1 | /* SPDX-License-Identifier: BSD-2-Clause */ |
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2 | |
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3 | /** |
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4 | * @file |
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5 | * |
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6 | * @ingroup RTEMSScoreScheduler |
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7 | * |
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8 | * @brief This header file provides interfaces of the |
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9 | * @ref RTEMSScoreScheduler related to scheduler nodes which are used by the |
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10 | * implementation and the @ref RTEMSImplApplConfig. |
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11 | */ |
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12 | |
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13 | /* |
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14 | * Copyright (c) 2014, 2016 embedded brains GmbH. All rights reserved. |
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15 | * |
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16 | * Redistribution and use in source and binary forms, with or without |
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17 | * modification, are permitted provided that the following conditions |
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18 | * are met: |
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19 | * 1. Redistributions of source code must retain the above copyright |
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20 | * notice, this list of conditions and the following disclaimer. |
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21 | * 2. Redistributions in binary form must reproduce the above copyright |
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22 | * notice, this list of conditions and the following disclaimer in the |
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23 | * documentation and/or other materials provided with the distribution. |
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24 | * |
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25 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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26 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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29 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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30 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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31 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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32 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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33 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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34 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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35 | * POSSIBILITY OF SUCH DAMAGE. |
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36 | */ |
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37 | |
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38 | #ifndef _RTEMS_SCORE_SCHEDULERNODE_H |
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39 | #define _RTEMS_SCORE_SCHEDULERNODE_H |
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40 | |
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41 | #include <rtems/score/basedefs.h> |
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42 | #include <rtems/score/chain.h> |
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43 | #include <rtems/score/priority.h> |
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44 | #include <rtems/score/isrlock.h> |
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45 | |
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46 | /** |
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47 | * @addtogroup RTEMSScoreScheduler |
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48 | * |
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49 | * @{ |
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50 | */ |
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51 | |
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52 | struct _Thread_Control; |
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53 | |
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54 | #ifdef __cplusplus |
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55 | extern "C" { |
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56 | #endif /* __cplusplus */ |
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57 | |
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58 | #if defined(RTEMS_SMP) |
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59 | /** |
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60 | * @brief The scheduler node requests. |
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61 | */ |
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62 | typedef enum { |
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63 | /** |
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64 | * @brief The scheduler node is not on the list of pending requests. |
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65 | */ |
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66 | SCHEDULER_NODE_REQUEST_NOT_PENDING, |
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67 | |
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68 | /** |
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69 | * @brief There is a pending scheduler node request to add this scheduler |
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70 | * node to the Thread_Control::Scheduler::Scheduler_nodes chain. |
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71 | */ |
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72 | SCHEDULER_NODE_REQUEST_ADD, |
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73 | |
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74 | /** |
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75 | * @brief There is a pending scheduler node request to remove this scheduler |
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76 | * node from the Thread_Control::Scheduler::Scheduler_nodes chain. |
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77 | */ |
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78 | SCHEDULER_NODE_REQUEST_REMOVE, |
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79 | |
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80 | /** |
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81 | * @brief The scheduler node is on the list of pending requests, but nothing |
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82 | * should change. |
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83 | */ |
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84 | SCHEDULER_NODE_REQUEST_NOTHING, |
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85 | |
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86 | } Scheduler_Node_request; |
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87 | #endif |
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88 | |
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89 | typedef struct Scheduler_Node Scheduler_Node; |
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90 | |
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91 | /** |
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92 | * @brief Scheduler node for per-thread data. |
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93 | */ |
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94 | struct Scheduler_Node { |
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95 | #if defined(RTEMS_SMP) |
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96 | /** |
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97 | * @brief Chain node for usage in various scheduler data structures. |
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98 | * |
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99 | * Strictly, this is the wrong place for this field since the data structures |
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100 | * to manage scheduler nodes belong to the particular scheduler |
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101 | * implementation. Currently, all SMP scheduler implementations use chains |
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102 | * or red-black trees. The node is here to simplify things, just like the |
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103 | * object node in the thread control block. |
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104 | */ |
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105 | union { |
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106 | Chain_Node Chain; |
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107 | RBTree_Node RBTree; |
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108 | } Node; |
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109 | |
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110 | /** |
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111 | * @brief The sticky level determines if this scheduler node should use an |
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112 | * idle thread in case this node is scheduled and the owner thread is |
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113 | * blocked. |
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114 | */ |
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115 | int sticky_level; |
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116 | |
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117 | /** |
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118 | * @brief The thread using this node. |
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119 | * |
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120 | * This is either the owner or an idle thread. |
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121 | */ |
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122 | struct _Thread_Control *user; |
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123 | |
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124 | /** |
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125 | * @brief The idle thread claimed by this node in case the sticky level is |
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126 | * greater than zero and the thread is block or is scheduled on another |
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127 | * scheduler instance. |
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128 | * |
