1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Thread Queue Operations |
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5 | * @ingroup ScoreThreadQ |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-2014. |
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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.org/license/LICENSE. |
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15 | */ |
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16 | |
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17 | #if HAVE_CONFIG_H |
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18 | #include "config.h" |
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19 | #endif |
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20 | |
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21 | #include <rtems/score/threadqimpl.h> |
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22 | #include <rtems/score/assert.h> |
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23 | #include <rtems/score/threaddispatch.h> |
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24 | #include <rtems/score/threadimpl.h> |
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25 | #include <rtems/score/status.h> |
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26 | #include <rtems/score/watchdogimpl.h> |
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27 | |
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28 | #define THREAD_QUEUE_INTEND_TO_BLOCK \ |
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29 | (THREAD_WAIT_CLASS_OBJECT | THREAD_WAIT_STATE_INTEND_TO_BLOCK) |
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30 | |
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31 | #define THREAD_QUEUE_BLOCKED \ |
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32 | (THREAD_WAIT_CLASS_OBJECT | THREAD_WAIT_STATE_BLOCKED) |
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33 | |
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34 | #define THREAD_QUEUE_READY_AGAIN \ |
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35 | (THREAD_WAIT_CLASS_OBJECT | THREAD_WAIT_STATE_READY_AGAIN) |
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36 | |
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37 | void _Thread_queue_Enqueue_critical( |
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38 | Thread_queue_Queue *queue, |
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39 | const Thread_queue_Operations *operations, |
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40 | Thread_Control *the_thread, |
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41 | States_Control state, |
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42 | Thread_queue_Context *queue_context |
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43 | ) |
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44 | { |
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45 | Thread_queue_Path path; |
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46 | Per_CPU_Control *cpu_self; |
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47 | bool success; |
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48 | |
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49 | #if defined(RTEMS_MULTIPROCESSING) |
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50 | if ( _Thread_MP_Is_receive( the_thread ) && the_thread->receive_packet ) { |
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51 | the_thread = _Thread_MP_Allocate_proxy( state ); |
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52 | } |
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53 | #endif |
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54 | |
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55 | _Thread_Lock_set( the_thread, &queue->Lock ); |
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56 | |
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57 | the_thread->Wait.return_code = STATUS_SUCCESSFUL; |
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58 | _Thread_Wait_set_queue( the_thread, queue ); |
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59 | _Thread_Wait_set_operations( the_thread, operations ); |
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60 | |
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61 | ( *operations->enqueue )( queue, the_thread, &path ); |
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62 | |
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63 | _Thread_Wait_flags_set( the_thread, THREAD_QUEUE_INTEND_TO_BLOCK ); |
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64 | cpu_self = _Thread_Dispatch_disable_critical( &queue_context->Lock_context ); |
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65 | _Thread_queue_Queue_release( queue, &queue_context->Lock_context ); |
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66 | |
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67 | if ( |
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68 | cpu_self->thread_dispatch_disable_level |
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69 | != queue_context->expected_thread_dispatch_disable_level |
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70 | ) { |
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71 | _Terminate( |
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72 | INTERNAL_ERROR_CORE, |
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73 | false, |
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74 | INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_FROM_BAD_STATE |
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75 | ); |
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76 | } |
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77 | |
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78 | /* |
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79 | * Set the blocking state for this thread queue in the thread. |
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80 | */ |
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81 | _Thread_Set_state( the_thread, state ); |
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82 | |
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83 | /* |
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84 | * If the thread wants to timeout, then schedule its timer. |
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85 | */ |
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86 | switch ( queue_context->timeout_discipline ) { |
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87 | case WATCHDOG_RELATIVE: |
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88 | /* A relative timeout of 0 is a special case indefinite (no) timeout */ |
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89 | if ( queue_context->timeout != 0 ) { |
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90 | _Thread_Timer_insert_relative( |
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91 | the_thread, |
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92 | cpu_self, |
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93 | _Thread_Timeout, |
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94 | (Watchdog_Interval) queue_context->timeout |
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95 | ); |
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96 | } |
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97 | break; |
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98 | case WATCHDOG_ABSOLUTE: |
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99 | _Thread_Timer_insert_absolute( |
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100 | the_thread, |
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101 | cpu_self, |
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102 | _Thread_Timeout, |
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103 | queue_context->timeout |
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104 | ); |
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105 | break; |
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106 | default: |
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107 | break; |
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108 | } |
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109 | |
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110 | /* |
