1 | /** |
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2 | * @file rtems/score/schedulercbs.h |
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3 | * |
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4 | * @brief Thread manipulation for the CBS scheduler |
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5 | * |
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6 | * This include file contains all the constants and structures associated |
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7 | * with the manipulation of threads for the CBS scheduler. |
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8 | */ |
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9 | |
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10 | /* |
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11 | * Copryight (c) 2011 Petr Benes. |
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12 | * Copyright (C) 2011 On-Line Applications Research Corporation (OAR). |
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13 | * |
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14 | * The license and distribution terms for this file may be |
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15 | * found in the file LICENSE in this distribution or at |
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16 | * http://www.rtems.org/license/LICENSE. |
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17 | */ |
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18 | |
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19 | #ifndef _RTEMS_SCORE_SCHEDULERCBS_H |
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20 | #define _RTEMS_SCORE_SCHEDULERCBS_H |
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21 | |
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22 | #include <rtems/score/chain.h> |
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23 | #include <rtems/score/priority.h> |
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24 | #include <rtems/score/scheduler.h> |
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25 | #include <rtems/score/rbtree.h> |
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26 | #include <rtems/score/scheduleredf.h> |
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27 | #include <rtems/rtems/signal.h> |
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28 | #include <rtems/rtems/timer.h> |
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29 | #include <rtems/score/thread.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 |
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34 | |
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35 | /** |
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36 | * @defgroup ScoreSchedulerCBS CBS Scheduler |
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37 | * |
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38 | * @ingroup ScoreScheduler |
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39 | */ |
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40 | /**@{*/ |
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41 | |
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42 | /** |
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43 | * Entry points for the Constant Bandwidth Server Scheduler. |
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44 | * |
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45 | * @note: The CBS scheduler is an enhancement of EDF scheduler, |
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46 | * therefor some routines are similar. |
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47 | */ |
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48 | #define SCHEDULER_CBS_ENTRY_POINTS \ |
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49 | { \ |
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50 | _Scheduler_EDF_Initialize, /* initialize entry point */ \ |
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51 | _Scheduler_EDF_Schedule, /* schedule entry point */ \ |
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52 | _Scheduler_EDF_Yield, /* yield entry point */ \ |
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53 | _Scheduler_EDF_Block, /* block entry point */ \ |
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54 | _Scheduler_CBS_Unblock, /* unblock entry point */ \ |
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55 | _Scheduler_EDF_Change_priority, /* change priority entry point */ \ |
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56 | SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP \ |
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57 | _Scheduler_CBS_Node_initialize, /* node initialize entry point */ \ |
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58 | _Scheduler_default_Node_destroy, /* node destroy entry point */ \ |
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59 | _Scheduler_EDF_Update_priority, /* update priority entry point */ \ |
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60 | _Scheduler_EDF_Priority_compare, /* compares two priorities */ \ |
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61 | _Scheduler_CBS_Release_job, /* new period of task */ \ |
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62 | _Scheduler_default_Tick, /* tick entry point */ \ |
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63 | _Scheduler_default_Start_idle /* start idle entry point */ \ |
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64 | SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY \ |
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65 | } |
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66 | |
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67 | /* Return values for CBS server. */ |
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68 | #define SCHEDULER_CBS_OK 0 |
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69 | #define SCHEDULER_CBS_ERROR_GENERIC -16 |
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70 | #define SCHEDULER_CBS_ERROR_NO_MEMORY -17 |
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71 | #define SCHEDULER_CBS_ERROR_INVALID_PARAMETER -18 |
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72 | #define SCHEDULER_CBS_ERROR_UNAUTHORIZED -19 |
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73 | #define SCHEDULER_CBS_ERROR_UNIMPLEMENTED -20 |
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74 | #define SCHEDULER_CBS_ERROR_MISSING_COMPONENT -21 |
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75 | #define SCHEDULER_CBS_ERROR_INCONSISTENT_STATE -22 |
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76 | #define SCHEDULER_CBS_ERROR_SYSTEM_OVERLOAD -23 |
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77 | #define SCHEDULER_CBS_ERROR_INTERNAL_ERROR -24 |
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78 | #define SCHEDULER_CBS_ERROR_NOT_FOUND -25 |
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79 | #define SCHEDULER_CBS_ERROR_FULL -26 |
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80 | #define SCHEDULER_CBS_ERROR_EMPTY -27 |
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81 | #define SCHEDULER_CBS_ERROR_NOSERVER SCHEDULER_CBS_ERROR_NOT_FOUND |
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82 | |
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83 | /** Maximum number of simultaneous servers. */ |
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84 | extern const uint32_t _Scheduler_CBS_Maximum_servers; |
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85 | |
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86 | /** Server id. */ |
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87 | typedef uint32_t Scheduler_CBS_Server_id; |
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88 | |
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89 | /** Callback function invoked when a budget overrun of a task occurs. */ |
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90 | typedef void (*Scheduler_CBS_Budget_overrun)( |
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91 | Scheduler_CBS_Server_id server_id |
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92 | ); |
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93 | |
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94 | /** |
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95 | * This structure handles server parameters. |
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96 | */ |
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97 | typedef struct { |
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98 | /** Relative deadline of the server. */ |
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99 | time_t deadline; |
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100 | /** Budget (computation time) of the server. */ |
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101 | time_t budget; |
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102 | } Scheduler_CBS_Parameters; |
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103 | |
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104 | /** |
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105 | * This structure represents a time server. |
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106 | */ |
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107 | typedef struct { |
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108 | /** |
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109 | * Task id. |
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110 | * |
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111 | * @note: The current implementation of CBS handles only one task per server. |
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112 | */ |
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113 | rtems_id task_id; |
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114 | /** Server paramenters. */ |
