1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief SMP Scheduler Implementation |
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5 | * |
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6 | * @ingroup ScoreSchedulerSMP |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Copyright (c) 2013-2014 embedded brains GmbH. All rights reserved. |
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11 | * |
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12 | * embedded brains GmbH |
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13 | * Dornierstr. 4 |
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14 | * 82178 Puchheim |
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15 | * Germany |
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16 | * <rtems@embedded-brains.de> |
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17 | * |
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18 | * The license and distribution terms for this file may be |
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19 | * found in the file LICENSE in this distribution or at |
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20 | * http://www.rtems.org/license/LICENSE. |
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21 | */ |
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22 | |
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23 | #ifndef _RTEMS_SCORE_SCHEDULERSMPIMPL_H |
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24 | #define _RTEMS_SCORE_SCHEDULERSMPIMPL_H |
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25 | |
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26 | #include <rtems/score/schedulersmp.h> |
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27 | #include <rtems/score/assert.h> |
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28 | #include <rtems/score/chainimpl.h> |
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29 | #include <rtems/score/schedulersimpleimpl.h> |
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30 | |
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31 | #ifdef __cplusplus |
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32 | extern "C" { |
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33 | #endif /* __cplusplus */ |
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34 | |
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35 | /** |
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36 | * @addtogroup ScoreSchedulerSMP |
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37 | * |
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38 | * The scheduler nodes can be in four states |
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39 | * - @ref SCHEDULER_SMP_NODE_BLOCKED, |
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40 | * - @ref SCHEDULER_SMP_NODE_SCHEDULED, and |
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41 | * - @ref SCHEDULER_SMP_NODE_READY. |
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42 | * |
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43 | * State transitions are triggered via basic operations |
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44 | * - _Scheduler_SMP_Enqueue_ordered(), |
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45 | * - _Scheduler_SMP_Enqueue_scheduled_ordered(), and |
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46 | * - _Scheduler_SMP_Block(). |
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47 | * |
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48 | * @dot |
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49 | * digraph { |
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50 | * node [style="filled"]; |
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51 | * |
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52 | * bs [label="BLOCKED"]; |
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53 | * ss [label="SCHEDULED", fillcolor="green"]; |
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54 | * rs [label="READY", fillcolor="red"]; |
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55 | * |
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56 | * edge [label="enqueue"]; |
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57 | * edge [fontcolor="darkgreen", color="darkgreen"]; |
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58 | * |
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59 | * bs -> ss; |
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60 | * |
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61 | * edge [fontcolor="red", color="red"]; |
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62 | * |
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63 | * bs -> rs; |
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64 | * |
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65 | * edge [label="enqueue other"]; |
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66 | * |
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67 | * ss -> rs; |
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68 | * |
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69 | * edge [label="block"]; |
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70 | * edge [fontcolor="black", color="black"]; |
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71 | * |
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72 | * ss -> bs; |
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73 | * rs -> bs; |
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74 | * |
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75 | * edge [label="block other"]; |
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76 | * edge [fontcolor="darkgreen", color="darkgreen"]; |
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77 | * |
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78 | * rs -> ss; |
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79 | * } |
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80 | * @enddot |
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81 | * |
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82 | * During system initialization each processor of the scheduler instance starts |
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83 | * with an idle thread assigned to it. Lets have a look at an example with two |
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84 | * idle threads I and J with priority 5. We also have blocked threads A, B and |
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85 | * C with priorities 1, 2 and 3 respectively. The scheduler nodes are ordered |
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86 | * with respect to the thread priority from left to right in the below |
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87 | * diagrams. The highest priority node (lowest priority number) is the |
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88 | * leftmost node. Since the processor assignment is independent of the thread |
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89 | * priority the processor indices may move from one state to the other. |
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90 | * |
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91 | * @dot |
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92 | * digraph { |
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93 | * node [style="filled"]; |
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94 | * edge [dir="none"]; |
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95 | * subgraph { |
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96 | * rank = same; |
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97 | * |
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98 | * i [label="I (5)", fillcolor="green"]; |
