1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Changes the Priority of a Thread |
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5 | * |
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6 | * @ingroup RTEMSScoreThread |
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7 | */ |
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8 | |
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9 | /* |
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10 | * COPYRIGHT (c) 1989-2014. |
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11 | * On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * Copyright (c) 2013, 2016 embedded brains GmbH |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.org/license/LICENSE. |
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18 | */ |
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19 | |
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20 | #if HAVE_CONFIG_H |
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21 | #include "config.h" |
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22 | #endif |
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23 | |
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24 | #include <rtems/score/threadimpl.h> |
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25 | #include <rtems/score/assert.h> |
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26 | #include <rtems/score/schedulerimpl.h> |
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27 | |
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28 | static void _Thread_Set_scheduler_node_priority( |
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29 | Priority_Aggregation *priority_aggregation, |
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30 | bool prepend_it |
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31 | ) |
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32 | { |
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33 | _Scheduler_Node_set_priority( |
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34 | SCHEDULER_NODE_OF_WAIT_PRIORITY_NODE( priority_aggregation ), |
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35 | _Priority_Get_priority( priority_aggregation ), |
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36 | prepend_it |
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37 | ); |
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38 | } |
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39 | |
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40 | #if defined(RTEMS_SMP) |
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41 | static void _Thread_Priority_action_add( |
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42 | Priority_Aggregation *priority_aggregation, |
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43 | Priority_Actions *priority_actions, |
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44 | void *arg |
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45 | ) |
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46 | { |
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47 | Scheduler_Node *scheduler_node; |
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48 | Thread_Control *the_thread; |
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49 | |
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50 | scheduler_node = SCHEDULER_NODE_OF_WAIT_PRIORITY( priority_aggregation ); |
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51 | the_thread = arg; |
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52 | |
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53 | _Thread_Scheduler_add_wait_node( the_thread, scheduler_node ); |
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54 | _Thread_Set_scheduler_node_priority( priority_aggregation, false ); |
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55 | _Priority_Set_action_type( priority_aggregation, PRIORITY_ACTION_ADD ); |
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56 | _Priority_Actions_add( priority_actions, priority_aggregation ); |
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57 | } |
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58 | |
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59 | static void _Thread_Priority_action_remove( |
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60 | Priority_Aggregation *priority_aggregation, |
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61 | Priority_Actions *priority_actions, |
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62 | void *arg |
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63 | ) |
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64 | { |
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65 | Scheduler_Node *scheduler_node; |
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66 | Thread_Control *the_thread; |
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67 | |
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68 | scheduler_node = SCHEDULER_NODE_OF_WAIT_PRIORITY( priority_aggregation ); |
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69 | the_thread = arg; |
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70 | |
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71 | _Thread_Scheduler_remove_wait_node( the_thread, scheduler_node ); |
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72 | _Thread_Set_scheduler_node_priority( priority_aggregation, true ); |
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73 | _Priority_Set_action_type( priority_aggregation, PRIORITY_ACTION_REMOVE ); |
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74 | _Priority_Actions_add( priority_actions, priority_aggregation ); |
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75 | } |
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76 | #endif |
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77 | |
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78 | static void _Thread_Priority_action_change( |
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79 | Priority_Aggregation *priority_aggregation, |
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80 | bool prepend_it, |
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81 | Priority_Actions *priority_actions, |
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82 | void *arg |
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83 | ) |
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84 | { |
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85 | _Thread_Set_scheduler_node_priority( priority_aggregation, prepend_it ); |
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86 | #if defined(RTEMS_SMP) || defined(RTEMS_DEBUG) |
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87 | _Priority_Set_action_type( priority_aggregation, PRIORITY_ACTION_CHANGE ); |
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88 | #endif |
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89 | _Priority_Actions_add( priority_actions, priority_aggregation ); |
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90 | } |
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91 | |
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92 | static void _Thread_Priority_do_perform_actions( |
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93 | Thread_Control *the_thread, |
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94 | Thread_queue_Queue *queue, |
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95 | const Thread_queue_Operations *operations, |
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96 | bool prepend_it, |
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97 | Thread_queue_Context *queue_context |
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98 | ) |
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99 | { |
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100 | Priority_Aggregation *priority_aggregation; |
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101 | |
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102 | _Assert( !_Priority_Actions_is_empty( &queue_context->Priority.Actions ) ); |
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103 | priority_aggregation = _Priority_Actions_move( &queue_context->Priority.Actions ); |
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104 | |
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105 | do { |
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106 | Priority_Aggregation *next_aggregation; |
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107 | Priority_Node *priority_action_node; |
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108 | Priority_Action_type priority_action_type; |
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109 | |
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110 | next_aggregation = _Priority_Get_next_action( priority_aggregation ); |
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111 | |
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112 | priority_action_node = priority_aggregation->Action.node; |
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113 | priority_action_type = priority_aggregation->Action.type; |
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114 | |
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115 | switch ( priority_action_type ) { |
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116 | case PRIORITY_ACTION_ADD: |
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117 | #if defined(RTEMS_SMP) |
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118 | _Priority_Insert( |
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119 | priority_aggregation, |
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120 | priority_action_node, |
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121 | &queue_context->Priority.Actions, |
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122 | _Thread_Priority_action_add, |
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123 | _Thread_Priority_action_change, |
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124 | the_thread |
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125 | ); |
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126 | #else |
