1 | /* |
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2 | * Copyright (c) 2014, 2016 embedded brains GmbH. All rights reserved. |
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3 | * |
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4 | * embedded brains GmbH |
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5 | * Dornierstr. 4 |
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6 | * 82178 Puchheim |
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7 | * Germany |
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8 | * <rtems@embedded-brains.de> |
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9 | * |
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10 | * The license and distribution terms for this file may be |
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11 | * found in the file LICENSE in this distribution or at |
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12 | * http://www.rtems.org/license/LICENSE. |
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13 | */ |
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14 | |
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15 | #ifndef _RTEMS_SCORE_MRSPIMPL_H |
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16 | #define _RTEMS_SCORE_MRSPIMPL_H |
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17 | |
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18 | #include <rtems/score/mrsp.h> |
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19 | |
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20 | #if defined(RTEMS_SMP) |
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21 | |
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22 | #include <rtems/score/assert.h> |
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23 | #include <rtems/score/chainimpl.h> |
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24 | #include <rtems/score/resourceimpl.h> |
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25 | #include <rtems/score/schedulerimpl.h> |
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26 | #include <rtems/score/status.h> |
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27 | #include <rtems/score/watchdogimpl.h> |
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28 | #include <rtems/score/wkspace.h> |
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29 | |
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30 | #ifdef __cplusplus |
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31 | extern "C" { |
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32 | #endif /* __cplusplus */ |
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33 | |
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34 | /** |
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35 | * @addtogroup ScoreMRSP |
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36 | * |
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37 | * @{ |
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38 | */ |
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39 | |
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40 | /** |
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41 | * @brief Internal state used for MRSP_Rival::status to indicate that this |
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42 | * rival waits for resource ownership. |
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43 | */ |
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44 | #define MRSP_WAIT_FOR_OWNERSHIP STATUS_MINUS_ONE |
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45 | |
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46 | /* |
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47 | * FIXME: Operations with the resource dependency tree are protected by the |
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48 | * global scheduler lock. Since the scheduler lock should be scheduler |
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49 | * instance specific in the future this will only work temporarily. A more |
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50 | * sophisticated locking strategy is necessary. |
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51 | */ |
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52 | |
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53 | RTEMS_INLINE_ROUTINE void _MRSP_Giant_acquire( ISR_lock_Context *lock_context ) |
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54 | { |
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55 | _ISR_lock_Acquire( &_Scheduler_Lock, lock_context ); |
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56 | } |
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57 | |
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58 | RTEMS_INLINE_ROUTINE void _MRSP_Giant_release( ISR_lock_Context *lock_context ) |
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59 | { |
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60 | _ISR_lock_Release( &_Scheduler_Lock, lock_context ); |
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61 | } |
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62 | |
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63 | RTEMS_INLINE_ROUTINE void _MRSP_Acquire_critical( |
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64 | MRSP_Control *mrsp, |
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65 | Thread_queue_Context *queue_context |
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66 | ) |
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67 | { |
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68 | _ISR_lock_Acquire( &mrsp->Lock, &queue_context->Lock_context ); |
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69 | } |
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70 | |
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71 | RTEMS_INLINE_ROUTINE void _MRSP_Release( |
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72 | MRSP_Control *mrsp, |
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73 | Thread_queue_Context *queue_context |
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74 | ) |
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75 | { |
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76 | _ISR_lock_Release_and_ISR_enable( &mrsp->Lock, &queue_context->Lock_context ); |
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77 | } |
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78 | |
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79 | RTEMS_INLINE_ROUTINE bool _MRSP_Restore_priority_filter( |
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80 | Thread_Control *thread, |
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81 | Priority_Control *new_priority, |
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82 | void *arg |
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83 | ) |
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84 | { |
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85 | *new_priority = _Thread_Priority_highest( |
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86 | thread->real_priority, |
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87 | *new_priority |
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88 | ); |
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89 | |
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90 | return *new_priority != thread->current_priority; |
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91 | } |
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92 | |
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93 | RTEMS_INLINE_ROUTINE void _MRSP_Restore_priority( |
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94 | Thread_Control *thread, |