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99 | * j [label="J (5)", fillcolor="green"]; |
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100 | * a [label="A (1)"]; |
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101 | * b [label="B (2)"]; |
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102 | * c [label="C (3)"]; |
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103 | * i -> j; |
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104 | * } |
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105 | * |
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106 | * subgraph { |
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107 | * rank = same; |
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108 | * |
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109 | * p0 [label="PROCESSOR 0", shape="box"]; |
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110 | * p1 [label="PROCESSOR 1", shape="box"]; |
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111 | * } |
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112 | * |
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113 | * i -> p0; |
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114 | * j -> p1; |
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115 | * } |
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116 | * @enddot |
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117 | * |
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118 | * Lets start A. For this an enqueue operation is performed. |
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119 | * |
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120 | * @dot |
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121 | * digraph { |
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122 | * node [style="filled"]; |
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123 | * edge [dir="none"]; |
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124 | * |
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125 | * subgraph { |
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126 | * rank = same; |
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127 | * |
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128 | * i [label="I (5)", fillcolor="green"]; |
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129 | * j [label="J (5)", fillcolor="red"]; |
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130 | * a [label="A (1)", fillcolor="green"]; |
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131 | * b [label="B (2)"]; |
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132 | * c [label="C (3)"]; |
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133 | * a -> i; |
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134 | * } |
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135 | * |
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136 | * subgraph { |
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137 | * rank = same; |
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138 | * |
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139 | * p0 [label="PROCESSOR 0", shape="box"]; |
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140 | * p1 [label="PROCESSOR 1", shape="box"]; |
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141 | * } |
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142 | * |
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143 | * i -> p0; |
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144 | * a -> p1; |
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145 | * } |
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146 | * @enddot |
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147 | * |
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148 | * Lets start C. |
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149 | * |
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150 | * @dot |
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151 | * digraph { |
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152 | * node [style="filled"]; |
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153 | * edge [dir="none"]; |
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154 | * |
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155 | * subgraph { |
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156 | * rank = same; |
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157 | * |
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158 | * a [label="A (1)", fillcolor="green"]; |
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159 | * c [label="C (3)", fillcolor="green"]; |
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160 | * i [label="I (5)", fillcolor="red"]; |
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161 | * j [label="J (5)", fillcolor="red"]; |
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162 | * b [label="B (2)"]; |
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163 | * a -> c; |
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164 | * i -> j; |
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165 | * } |
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166 | * |
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167 | * subgraph { |
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168 | * rank = same; |
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169 | * |
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170 | * p0 [label="PROCESSOR 0", shape="box"]; |
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171 | * p1 [label="PROCESSOR 1", shape="box"]; |
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172 | * } |
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173 | * |
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174 | * c -> p0; |
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175 | * a -> p1; |
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176 | * } |
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177 | * @enddot |
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178 | * |
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179 | * Lets start B. |
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180 | * |
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181 | * @dot |
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182 | * digraph { |
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183 | * node [style="filled"]; |
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184 | * edge [dir="none"]; |
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185 | * |
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186 | * subgraph { |
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187 | * rank = same; |
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188 | * |
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189 | * a [label="A (1)", fillcolor="green"]; |
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190 | * b [label="B (2)", fillcolor="green"]; |
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191 | * c [label="C (3)", fillcolor="red"]; |
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192 | * i [label="I (5)", fillcolor="red"]; |
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193 | * j [label="J (5)", fillcolor="red"]; |
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194 | * a -> b; |
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195 | * c -> i -> j; |
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196 | * } |
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197 | * |
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198 | * subgraph { |
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199 | * rank = same; |
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200 | * |
