1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup rtems_bsd_rtems |
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5 | * |
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6 | * @brief TODO. |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Copyright (c) 2017 embedded brains GmbH. All rights reserved. |
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11 | * |
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12 | * embedded brains GmbH |
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13 | * Dornierstr. 4 |
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14 | * 82178 Puchheim |
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15 | * Germany |
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16 | * <rtems@embedded-brains.de> |
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17 | * |
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18 | * Redistribution and use in source and binary forms, with or without |
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19 | * modification, are permitted provided that the following conditions |
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20 | * are met: |
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21 | * 1. Redistributions of source code must retain the above copyright |
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22 | * notice, this list of conditions and the following disclaimer. |
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23 | * 2. Redistributions in binary form must reproduce the above copyright |
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24 | * notice, this list of conditions and the following disclaimer in the |
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25 | * documentation and/or other materials provided with the distribution. |
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26 | * |
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27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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28 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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29 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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30 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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31 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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32 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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33 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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34 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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35 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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36 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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37 | * SUCH DAMAGE. |
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38 | */ |
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39 | |
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40 | #include <machine/rtems-bsd-kernel-space.h> |
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41 | #include <machine/rtems-bsd-rwlockimpl.h> |
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42 | |
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43 | #include <rtems/score/schedulerimpl.h> |
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44 | |
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45 | void |
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46 | rtems_bsd_rwlock_wlock_more(const struct lock_object *lock, |
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47 | rtems_bsd_rwlock *rw, Thread_Control *executing, |
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48 | rtems_bsd_rwlock_context *context) |
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49 | { |
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50 | Thread_Control *wowner; |
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51 | |
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52 | wowner = rtems_bsd_rwlock_wowner(rw); |
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53 | |
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54 | if (wowner == executing) { |
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55 | BSD_ASSERT(lock->lo_flags & LO_RECURSABLE); |
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56 | ++rw->nest_level; |
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57 | |
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58 | _Thread_queue_Release(&rw->writer_queue, &context->writer); |
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59 | } else { |
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60 | _Thread_queue_Context_set_thread_state(&context->writer, |
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61 | STATES_WAITING_FOR_RWLOCK); |
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62 | _Thread_queue_Context_set_enqueue_do_nothing_extra( |
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63 | &context->writer); |
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64 | _Thread_queue_Context_set_deadlock_callout(&context->writer, |
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65 | _Thread_queue_Deadlock_fatal); |
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66 | _Thread_queue_Enqueue(&rw->writer_queue.Queue, |
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67 | &_Thread_queue_Operations_priority, executing, |
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68 | &context->writer); |
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69 | } |
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70 | } |
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71 | |
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72 | static Thread_Control * |
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73 | rtems_bsd_rwlock_flush_reader_filter(Thread_Control *reader, |
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74 | Thread_queue_Queue *queue, Thread_queue_Context *queue_context) |
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75 | { |
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76 | rtems_bsd_rwlock *rw; |
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77 | |
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78 | rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); |
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79 | ++rw->readers; |
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80 | _Thread_Resource_count_increment(reader); |
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81 | return (reader); |
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82 | } |
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83 | |
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84 | static void |
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85 | rtems_bsd_rwlock_flush_reader_post_release(Thread_queue_Queue *queue, |
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86 | Thread_queue_Context *queue_context) |
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87 | { |
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88 | rtems_bsd_rwlock *rw; |
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89 | rtems_bsd_rwlock_context *context; |
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90 | |
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91 | rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); |