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111 | * At this point thread dispatching is disabled, however, we already released |
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112 | * the thread queue lock. Thus, interrupts or threads on other processors |
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113 | * may already changed our state with respect to the thread queue object. |
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114 | * The request could be satisfied or timed out. This situation is indicated |
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115 | * by the thread wait flags. Other parties must not modify our thread state |
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116 | * as long as we are in the THREAD_QUEUE_INTEND_TO_BLOCK thread wait state, |
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117 | * thus we have to cancel the blocking operation ourself if necessary. |
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118 | */ |
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119 | success = _Thread_Wait_flags_try_change_acquire( |
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120 | the_thread, |
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121 | THREAD_QUEUE_INTEND_TO_BLOCK, |
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122 | THREAD_QUEUE_BLOCKED |
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123 | ); |
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124 | if ( !success ) { |
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125 | _Thread_Remove_timer_and_unblock( the_thread, queue ); |
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126 | } |
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127 | |
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128 | _Thread_Update_priority( path.update_priority ); |
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129 | _Thread_Dispatch_enable( cpu_self ); |
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130 | } |
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131 | |
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132 | bool _Thread_queue_Do_extract_locked( |
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133 | Thread_queue_Queue *queue, |
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134 | const Thread_queue_Operations *operations, |
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135 | Thread_Control *the_thread |
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136 | #if defined(RTEMS_MULTIPROCESSING) |
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137 | , |
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138 | const Thread_queue_Context *queue_context |
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139 | #endif |
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140 | ) |
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141 | { |
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142 | bool success; |
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143 | bool unblock; |
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144 | |
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145 | #if defined(RTEMS_MULTIPROCESSING) |
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146 | if ( !_Objects_Is_local_id( the_thread->Object.id ) ) { |
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147 | Thread_Proxy_control *the_proxy; |
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148 | Thread_queue_MP_callout mp_callout; |
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149 | |
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150 | the_proxy = (Thread_Proxy_control *) the_thread; |
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151 | mp_callout = queue_context->mp_callout; |
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152 | _Assert( mp_callout != NULL ); |
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153 | the_proxy->thread_queue_callout = queue_context->mp_callout; |
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154 | } |
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155 | #endif |
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156 | |
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157 | ( *operations->extract )( queue, the_thread ); |
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158 | |
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159 | /* |
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160 | * We must update the wait flags under protection of the current thread lock, |
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161 | * otherwise a _Thread_Timeout() running on another processor may interfere. |
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162 | */ |
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163 | success = _Thread_Wait_flags_try_change_release( |
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164 | the_thread, |
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165 | THREAD_QUEUE_INTEND_TO_BLOCK, |
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166 | THREAD_QUEUE_READY_AGAIN |
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167 | ); |
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168 | if ( success ) { |
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169 | unblock = false; |
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170 | } else { |
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171 | _Assert( _Thread_Wait_flags_get( the_thread ) == THREAD_QUEUE_BLOCKED ); |
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172 | _Thread_Wait_flags_set( the_thread, THREAD_QUEUE_READY_AGAIN ); |
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173 | unblock = true; |
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174 | } |
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175 | |
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176 | _Thread_Wait_set_queue( the_thread, NULL ); |
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177 | _Thread_Wait_restore_default_operations( the_thread ); |
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178 | _Thread_Lock_restore_default( the_thread ); |
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179 | |
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180 | return unblock; |
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181 | } |
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182 | |
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183 | void _Thread_queue_Unblock_critical( |
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184 | bool unblock, |
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185 | Thread_queue_Queue *queue, |
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186 | Thread_Control *the_thread, |
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187 | ISR_lock_Context *lock_context |
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188 | ) |
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189 | { |
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190 | if ( unblock ) { |
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191 | Per_CPU_Control *cpu_self; |
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192 | |
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193 | cpu_self = _Thread_Dispatch_disable_critical( lock_context ); |
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194 | _Thread_queue_Queue_release( queue, lock_context ); |
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195 | |
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196 | _Thread_Remove_timer_and_unblock( the_thread, queue ); |
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197 | |
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198 | _Thread_Dispatch_enable( cpu_self ); |
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199 | } else { |
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200 | _Thread_queue_Queue_release( queue, lock_context ); |
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201 | } |
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202 | } |
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203 | |
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204 | void _Thread_queue_Extract_critical( |
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205 | Thread_queue_Queue *queue, |
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206 | const Thread_queue_Operations *operations, |
