1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup RTEMSScoreSchedulerEDF |
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5 | * |
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6 | * @brief EDF Scheduler Implementation |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Copryight (c) 2011 Petr Benes. |
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11 | * Copyright (C) 2011 On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * The license and distribution terms for this file may be |
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14 | * found in the file LICENSE in this distribution or at |
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15 | * http://www.rtems.org/license/LICENSE. |
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16 | */ |
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17 | |
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18 | #ifndef _RTEMS_SCORE_SCHEDULEREDFIMPL_H |
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19 | #define _RTEMS_SCORE_SCHEDULEREDFIMPL_H |
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20 | |
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21 | #include <rtems/score/scheduleredf.h> |
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22 | #include <rtems/score/schedulerimpl.h> |
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23 | |
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24 | #ifdef __cplusplus |
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25 | extern "C" { |
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26 | #endif |
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27 | |
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28 | /** |
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29 | * @addtogroup RTEMSScoreSchedulerEDF |
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30 | * |
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31 | * @{ |
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32 | */ |
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33 | |
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34 | /** |
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35 | * This is just a most significant bit of Priority_Control type. It |
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36 | * distinguishes threads which are deadline driven (priority |
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37 | * represented by a lower number than @a SCHEDULER_EDF_PRIO_MSB) from those |
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38 | * ones who do not have any deadlines and thus are considered background |
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39 | * tasks. |
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40 | */ |
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41 | #define SCHEDULER_EDF_PRIO_MSB 0x8000000000000000 |
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42 | |
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43 | /** |
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44 | * @brief Gets the context of the scheduler. |
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45 | * |
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46 | * @param scheduler The scheduler instance. |
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47 | * |
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48 | * @return The scheduler context of @a scheduler. |
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49 | */ |
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50 | RTEMS_INLINE_ROUTINE Scheduler_EDF_Context * |
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51 | _Scheduler_EDF_Get_context( const Scheduler_Control *scheduler ) |
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52 | { |
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53 | return (Scheduler_EDF_Context *) _Scheduler_Get_context( scheduler ); |
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54 | } |
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55 | |
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56 | /** |
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57 | * @brief Gets the scheduler EDF node of the thread. |
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58 | * |
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59 | * @param the_thread The thread to get the scheduler node of. |
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60 | * |
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61 | * @return The EDF scheduler node of @a the_thread. |
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62 | */ |
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63 | RTEMS_INLINE_ROUTINE Scheduler_EDF_Node *_Scheduler_EDF_Thread_get_node( |
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64 | Thread_Control *the_thread |
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65 | ) |
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66 | { |
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67 | return (Scheduler_EDF_Node *) _Thread_Scheduler_get_home_node( the_thread ); |
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68 | } |
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69 | |
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70 | /** |
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71 | * @brief Returns the scheduler EDF node for the scheduler node. |
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72 | * |
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73 | * @param node The scheduler node of which the scheduler EDF node is returned. |
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74 | * |
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75 | * @return The corresponding scheduler EDF node. |
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76 | */ |
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77 | RTEMS_INLINE_ROUTINE Scheduler_EDF_Node * _Scheduler_EDF_Node_downcast( |
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78 | Scheduler_Node *node |
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79 | ) |
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80 | { |
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81 | return (Scheduler_EDF_Node *) node; |
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82 | } |
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83 | |
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84 | /** |
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85 | * @brief Checks if @a left is less than the priority of the node @a right. |
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86 | * |
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87 | * @param left The priority on the left hand side of the comparison. |
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88 | * @param right The node of which the priority is compared to left. |
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89 | * |
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90 | * @retval true @a left is less than the priority of @a right. |
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91 | * @retval false @a left is greater or equal than the priority of @a right. |
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92 | */ |
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93 | RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less( |
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94 | const void *left, |
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95 | const RBTree_Node *right |
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96 | ) |
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97 | { |
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98 | const Priority_Control *the_left; |
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99 | const Scheduler_EDF_Node *the_right; |
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100 | Priority_Control prio_left; |
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101 | Priority_Control prio_right; |
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102 | |
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103 | the_left = (const Priority_Control*) left; |
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104 | the_right = RTEMS_CONTAINER_OF( right, Scheduler_EDF_Node, Node ); |
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105 | |
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106 | prio_left = *the_left; |
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107 | prio_right = the_right->priority; |
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108 | |
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109 | return prio_left < prio_right; |
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110 | } |
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111 | |
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112 | /** |
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113 | * @brief Checks if @a left is less or equal than the priority of the node @a right. |
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114 | * |
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115 | * @param left The priority on the left hand side of the comparison. |
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116 | * @param right The node of which the priority is compared to left. |
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117 | * |
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118 | * @retval true @a left is less or equal than the priority of @a right. |
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119 | * @retval false @a left is greater than the priority of @a right. |
