1 | /** |
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2 | * @file rtems/score/thread.h |
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3 | * |
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4 | * @brief Constants and Structures Related with the Thread Control Block |
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5 | * |
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6 | * This include file contains all constants and structures associated |
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7 | * with the thread control block. |
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8 | */ |
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9 | |
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10 | /* |
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11 | * COPYRIGHT (c) 1989-2014. |
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12 | * On-Line Applications Research Corporation (OAR). |
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13 | * |
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14 | * Copyright (c) 2014 embedded brains GmbH. |
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15 | * |
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16 | * The license and distribution terms for this file may be |
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17 | * found in the file LICENSE in this distribution or at |
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18 | * http://www.rtems.org/license/LICENSE. |
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19 | */ |
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20 | |
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21 | #ifndef _RTEMS_SCORE_THREAD_H |
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22 | #define _RTEMS_SCORE_THREAD_H |
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23 | |
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24 | #include <rtems/score/atomic.h> |
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25 | #include <rtems/score/context.h> |
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26 | #if defined(RTEMS_MULTIPROCESSING) |
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27 | #include <rtems/score/mppkt.h> |
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28 | #endif |
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29 | #include <rtems/score/isrlock.h> |
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30 | #include <rtems/score/object.h> |
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31 | #include <rtems/score/priority.h> |
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32 | #include <rtems/score/resource.h> |
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33 | #include <rtems/score/stack.h> |
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34 | #include <rtems/score/states.h> |
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35 | #include <rtems/score/threadq.h> |
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36 | #include <rtems/score/watchdog.h> |
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37 | |
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38 | #if defined(RTEMS_SMP) |
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39 | #include <rtems/score/cpuset.h> |
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40 | #endif |
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41 | |
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42 | struct Per_CPU_Control; |
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43 | |
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44 | struct Scheduler_Control; |
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45 | |
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46 | struct Scheduler_Node; |
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47 | |
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48 | #ifdef __cplusplus |
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49 | extern "C" { |
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50 | #endif |
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51 | |
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52 | /** |
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53 | * @defgroup ScoreThread Thread Handler |
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54 | * |
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55 | * @ingroup Score |
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56 | * |
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57 | * This handler encapsulates functionality related to the management of |
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58 | * threads. This includes the creation, deletion, and scheduling of threads. |
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59 | * |
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60 | * The following variables are maintained as part of the per cpu data |
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61 | * structure. |
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62 | * |
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63 | * + Idle thread pointer |
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64 | * + Executing thread pointer |
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65 | * + Heir thread pointer |
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66 | */ |
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67 | /**@{*/ |
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68 | |
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69 | #if defined(RTEMS_POSIX_API) |
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70 | #define RTEMS_SCORE_THREAD_ENABLE_EXHAUST_TIMESLICE |
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71 | #endif |
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72 | |
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73 | /* |
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74 | * With the addition of the Constant Block Scheduler (CBS), |
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75 | * this feature is needed even when POSIX is disabled. |
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76 | */ |
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77 | #define RTEMS_SCORE_THREAD_ENABLE_SCHEDULER_CALLOUT |
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78 | |
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79 | #if defined(RTEMS_POSIX_API) |
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80 | #define RTEMS_SCORE_THREAD_ENABLE_USER_PROVIDED_STACK_VIA_API |
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81 | #endif |
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82 | |
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83 | /* |
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84 | * The user can define this at configure time and go back to ticks |
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85 | * resolution. |
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86 | */ |
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87 | #include <rtems/score/timestamp.h> |
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88 | |
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89 | typedef Timestamp_Control Thread_CPU_usage_t; |
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90 | |
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91 | /** |
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92 | * The following defines the "return type" of a thread. |
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93 | * |
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94 | * @note This cannot always be right. Some APIs have void |
