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) 1989-2009. |
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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 | |
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33 | /*PAGE |
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34 | * |
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35 | * _CORE_message_queue_Submit |
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36 | * |
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37 | * This routine implements the send and urgent message functions. It |
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38 | * processes a message that is to be submitted to the designated |
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39 | * message queue. The message will either be processed as a |
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40 | * send message which it will be inserted at the rear of the queue |
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41 | * or it will be processed as an urgent message which will be inserted |
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42 | * at the front of the queue. |
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43 | * |
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44 | * Input parameters: |
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45 | * the_message_queue - message is submitted to this message queue |
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46 | * buffer - pointer to message buffer |
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47 | * size - size in bytes of message to send |
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48 | * id - id of message queue |
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49 | * api_message_queue_mp_support - api specific mp support callout |
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50 | * submit_type - send or urgent message |
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51 | * |
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52 | * Output parameters: |
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53 | * CORE_MESSAGE_QUEUE_SUCCESSFUL - if successful |
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54 | * error code - if unsuccessful |
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55 | */ |
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56 | |
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57 | CORE_message_queue_Status _CORE_message_queue_Submit( |
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58 | CORE_message_queue_Control *the_message_queue, |
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59 | const void *buffer, |
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60 | size_t size, |
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61 | Objects_Id id, |
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62 | #if defined(RTEMS_MULTIPROCESSING) |
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63 | CORE_message_queue_API_mp_support_callout api_message_queue_mp_support, |
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64 | #else |
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65 | CORE_message_queue_API_mp_support_callout api_message_queue_mp_support __attribute__((unused)), |
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66 | #endif |
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67 | CORE_message_queue_Submit_types submit_type, |
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68 | bool wait, |
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69 | Watchdog_Interval timeout |
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70 | ) |
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71 | { |
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72 | CORE_message_queue_Buffer_control *the_message; |
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73 | Thread_Control *the_thread; |
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74 | |
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75 | if ( size > the_message_queue->maximum_message_size ) { |
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76 | return CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE; |
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77 | } |
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78 | |
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79 | /* |
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80 | * Is there a thread currently waiting on this message queue? |
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81 | */ |
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82 | if ( the_message_queue->number_of_pending_messages == 0 ) { |
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83 | the_thread = _Thread_queue_Dequeue( &the_message_queue->Wait_queue ); |
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84 | if ( the_thread ) { |
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85 | _CORE_message_queue_Copy_buffer( |
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86 | buffer, |
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87 | the_thread->Wait.return_argument_second.mutable_object, |
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88 | size |
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89 | ); |
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90 | *(size_t *) the_thread->Wait.return_argument = size; |
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91 | the_thread->Wait.count = submit_type; |
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92 | |
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93 | #if defined(RTEMS_MULTIPROCESSING) |
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94 | if ( !_Objects_Is_local_id( the_thread->Object.id ) ) |
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95 | (*api_message_queue_mp_support) ( the_thread, id ); |
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96 | #endif |
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97 | return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL; |
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98 | } |
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99 | } |
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100 | |
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101 | /* |
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102 | * No one waiting on the message queue at this time, so attempt to |
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103 | * queue the message up for a future receive. |
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104 | */ |
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105 | if ( the_message_queue->number_of_pending_messages < |
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106 | the_message_queue->maximum_pending_messages ) { |
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107 | |
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108 | the_message = |
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109 | _CORE_message_queue_Allocate_message_buffer( the_message_queue ); |
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110 | |
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111 | #if defined(RTEMS_DEBUG) |
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112 | /* |
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113 | * NOTE: If the system is consistent, this error should never occur. |
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114 | */ |
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115 | |
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116 | if ( !the_message ) |
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117 | return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED; |
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118 | #endif |
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119 | |
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120 | _CORE_message_queue_Copy_buffer( |
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121 | buffer, |
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122 | the_message->Contents.buffer, |
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123 | size |
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124 | ); |
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125 | the_message->Contents.size = size; |
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126 | #if defined(RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY) |
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127 | the_message->priority = submit_type; |
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128 | #endif |
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129 | |
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130 | _CORE_message_queue_Insert_message( |
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131 | the_message_queue, |
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132 | the_message, |
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133 | submit_type |
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134 | ); |
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135 | return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL; |
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136 | } |
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137 | |
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138 | #if !defined(RTEMS_SCORE_COREMSG_ENABLE_BLOCKING_SEND) |
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139 | return CORE_MESSAGE_QUEUE_STATUS_TOO_MANY; |
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140 | #else |
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141 | /* |
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142 | * No message buffers were available so we may need to return an |
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143 | * overflow error or block the sender until the message is placed |
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144 | * on the queue. |
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145 | */ |
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146 | if ( !wait ) { |
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147 | return CORE_MESSAGE_QUEUE_STATUS_TOO_MANY; |
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148 | } |
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149 | |
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150 | /* |
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151 | * Do NOT block on a send if the caller is in an ISR. It is |
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152 | * deadly to block in an ISR. |
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153 | */ |
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154 | if ( _ISR_Is_in_progress() ) { |
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155 | return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED; |
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156 | } |
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157 | |
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158 | /* |
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159 | * WARNING!! executing should NOT be used prior to this point. |
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160 | * Thus the unusual choice to open a new scope and declare |
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161 | * it as a variable. Doing this emphasizes how dangerous it |
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162 | * would be to use this variable prior to here. |
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163 | */ |
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164 | { |
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165 | Thread_Control *executing = _Thread_Executing; |
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166 | ISR_Level level; |
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167 | |
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168 | _ISR_Disable( level ); |
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169 | _Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue ); |
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170 | executing->Wait.queue = &the_message_queue->Wait_queue; |
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171 | executing->Wait.id = id; |
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172 | executing->Wait.return_argument_second.immutable_object = buffer; |
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173 | executing->Wait.option = (uint32_t) size; |
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174 | executing->Wait.count = submit_type; |
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175 | _ISR_Enable( level ); |
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176 | |
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177 | _Thread_queue_Enqueue( &the_message_queue->Wait_queue, timeout ); |
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178 | } |
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179 | |
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180 | return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_WAIT; |
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181 | #endif |
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182 | } |
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