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201 | * p0 [label="PROCESSOR 0", shape="box"]; |
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202 | * p1 [label="PROCESSOR 1", shape="box"]; |
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203 | * } |
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204 | * |
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205 | * b -> p0; |
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206 | * a -> p1; |
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207 | * } |
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208 | * @enddot |
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209 | * |
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210 | * Lets change the priority of thread A to 4. |
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211 | * |
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212 | * @dot |
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213 | * digraph { |
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214 | * node [style="filled"]; |
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215 | * edge [dir="none"]; |
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216 | * |
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217 | * subgraph { |
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218 | * rank = same; |
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219 | * |
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220 | * b [label="B (2)", fillcolor="green"]; |
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221 | * c [label="C (3)", fillcolor="green"]; |
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222 | * a [label="A (4)", fillcolor="red"]; |
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223 | * i [label="I (5)", fillcolor="red"]; |
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224 | * j [label="J (5)", fillcolor="red"]; |
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225 | * b -> c; |
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226 | * a -> i -> j; |
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227 | * } |
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228 | * |
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229 | * subgraph { |
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230 | * rank = same; |
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231 | * |
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232 | * p0 [label="PROCESSOR 0", shape="box"]; |
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233 | * p1 [label="PROCESSOR 1", shape="box"]; |
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234 | * } |
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235 | * |
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236 | * b -> p0; |
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237 | * c -> p1; |
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238 | * } |
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239 | * @enddot |
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240 | * |
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241 | * Now perform a blocking operation with thread B. Please note that thread A |
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242 | * migrated now from processor 0 to processor 1 and thread C still executes on |
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243 | * processor 1. |
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244 | * |
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245 | * @dot |
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246 | * digraph { |
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247 | * node [style="filled"]; |
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248 | * edge [dir="none"]; |
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249 | * |
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250 | * subgraph { |
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251 | * rank = same; |
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252 | * |
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253 | * c [label="C (3)", fillcolor="green"]; |
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254 | * a [label="A (4)", fillcolor="green"]; |
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255 | * i [label="I (5)", fillcolor="red"]; |
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256 | * j [label="J (5)", fillcolor="red"]; |
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257 | * b [label="B (2)"]; |
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258 | * c -> a; |
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259 | * i -> j; |
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260 | * } |
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261 | * |
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262 | * subgraph { |
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263 | * rank = same; |
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264 | * |
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265 | * p0 [label="PROCESSOR 0", shape="box"]; |
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266 | * p1 [label="PROCESSOR 1", shape="box"]; |
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267 | * } |
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268 | * |
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269 | * a -> p0; |
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270 | * c -> p1; |
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271 | * } |
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272 | * @enddot |
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273 | * |
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274 | * @{ |
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275 | */ |
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276 | |
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277 | typedef Scheduler_Node *( *Scheduler_SMP_Get_highest_ready )( |
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278 | Scheduler_Context *context, |
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279 | Scheduler_Node *node |
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280 | ); |
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281 | |
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282 | typedef Scheduler_Node *( *Scheduler_SMP_Get_lowest_scheduled )( |
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283 | Scheduler_Context *context, |
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284 | Scheduler_Node *filter, |
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285 | Chain_Node_order order |
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286 | ); |
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287 | |
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288 | typedef void ( *Scheduler_SMP_Extract )( |
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289 | Scheduler_Context *context, |
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290 | Scheduler_Node *node_to_extract |
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291 | ); |
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292 | |
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293 | typedef void ( *Scheduler_SMP_Insert )( |
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294 | Scheduler_Context *context, |
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295 | Scheduler_Node *node_to_insert |
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296 | ); |
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297 | |
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298 | typedef void ( *Scheduler_SMP_Move )( |
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299 | Scheduler_Context *context, |