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95 | * tasks/threads, others return pointers, others may |
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96 | * return a numeric value. Hopefully a pointer is |
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97 | * always at least as big as an uint32_t . :) |
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98 | */ |
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99 | typedef void *Thread; |
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100 | |
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101 | /** |
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102 | * @brief Type of the numeric argument of a thread entry function with at |
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103 | * least one numeric argument. |
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104 | * |
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105 | * This numeric argument type designates an unsigned integer type with the |
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106 | * property that any valid pointer to void can be converted to this type and |
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107 | * then converted back to a pointer to void. The result will compare equal to |
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108 | * the original pointer. |
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109 | */ |
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110 | typedef CPU_Uint32ptr Thread_Entry_numeric_type; |
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111 | |
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112 | /** |
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113 | * The following defines the ways in which the entry point for a |
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114 | * thread can be invoked. Basically, it can be passed any |
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115 | * combination/permutation of a pointer and an uint32_t value. |
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116 | * |
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117 | * @note For now, we are ignoring the return type. |
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118 | */ |
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119 | typedef enum { |
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120 | THREAD_START_NUMERIC, |
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121 | THREAD_START_POINTER, |
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122 | #if defined(FUNCTIONALITY_NOT_CURRENTLY_USED_BY_ANY_API) |
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123 | THREAD_START_BOTH_POINTER_FIRST, |
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124 | THREAD_START_BOTH_NUMERIC_FIRST |
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125 | #endif |
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126 | } Thread_Start_types; |
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127 | |
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128 | /** This type corresponds to a very simple style thread entry point. */ |
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129 | typedef Thread ( *Thread_Entry )( void ); /* basic type */ |
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130 | |
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131 | /** This type corresponds to a thread entry point which takes a single |
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132 | * unsigned thirty-two bit integer as an argument. |
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133 | */ |
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134 | typedef Thread ( *Thread_Entry_numeric )( Thread_Entry_numeric_type ); |
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135 | |
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136 | /** This type corresponds to a thread entry point which takes a single |
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137 | * untyped pointer as an argument. |
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138 | */ |
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139 | typedef Thread ( *Thread_Entry_pointer )( void * ); |
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140 | |
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141 | /** This type corresponds to a thread entry point which takes a single |
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142 | * untyped pointer and an unsigned thirty-two bit integer as arguments. |
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143 | */ |
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144 | typedef Thread ( *Thread_Entry_both_pointer_first )( void *, Thread_Entry_numeric_type ); |
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145 | |
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146 | /** This type corresponds to a thread entry point which takes a single |
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147 | * unsigned thirty-two bit integer and an untyped pointer and an |
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148 | * as arguments. |
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149 | */ |
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150 | typedef Thread ( *Thread_Entry_both_numeric_first )( Thread_Entry_numeric_type, void * ); |
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151 | |
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152 | /** |
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153 | * The following lists the algorithms used to manage the thread cpu budget. |
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154 | * |
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155 | * Reset Timeslice: At each context switch, reset the time quantum. |
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156 | * Exhaust Timeslice: Only reset the quantum once it is consumed. |
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157 | * Callout: Execute routine when budget is consumed. |
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158 | */ |
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159 | typedef enum { |
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160 | THREAD_CPU_BUDGET_ALGORITHM_NONE, |
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161 | THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE, |
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162 | #if defined(RTEMS_SCORE_THREAD_ENABLE_EXHAUST_TIMESLICE) |
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163 | THREAD_CPU_BUDGET_ALGORITHM_EXHAUST_TIMESLICE, |
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164 | #endif |
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165 | #if defined(RTEMS_SCORE_THREAD_ENABLE_SCHEDULER_CALLOUT) |
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166 | THREAD_CPU_BUDGET_ALGORITHM_CALLOUT |
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167 | #endif |
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168 | } Thread_CPU_budget_algorithms; |
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169 | |
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170 | /** This defines thes the entry point for the thread specific timeslice |
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171 | * budget management algorithm. |
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172 | */ |
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173 | typedef void (*Thread_CPU_budget_algorithm_callout )( Thread_Control * ); |
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174 | |