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120 | */ |
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121 | RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Priority_less_equal( |
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122 | const void *left, |
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123 | const RBTree_Node *right |
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124 | ) |
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125 | { |
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126 | const Priority_Control *the_left; |
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127 | const Scheduler_EDF_Node *the_right; |
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128 | Priority_Control prio_left; |
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129 | Priority_Control prio_right; |
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130 | |
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131 | the_left = (const Priority_Control*) left; |
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132 | the_right = RTEMS_CONTAINER_OF( right, Scheduler_EDF_Node, Node ); |
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133 | |
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134 | prio_left = *the_left; |
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135 | prio_right = the_right->priority; |
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136 | |
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137 | return prio_left <= prio_right; |
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138 | } |
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139 | |
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140 | /** |
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141 | * @brief Inserts the scheduler node with the given priority in the ready |
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142 | * queue of the context. |
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143 | * |
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144 | * @param[in, out] context The context to insert the node in. |
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145 | * @param node The node to be inserted. |
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146 | * @param insert_priority The priority with which the node will be inserted. |
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147 | */ |
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148 | RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Enqueue( |
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149 | Scheduler_EDF_Context *context, |
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150 | Scheduler_EDF_Node *node, |
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151 | Priority_Control insert_priority |
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152 | ) |
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153 | { |
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154 | _RBTree_Insert_inline( |
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155 | &context->Ready, |
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156 | &node->Node, |
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157 | &insert_priority, |
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158 | _Scheduler_EDF_Priority_less_equal |
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159 | ); |
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160 | } |
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161 | |
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162 | /** |
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163 | * @brief Extracts the scheduler node from the ready queue of the context. |
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164 | * |
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165 | * @param[in, out] context The context to extract the node from. |
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166 | * @param[in, out] node The node to extract. |
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167 | */ |
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168 | RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract( |
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169 | Scheduler_EDF_Context *context, |
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170 | Scheduler_EDF_Node *node |
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171 | ) |
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172 | { |
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173 | _RBTree_Extract( &context->Ready, &node->Node ); |
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174 | } |
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175 | |
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176 | /** |
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177 | * @brief Extracts the node from the context of the given scheduler. |
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178 | * |
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179 | * @param scheduler The scheduler instance. |
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180 | * @param the_thread The thread is not used in this method. |
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181 | * @param[in, out] node The node to be extracted. |
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182 | */ |
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183 | RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract_body( |
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184 | const Scheduler_Control *scheduler, |
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185 | Thread_Control *the_thread, |
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186 | Scheduler_Node *node |
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187 | ) |
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188 | { |
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189 | Scheduler_EDF_Context *context; |
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190 | Scheduler_EDF_Node *the_node; |
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191 | |
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192 | context = _Scheduler_EDF_Get_context( scheduler ); |
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193 | the_node = _Scheduler_EDF_Node_downcast( node ); |
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194 | |
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195 | _Scheduler_EDF_Extract( context, the_node ); |
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196 | } |
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197 | |
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198 | /** |
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199 | * @brief Schedules the next ready thread as the heir. |
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200 | * |
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201 | * @param scheduler The scheduler instance to schedule the minimum of the context of. |
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202 | * @param the_thread This parameter is not used. |
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203 | * @param force_dispatch Indicates whether the current heir is blocked even if it is |
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204 | * not set as preemptible. |
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205 | */ |
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206 | RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Schedule_body( |
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207 | const Scheduler_Control *scheduler, |
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208 | Thread_Control *the_thread, |
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209 | bool force_dispatch |
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210 | ) |
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211 | { |
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212 | Scheduler_EDF_Context *context; |
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213 | RBTree_Node *first; |
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214 | Scheduler_EDF_Node *node; |
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215 | |
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216 | (void) the_thread; |
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217 | |
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218 | context = _Scheduler_EDF_Get_context( scheduler ); |
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219 | first = _RBTree_Minimum( &context->Ready ); |
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220 | node = RTEMS_CONTAINER_OF( first, Scheduler_EDF_Node, Node ); |
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221 | |
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222 | _Scheduler_Update_heir( node->Base.owner, force_dispatch ); |
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223 | } |
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224 | |
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225 | /** @} */ |
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226 | |
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227 | #ifdef __cplusplus |
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228 | } |
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229 | #endif |
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230 | |
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231 | #endif |
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232 | /* end of include file */ |
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