1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief rtems_semaphore_create |
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5 | * @ingroup ClassicSem Semaphores |
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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/system.h> |
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22 | #include <rtems/rtems/status.h> |
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23 | #include <rtems/rtems/support.h> |
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24 | #include <rtems/rtems/attrimpl.h> |
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25 | #include <rtems/score/isr.h> |
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26 | #include <rtems/rtems/options.h> |
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27 | #include <rtems/rtems/semimpl.h> |
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28 | #include <rtems/rtems/statusimpl.h> |
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29 | #include <rtems/rtems/tasksimpl.h> |
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30 | #include <rtems/score/coremuteximpl.h> |
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31 | #include <rtems/score/coresemimpl.h> |
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32 | #include <rtems/score/threaddispatch.h> |
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33 | #include <rtems/score/sysstate.h> |
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34 | |
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35 | #include <rtems/score/interr.h> |
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36 | |
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37 | /* |
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38 | * rtems_semaphore_create |
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39 | * |
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40 | * This directive creates a semaphore and sets the initial value based |
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41 | * on the given count. A semaphore id is returned. |
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42 | * |
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43 | * Input parameters: |
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44 | * name - user defined semaphore name |
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45 | * count - initial count of semaphore |
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46 | * attribute_set - semaphore attributes |
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47 | * priority_ceiling - semaphore's ceiling priority |
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48 | * id - pointer to semaphore id |
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49 | * |
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50 | * Output parameters: |
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51 | * id - semaphore id |
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52 | * RTEMS_SUCCESSFUL - if successful |
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53 | * error code - if unsuccessful |
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54 | */ |
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55 | |
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56 | rtems_status_code rtems_semaphore_create( |
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57 | rtems_name name, |
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58 | uint32_t count, |
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59 | rtems_attribute attribute_set, |
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60 | rtems_task_priority priority_ceiling, |
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61 | rtems_id *id |
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62 | ) |
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63 | { |
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64 | Semaphore_Control *the_semaphore; |
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65 | Thread_Control *executing; |
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66 | Status_Control status; |
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67 | |
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68 | if ( !rtems_is_name_valid( name ) ) |
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69 | return RTEMS_INVALID_NAME; |
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70 | |
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71 | if ( !id ) |
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72 | return RTEMS_INVALID_ADDRESS; |
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73 | |
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74 | #if defined(RTEMS_MULTIPROCESSING) |
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75 | if ( _Attributes_Is_global( attribute_set ) ) { |
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76 | |
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77 | if ( !_System_state_Is_multiprocessing ) |
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78 | return RTEMS_MP_NOT_CONFIGURED; |
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79 | |
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80 | if ( _Attributes_Is_inherit_priority( attribute_set ) || |
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81 | _Attributes_Is_priority_ceiling( attribute_set ) || |
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82 | _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) |
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83 | return RTEMS_NOT_DEFINED; |
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84 | |
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85 | } else |
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86 | #endif |
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87 | |
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88 | if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) && |
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89 | !( _Attributes_Is_binary_semaphore( attribute_set ) && |
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90 | !_Attributes_Is_priority( attribute_set ) ) ) { |
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91 | return RTEMS_NOT_DEFINED; |
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92 | } |
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93 | |
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94 | if ( _Attributes_Is_inherit_priority( attribute_set ) || |
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95 | _Attributes_Is_priority_ceiling( attribute_set ) ) { |
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96 | |
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97 | if ( ! (_Attributes_Is_binary_semaphore( attribute_set ) && |
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98 | _Attributes_Is_priority( attribute_set ) ) ) |
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99 | return RTEMS_NOT_DEFINED; |
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100 | |
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101 | } |
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102 | |
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103 | if ( !_Attributes_Has_at_most_one_protocol( attribute_set ) ) |
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104 | return RTEMS_NOT_DEFINED; |
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105 | |
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106 | if ( !_Attributes_Is_counting_semaphore( attribute_set ) && ( count > 1 ) ) |
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107 | return RTEMS_INVALID_NUMBER; |
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108 | |
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109 | #if !defined(RTEMS_SMP) |
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110 | /* |
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111 | * On uni-processor configurations the Multiprocessor Resource Sharing |
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112 | * Protocol is equivalent to the Priority Ceiling Protocol. |
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113 | */ |
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114 | if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) { |
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115 | attribute_set |= RTEMS_PRIORITY_CEILING | RTEMS_PRIORITY; |
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116 | } |
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117 | #endif |
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118 | |
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119 | the_semaphore = _Semaphore_Allocate(); |
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120 | |
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121 | if ( !the_semaphore ) { |
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122 | _Objects_Allocator_unlock(); |
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123 | return RTEMS_TOO_MANY; |
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124 | } |
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125 | |
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126 | #if defined(RTEMS_MULTIPROCESSING) |
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127 | the_semaphore->is_global = _Attributes_Is_global( attribute_set ); |
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128 | |
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129 | if ( _Attributes_Is_global( attribute_set ) && |
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130 | ! ( _Objects_MP_Allocate_and_open( &_Semaphore_Information, name, |
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131 | the_semaphore->Object.id, false ) ) ) { |
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132 | _Semaphore_Free( the_semaphore ); |
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133 | _Objects_Allocator_unlock(); |
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134 | return RTEMS_TOO_MANY; |