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300 | Scheduler_Node *node_to_move |
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301 | ); |
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302 | |
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303 | typedef void ( *Scheduler_SMP_Update )( |
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304 | Scheduler_Context *context, |
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305 | Scheduler_Node *node_to_update, |
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306 | Priority_Control new_priority |
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307 | ); |
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308 | |
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309 | typedef Thread_Control *( *Scheduler_SMP_Enqueue )( |
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310 | Scheduler_Context *context, |
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311 | Scheduler_Node *node_to_enqueue, |
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312 | Thread_Control *needs_help |
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313 | ); |
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314 | |
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315 | typedef Thread_Control *( *Scheduler_SMP_Enqueue_scheduled )( |
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316 | Scheduler_Context *context, |
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317 | Scheduler_Node *node_to_enqueue |
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318 | ); |
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319 | |
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320 | typedef void ( *Scheduler_SMP_Allocate_processor )( |
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321 | Scheduler_Context *context, |
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322 | Thread_Control *scheduled, |
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323 | Thread_Control *victim |
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324 | ); |
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325 | |
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326 | static inline bool _Scheduler_SMP_Insert_priority_lifo_order( |
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327 | const Chain_Node *to_insert, |
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328 | const Chain_Node *next |
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329 | ) |
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330 | { |
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331 | const Scheduler_SMP_Node *node_to_insert = |
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332 | (const Scheduler_SMP_Node *) to_insert; |
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333 | const Scheduler_SMP_Node *node_next = |
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334 | (const Scheduler_SMP_Node *) next; |
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335 | |
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336 | return node_to_insert->priority <= node_next->priority; |
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337 | } |
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338 | |
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339 | static inline bool _Scheduler_SMP_Insert_priority_fifo_order( |
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340 | const Chain_Node *to_insert, |
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341 | const Chain_Node *next |
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342 | ) |
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343 | { |
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344 | const Scheduler_SMP_Node *node_to_insert = |
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345 | (const Scheduler_SMP_Node *) to_insert; |
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346 | const Scheduler_SMP_Node *node_next = |
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347 | (const Scheduler_SMP_Node *) next; |
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348 | |
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349 | return node_to_insert->priority < node_next->priority; |
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350 | } |
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351 | |
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352 | static inline Scheduler_SMP_Context *_Scheduler_SMP_Get_self( |
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353 | Scheduler_Context *context |
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354 | ) |
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355 | { |
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356 | return (Scheduler_SMP_Context *) context; |
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357 | } |
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358 | |
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359 | static inline void _Scheduler_SMP_Initialize( |
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360 | Scheduler_SMP_Context *self |
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361 | ) |
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362 | { |
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363 | _Chain_Initialize_empty( &self->Scheduled ); |
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364 | _Chain_Initialize_empty( &self->Idle_threads ); |
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365 | } |
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366 | |
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367 | static inline Scheduler_SMP_Node *_Scheduler_SMP_Thread_get_node( |
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368 | Thread_Control *thread |
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369 | ) |
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370 | { |
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371 | return (Scheduler_SMP_Node *) _Scheduler_Thread_get_node( thread ); |
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372 | } |
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373 | |
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374 | static inline Scheduler_SMP_Node *_Scheduler_SMP_Thread_get_own_node( |
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375 | Thread_Control *thread |
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376 | ) |
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377 | { |
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378 | return (Scheduler_SMP_Node *) _Scheduler_Thread_get_own_node( thread ); |
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379 | } |
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380 | |
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381 | static inline Scheduler_SMP_Node *_Scheduler_SMP_Node_downcast( |
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382 | Scheduler_Node *node |
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383 | ) |
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384 | { |
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385 | return (Scheduler_SMP_Node *) node; |
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386 | } |
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387 | |
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388 | static inline void _Scheduler_SMP_Node_initialize( |
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389 | Scheduler_SMP_Node *node, |
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390 | Thread_Control *thread |
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391 | ) |
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392 | { |