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175 | #if !defined(RTEMS_SMP) |
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176 | /** |
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177 | * @brief Forward reference to the per task variable structure.. |
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178 | * |
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179 | * Forward reference to the per task variable structure. |
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180 | */ |
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181 | struct rtems_task_variable_tt; |
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182 | |
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183 | /** |
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184 | * @brief Internal structure used to manager per task variables. |
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185 | * |
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186 | * This is the internal structure used to manager per Task Variables. |
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187 | */ |
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188 | typedef struct { |
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189 | /** This field points to the next per task variable for this task. */ |
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190 | struct rtems_task_variable_tt *next; |
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191 | /** This field points to the physical memory location of this per |
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192 | * task variable. |
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193 | */ |
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194 | void **ptr; |
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195 | /** This field is to the global value for this per task variable. */ |
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196 | void *gval; |
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197 | /** This field is to this thread's value for this per task variable. */ |
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198 | void *tval; |
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199 | /** This field points to the destructor for this per task variable. */ |
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200 | void (*dtor)(void *); |
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201 | } rtems_task_variable_t; |
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202 | #endif |
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203 | |
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204 | /** |
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205 | * The following structure contains the information which defines |
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206 | * the starting state of a thread. |
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207 | */ |
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208 | typedef struct { |
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209 | /** This field is the starting address for the thread. */ |
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210 | Thread_Entry entry_point; |
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211 | /** This field indicates the how task is invoked. */ |
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212 | Thread_Start_types prototype; |
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213 | /** This field is the pointer argument passed at thread start. */ |
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214 | void *pointer_argument; |
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215 | /** This field is the numeric argument passed at thread start. */ |
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216 | Thread_Entry_numeric_type numeric_argument; |
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217 | /*-------------- initial execution modes ----------------- */ |
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218 | /** This field indicates whether the thread was preemptible when |
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219 | * it started. |
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220 | */ |
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221 | bool is_preemptible; |
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222 | /** This field indicates the CPU budget algorith. */ |
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223 | Thread_CPU_budget_algorithms budget_algorithm; |
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224 | /** This field is the routine to invoke when the CPU allotment is |
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225 | * consumed. |
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226 | */ |
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227 | Thread_CPU_budget_algorithm_callout budget_callout; |
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228 | /** This field is the initial ISR disable level of this thread. */ |
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229 | uint32_t isr_level; |
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230 | /** This field is the initial priority. */ |
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231 | Priority_Control initial_priority; |
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232 | #if defined(RTEMS_SCORE_THREAD_ENABLE_USER_PROVIDED_STACK_VIA_API) |
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233 | /** This field indicates whether the SuperCore allocated the stack. */ |
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234 | bool core_allocated_stack; |
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235 | #endif |
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236 | /** This field is the stack information. */ |
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237 | Stack_Control Initial_stack; |
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238 | #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE ) |
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239 | /** This field is the initial FP context area address. */ |
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240 | Context_Control_fp *fp_context; |
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241 | #endif |
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242 | /** This field is the initial stack area address. */ |
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243 | void *stack; |
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244 | /** The thread-local storage (TLS) area */ |
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245 | void *tls_area; |
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246 | } Thread_Start_information; |
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247 | |
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248 | /** |
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249 | * @brief Union type to hold a pointer to an immutable or a mutable object. |
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250 | * |
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251 | * The main purpose is to enable passing of pointers to read-only send buffers |
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252 | * in the message passing subsystem. This approach is somewhat fragile since |
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253 | * it prevents the compiler to check if the operations on objects are valid |
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254 | * with respect to the constant qualifier. An alternative would be to add a |