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127 | _Priority_Non_empty_insert( |
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128 | priority_aggregation, |
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129 | priority_action_node, |
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130 | &queue_context->Priority.Actions, |
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131 | _Thread_Priority_action_change, |
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132 | NULL |
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133 | ); |
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134 | #endif |
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135 | break; |
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136 | case PRIORITY_ACTION_REMOVE: |
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137 | #if defined(RTEMS_SMP) |
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138 | _Priority_Extract( |
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139 | priority_aggregation, |
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140 | priority_action_node, |
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141 | &queue_context->Priority.Actions, |
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142 | _Thread_Priority_action_remove, |
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143 | _Thread_Priority_action_change, |
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144 | the_thread |
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145 | ); |
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146 | #else |
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147 | _Priority_Extract_non_empty( |
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148 | priority_aggregation, |
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149 | priority_action_node, |
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150 | &queue_context->Priority.Actions, |
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151 | _Thread_Priority_action_change, |
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152 | NULL |
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153 | ); |
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154 | #endif |
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155 | break; |
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156 | default: |
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157 | _Assert( priority_action_type == PRIORITY_ACTION_CHANGE ); |
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158 | _Priority_Changed( |
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159 | priority_aggregation, |
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160 | priority_action_node, |
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161 | prepend_it, |
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162 | &queue_context->Priority.Actions, |
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163 | _Thread_Priority_action_change, |
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164 | NULL |
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165 | ); |
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166 | break; |
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167 | } |
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168 | |
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169 | priority_aggregation = next_aggregation; |
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170 | } while ( _Priority_Actions_is_valid( priority_aggregation ) ); |
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171 | |
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172 | if ( !_Priority_Actions_is_empty( &queue_context->Priority.Actions ) ) { |
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173 | _Thread_queue_Context_add_priority_update( queue_context, the_thread ); |
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174 | |
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175 | ( *operations->priority_actions )( |
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176 | queue, |
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177 | &queue_context->Priority.Actions |
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178 | ); |
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179 | } |
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180 | } |
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181 | |
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182 | void _Thread_Priority_perform_actions( |
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183 | Thread_Control *start_of_path, |
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184 | Thread_queue_Context *queue_context |
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185 | ) |
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186 | { |
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187 | Thread_Control *the_thread; |
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188 | size_t update_count; |
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189 | |
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190 | _Assert( start_of_path != NULL ); |
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191 | |
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192 | /* |
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193 | * This function is tricky on SMP configurations. Please note that we do not |
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194 | * use the thread queue path available via the thread queue context. Instead |
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195 | * we directly use the thread wait information to traverse the thread queue |
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196 | * path. Thus, we do not necessarily acquire all thread queue locks on our |
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197 | * own. In case of a deadlock, we use locks acquired by other processors |
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198 | * along the path. |
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199 | */ |
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200 | |
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201 | the_thread = start_of_path; |
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202 | update_count = _Thread_queue_Context_save_priority_updates( queue_context ); |
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203 | |
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204 | while ( true ) { |
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205 | Thread_queue_Queue *queue; |
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206 | |
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207 | queue = the_thread->Wait.queue; |
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208 | |
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209 | _Thread_Priority_do_perform_actions( |
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210 | the_thread, |
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211 | queue, |
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212 | the_thread->Wait.operations, |
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213 | false, |
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214 | queue_context |
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215 | ); |
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216 | |
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217 | if ( _Priority_Actions_is_empty( &queue_context->Priority.Actions ) ) { |
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218 | return; |
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219 | } |
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220 | |
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221 | _Assert( queue != NULL ); |
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222 | the_thread = queue->owner; |
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223 | _Assert( the_thread != NULL ); |
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224 | |
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225 | /* |
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226 | * In case the priority action list is non-empty, then the current thread |
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227 | * is enqueued on a thread queue. There is no need to notify the scheduler |
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228 | * about a priority change, since it will pick up the new priority once it |
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229 | * is unblocked. Restore the previous set of threads bound to update the |
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230 | * priority. |
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231 | */ |
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232 | _Thread_queue_Context_restore_priority_updates( |
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233 | queue_context, |
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234 | update_count |
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235 | ); |
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236 | } |
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237 | } |
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238 | |
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239 | static void _Thread_Priority_apply( |
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240 | Thread_Control *the_thread, |
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241 | Priority_Node *priority_action_node, |
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242 | Thread_queue_Context *queue_context, |
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243 | bool prepend_it, |
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244 | Priority_Action_type priority_action_type |
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245 | ) |
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246 | { |
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247 | Scheduler_Node *scheduler_node; |
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248 | Thread_queue_Queue *queue; |
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249 | |
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250 | scheduler_node = _Thread_Scheduler_get_home_node( the_thread ); |