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393 | _Scheduler_Node_do_initialize( &node->Base, thread ); |
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394 | node->state = SCHEDULER_SMP_NODE_BLOCKED; |
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395 | } |
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396 | |
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397 | static inline void _Scheduler_SMP_Node_update_priority( |
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398 | Scheduler_SMP_Node *node, |
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399 | Priority_Control new_priority |
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400 | ) |
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401 | { |
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402 | node->priority = new_priority; |
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403 | } |
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404 | |
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405 | extern const bool _Scheduler_SMP_Node_valid_state_changes[ 3 ][ 3 ]; |
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406 | |
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407 | static inline void _Scheduler_SMP_Node_change_state( |
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408 | Scheduler_SMP_Node *node, |
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409 | Scheduler_SMP_Node_state new_state |
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410 | ) |
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411 | { |
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412 | _Assert( |
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413 | _Scheduler_SMP_Node_valid_state_changes[ node->state ][ new_state ] |
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414 | ); |
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415 | |
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416 | node->state = new_state; |
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417 | } |
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418 | |
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419 | static inline bool _Scheduler_SMP_Is_processor_owned_by_us( |
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420 | const Scheduler_Context *context, |
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421 | const Per_CPU_Control *cpu |
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422 | ) |
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423 | { |
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424 | return cpu->scheduler_context == context; |
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425 | } |
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426 | |
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427 | static inline Thread_Control *_Scheduler_SMP_Get_idle_thread( |
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428 | Scheduler_Context *context |
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429 | ) |
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430 | { |
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431 | Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context ); |
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432 | Thread_Control *idle = (Thread_Control *) |
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433 | _Chain_Get_first_unprotected( &self->Idle_threads ); |
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434 | |
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435 | _Assert( &idle->Object.Node != _Chain_Tail( &self->Idle_threads ) ); |
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436 | |
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437 | return idle; |
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438 | } |
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439 | |
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440 | static inline void _Scheduler_SMP_Release_idle_thread( |
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441 | Scheduler_Context *context, |
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442 | Thread_Control *idle |
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443 | ) |
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444 | { |
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445 | Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context ); |
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446 | |
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447 | _Chain_Prepend_unprotected( &self->Idle_threads, &idle->Object.Node ); |
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448 | } |
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449 | |
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450 | static inline void _Scheduler_SMP_Allocate_processor_lazy( |
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451 | Scheduler_Context *context, |
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452 | Thread_Control *scheduled_thread, |
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453 | Thread_Control *victim_thread |
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454 | ) |
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455 | { |
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456 | Per_CPU_Control *scheduled_cpu = _Thread_Get_CPU( scheduled_thread ); |
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457 | Per_CPU_Control *victim_cpu = _Thread_Get_CPU( victim_thread ); |
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458 | Per_CPU_Control *cpu_self = _Per_CPU_Get(); |
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459 | Thread_Control *heir; |
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460 | |
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461 | _Assert( _ISR_Get_level() != 0 ); |
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462 | |
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463 | if ( _Thread_Is_executing_on_a_processor( scheduled_thread ) ) { |
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464 | if ( _Scheduler_SMP_Is_processor_owned_by_us( context, scheduled_cpu ) ) { |
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465 | heir = scheduled_cpu->heir; |
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466 | _Thread_Dispatch_update_heir( |
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467 | cpu_self, |
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468 | scheduled_cpu, |
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469 | scheduled_thread |
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470 | ); |
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471 | } else { |
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472 | /* We have to force a migration to our processor set */ |
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473 | _Assert( |
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474 | scheduled_thread->Scheduler.debug_real_cpu->heir != scheduled_thread |
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475 | ); |
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476 | heir = scheduled_thread; |
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477 | } |
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478 | } else { |
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479 | heir = scheduled_thread; |
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480 | } |
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481 | |
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482 | if ( heir != victim_thread ) { |
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483 | _Thread_Set_CPU( heir, victim_cpu ); |
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484 | _Thread_Dispatch_update_heir( cpu_self, victim_cpu, heir ); |