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255 | * third pointer argument for immutable objects, but this would increase the |
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256 | * structure size. |
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257 | */ |
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258 | typedef union { |
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259 | void *mutable_object; |
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260 | const void *immutable_object; |
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261 | } Thread_Wait_information_Object_argument_type; |
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262 | |
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263 | /** |
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264 | * @brief This type is able to contain several flags used to control the wait |
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265 | * class and state of a thread. |
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266 | * |
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267 | * The mutually exclusive wait class flags are |
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268 | * - @ref THREAD_WAIT_CLASS_EVENT, |
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269 | * - @ref THREAD_WAIT_CLASS_SYSTEM_EVENT, and |
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270 | * - @ref THREAD_WAIT_CLASS_OBJECT. |
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271 | * |
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272 | * The mutually exclusive wait state flags are |
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273 | * - @ref THREAD_WAIT_STATE_INTEND_TO_BLOCK, |
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274 | * - @ref THREAD_WAIT_STATE_BLOCKED, and |
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275 | * - @ref THREAD_WAIT_STATE_READY_AGAIN. |
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276 | */ |
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277 | typedef unsigned int Thread_Wait_flags; |
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278 | |
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279 | /** |
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280 | * @brief Information required to manage a thread while it is blocked. |
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281 | * |
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282 | * This contains the information required to manage a thread while it is |
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283 | * blocked and to return information to it. |
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284 | */ |
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285 | typedef struct { |
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286 | /** |
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287 | * @brief Node for thread queues. |
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288 | */ |
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289 | union { |
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290 | /** |
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291 | * @brief A node for chains. |
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292 | */ |
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293 | Chain_Node Chain; |
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294 | |
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295 | /** |
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296 | * @brief A node for red-black trees. |
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297 | */ |
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298 | RBTree_Node RBTree; |
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299 | } Node; |
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300 | |
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301 | /** This field is the Id of the object this thread is waiting upon. */ |
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302 | Objects_Id id; |
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303 | /** This field is used to return an integer while when blocked. */ |
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304 | uint32_t count; |
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305 | /** This field is for a pointer to a user return argument. */ |
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306 | void *return_argument; |
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307 | /** This field is for a pointer to a second user return argument. */ |
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308 | Thread_Wait_information_Object_argument_type |
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309 | return_argument_second; |
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310 | /** This field contains any options in effect on this blocking operation. */ |
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311 | uint32_t option; |
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312 | /** This field will contain the return status from a blocking operation. |
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313 | * |
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314 | * @note The following assumes that all API return codes can be |
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315 | * treated as an uint32_t. |
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316 | */ |
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317 | uint32_t return_code; |
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318 | |
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319 | /** |
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320 | * @brief Code to set the timeout return code in _Thread_Timeout(). |
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321 | */ |
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322 | uint32_t timeout_code; |
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323 | |
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324 | /** |
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325 | * @brief The current thread queue. |
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326 | * |
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327 | * In case this field is @c NULL, then the thread is not blocked on a thread |
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328 | * queue. This field is protected by the thread lock. |
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329 | * |
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330 | * @see _Thread_Lock_set() and _Thread_Wait_set_queue(). |
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331 | */ |
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332 | Thread_queue_Queue *queue; |
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333 | |
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334 | /** |
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335 | * @brief This field contains several flags used to control the wait class |
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336 | * and state of a thread in case fine-grained locking is used. |
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337 | */ |
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338 | #if defined(RTEMS_SMP) |
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339 | Atomic_Uint flags; |
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340 | #else |
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341 | Thread_Wait_flags flags; |
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342 | #endif |
