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101 | *(unsigned32 *)the_thread->Wait.return_argument_1 = size; |
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102 | |
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103 | #if defined(RTEMS_MULTIPROCESSING) |
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104 | if ( !_Objects_Is_local_id( the_thread->Object.id ) ) |
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105 | (*api_message_queue_mp_support) ( the_thread, id ); |
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106 | #endif |
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107 | |
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108 | } |
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109 | *count = number_broadcasted; |
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110 | return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL; |
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111 | } |
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112 | |
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