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485 | } |
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486 | } |
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487 | |
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488 | static inline void _Scheduler_SMP_Allocate_processor( |
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489 | Scheduler_Context *context, |
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490 | Scheduler_Node *scheduled, |
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491 | Scheduler_Node *victim, |
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492 | Scheduler_SMP_Allocate_processor allocate_processor |
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493 | ) |
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494 | { |
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495 | Thread_Control *scheduled_thread = _Scheduler_Node_get_user( scheduled ); |
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496 | Thread_Control *victim_thread = _Scheduler_Node_get_user( victim ); |
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497 | |
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498 | _Scheduler_SMP_Node_change_state( |
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499 | _Scheduler_SMP_Node_downcast( scheduled ), |
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500 | SCHEDULER_SMP_NODE_SCHEDULED |
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501 | ); |
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502 | _Scheduler_Thread_change_state( scheduled_thread, THREAD_SCHEDULER_SCHEDULED ); |
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503 | |
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504 | ( *allocate_processor )( context, scheduled_thread, victim_thread ); |
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505 | } |
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506 | |
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507 | static inline Scheduler_Node *_Scheduler_SMP_Get_lowest_scheduled( |
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508 | Scheduler_Context *context, |
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509 | Scheduler_Node *filter, |
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510 | Chain_Node_order order |
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511 | ) |
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512 | { |
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513 | Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context ); |
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514 | Chain_Control *scheduled = &self->Scheduled; |
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515 | Scheduler_Node *lowest_scheduled = |
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516 | (Scheduler_Node *) _Chain_Last( scheduled ); |
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517 | |
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518 | (void) filter; |
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519 | (void) order; |
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520 | |
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521 | _Assert( &lowest_scheduled->Node != _Chain_Tail( scheduled ) ); |
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522 | |
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523 | return lowest_scheduled; |
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524 | } |
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525 | |
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526 | static inline Thread_Control *_Scheduler_SMP_Enqueue_to_scheduled( |
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527 | Scheduler_Context *context, |
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528 | Scheduler_Node *node, |
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529 | Scheduler_Node *lowest_scheduled, |
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530 | Scheduler_SMP_Insert insert_scheduled, |
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531 | Scheduler_SMP_Move move_from_scheduled_to_ready, |
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532 | Scheduler_SMP_Allocate_processor allocate_processor |
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533 | ) |
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534 | { |
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535 | Thread_Control *user = _Scheduler_Node_get_user( node ); |
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536 | Thread_Control *lowest_scheduled_user = |
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537 | _Scheduler_Node_get_user( lowest_scheduled ); |
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538 | Thread_Control *needs_help; |
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539 | Thread_Control *idle; |
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540 | |
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541 | _Scheduler_SMP_Node_change_state( |
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542 | _Scheduler_SMP_Node_downcast( lowest_scheduled ), |
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543 | SCHEDULER_SMP_NODE_READY |
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544 | ); |
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545 | _Scheduler_Thread_change_state( |
---|
546 | lowest_scheduled_user, |
---|
547 | THREAD_SCHEDULER_READY |
---|
548 | ); |
---|
549 | |
---|
550 | _Scheduler_Thread_set_node( user, node ); |
---|
551 | |
---|
552 | _Scheduler_SMP_Allocate_processor( |
---|
553 | context, |
---|
554 | node, |
---|
555 | lowest_scheduled, |
---|
556 | allocate_processor |
---|
557 | ); |
---|
558 | |
---|
559 | ( *insert_scheduled )( context, node ); |
---|
560 | ( *move_from_scheduled_to_ready )( context, lowest_scheduled ); |
---|
561 | |
---|
562 | idle = _Scheduler_Release_idle_thread( |
---|
563 | context, |
---|
564 | lowest_scheduled, |
---|
565 | _Scheduler_SMP_Release_idle_thread |
---|
566 | ); |
---|
567 | if ( idle == NULL ) { |
---|
568 | needs_help = lowest_scheduled_user; |
---|
569 | } else { |
---|
570 | needs_help = NULL; |
---|
571 | } |
---|
572 | |
---|
573 | return needs_help; |
---|
574 | } |
---|
575 | |
---|
576 | /** |
---|
577 | * @brief Enqueues a node according to the specified order function. |
---|
578 | * |
---|
579 | * The node must not be in the scheduled state. |
---|
580 | * |
---|
581 | * @param[in] context The scheduler instance context. |
---|
582 | * @param[in] node The node to enqueue. |
---|
583 | * @param[in] needs_help The thread needing help in case the node cannot be |
---|
584 | * scheduled. |
---|
585 | * @param[in] order The order function. |
---|
586 | * @param[in] insert_ready Function to insert a node into the set of ready |
---|
587 | * nodes. |
---|
588 | * @param[in] insert_scheduled Function to insert a node into the set of |
---|
589 | * scheduled nodes. |
---|
590 | * @param[in] move_from_scheduled_to_ready Function to move a node from the set |
---|
591 | * of scheduled nodes to the set of ready nodes. |
---|
592 | * @param[in] get_lowest_scheduled Function to select the node from the |
---|
593 | * scheduled nodes to replace. It may not be possible to find one, in this |
---|
594 | * case a pointer must be returned so that the order functions returns false |
---|
595 | * if this pointer is passed as the second argument to the order function. |
---|
596 | * @param[in] allocate_processor Function to allocate a processor to a node |
---|
597 | * based on the rules of the scheduler. |
---|
598 | */ |
---|
599 | static inline Thread_Control *_Scheduler_SMP_Enqueue_ordered( |
---|
600 | Scheduler_Context *context, |
---|
601 | Scheduler_Node *node, |
---|
602 | Thread_Control *needs_help, |
---|