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95 | Priority_Control initial_priority |
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96 | ) |
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97 | { |
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98 | /* |
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99 | * The Thread_Control::resource_count is used by the normal priority ceiling |
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100 | * or priority inheritance semaphores. |
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101 | */ |
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102 | if ( thread->resource_count == 0 ) { |
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103 | _Thread_Change_priority( |
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104 | thread, |
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105 | initial_priority, |
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106 | NULL, |
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107 | _MRSP_Restore_priority_filter, |
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108 | true |
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109 | ); |
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110 | } |
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111 | } |
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112 | |
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113 | RTEMS_INLINE_ROUTINE void _MRSP_Claim_ownership( |
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114 | MRSP_Control *mrsp, |
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115 | Thread_Control *new_owner, |
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116 | Priority_Control initial_priority, |
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117 | Priority_Control ceiling_priority, |
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118 | Thread_queue_Context *queue_context |
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119 | ) |
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120 | { |
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121 | Per_CPU_Control *cpu_self; |
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122 | |
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123 | _Resource_Node_add_resource( &new_owner->Resource_node, &mrsp->Resource ); |
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124 | _Resource_Set_owner( &mrsp->Resource, &new_owner->Resource_node ); |
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125 | mrsp->initial_priority_of_owner = initial_priority; |
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126 | _Scheduler_Thread_change_help_state( new_owner, SCHEDULER_HELP_ACTIVE_OWNER ); |
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127 | |
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128 | cpu_self = _Thread_Dispatch_disable_critical( &queue_context->Lock_context ); |
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129 | _MRSP_Release( mrsp, queue_context ); |
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130 | |
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131 | _Thread_Raise_priority( new_owner, ceiling_priority ); |
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132 | |
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133 | _Thread_Dispatch_enable( cpu_self ); |
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134 | } |
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135 | |
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136 | RTEMS_INLINE_ROUTINE Status_Control _MRSP_Initialize( |
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137 | MRSP_Control *mrsp, |
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138 | Priority_Control ceiling_priority, |
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139 | Thread_Control *executing, |
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140 | bool initially_locked |
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141 | ) |
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142 | { |
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143 | uint32_t scheduler_count = _Scheduler_Count; |
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144 | uint32_t i; |
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145 | |
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146 | if ( initially_locked ) { |
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147 | return STATUS_INVALID_NUMBER; |
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148 | } |
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149 | |
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150 | mrsp->ceiling_priorities = _Workspace_Allocate( |
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151 | sizeof( *mrsp->ceiling_priorities ) * scheduler_count |
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152 | ); |
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153 | if ( mrsp->ceiling_priorities == NULL ) { |
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154 | return STATUS_NO_MEMORY; |
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155 | } |
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156 | |
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157 | for ( i = 0 ; i < scheduler_count ; ++i ) { |
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158 | mrsp->ceiling_priorities[ i ] = ceiling_priority; |
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159 | } |
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160 | |
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161 | _Resource_Initialize( &mrsp->Resource ); |
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162 | _Chain_Initialize_empty( &mrsp->Rivals ); |
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163 | _ISR_lock_Initialize( &mrsp->Lock, "MrsP" ); |
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164 | |
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165 | return STATUS_SUCCESSFUL; |
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166 | } |
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167 | |
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168 | RTEMS_INLINE_ROUTINE Priority_Control _MRSP_Get_ceiling_priority( |
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169 | MRSP_Control *mrsp, |
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170 | uint32_t scheduler_index |
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171 | ) |
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172 | { |
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173 | return mrsp->ceiling_priorities[ scheduler_index ]; |
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174 | } |
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175 | |
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176 | RTEMS_INLINE_ROUTINE void _MRSP_Set_ceiling_priority( |
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177 | MRSP_Control *mrsp, |
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178 | uint32_t scheduler_index, |
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179 | Priority_Control ceiling_priority |
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180 | ) |
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181 | { |
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182 | mrsp->ceiling_priorities[ scheduler_index ] = ceiling_priority; |
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183 | } |
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184 | |
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185 | RTEMS_INLINE_ROUTINE void _MRSP_Timeout( Watchdog_Control *watchdog ) |
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186 | { |