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343 | |
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344 | /** |
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345 | * @brief The current thread queue operations. |
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346 | * |
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347 | * This field is protected by the thread lock. |
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348 | * |
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349 | * @see _Thread_Lock_set() and _Thread_Wait_set_operations(). |
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350 | */ |
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351 | const Thread_queue_Operations *operations; |
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352 | |
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353 | Thread_queue_Heads *spare_heads; |
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354 | } Thread_Wait_information; |
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355 | |
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356 | /** |
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357 | * The following defines the control block used to manage |
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358 | * each thread proxy. |
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359 | * |
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360 | * @note It is critical that proxies and threads have identical |
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361 | * memory images for the shared part. |
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362 | */ |
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363 | typedef struct { |
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364 | /** This field is the object management structure for each proxy. */ |
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365 | Objects_Control Object; |
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366 | /** This field is the current execution state of this proxy. */ |
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367 | States_Control current_state; |
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368 | |
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369 | /** |
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370 | * @brief This field is the current priority state of this thread. |
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371 | * |
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372 | * Writes to this field are only allowed in _Thread_Initialize() or via |
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373 | * _Thread_Change_priority(). |
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374 | */ |
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375 | Priority_Control current_priority; |
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376 | |
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377 | /** |
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378 | * @brief This field is the base priority of this thread. |
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379 | * |
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380 | * Writes to this field are only allowed in _Thread_Initialize() or via |
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381 | * _Thread_Change_priority(). |
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382 | */ |
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383 | Priority_Control real_priority; |
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384 | |
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385 | /** |
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386 | * @brief Generation of the current priority value. |
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387 | * |
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388 | * It is used in _Thread_Change_priority() to serialize the update of |
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389 | * priority related data structures. |
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390 | */ |
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391 | uint32_t priority_generation; |
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392 | |
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393 | /** |
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394 | * @brief Hints if a priority restore is necessary once the resource count |
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395 | * changes from one to zero. |
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396 | * |
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397 | * This is an optimization to speed up the mutex surrender sequence in case |
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398 | * no attempt to change the priority was made during the mutex ownership. On |
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399 | * SMP configurations atomic fences must synchronize writes to |
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400 | * Thread_Control::priority_restore_hint and Thread_Control::resource_count. |
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401 | */ |
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402 | bool priority_restore_hint; |
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403 | |
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404 | /** This field is the number of mutexes currently held by this proxy. */ |
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405 | uint32_t resource_count; |
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406 | |
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407 | /** This field is the blocking information for this proxy. */ |
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408 | Thread_Wait_information Wait; |
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409 | /** This field is the Watchdog used to manage proxy delays and timeouts. */ |
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410 | Watchdog_Control Timer; |
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411 | #if defined(RTEMS_MULTIPROCESSING) |
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412 | /** This field is the received response packet in an MP system. */ |
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413 | MP_packet_Prefix *receive_packet; |
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414 | #endif |
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415 | /****************** end of common block ********************/ |
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416 | /** This field is used to manage the set of proxies in the system. */ |
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417 | Chain_Node Active; |
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418 | } Thread_Proxy_control; |
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419 | |
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420 | /** |
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421 | * The following record defines the control block used |
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422 | * to manage each thread. |
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423 | * |
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424 | * @note It is critical that proxies and threads have identical |
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425 | * memory images for the shared part. |
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426 | */ |
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427 | typedef enum { |