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135 | } |
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136 | #endif |
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137 | |
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138 | priority_ceiling = _RTEMS_tasks_Priority_to_Core( priority_ceiling ); |
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139 | executing = _Thread_Get_executing(); |
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140 | |
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141 | if ( _Attributes_Is_priority( attribute_set ) ) { |
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142 | the_semaphore->discipline = SEMAPHORE_DISCIPLINE_PRIORITY; |
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143 | } else { |
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144 | the_semaphore->discipline = SEMAPHORE_DISCIPLINE_FIFO; |
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145 | } |
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146 | |
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147 | if ( _Attributes_Is_counting_semaphore( attribute_set ) ) { |
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148 | the_semaphore->variant = SEMAPHORE_VARIANT_COUNTING; |
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149 | _CORE_semaphore_Initialize( |
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150 | &the_semaphore->Core_control.semaphore, |
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151 | count |
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152 | ); |
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153 | status = STATUS_SUCCESSFUL; |
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154 | } else if ( _Attributes_Is_simple_binary_semaphore( attribute_set ) ) { |
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155 | the_semaphore->variant = SEMAPHORE_VARIANT_SIMPLE_BINARY; |
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156 | _CORE_semaphore_Initialize( |
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157 | &the_semaphore->Core_control.semaphore, |
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158 | count != 0 |
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159 | ); |
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160 | status = STATUS_SUCCESSFUL; |
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161 | #if defined(RTEMS_SMP) |
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162 | } else if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) { |
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163 | the_semaphore->variant = SEMAPHORE_VARIANT_MRSP; |
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164 | status = _MRSP_Initialize( |
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165 | &the_semaphore->Core_control.MRSP, |
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166 | priority_ceiling, |
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167 | executing, |
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168 | count != 1 |
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169 | ); |
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170 | #endif |
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171 | } else if ( _Attributes_Is_priority_ceiling( attribute_set ) ) { |
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172 | _Assert( _Attributes_Is_binary_semaphore( attribute_set ) ); |
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173 | the_semaphore->variant = SEMAPHORE_VARIANT_MUTEX_PRIORITY_CEILING; |
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174 | _CORE_ceiling_mutex_Initialize( |
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175 | &the_semaphore->Core_control.Mutex, |
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176 | priority_ceiling |
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177 | ); |
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178 | |
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179 | if ( count == 0 ) { |
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180 | Thread_queue_Context queue_context; |
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181 | |
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182 | _Thread_queue_Context_initialize( &queue_context ); |
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183 | _ISR_lock_ISR_disable( &queue_context.Lock_context ); |
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184 | _CORE_mutex_Acquire_critical( |
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185 | &the_semaphore->Core_control.Mutex.Recursive.Mutex, |
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186 | &queue_context |
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187 | ); |
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188 | status = _CORE_ceiling_mutex_Set_owner( |
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189 | &the_semaphore->Core_control.Mutex, |
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190 | executing, |
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191 | &queue_context |
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192 | ); |
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193 | } else { |
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194 | status = STATUS_SUCCESSFUL; |
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195 | } |
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196 | } else { |
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197 | _Assert( _Attributes_Is_binary_semaphore( attribute_set ) ); |
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198 | |
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199 | if ( _Attributes_Is_inherit_priority( attribute_set ) ) { |
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200 | the_semaphore->variant = SEMAPHORE_VARIANT_MUTEX_INHERIT_PRIORITY; |
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201 | } else { |
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202 | the_semaphore->variant = SEMAPHORE_VARIANT_MUTEX_NO_PROTOCOL; |
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203 | } |
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204 | |
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205 | _CORE_recursive_mutex_Initialize( |
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206 | &the_semaphore->Core_control.Mutex.Recursive |
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207 | ); |
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208 | |
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209 | if ( count == 0 ) { |
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210 | _CORE_mutex_Set_owner( |
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211 | &the_semaphore->Core_control.Mutex.Recursive.Mutex, |
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212 | executing |
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213 | ); |
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214 | |
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215 | if ( _Attributes_Is_inherit_priority( attribute_set ) ) { |
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216 | ++executing->resource_count; |
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217 | } |
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218 | } |
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219 | |
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220 | status = STATUS_SUCCESSFUL; |
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221 | } |
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222 | |
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223 | if ( status != STATUS_SUCCESSFUL ) { |
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224 | _Semaphore_Free( the_semaphore ); |
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225 | _Objects_Allocator_unlock(); |
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226 | return _Status_Get( status ); |
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227 | } |
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228 | |
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229 | /* |
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230 | * Whether we initialized it as a mutex or counting semaphore, it is |
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231 | * now ready to be "offered" for use as a Classic API Semaphore. |
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232 | */ |
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233 | _Objects_Open( |
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234 | &_Semaphore_Information, |
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235 | &the_semaphore->Object, |
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236 | (Objects_Name) name |
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237 | ); |
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238 | |
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239 | *id = the_semaphore->Object.id; |
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240 | |
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241 | #if defined(RTEMS_MULTIPROCESSING) |
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242 | if ( _Attributes_Is_global( attribute_set ) ) |
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243 | _Semaphore_MP_Send_process_packet( |
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244 | SEMAPHORE_MP_ANNOUNCE_CREATE, |
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245 | the_semaphore->Object.id, |
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246 | name, |
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247 | 0 /* Not used */ |
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248 | ); |
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249 | #endif |
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250 | _Objects_Allocator_unlock(); |
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251 | return RTEMS_SUCCESSFUL; |
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252 | } |
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