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187 | MRSP_Rival *rival = RTEMS_CONTAINER_OF( watchdog, MRSP_Rival, Watchdog ); |
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188 | MRSP_Control *mrsp = rival->resource; |
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189 | Thread_Control *thread = rival->thread; |
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190 | Thread_queue_Context queue_context; |
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191 | |
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192 | _Thread_queue_Context_initialize( &queue_context ); |
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193 | _ISR_lock_ISR_disable( &queue_context.Lock_context ); |
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194 | _MRSP_Acquire_critical( mrsp, &queue_context ); |
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195 | |
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196 | if ( rival->status == MRSP_WAIT_FOR_OWNERSHIP ) { |
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197 | ISR_lock_Context giant_lock_context; |
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198 | |
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199 | _MRSP_Giant_acquire( &giant_lock_context ); |
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200 | |
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201 | _Chain_Extract_unprotected( &rival->Node ); |
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202 | _Resource_Node_extract( &thread->Resource_node ); |
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203 | _Resource_Node_set_dependency( &thread->Resource_node, NULL ); |
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204 | _Scheduler_Thread_change_help_state( thread, rival->initial_help_state ); |
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205 | _Scheduler_Thread_change_resource_root( thread, thread ); |
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206 | |
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207 | _MRSP_Giant_release( &giant_lock_context ); |
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208 | |
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209 | rival->status = STATUS_TIMEOUT; |
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210 | |
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211 | _MRSP_Release( mrsp, &queue_context ); |
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212 | } else { |
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213 | _MRSP_Release( mrsp, &queue_context ); |
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214 | } |
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215 | } |
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216 | |
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217 | RTEMS_INLINE_ROUTINE Status_Control _MRSP_Wait_for_ownership( |
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218 | MRSP_Control *mrsp, |
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219 | Resource_Node *owner, |
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220 | Thread_Control *executing, |
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221 | Priority_Control initial_priority, |
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222 | Priority_Control ceiling_priority, |
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223 | Watchdog_Interval timeout, |
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224 | Thread_queue_Context *queue_context |
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225 | ) |
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226 | { |
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227 | Status_Control status; |
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228 | MRSP_Rival rival; |
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229 | Thread_Life_state life_state; |
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230 | Per_CPU_Control *cpu_self; |
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231 | ISR_lock_Context giant_lock_context; |
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232 | ISR_Level level; |
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233 | |
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234 | rival.thread = executing; |
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235 | rival.resource = mrsp; |
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236 | rival.initial_priority = initial_priority; |
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237 | |
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238 | _MRSP_Giant_acquire( &giant_lock_context ); |
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239 | |
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240 | rival.initial_help_state = |
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241 | _Scheduler_Thread_change_help_state( executing, SCHEDULER_HELP_ACTIVE_RIVAL ); |
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242 | rival.status = MRSP_WAIT_FOR_OWNERSHIP; |
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243 | |
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244 | _Chain_Append_unprotected( &mrsp->Rivals, &rival.Node ); |
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245 | _Resource_Add_rival( &mrsp->Resource, &executing->Resource_node ); |
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246 | _Resource_Node_set_dependency( &executing->Resource_node, &mrsp->Resource ); |
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247 | _Scheduler_Thread_change_resource_root( |
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248 | executing, |
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249 | THREAD_RESOURCE_NODE_TO_THREAD( _Resource_Node_get_root( owner ) ) |
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250 | ); |
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251 | |
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252 | _MRSP_Giant_release( &giant_lock_context ); |
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253 | |
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254 | cpu_self = _Thread_Dispatch_disable_critical( &queue_context->Lock_context ); |
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255 | _MRSP_Release( mrsp, queue_context ); |
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256 | |
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257 | _Thread_Raise_priority( executing, ceiling_priority ); |
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258 | |
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259 | if ( timeout > 0 ) { |
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260 | _Watchdog_Preinitialize( &rival.Watchdog, cpu_self ); |
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261 | _Watchdog_Initialize( &rival.Watchdog, _MRSP_Timeout ); |
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262 | _ISR_Local_disable( level ); |
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263 | _Watchdog_Per_CPU_insert_relative( &rival.Watchdog, cpu_self, timeout ); |
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264 | _ISR_Local_enable( level ); |
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265 | } |
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266 | |
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267 | life_state = _Thread_Set_life_protection( THREAD_LIFE_PROTECTED ); |
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268 | _Thread_Dispatch_enable( cpu_self ); |
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269 | |
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270 | _Assert( _Debug_Is_thread_dispatching_allowed() ); |