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428 | /** This value is for the Classic RTEMS API. */ |
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429 | THREAD_API_RTEMS, |
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430 | /** This value is for the POSIX API. */ |
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431 | THREAD_API_POSIX |
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432 | } Thread_APIs; |
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433 | |
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434 | /** This macro defines the first API which has threads. */ |
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435 | #define THREAD_API_FIRST THREAD_API_RTEMS |
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436 | |
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437 | /** This macro defines the last API which has threads. */ |
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438 | #define THREAD_API_LAST THREAD_API_POSIX |
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439 | |
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440 | typedef struct Thread_Action Thread_Action; |
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441 | |
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442 | /** |
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443 | * @brief Thread action handler. |
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444 | * |
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445 | * The thread action handler will be called with interrupts disabled and the |
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446 | * thread action lock acquired. The handler must release the thread action |
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447 | * lock with _Thread_Action_release_and_ISR_enable(). So the thread action |
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448 | * lock can be used to protect private data fields of the particular action. |
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449 | * |
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450 | * Since the action is passed to the handler private data fields can be added |
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451 | * below the common thread action fields. |
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452 | * |
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453 | * @param[in] thread The thread performing the action. |
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454 | * @param[in] action The thread action. |
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455 | * @param[in] cpu The processor of the thread. |
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456 | * @param[in] level The ISR level for _Thread_Action_release_and_ISR_enable(). |
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457 | */ |
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458 | typedef void ( *Thread_Action_handler )( |
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459 | Thread_Control *thread, |
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460 | Thread_Action *action, |
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461 | struct Per_CPU_Control *cpu, |
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462 | ISR_Level level |
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463 | ); |
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464 | |
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465 | /** |
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466 | * @brief Thread action. |
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467 | * |
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468 | * Thread actions can be chained together to trigger a set of actions on |
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469 | * particular events like for example a thread post-switch. Use |
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470 | * _Thread_Action_initialize() to initialize this structure. |
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471 | * |
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472 | * Thread actions are the building block for efficient implementation of |
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473 | * - Classic signals delivery, |
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474 | * - POSIX signals delivery, |
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475 | * - thread restart notification, |
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476 | * - thread delete notification, |
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477 | * - forced thread migration on SMP configurations, and |
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478 | * - the Multiprocessor Resource Sharing Protocol (MrsP). |
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479 | * |
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480 | * @see _Thread_Run_post_switch_actions(). |
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481 | */ |
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482 | struct Thread_Action { |
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483 | Chain_Node Node; |
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484 | Thread_Action_handler handler; |
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485 | }; |
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486 | |
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487 | /** |
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488 | * @brief Control block to manage thread actions. |
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489 | * |
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490 | * Use _Thread_Action_control_initialize() to initialize this structure. |
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491 | */ |
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492 | typedef struct { |
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493 | Chain_Control Chain; |
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494 | } Thread_Action_control; |
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495 | |
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496 | /** |
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497 | * @brief Thread life states. |
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498 | * |
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499 | * The thread life states are orthogonal to the thread states used for |
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500 | * synchronization primitives and blocking operations. They reflect the state |
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501 | * changes triggered with thread restart and delete requests. |
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502 | */ |
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503 | typedef enum { |
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504 | THREAD_LIFE_NORMAL = 0x0, |
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505 | THREAD_LIFE_PROTECTED = 0x1, |
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506 | THREAD_LIFE_RESTARTING = 0x2, |
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507 | THREAD_LIFE_PROTECTED_RESTARTING = 0x3, |
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508 | THREAD_LIFE_TERMINATING = 0x4, |
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509 | THREAD_LIFE_PROTECTED_TERMINATING = 0x5, |
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510 | THREAD_LIFE_RESTARTING_TERMINATING = 0x6, |
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511 | THREAD_LIFE_PROTECTED_RESTARTING_TERMINATING = 0x7 |