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115 | Scheduler_CBS_Parameters parameters; |
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116 | /** Callback function invoked when a budget overrun occurs. */ |
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117 | Scheduler_CBS_Budget_overrun cbs_budget_overrun; |
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118 | |
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119 | /** |
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120 | * @brief Indicates if this CBS server is initialized. |
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121 | * |
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122 | * @see _Scheduler_CBS_Create_server() and _Scheduler_CBS_Destroy_server(). |
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123 | */ |
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124 | bool initialized; |
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125 | } Scheduler_CBS_Server; |
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126 | |
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127 | /** |
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128 | * This structure handles CBS specific data of a thread. |
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129 | */ |
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130 | typedef struct { |
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131 | /** EDF scheduler specific data of a task. */ |
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132 | Scheduler_EDF_Node Base; |
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133 | /** CBS server specific data of a task. */ |
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134 | Scheduler_CBS_Server *cbs_server; |
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135 | } Scheduler_CBS_Node; |
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136 | |
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137 | |
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138 | /** |
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139 | * List of servers. The @a Scheduler_CBS_Server is the index to the array |
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140 | * of pointers to @a _Scheduler_CBS_Server_list. |
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141 | */ |
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142 | extern Scheduler_CBS_Server _Scheduler_CBS_Server_list[]; |
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143 | |
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144 | /** |
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145 | * @brief Unblocks a thread from the queue. |
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146 | * |
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147 | * This routine adds @a the_thread to the scheduling decision, that is, |
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148 | * adds it to the ready queue and updates any appropriate scheduling |
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149 | * variables, for example the heir thread. It is checked whether the |
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150 | * remaining budget is sufficient. If not, the thread continues as a |
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151 | * new job in order to protect concurrent threads. |
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152 | * |
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153 | * @param[in] the_thread will be unblocked. |
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154 | * |
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155 | * @note This has to be asessed as missed deadline of the current job. |
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156 | */ |
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157 | Scheduler_Void_or_thread _Scheduler_CBS_Unblock( |
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158 | const Scheduler_Control *scheduler, |
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159 | Thread_Control *the_thread |
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160 | ); |
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161 | |
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162 | /** |
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163 | * @brief Called when a new job of task is released. |
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164 | * |
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165 | * This routine is called when a new job of task is released. |
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166 | * It is called only from Rate Monotonic manager in the beginning |
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167 | * of new period. Deadline has to be shifted and budget replenished. |
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168 | * |
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169 | * @param[in] the_thread is the owner of the job. |
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170 | * @param[in] length of the new job from now. If equal to 0, |
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171 | * the job was cancelled or deleted. |
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172 | */ |
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173 | |
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174 | void _Scheduler_CBS_Release_job ( |
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175 | const Scheduler_Control *scheduler, |
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176 | Thread_Control *the_thread, |
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177 | uint32_t length |
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178 | ); |
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179 | |
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180 | /** |
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181 | * @brief _Scheduler_CBS_Initialize |
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182 | * |
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183 | * Initializes the CBS library. |
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184 | * |
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185 | * @retval status code. |
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186 | */ |
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187 | int _Scheduler_CBS_Initialize(void); |
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188 | |
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189 | /** |
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190 | * @brief Attach a task to an already existing server. |
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191 | * |
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192 | * Attach a task to an already existing server. |
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193 | * |
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194 | * @retval status code. |
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195 | */ |
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196 | int _Scheduler_CBS_Attach_thread ( |
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197 | Scheduler_CBS_Server_id server_id, |
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198 | rtems_id task_id |
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199 | ); |
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200 | |
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201 | /** |
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202 | * @brief Detach from the CBS Server. |
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203 | * |
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204 | * Detach from the CBS Server. |
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205 | * |
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206 | * @retval status code. |
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207 | */ |
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208 | int _Scheduler_CBS_Detach_thread ( |
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209 | Scheduler_CBS_Server_id server_id, |
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210 | rtems_id task_id |
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211 | ); |
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212 | |
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213 | /** |
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214 | * @brief Cleanup resources associated to the CBS Library. |
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215 | * |
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216 | * Cleanup resources associated to the CBS Library. |
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217 | * |
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218 | * @retval status code. |
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219 | */ |
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220 | int _Scheduler_CBS_Cleanup (void); |
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221 | |
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222 | /** |
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223 | * @brief Create a new server with specified parameters. |
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224 | * |
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225 | * Create a new server with specified parameters. |
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226 | * |
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227 | * @retval status code. |
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228 | */ |
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229 | int _Scheduler_CBS_Create_server ( |
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230 | Scheduler_CBS_Parameters *params, |
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231 | Scheduler_CBS_Budget_overrun budget_overrun_callback, |