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271 | |
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272 | /* Wait for state change */ |
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273 | do { |
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274 | status = rival.status; |
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275 | } while ( status == MRSP_WAIT_FOR_OWNERSHIP ); |
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276 | |
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277 | _Thread_Set_life_protection( life_state ); |
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278 | |
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279 | if ( timeout > 0 ) { |
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280 | _ISR_Local_disable( level ); |
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281 | _Watchdog_Per_CPU_remove( |
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282 | &rival.Watchdog, |
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283 | cpu_self, |
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284 | &cpu_self->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ] |
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285 | ); |
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286 | _ISR_Local_enable( level ); |
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287 | |
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288 | if ( status == STATUS_TIMEOUT ) { |
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289 | _MRSP_Restore_priority( executing, initial_priority ); |
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290 | } |
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291 | } |
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292 | |
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293 | return status; |
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294 | } |
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295 | |
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296 | RTEMS_INLINE_ROUTINE Status_Control _MRSP_Seize( |
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297 | MRSP_Control *mrsp, |
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298 | Thread_Control *executing, |
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299 | bool wait, |
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300 | Watchdog_Interval timeout, |
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301 | Thread_queue_Context *queue_context |
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302 | ) |
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303 | { |
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304 | Status_Control status; |
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305 | const Scheduler_Control *scheduler = _Scheduler_Get_own( executing ); |
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306 | uint32_t scheduler_index = _Scheduler_Get_index( scheduler ); |
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307 | Priority_Control initial_priority = executing->current_priority; |
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308 | Priority_Control ceiling_priority = |
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309 | _MRSP_Get_ceiling_priority( mrsp, scheduler_index ); |
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310 | bool priority_ok = !_Thread_Priority_less_than( |
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311 | ceiling_priority, |
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312 | initial_priority |
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313 | ); |
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314 | Resource_Node *owner; |
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315 | |
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316 | if ( !priority_ok) { |
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317 | _ISR_lock_ISR_enable( &queue_context->Lock_context ); |
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318 | return STATUS_MUTEX_CEILING_VIOLATED; |
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319 | } |
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320 | |
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321 | _MRSP_Acquire_critical( mrsp, queue_context ); |
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322 | owner = _Resource_Get_owner( &mrsp->Resource ); |
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323 | if ( owner == NULL ) { |
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324 | _MRSP_Claim_ownership( |
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325 | mrsp, |
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326 | executing, |
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327 | initial_priority, |
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328 | ceiling_priority, |
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329 | queue_context |
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330 | ); |
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331 | status = STATUS_SUCCESSFUL; |
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332 | } else if ( |
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333 | wait |
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334 | && _Resource_Node_get_root( owner ) != &executing->Resource_node |
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335 | ) { |
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336 | status = _MRSP_Wait_for_ownership( |
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337 | mrsp, |
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338 | owner, |
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339 | executing, |
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340 | initial_priority, |
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341 | ceiling_priority, |
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342 | timeout, |
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343 | queue_context |
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344 | ); |
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345 | } else { |
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346 | _MRSP_Release( mrsp, queue_context ); |
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347 | /* Not available, nested access or deadlock */ |
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348 | status = STATUS_UNAVAILABLE; |
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349 | } |
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350 | |
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351 | return status; |
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352 | } |
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353 | |
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354 | RTEMS_INLINE_ROUTINE Status_Control _MRSP_Surrender( |
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355 | MRSP_Control *mrsp, |
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356 | Thread_Control *executing, |
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357 | Thread_queue_Context *queue_context |
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358 | ) |
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359 | { |
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360 | Priority_Control initial_priority; |
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361 | Per_CPU_Control *cpu_self; |
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362 | ISR_lock_Context giant_lock_context; |
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363 | |
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364 | if ( _Resource_Get_owner( &mrsp->Resource ) != &executing->Resource_node ) { |