603 | Chain_Node_order order, |
---|
604 | Scheduler_SMP_Insert insert_ready, |
---|
605 | Scheduler_SMP_Insert insert_scheduled, |
---|
606 | Scheduler_SMP_Move move_from_scheduled_to_ready, |
---|
607 | Scheduler_SMP_Get_lowest_scheduled get_lowest_scheduled, |
---|
608 | Scheduler_SMP_Allocate_processor allocate_processor |
---|
609 | ) |
---|
610 | { |
---|
611 | Scheduler_Node *lowest_scheduled = |
---|
612 | ( *get_lowest_scheduled )( context, node, order ); |
---|
613 | |
---|
614 | if ( ( *order )( &node->Node, &lowest_scheduled->Node ) ) { |
---|
615 | needs_help = _Scheduler_SMP_Enqueue_to_scheduled( |
---|
616 | context, |
---|
617 | node, |
---|
618 | lowest_scheduled, |
---|
619 | insert_scheduled, |
---|
620 | move_from_scheduled_to_ready, |
---|
621 | allocate_processor |
---|
622 | ); |
---|
623 | } else { |
---|
624 | ( *insert_ready )( context, node ); |
---|
625 | } |
---|
626 | |
---|
627 | return needs_help; |
---|
628 | } |
---|
629 | |
---|
630 | /** |
---|
631 | * @brief Enqueues a scheduled node according to the specified order |
---|
632 | * function. |
---|
633 | * |
---|
634 | * @param[in] context The scheduler instance context. |
---|
635 | * @param[in] node The node to enqueue. |
---|
636 | * @param[in] order The order function. |
---|
637 | * @param[in] extract_from_ready Function to extract a node from the set of |
---|
638 | * ready nodes. |
---|
639 | * @param[in] get_highest_ready Function to get the highest ready node. |
---|
640 | * @param[in] insert_ready Function to insert a node into the set of ready |
---|
641 | * nodes. |
---|
642 | * @param[in] insert_scheduled Function to insert a node into the set of |
---|
643 | * scheduled nodes. |
---|
644 | * @param[in] move_from_ready_to_scheduled Function to move a node from the set |
---|
645 | * of ready nodes to the set of scheduled nodes. |
---|
646 | * @param[in] allocate_processor Function to allocate a processor to a node |
---|
647 | * based on the rules of the scheduler. |
---|
648 | */ |
---|
649 | static inline Thread_Control *_Scheduler_SMP_Enqueue_scheduled_ordered( |
---|
650 | Scheduler_Context *context, |
---|
651 | Scheduler_Node *node, |
---|
652 | Chain_Node_order order, |
---|
653 | Scheduler_SMP_Extract extract_from_ready, |
---|
654 | Scheduler_SMP_Get_highest_ready get_highest_ready, |
---|
655 | Scheduler_SMP_Insert insert_ready, |
---|
656 | Scheduler_SMP_Insert insert_scheduled, |
---|
657 | Scheduler_SMP_Move move_from_ready_to_scheduled, |
---|
658 | Scheduler_SMP_Allocate_processor allocate_processor |
---|
659 | ) |
---|
660 | { |
---|
661 | Thread_Control *needs_help; |
---|
662 | |
---|
663 | while ( true ) { |
---|
664 | Scheduler_Node *highest_ready = ( *get_highest_ready )( context, node ); |
---|
665 | |
---|
666 | /* |
---|
667 | * The node has been extracted from the scheduled chain. We have to place |
---|
668 | * it now on the scheduled or ready set. |
---|
669 | */ |
---|
670 | if ( ( *order )( &node->Node, &highest_ready->Node ) ) { |
---|
671 | ( *insert_scheduled )( context, node ); |
---|
672 | |
---|
673 | needs_help = NULL; |
---|
674 | |
---|
675 | break; |
---|
676 | } else if ( |
---|
677 | _Scheduler_Try_to_schedule_node( |
---|
678 | context, |
---|
679 | highest_ready, |
---|
680 | _Scheduler_SMP_Get_idle_thread |
---|
681 | ) |
---|
682 | ) { |
---|
683 | Thread_Control *user = _Scheduler_Node_get_user( node ); |
---|
684 | Thread_Control *idle; |
---|
685 | |
---|
686 | _Scheduler_SMP_Node_change_state( |
---|
687 | _Scheduler_SMP_Node_downcast( node ), |
---|
688 | SCHEDULER_SMP_NODE_READY |
---|
689 | ); |
---|
690 | _Scheduler_Thread_change_state( user, THREAD_SCHEDULER_READY ); |
---|
691 | |
---|
692 | _Scheduler_SMP_Allocate_processor( |
---|
693 | context, |
---|
694 | highest_ready, |
---|
695 | node, |
---|
696 | allocate_processor |
---|
697 | ); |
---|
698 | |
---|
699 | ( *insert_ready )( context, node ); |
---|
700 | ( *move_from_ready_to_scheduled )( context, highest_ready ); |
---|
701 | |
---|
702 | idle = _Scheduler_Release_idle_thread( |
---|
703 | context, |
---|
704 | node, |
---|
705 | _Scheduler_SMP_Release_idle_thread |
---|
706 | ); |
---|
707 | if ( idle == NULL ) { |
---|
708 | needs_help = user; |
---|
709 | } else { |
---|
710 | needs_help = NULL; |
---|
711 | } |
---|
712 | |
---|
713 | break; |
---|
714 | } else { |
---|
715 | _Scheduler_SMP_Node_change_state( |
---|
716 | _Scheduler_SMP_Node_downcast( highest_ready ), |
---|
717 | SCHEDULER_SMP_NODE_BLOCKED |
---|
718 | ); |
---|
719 | |
---|
720 | ( *extract_from_ready )( context, highest_ready ); |
---|
721 | } |
---|
722 | } |
---|
723 | |
---|
724 | return needs_help; |
---|
725 | } |
---|
726 | |
---|
727 | static inline void _Scheduler_SMP_Extract_from_scheduled( |
---|
728 | Scheduler_Node *node |
---|
729 | ) |
---|
730 | { |
---|
731 | _Chain_Extract_unprotected( &node->Node ); |
---|
732 | } |
---|
733 | |
---|
734 | static inline void _Scheduler_SMP_Schedule_highest_ready( |
---|
735 | Scheduler_Context *context, |
---|
736 | Scheduler_Node *victim, |
---|
737 | Scheduler_SMP_Extract extract_from_ready, |
---|
738 | Scheduler_SMP_Get_highest_ready get_highest_ready, |
---|
739 | Scheduler_SMP_Move move_from_ready_to_scheduled, |
---|
740 | Scheduler_SMP_Allocate_processor allocate_processor |
---|
741 | ) |
---|
742 | { |
---|
743 | while ( true ) { |
---|
744 | Scheduler_Node *highest_ready = ( *get_highest_ready )( context, victim ); |
---|
745 | |
---|
746 | if ( |
---|
747 | _Scheduler_Try_to_schedule_node( |
---|
748 | context, |
---|
749 | highest_ready, |
---|
750 | _Scheduler_SMP_Get_idle_thread |
---|
751 | ) |
---|
752 | ) { |
---|
753 | _Scheduler_SMP_Allocate_processor( |
---|
754 | context, |
---|
755 | highest_ready, |
---|
756 | victim, |
---|
757 | allocate_processor |
---|
758 | ); |
---|
759 | |
---|
760 | ( *move_from_ready_to_scheduled )( context, highest_ready ); |
---|
761 | |
---|
762 | break; |
---|
763 | } else { |
---|
764 | _Scheduler_SMP_Node_change_state( |
---|
765 | _Scheduler_SMP_Node_downcast( highest_ready ), |
---|
766 | SCHEDULER_SMP_NODE_BLOCKED |
---|
767 | ); |
---|
768 | |
---|
769 | ( *extract_from_ready )( context, highest_ready ); |
---|
770 | } |
---|
771 | } |
---|
772 | } |
---|
773 | |
---|
774 | /** |
---|
775 | * @brief Blocks a thread. |
---|
776 | * |
---|
777 | * @param[in] context The scheduler instance context. |
---|
778 | * @param[in] thread The thread of the scheduling operation. |
---|
779 | * @param[in] extract_from_ready Function to extract a node from the set of |
---|
780 | * ready nodes. |
---|
781 | * @param[in] get_highest_ready Function to get the highest ready node. |
---|
782 | * @param[in] move_from_ready_to_scheduled Function to move a node from the set |
---|
783 | * of ready nodes to the set of scheduled nodes. |
---|
784 | */ |
---|
785 | static inline void _Scheduler_SMP_Block( |
---|
786 | Scheduler_Context *context, |
---|
787 | Thread_Control *thread, |
---|
788 | Scheduler_SMP_Extract extract_from_ready, |
---|
789 | Scheduler_SMP_Get_highest_ready get_highest_ready, |
---|
790 | Scheduler_SMP_Move move_from_ready_to_scheduled, |
---|
791 | Scheduler_SMP_Allocate_processor allocate_processor |
---|
792 | ) |
---|
793 | { |
---|
794 | Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_node( thread ); |
---|
795 | bool is_scheduled = node->state == SCHEDULER_SMP_NODE_SCHEDULED; |
---|
796 | bool block; |
---|
797 | |
---|
798 | _Assert( is_scheduled || node->state == SCHEDULER_SMP_NODE_READY ); |
---|
799 | |
---|
800 | block = _Scheduler_Block_node( |
---|
801 | context, |
---|
802 | thread, |
---|
803 | &node->Base, |
---|
804 | is_scheduled, |
---|
805 | _Scheduler_SMP_Get_idle_thread |
---|
806 | ); |
---|
807 | if ( block ) { |
---|
808 | _Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_BLOCKED ); |