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129 | * This is necessary to ensure the priority ceiling protocols work across |
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130 | * scheduler boundaries. |
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131 | */ |
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132 | struct _Thread_Control *idle; |
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133 | #endif |
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134 | |
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135 | /** |
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136 | * @brief The thread owning this node. |
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137 | */ |
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138 | struct _Thread_Control *owner; |
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139 | |
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140 | #if defined(RTEMS_SMP) |
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141 | /** |
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142 | * @brief Block to register and manage this scheduler node in the thread |
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143 | * control block of the owner of this scheduler node. |
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144 | */ |
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145 | struct { |
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146 | /** |
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147 | * @brief Node to add this scheduler node to |
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148 | * Thread_Control::Scheduler::Wait_nodes. |
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149 | */ |
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150 | Chain_Node Wait_node; |
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151 | |
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152 | /** |
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153 | * @brief Node to add this scheduler node to |
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154 | * Thread_Control::Scheduler::Scheduler_nodes or a temporary remove list. |
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155 | */ |
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156 | union { |
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157 | /** |
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158 | * @brief The node for Thread_Control::Scheduler::Scheduler_nodes. |
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159 | */ |
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160 | Chain_Node Chain; |
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161 | |
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162 | /** |
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163 | * @brief The next pointer for a temporary remove list. |
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164 | * |
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165 | * @see _Thread_Scheduler_process_requests(). |
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166 | */ |
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167 | Scheduler_Node *next; |
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168 | } Scheduler_node; |
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169 | |
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170 | /** |
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171 | * @brief Link to the next scheduler node in the |
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172 | * Thread_Control::Scheduler::requests list. |
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173 | */ |
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174 | Scheduler_Node *next_request; |
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175 | |
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176 | /** |
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177 | * @brief The current scheduler node request. |
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178 | */ |
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179 | Scheduler_Node_request request; |
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180 | } Thread; |
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181 | #endif |
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182 | |
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183 | /** |
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184 | * @brief Thread wait support block. |
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185 | */ |
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186 | struct { |
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187 | Priority_Aggregation Priority; |
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188 | } Wait; |
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189 | |
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190 | /** |
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191 | * @brief The thread priority information used by the scheduler. |
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192 | * |
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193 | * The thread priority is manifest in two independent areas. One area is the |
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194 | * user visible thread priority along with a potential thread queue. The |
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195 | * other is the scheduler. During a thread priority change, the user visible |
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196 | * thread priority and the thread queue are first updated and the thread |
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197 | * priority value here is changed. Once this is done the scheduler is |
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198 | * notified via the update priority operation, so that it can update its |
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199 | * internal state and honour a new thread priority value. |
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200 | */ |
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201 | struct { |
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202 | /** |
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203 | * @brief The thread priority value of this scheduler node. |
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204 | * |
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205 | * The producer of this value is _Thread_Change_priority(). The consumer |
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206 | * is the scheduler via the unblock and update priority operations. |
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207 | * |
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208 | * This priority control consists of two parts. One part is the plain |
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209 | * priority value (most-significant 63 bits). The other part is the |
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210 | * least-significant bit which indicates if the thread should be appended |
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211 | * (bit set) or prepended (bit cleared) to its priority group, see |
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212 | * SCHEDULER_PRIORITY_APPEND(). |
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213 | * |
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214 | * @see _Scheduler_Node_get_priority() and _Scheduler_Node_set_priority(). |
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215 | */ |
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216 | #if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER == 8 |
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217 | Atomic_Ulong value; |
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218 | #else |
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219 | Priority_Control value; |
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220 | #endif |
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221 | |
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222 | #if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER != 8 |
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223 | /** |
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224 | * @brief The lock protects the priority value. |
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225 | */ |
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226 | ISR_lock_Control Lock; |
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227 | #endif |
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228 | } Priority; |
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229 | }; |
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230 | |
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231 | #if defined(RTEMS_SMP) |
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232 | /** |
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233 | * @brief The size of a scheduler node. |
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234 | * |
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235 | * This value is provided via <rtems/confdefs.h>. |
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236 | */ |
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237 | extern const size_t _Scheduler_Node_size; |
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238 | #endif |
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239 | |
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240 | #if defined(RTEMS_SMP) |
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241 | #define SCHEDULER_NODE_OF_THREAD_WAIT_NODE( node ) \ |
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242 | RTEMS_CONTAINER_OF( node, Scheduler_Node, Thread.Wait_node ) |
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243 | |
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244 | #define SCHEDULER_NODE_OF_THREAD_SCHEDULER_NODE( node ) \ |
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245 | RTEMS_CONTAINER_OF( node, Scheduler_Node, Thread.Scheduler_node.Chain ) |
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246 | #endif |
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247 | |
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248 | #ifdef __cplusplus |
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249 | } |
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250 | #endif /* __cplusplus */ |
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251 | |
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252 | /** @} */ |
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253 | |
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254 | #endif /* _RTEMS_SCORE_SCHEDULERNODE_H */ |
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