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365 | _ISR_lock_ISR_enable( &queue_context->Lock_context ); |
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366 | return STATUS_NOT_OWNER; |
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367 | } |
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368 | |
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369 | if ( |
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370 | !_Resource_Is_most_recently_obtained( |
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371 | &mrsp->Resource, |
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372 | &executing->Resource_node |
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373 | ) |
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374 | ) { |
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375 | _ISR_lock_ISR_enable( &queue_context->Lock_context ); |
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376 | return STATUS_RELEASE_ORDER_VIOLATION; |
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377 | } |
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378 | |
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379 | initial_priority = mrsp->initial_priority_of_owner; |
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380 | |
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381 | _MRSP_Acquire_critical( mrsp, queue_context ); |
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382 | |
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383 | _MRSP_Giant_acquire( &giant_lock_context ); |
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384 | |
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385 | _Resource_Extract( &mrsp->Resource ); |
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386 | |
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387 | if ( _Chain_Is_empty( &mrsp->Rivals ) ) { |
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388 | _Resource_Set_owner( &mrsp->Resource, NULL ); |
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389 | } else { |
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390 | MRSP_Rival *rival = (MRSP_Rival *) |
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391 | _Chain_Get_first_unprotected( &mrsp->Rivals ); |
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392 | Thread_Control *new_owner; |
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393 | |
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394 | /* |
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395 | * This must be inside the critical section since the status prevents a |
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396 | * potential double extraction in _MRSP_Timeout(). |
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397 | */ |
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398 | rival->status = STATUS_SUCCESSFUL; |
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399 | |
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400 | new_owner = rival->thread; |
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401 | mrsp->initial_priority_of_owner = rival->initial_priority; |
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402 | _Resource_Node_extract( &new_owner->Resource_node ); |
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403 | _Resource_Node_set_dependency( &new_owner->Resource_node, NULL ); |
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404 | _Resource_Node_add_resource( &new_owner->Resource_node, &mrsp->Resource ); |
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405 | _Resource_Set_owner( &mrsp->Resource, &new_owner->Resource_node ); |
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406 | _Scheduler_Thread_change_help_state( new_owner, SCHEDULER_HELP_ACTIVE_OWNER ); |
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407 | _Scheduler_Thread_change_resource_root( new_owner, new_owner ); |
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408 | } |
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409 | |
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410 | if ( !_Resource_Node_owns_resources( &executing->Resource_node ) ) { |
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411 | _Scheduler_Thread_change_help_state( executing, SCHEDULER_HELP_YOURSELF ); |
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412 | } |
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413 | |
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414 | _MRSP_Giant_release( &giant_lock_context ); |
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415 | |
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416 | cpu_self = _Thread_Dispatch_disable_critical( &queue_context->Lock_context ); |
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417 | _MRSP_Release( mrsp, queue_context ); |
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418 | |
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419 | _MRSP_Restore_priority( executing, initial_priority ); |
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420 | |
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421 | _Thread_Dispatch_enable( cpu_self ); |
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422 | |
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423 | return STATUS_SUCCESSFUL; |
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424 | } |
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425 | |
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426 | RTEMS_INLINE_ROUTINE Status_Control _MRSP_Can_destroy( MRSP_Control *mrsp ) |
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427 | { |
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428 | if ( _Resource_Get_owner( &mrsp->Resource ) != NULL ) { |
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429 | return STATUS_RESOURCE_IN_USE; |
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430 | } |
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431 | |
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432 | return STATUS_SUCCESSFUL; |
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433 | } |
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434 | |
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435 | RTEMS_INLINE_ROUTINE void _MRSP_Destroy( |
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436 | MRSP_Control *mrsp, |
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437 | Thread_queue_Context *queue_context |
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438 | ) |
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439 | { |
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440 | _MRSP_Release( mrsp, queue_context ); |
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441 | _ISR_lock_Destroy( &mrsp->Lock ); |
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442 | _Workspace_Free( mrsp->ceiling_priorities ); |
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443 | } |
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444 | |
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445 | /** @} */ |
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446 | |
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447 | #ifdef __cplusplus |
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448 | } |
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449 | #endif /* __cplusplus */ |
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450 | |
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451 | #endif /* RTEMS_SMP */ |
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452 | |
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453 | #endif /* _RTEMS_SCORE_MRSPIMPL_H */ |
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