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232 | rtems_id *server_id |
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233 | ); |
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234 | |
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235 | /** |
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236 | * @brief Detach all tasks from a server and destroy it. |
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237 | * |
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238 | * Detach all tasks from a server and destroy it. |
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239 | * |
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240 | * @param[in] server_id is the ID of the server |
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241 | * |
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242 | * @retval status code. |
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243 | */ |
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244 | int _Scheduler_CBS_Destroy_server ( |
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245 | Scheduler_CBS_Server_id server_id |
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246 | ); |
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247 | |
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248 | /** |
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249 | * @brief Retrieve the approved budget. |
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250 | * |
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251 | * Retrieve the budget that has been approved for the subsequent |
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252 | * server instances. |
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253 | * |
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254 | * @retval status code. |
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255 | */ |
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256 | int _Scheduler_CBS_Get_approved_budget ( |
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257 | Scheduler_CBS_Server_id server_id, |
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258 | time_t *approved_budget |
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259 | ); |
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260 | |
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261 | /** |
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262 | * @brief Retrieve remaining budget for the current server instance. |
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263 | * |
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264 | * Retrieve remaining budget for the current server instance. |
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265 | * |
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266 | * @retval status code. |
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267 | */ |
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268 | int _Scheduler_CBS_Get_remaining_budget ( |
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269 | Scheduler_CBS_Server_id server_id, |
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270 | time_t *remaining_budget |
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271 | ); |
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272 | |
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273 | /** |
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274 | * @brief Get relative time info. |
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275 | * |
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276 | * Retrieve time info relative to @a server_id. The server status code is returned. |
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277 | * |
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278 | * @param[in] server_id is the server to get the status code from. |
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279 | * @param[in] exec_time is the execution time. |
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280 | * @param[in] abs_time is not apparently used. |
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281 | * |
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282 | * @retval status code. |
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283 | */ |
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284 | int _Scheduler_CBS_Get_execution_time ( |
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285 | Scheduler_CBS_Server_id server_id, |
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286 | time_t *exec_time, |
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287 | time_t *abs_time |
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288 | ); |
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289 | |
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290 | /** |
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291 | * @brief Retrieve CBS scheduling parameters. |
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292 | * |
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293 | * Retrieve CBS scheduling parameters. |
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294 | * |
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295 | * @retval status code. |
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296 | */ |
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297 | int _Scheduler_CBS_Get_parameters ( |
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298 | Scheduler_CBS_Server_id server_id, |
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299 | Scheduler_CBS_Parameters *params |
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300 | ); |
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301 | |
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302 | /** |
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303 | * @brief Get a thread server id. |
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304 | * |
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305 | * Get a thread server id, or SCHEDULER_CBS_ERROR_NOT_FOUND if it is not |
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306 | * attached to any server. |
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307 | * |
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308 | * @retval status code. |
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309 | */ |
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310 | int _Scheduler_CBS_Get_server_id ( |
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311 | rtems_id task_id, |
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312 | Scheduler_CBS_Server_id *server_id |
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313 | ); |
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314 | |
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315 | /** |
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316 | * @brief Set parameters for CBS scheduling. |
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317 | * |
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318 | * Change CBS scheduling parameters. |
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319 | * |
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320 | * @param[in] server_id is the ID of the server. |
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321 | * @param[in] parameters are the parameters to set. |
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322 | * |
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323 | * @retval status code. |
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324 | */ |
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325 | int _Scheduler_CBS_Set_parameters ( |
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326 | Scheduler_CBS_Server_id server_id, |
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327 | Scheduler_CBS_Parameters *parameters |
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328 | ); |
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329 | |
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330 | /** |
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331 | * @brief Invoked when a limited time quantum is exceeded. |
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332 | * |
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333 | * This routine is invoked when a limited time quantum is exceeded. |
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334 | */ |
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335 | void _Scheduler_CBS_Budget_callout( |
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336 | Thread_Control *the_thread |
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337 | ); |
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338 | |
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339 | /** |
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340 | * @brief Initializes a CBS specific scheduler node of @a the_thread. |
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341 | */ |
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342 | void _Scheduler_CBS_Node_initialize( |
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343 | const Scheduler_Control *scheduler, |
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344 | Thread_Control *the_thread |
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345 | ); |
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346 | |
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347 | #ifdef __cplusplus |
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348 | } |
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349 | #endif |
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350 | |
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351 | /**@}*/ |
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352 | |
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353 | #endif |
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354 | /* end of include file */ |
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