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.rtems.com/license/LICENSE. |
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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 | #if HAVE_CONFIG_H |
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21 | #include "config.h" |
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22 | #endif |
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23 | |
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24 | #include <rtems/system.h> |
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25 | #include <rtems/score/chain.h> |
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26 | #include <rtems/score/isr.h> |
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27 | #include <rtems/score/object.h> |
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28 | #include <rtems/score/coremsg.h> |
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29 | #include <rtems/score/states.h> |
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30 | #include <rtems/score/thread.h> |
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31 | #include <rtems/score/wkspace.h> |
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32 | #if defined(RTEMS_MULTIPROCESSING) |
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33 | #include <rtems/score/mpci.h> |
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34 | #endif |
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35 | |
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36 | /*PAGE |
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37 | * |
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38 | * _CORE_message_queue_Initialize |
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39 | * |
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40 | * This routine initializes a newly created message queue based on the |
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41 | * specified data. |
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42 | * |
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43 | * Input parameters: |
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44 | * the_message_queue - the message queue to initialize |
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45 | * the_class - the API specific object class |
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46 | * the_message_queue_attributes - the message queue's attributes |
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47 | * maximum_pending_messages - maximum message and reserved buffer count |
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48 | * maximum_message_size - maximum size of each message |
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49 | * |
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50 | * Output parameters: |
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51 | * TRUE - if the message queue is initialized |
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52 | * FALSE - if the message queue is NOT initialized |
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53 | */ |
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54 | |
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55 | bool _CORE_message_queue_Initialize( |
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56 | CORE_message_queue_Control *the_message_queue, |
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57 | CORE_message_queue_Attributes *the_message_queue_attributes, |
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58 | uint32_t maximum_pending_messages, |
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59 | size_t maximum_message_size |
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60 | ) |
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61 | { |
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62 | size_t message_buffering_required; |
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63 | size_t allocated_message_size; |
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64 | |
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65 | the_message_queue->maximum_pending_messages = maximum_pending_messages; |
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66 | the_message_queue->number_of_pending_messages = 0; |
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67 | the_message_queue->maximum_message_size = maximum_message_size; |
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68 | _CORE_message_queue_Set_notify( the_message_queue, NULL, NULL ); |
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69 | |
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70 | /* |
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71 | * Round size up to multiple of a pointer for chain init and |
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72 | * check for overflow on adding overhead to each message. |
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73 | */ |
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74 | |
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75 | allocated_message_size = maximum_message_size; |
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76 | if (allocated_message_size & (sizeof(uint32_t) - 1)) { |
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77 | allocated_message_size += sizeof(uint32_t); |
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78 | allocated_message_size &= ~(sizeof(uint32_t) - 1); |
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79 | } |
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80 | |
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81 | if (allocated_message_size < maximum_message_size) |
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82 | return false; |
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83 | |
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84 | /* |
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85 | * Calculate how much total memory is required for message buffering and |
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86 | * check for overflow on the multiplication. |
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87 | */ |
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88 | message_buffering_required = (size_t) maximum_pending_messages * |
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89 | (allocated_message_size + sizeof(CORE_message_queue_Buffer_control)); |
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90 | |
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91 | if (message_buffering_required < allocated_message_size) |
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92 | return false; |
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93 | |
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94 | /* |
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95 | * Attempt to allocate the message memory |
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96 | */ |
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97 | the_message_queue->message_buffers = (CORE_message_queue_Buffer *) |
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98 | _Workspace_Allocate( message_buffering_required ); |
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99 | |
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100 | if (the_message_queue->message_buffers == 0) |
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101 | return false; |
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102 | |
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103 | /* |
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104 | * Initialize the pool of inactive messages, pending messages, |
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105 | * and set of waiting threads. |
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106 | */ |
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107 | _Chain_Initialize ( |
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108 | &the_message_queue->Inactive_messages, |
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109 | the_message_queue->message_buffers, |
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110 | (size_t) maximum_pending_messages, |
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111 | allocated_message_size + sizeof( CORE_message_queue_Buffer_control ) |
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112 | ); |
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113 | |
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114 | _Chain_Initialize_empty( &the_message_queue->Pending_messages ); |
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115 | |
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116 | _Thread_queue_Initialize( |
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117 | &the_message_queue->Wait_queue, |
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118 | _CORE_message_queue_Is_priority( the_message_queue_attributes ) ? |
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119 | THREAD_QUEUE_DISCIPLINE_PRIORITY : THREAD_QUEUE_DISCIPLINE_FIFO, |
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120 | STATES_WAITING_FOR_MESSAGE, |
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121 | CORE_MESSAGE_QUEUE_STATUS_TIMEOUT |
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122 | ); |
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123 | |
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124 | return true; |
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125 | } |
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