---|
809 | |
---|
810 | if ( is_scheduled ) { |
---|
811 | _Scheduler_SMP_Extract_from_scheduled( &node->Base ); |
---|
812 | |
---|
813 | _Scheduler_SMP_Schedule_highest_ready( |
---|
814 | context, |
---|
815 | &node->Base, |
---|
816 | extract_from_ready, |
---|
817 | get_highest_ready, |
---|
818 | move_from_ready_to_scheduled, |
---|
819 | allocate_processor |
---|
820 | ); |
---|
821 | } else { |
---|
822 | ( *extract_from_ready )( context, &node->Base ); |
---|
823 | } |
---|
824 | } |
---|
825 | } |
---|
826 | |
---|
827 | static inline Thread_Control *_Scheduler_SMP_Unblock( |
---|
828 | Scheduler_Context *context, |
---|
829 | Thread_Control *thread, |
---|
830 | Scheduler_SMP_Enqueue enqueue_fifo |
---|
831 | ) |
---|
832 | { |
---|
833 | Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_node( thread ); |
---|
834 | bool is_scheduled = node->state == SCHEDULER_SMP_NODE_SCHEDULED; |
---|
835 | bool unblock = _Scheduler_Unblock_node( |
---|
836 | context, |
---|
837 | thread, |
---|
838 | &node->Base, |
---|
839 | is_scheduled, |
---|
840 | _Scheduler_SMP_Release_idle_thread |
---|
841 | ); |
---|
842 | Thread_Control *needs_help; |
---|
843 | |
---|
844 | if ( unblock ) { |
---|
845 | if ( node->state != SCHEDULER_SMP_NODE_READY ) { |
---|
846 | _Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_READY ); |
---|
847 | |
---|
848 | needs_help = ( *enqueue_fifo )( context, &node->Base, thread ); |
---|
849 | } else { |
---|
850 | _Assert( node->state == SCHEDULER_SMP_NODE_READY ); |
---|
851 | _Assert( node->Base.idle == NULL ); |
---|
852 | |
---|
853 | if ( node->Base.accepts_help == thread ) { |
---|
854 | _Assert( node->Base.help_state == SCHEDULER_HELP_ACTIVE_OWNER ); |
---|
855 | needs_help = thread; |
---|
856 | } else { |
---|
857 | _Assert( node->Base.help_state == SCHEDULER_HELP_ACTIVE_RIVAL ); |
---|
858 | needs_help = NULL; |
---|
859 | } |
---|
860 | } |
---|
861 | } else { |
---|
862 | needs_help = NULL; |
---|
863 | } |
---|
864 | |
---|
865 | return needs_help; |
---|
866 | } |
---|
867 | |
---|
868 | static inline Thread_Control *_Scheduler_SMP_Change_priority( |
---|
869 | Scheduler_Context *context, |
---|
870 | Thread_Control *thread, |
---|
871 | Priority_Control new_priority, |
---|
872 | bool prepend_it, |
---|
873 | Scheduler_SMP_Extract extract_from_ready, |
---|
874 | Scheduler_SMP_Update update, |
---|
875 | Scheduler_SMP_Enqueue enqueue_fifo, |
---|
876 | Scheduler_SMP_Enqueue enqueue_lifo, |
---|
877 | Scheduler_SMP_Enqueue_scheduled enqueue_scheduled_fifo, |
---|
878 | Scheduler_SMP_Enqueue_scheduled enqueue_scheduled_lifo |
---|
879 | ) |
---|
880 | { |
---|
881 | Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_own_node( thread ); |
---|
882 | Thread_Control *needs_help; |
---|
883 | |
---|
884 | if ( node->state == SCHEDULER_SMP_NODE_SCHEDULED ) { |
---|
885 | _Scheduler_SMP_Extract_from_scheduled( &node->Base ); |
---|
886 | |
---|
887 | ( *update )( context, &node->Base, new_priority ); |
---|
888 | |
---|
889 | if ( prepend_it ) { |
---|
890 | needs_help = ( *enqueue_scheduled_lifo )( context, &node->Base ); |
---|
891 | } else { |
---|
892 | needs_help = ( *enqueue_scheduled_fifo )( context, &node->Base ); |
---|
893 | } |
---|
894 | } else if ( node->state == SCHEDULER_SMP_NODE_READY ) { |
---|
895 | ( *extract_from_ready )( context, &node->Base ); |
---|
896 | |
---|
897 | ( *update )( context, &node->Base, new_priority ); |
---|
898 | |
---|
899 | if ( prepend_it ) { |
---|
900 | needs_help = ( *enqueue_lifo )( context, &node->Base, NULL ); |
---|
901 | } else { |
---|
902 | needs_help = ( *enqueue_fifo )( context, &node->Base, NULL ); |
---|
903 | } |
---|
904 | } else { |
---|
905 | ( *update )( context, &node->Base, new_priority ); |
---|
906 | |
---|
907 | needs_help = NULL; |
---|
908 | } |
---|
909 | |
---|
910 | return needs_help; |
---|
911 | } |
---|
912 | |
---|
913 | static inline Thread_Control *_Scheduler_SMP_Ask_for_help( |
---|
914 | Scheduler_Context *context, |
---|
915 | Thread_Control *offers_help, |
---|
916 | Thread_Control *needs_help, |
---|
917 | Scheduler_SMP_Enqueue enqueue_fifo |
---|
918 | ) |
---|
919 | { |
---|
920 | Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_own_node( offers_help ); |
---|
921 | Thread_Control *next_needs_help = NULL; |
---|
922 | Thread_Control *previous_accepts_help; |
---|
923 | |
---|
924 | previous_accepts_help = node->Base.accepts_help; |
---|
925 | node->Base.accepts_help = needs_help; |
---|
926 | |
---|
927 | switch ( node->state ) { |
---|
928 | case SCHEDULER_SMP_NODE_READY: |
---|
929 | next_needs_help = |
---|
930 | _Scheduler_Ask_ready_node_for_help( &node->Base, needs_help ); |
---|
931 | break; |
---|
932 | case SCHEDULER_SMP_NODE_SCHEDULED: |
---|
933 | next_needs_help = _Scheduler_Ask_scheduled_node_for_help( |
---|
934 | context, |
---|
935 | &node->Base, |
---|
936 | offers_help, |
---|
937 | needs_help, |
---|
938 | previous_accepts_help, |
---|
939 | _Scheduler_SMP_Release_idle_thread |
---|
940 | ); |
---|
941 | break; |
---|
942 | case SCHEDULER_SMP_NODE_BLOCKED: |
---|
943 | if ( |
---|
944 | _Scheduler_Ask_blocked_node_for_help( |
---|
945 | context, |
---|
946 | &node->Base, |
---|
947 | offers_help, |
---|
948 | needs_help |
---|
949 | ) |
---|
950 | ) { |
---|
951 | _Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_READY ); |
---|
952 | |
---|
953 | next_needs_help = ( *enqueue_fifo )( |
---|
954 | context, |
---|
955 | &node->Base, |
---|
956 | needs_help |
---|
957 | ); |
---|
958 | } |
---|
959 | break; |
---|
960 | } |
---|
961 | |
---|
962 | return next_needs_help; |
---|
963 | } |
---|
964 | |
---|
965 | static inline Thread_Control *_Scheduler_SMP_Yield( |
---|
966 | Scheduler_Context *context, |
---|
967 | Thread_Control *thread, |
---|
968 | Scheduler_SMP_Extract extract_from_ready, |
---|
969 | Scheduler_SMP_Enqueue enqueue_fifo, |
---|
970 | Scheduler_SMP_Enqueue_scheduled enqueue_scheduled_fifo |
---|
971 | ) |
---|
972 | { |
---|
973 | Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_node( thread ); |
---|
974 | Thread_Control *needs_help; |
---|
975 | |
---|
976 | if ( node->state == SCHEDULER_SMP_NODE_SCHEDULED ) { |
---|
977 | _Scheduler_SMP_Extract_from_scheduled( &node->Base ); |
---|
978 | |
---|
979 | needs_help = ( *enqueue_scheduled_fifo )( context, &node->Base ); |
---|
980 | } else { |
---|
981 | ( *extract_from_ready )( context, &node->Base ); |
---|
982 | |
---|
983 | needs_help = ( *enqueue_fifo )( context, &node->Base, NULL ); |
---|
984 | } |
---|
985 | |
---|
986 | return needs_help; |
---|
987 | } |
---|
988 | |
---|
989 | static inline void _Scheduler_SMP_Insert_scheduled_lifo( |
---|
990 | Scheduler_Context *context, |
---|
991 | Scheduler_Node *node_to_insert |
---|
992 | ) |
---|
993 | { |
---|
994 | Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context ); |
---|
995 | |
---|
996 | _Chain_Insert_ordered_unprotected( |
---|
997 | &self->Scheduled, |
---|
998 | &node_to_insert->Node, |
---|
999 | _Scheduler_SMP_Insert_priority_lifo_order |
---|
1000 | ); |
---|
1001 | } |
---|
1002 | |
---|
1003 | static inline void _Scheduler_SMP_Insert_scheduled_fifo( |
---|
1004 | Scheduler_Context *context, |
---|
1005 | Scheduler_Node *node_to_insert |
---|
1006 | ) |
---|
1007 | { |
---|
1008 | Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context ); |
---|
1009 | |
---|
1010 | _Chain_Insert_ordered_unprotected( |
---|
1011 | &self->Scheduled, |
---|
1012 | &node_to_insert->Node, |
---|
1013 | _Scheduler_SMP_Insert_priority_fifo_order |
---|
1014 | ); |
---|
1015 | } |
---|
1016 | |
---|
1017 | /** @} */ |
---|
1018 | |
---|
1019 | #ifdef __cplusplus |
---|
1020 | } |
---|
1021 | #endif /* __cplusplus */ |
---|
1022 | |
---|
1023 | #endif /* _RTEMS_SCORE_SCHEDULERSMPIMPL_H */ |
---|