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251 | _Priority_Actions_initialize_one( |
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252 | &queue_context->Priority.Actions, |
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253 | &scheduler_node->Wait.Priority, |
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254 | priority_action_node, |
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255 | priority_action_type |
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256 | ); |
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257 | queue = the_thread->Wait.queue; |
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258 | _Thread_Priority_do_perform_actions( |
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259 | the_thread, |
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260 | queue, |
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261 | the_thread->Wait.operations, |
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262 | prepend_it, |
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263 | queue_context |
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264 | ); |
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265 | |
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266 | if ( !_Priority_Actions_is_empty( &queue_context->Priority.Actions ) ) { |
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267 | #if defined(RTEMS_SMP) |
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268 | _Thread_queue_Path_acquire_critical( queue, the_thread, queue_context ); |
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269 | #endif |
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270 | _Thread_Priority_perform_actions( queue->owner, queue_context ); |
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271 | #if defined(RTEMS_SMP) |
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272 | _Thread_queue_Path_release_critical( queue_context ); |
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273 | #endif |
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274 | } |
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275 | } |
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276 | |
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277 | void _Thread_Priority_add( |
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278 | Thread_Control *the_thread, |
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279 | Priority_Node *priority_node, |
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280 | Thread_queue_Context *queue_context |
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281 | ) |
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282 | { |
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283 | _Thread_Priority_apply( |
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284 | the_thread, |
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285 | priority_node, |
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286 | queue_context, |
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287 | false, |
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288 | PRIORITY_ACTION_ADD |
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289 | ); |
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290 | } |
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291 | |
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292 | void _Thread_Priority_remove( |
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293 | Thread_Control *the_thread, |
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294 | Priority_Node *priority_node, |
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295 | Thread_queue_Context *queue_context |
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296 | ) |
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297 | { |
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298 | _Thread_Priority_apply( |
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299 | the_thread, |
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300 | priority_node, |
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301 | queue_context, |
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302 | true, |
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303 | PRIORITY_ACTION_REMOVE |
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304 | ); |
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305 | } |
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306 | |
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307 | void _Thread_Priority_changed( |
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308 | Thread_Control *the_thread, |
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309 | Priority_Node *priority_node, |
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310 | bool prepend_it, |
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311 | Thread_queue_Context *queue_context |
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312 | ) |
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313 | { |
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314 | _Thread_Priority_apply( |
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315 | the_thread, |
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316 | priority_node, |
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317 | queue_context, |
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318 | prepend_it, |
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319 | PRIORITY_ACTION_CHANGE |
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320 | ); |
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321 | } |
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322 | |
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323 | void _Thread_Priority_replace( |
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324 | Thread_Control *the_thread, |
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325 | Priority_Node *victim_node, |
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326 | Priority_Node *replacement_node |
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327 | ) |
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328 | { |
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329 | Scheduler_Node *scheduler_node; |
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330 | |
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331 | scheduler_node = _Thread_Scheduler_get_home_node( the_thread ); |
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332 | _Priority_Replace( |
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333 | &scheduler_node->Wait.Priority, |
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334 | victim_node, |
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335 | replacement_node |
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336 | ); |
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337 | } |
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338 | |
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339 | void _Thread_Priority_update( Thread_queue_Context *queue_context ) |
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340 | { |
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341 | size_t i; |
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342 | size_t n; |
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343 | |
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344 | n = queue_context->Priority.update_count; |
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345 | |
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346 | /* |
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347 | * Update the priority of all threads of the set. Do not care to clear the |
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348 | * set, since the thread queue context will soon get destroyed anyway. |
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349 | */ |
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350 | for ( i = 0; i < n ; ++i ) { |
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351 | Thread_Control *the_thread; |
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352 | ISR_lock_Context lock_context; |
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353 | |
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354 | the_thread = queue_context->Priority.update[ i ]; |
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355 | _Thread_State_acquire( the_thread, &lock_context ); |
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356 | _Scheduler_Update_priority( the_thread ); |
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357 | _Thread_State_release( the_thread, &lock_context ); |
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358 | } |
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359 | } |
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360 | |
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361 | #if defined(RTEMS_SMP) |
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362 | void _Thread_Priority_and_sticky_update( |
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363 | Thread_Control *the_thread, |
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364 | int sticky_level_change |
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365 | ) |
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366 | { |
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367 | ISR_lock_Context lock_context; |
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368 | |
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369 | _Thread_State_acquire( the_thread, &lock_context ); |
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370 | _Scheduler_Priority_and_sticky_update( |
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371 | the_thread, |
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372 | sticky_level_change |
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373 | ); |
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374 | _Thread_State_release( the_thread, &lock_context ); |
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375 | } |
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376 | #endif |
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