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92 | context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, |
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93 | reader); |
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94 | _Thread_queue_Release(&rw->writer_queue, &context->writer); |
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95 | } |
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96 | |
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97 | void |
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98 | rtems_bsd_rwlock_wunlock_more(rtems_bsd_rwlock *rw, Thread_Control *wowner, |
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99 | rtems_bsd_rwlock_context *context) |
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100 | { |
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101 | |
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102 | if (!_Thread_queue_Is_empty(&rw->reader_queue.Queue)) { |
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103 | BSD_ASSERT(rw->readers == 0); |
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104 | rtems_bsd_rwlock_ready_waiting_readers(rw, context); |
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105 | } else { |
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106 | BSD_ASSERT(!_Thread_queue_Is_empty(&rw->writer_queue.Queue)); |
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107 | _Thread_queue_Surrender(&rw->writer_queue.Queue, |
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108 | rw->writer_queue.Queue.heads, wowner, &context->writer, |
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109 | &_Thread_queue_Operations_priority); |
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110 | } |
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111 | } |
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112 | |
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113 | static void |
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114 | rtems_bsd_rwlock_reader_enqueue(Thread_queue_Queue *queue, |
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115 | Thread_Control *executing, Per_CPU_Control *cpu_self, |
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116 | Thread_queue_Context *queue_context |
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117 | ) |
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118 | { |
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119 | rtems_bsd_rwlock *rw; |
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120 | rtems_bsd_rwlock_context *context; |
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121 | |
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122 | rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); |
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123 | context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, |
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124 | reader); |
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125 | _Thread_queue_Release(&rw->writer_queue, &context->writer); |
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126 | } |
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127 | |
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128 | void |
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129 | rtems_bsd_rwlock_rlock_more(rtems_bsd_rwlock *rw, |
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130 | rtems_bsd_rwlock_context *context) |
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131 | { |
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132 | Thread_Control *executing; |
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133 | |
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134 | executing = _Thread_Executing; |
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135 | |
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136 | _Thread_queue_Context_initialize(&context->reader); |
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137 | _Thread_queue_Context_set_thread_state(&context->reader, |
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138 | STATES_WAITING_FOR_RWLOCK); |
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139 | _Thread_queue_Context_set_enqueue_callout( |
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140 | &context->reader, rtems_bsd_rwlock_reader_enqueue); |
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141 | _Thread_queue_Context_set_deadlock_callout(&context->reader, |
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142 | _Thread_queue_Deadlock_fatal); |
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143 | _Thread_queue_Acquire(&rw->reader_queue, &context->reader); |
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144 | _Thread_queue_Enqueue(&rw->reader_queue.Queue, |
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145 | &_Thread_queue_Operations_FIFO, executing, &context->reader); |
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146 | } |
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147 | |
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148 | void |
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149 | rtems_bsd_rwlock_runlock_more(rtems_bsd_rwlock *rw, |
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150 | rtems_bsd_rwlock_context *context) |
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151 | { |
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152 | |
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153 | if (!_Thread_queue_Is_empty(&rw->writer_queue.Queue)) { |
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154 | BSD_ASSERT(rw->readers == 0); |
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155 | |
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156 | _Thread_queue_Surrender(&rw->writer_queue.Queue, |
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157 | rw->writer_queue.Queue.heads, NULL, &context->writer, |
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158 | &_Thread_queue_Operations_priority); |
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159 | } else { |
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160 | BSD_ASSERT(!_Thread_queue_Is_empty(&rw->reader_queue.Queue)); |
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161 | rtems_bsd_rwlock_ready_waiting_readers(rw, context); |
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162 | } |
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163 | } |
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164 | |
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165 | void |
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166 | rtems_bsd_rwlock_ready_waiting_readers(rtems_bsd_rwlock *rw, |
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167 | rtems_bsd_rwlock_context *context) |
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168 | { |
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169 | |
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170 | _Thread_queue_Context_initialize(&context->reader); |
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171 | _Thread_queue_Acquire(&rw->reader_queue, &context->reader); |
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172 | _Thread_queue_Flush_critical(&rw->reader_queue.Queue, |
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173 | &_Thread_queue_Operations_FIFO, |
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174 | rtems_bsd_rwlock_flush_reader_filter, |
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175 | rtems_bsd_rwlock_flush_reader_post_release, |
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176 | &context->reader); |
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177 | } |
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