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207 | Thread_Control *the_thread, |
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208 | Thread_queue_Context *queue_context |
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209 | ) |
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210 | { |
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211 | bool unblock; |
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212 | |
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213 | unblock = _Thread_queue_Extract_locked( |
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214 | queue, |
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215 | operations, |
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216 | the_thread, |
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217 | queue_context |
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218 | ); |
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219 | |
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220 | _Thread_queue_Unblock_critical( |
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221 | unblock, |
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222 | queue, |
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223 | the_thread, |
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224 | &queue_context->Lock_context |
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225 | ); |
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226 | } |
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227 | |
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228 | void _Thread_queue_Extract( Thread_Control *the_thread ) |
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229 | { |
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230 | Thread_queue_Context queue_context; |
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231 | void *lock; |
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232 | Thread_queue_Queue *queue; |
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233 | |
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234 | _Thread_queue_Context_initialize( &queue_context ); |
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235 | lock = _Thread_Lock_acquire( the_thread, &queue_context.Lock_context ); |
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236 | |
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237 | queue = the_thread->Wait.queue; |
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238 | |
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239 | if ( queue != NULL ) { |
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240 | _SMP_Assert( lock == &queue->Lock ); |
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241 | |
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242 | _Thread_queue_Context_set_MP_callout( |
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243 | &queue_context, |
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244 | _Thread_queue_MP_callout_do_nothing |
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245 | ); |
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246 | _Thread_queue_Extract_critical( |
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247 | queue, |
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248 | the_thread->Wait.operations, |
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249 | the_thread, |
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250 | &queue_context |
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251 | ); |
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252 | } else { |
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253 | _Thread_Lock_release( lock, &queue_context.Lock_context ); |
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254 | } |
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255 | } |
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256 | |
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257 | Thread_Control *_Thread_queue_Do_dequeue( |
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258 | Thread_queue_Control *the_thread_queue, |
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259 | const Thread_queue_Operations *operations |
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260 | #if defined(RTEMS_MULTIPROCESSING) |
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261 | , |
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262 | Thread_queue_MP_callout mp_callout |
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263 | #endif |
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264 | ) |
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265 | { |
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266 | Thread_queue_Context queue_context; |
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267 | Thread_Control *the_thread; |
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268 | |
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269 | _Thread_queue_Context_initialize( &queue_context ); |
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270 | _Thread_queue_Context_set_MP_callout( &queue_context, mp_callout ); |
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271 | _Thread_queue_Acquire( the_thread_queue, &queue_context.Lock_context ); |
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272 | |
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273 | the_thread = _Thread_queue_First_locked( the_thread_queue, operations ); |
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274 | |
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275 | if ( the_thread != NULL ) { |
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276 | _SMP_Assert( the_thread->Lock.current.normal == &the_thread_queue->Queue.Lock ); |
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277 | |
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278 | _Thread_queue_Extract_critical( |
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279 | &the_thread_queue->Queue, |
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280 | operations, |
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281 | the_thread, |
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282 | &queue_context |
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283 | ); |
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284 | } else { |
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285 | _Thread_queue_Release( the_thread_queue, &queue_context.Lock_context ); |
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286 | } |
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287 | |
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288 | return the_thread; |
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289 | } |
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290 | |
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291 | #if defined(RTEMS_MULTIPROCESSING) |
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292 | void _Thread_queue_Unblock_proxy( |
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293 | Thread_queue_Queue *queue, |
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294 | Thread_Control *the_thread |
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295 | ) |
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296 | { |
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297 | const Thread_queue_Object *the_queue_object; |
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298 | Thread_Proxy_control *the_proxy; |
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299 | Thread_queue_MP_callout mp_callout; |
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300 | |
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301 | the_queue_object = THREAD_QUEUE_QUEUE_TO_OBJECT( queue ); |
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302 | the_proxy = (Thread_Proxy_control *) the_thread; |
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303 | mp_callout = the_proxy->thread_queue_callout; |
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304 | ( *mp_callout )( the_thread, the_queue_object->Object.id ); |
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305 | |
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306 | _Thread_MP_Free_proxy( the_thread ); |
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307 | } |
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308 | #endif |
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