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512 | } Thread_Life_state; |
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513 | |
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514 | /** |
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515 | * @brief Thread life control. |
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516 | */ |
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517 | typedef struct { |
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518 | /** |
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519 | * @brief Thread life action used to react upon thread restart and delete |
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520 | * requests. |
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521 | */ |
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522 | Thread_Action Action; |
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523 | |
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524 | /** |
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525 | * @brief The current thread life state. |
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526 | */ |
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527 | Thread_Life_state state; |
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528 | |
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529 | /** |
---|
530 | * @brief The terminator thread of this thread. |
---|
531 | * |
---|
532 | * In case the thread is terminated and another thread (the terminator) waits |
---|
533 | * for the actual termination completion, then this field references the |
---|
534 | * terminator thread. |
---|
535 | */ |
---|
536 | Thread_Control *terminator; |
---|
537 | } Thread_Life_control; |
---|
538 | |
---|
539 | #if defined(RTEMS_SMP) |
---|
540 | /** |
---|
541 | * @brief The thread state with respect to the scheduler. |
---|
542 | */ |
---|
543 | typedef enum { |
---|
544 | /** |
---|
545 | * @brief This thread is blocked with respect to the scheduler. |
---|
546 | * |
---|
547 | * This thread uses no scheduler nodes. |
---|
548 | */ |
---|
549 | THREAD_SCHEDULER_BLOCKED, |
---|
550 | |
---|
551 | /** |
---|
552 | * @brief This thread is scheduled with respect to the scheduler. |
---|
553 | * |
---|
554 | * This thread executes using one of its scheduler nodes. This could be its |
---|
555 | * own scheduler node or in case it owns resources taking part in the |
---|
556 | * scheduler helping protocol a scheduler node of another thread. |
---|
557 | */ |
---|
558 | THREAD_SCHEDULER_SCHEDULED, |
---|
559 | |
---|
560 | /** |
---|
561 | * @brief This thread is ready with respect to the scheduler. |
---|
562 | * |
---|
563 | * None of the scheduler nodes of this thread is scheduled. |
---|
564 | */ |
---|
565 | THREAD_SCHEDULER_READY |
---|
566 | } Thread_Scheduler_state; |
---|
567 | #endif |
---|
568 | |
---|
569 | /** |
---|
570 | * @brief Thread scheduler control. |
---|
571 | */ |
---|
572 | typedef struct { |
---|
573 | #if defined(RTEMS_SMP) |
---|
574 | /** |
---|
575 | * @brief The current scheduler state of this thread. |
---|
576 | */ |
---|
577 | Thread_Scheduler_state state; |
---|
578 | |
---|
579 | /** |
---|
580 | * @brief The own scheduler control of this thread. |
---|
581 | * |
---|
582 | * This field is constant after initialization. |
---|
583 | */ |
---|
584 | const struct Scheduler_Control *own_control; |
---|
585 | |
---|
586 | /** |
---|
587 | * @brief The scheduler control of this thread. |
---|
588 | * |
---|
589 | * The scheduler helping protocol may change this field. |
---|
590 | */ |
---|
591 | const struct Scheduler_Control *control; |
---|
592 | |
---|
593 | /** |
---|
594 | * @brief The own scheduler node of this thread. |
---|
595 | * |
---|
596 | * This field is constant after initialization. It is used by change |
---|
597 | * priority and ask for help operations. |
---|
598 | */ |
---|
599 | struct Scheduler_Node *own_node; |
---|
600 | #endif |
---|
601 | |
---|
602 | /** |
---|
603 | * @brief The scheduler node of this thread. |
---|
604 | * |
---|
605 | * On uni-processor configurations this field is constant after |
---|
606 | * initialization. |
---|
607 | * |
---|
608 | * On SMP configurations the scheduler helping protocol may change this |
---|
609 | * field. |
---|
610 | */ |
---|
611 | struct Scheduler_Node *node; |
---|
612 | |
---|
613 | #if defined(RTEMS_SMP) |
---|
614 | /** |
---|
615 | * @brief The processor assigned by the current scheduler. |
---|
616 | */ |
---|
617 | struct Per_CPU_Control *cpu; |
---|
618 | |
---|
619 | #if defined(RTEMS_DEBUG) |
---|
620 | /** |
---|
621 | * @brief The processor on which this thread executed the last time or is |
---|
622 | * executing. |
---|
623 | */ |
---|
624 | struct Per_CPU_Control *debug_real_cpu; |
---|
625 | #endif |
---|
626 | #endif |
---|
627 | } Thread_Scheduler_control; |
---|
628 | |
---|
629 | typedef struct { |
---|
630 | uint32_t flags; |
---|
631 | void * control; |
---|
632 | }Thread_Capture_control; |
---|
633 | |
---|
634 | #if defined(RTEMS_SMP) |
---|
635 | /** |
---|
636 | * @brief Thread lock control. |
---|
637 | * |
---|
638 | * The thread lock is either the default lock or the lock of the resource on |
---|
639 | * which the thread is currently blocked. The generation number takes care |
---|
640 | * that the up to date lock is used. Only resources using fine grained locking |
---|
641 | * provide their own lock. |
---|
642 | * |
---|
643 | * The thread lock protects the following thread variables |
---|
644 | * - Thread_Control::current_priority, |
---|
645 | * - Thread_Control::Wait::queue, and |
---|
646 | * - Thread_Control::Wait::operations. |
---|
647 | * |
---|
648 | * @see _Thread_Lock_acquire(), _Thread_Lock_release(), _Thread_Lock_set() and |
---|
649 | * _Thread_Lock_restore_default(). |
---|
650 | */ |
---|
651 | typedef struct { |
---|
652 | /** |
---|
653 | * @brief The current thread lock. |
---|
654 | * |
---|
655 | * This is a plain ticket lock without SMP lock statistics support. This |
---|
656 | * enables external libraries to use thread locks since they are independent |
---|
657 | * of the actual RTEMS build configuration, e.g. profiling enabled or |
---|
658 | * disabled. |
---|
659 | */ |
---|
660 | SMP_ticket_lock_Control *current; |
---|
661 | |
---|
662 | /** |
---|
663 | * @brief The default thread lock in case the thread is not blocked on a |
---|
664 | * resource. |
---|
665 | */ |
---|
666 | SMP_ticket_lock_Control Default; |
---|
667 | |
---|
668 | #if defined(RTEMS_PROFILING) |
---|
669 | /** |
---|
670 | * @brief The thread lock statistics. |
---|
671 | * |
---|
672 | * These statistics are used by the executing thread in case it acquires a |
---|
673 | * thread lock. Thus the statistics are an aggregation of acquire and |
---|
674 | * release operations of diffent locks. |
---|
675 | */ |
---|
676 | SMP_lock_Stats Stats; |
---|
677 | #endif |
---|
678 | |
---|
679 | /** |
---|
680 | * @brief Generation number to invalidate stale locks. |
---|
681 | */ |
---|
682 | Atomic_Uint generation; |
---|
683 | } Thread_Lock_control; |
---|
684 | #endif |
---|
685 | |
---|
686 | /** |
---|
687 | * This structure defines the Thread Control Block (TCB). |
---|
688 | * |
---|
689 | * Uses a leading underscore in the structure name to allow forward |
---|
690 | * declarations in standard header files provided by Newlib and GCC. |
---|
691 | */ |
---|
692 | struct _Thread_Control { |
---|
693 | /** This field is the object management structure for each thread. */ |
---|
694 | Objects_Control Object; |
---|
695 | /** This field is the current execution state of this thread. */ |
---|
696 | States_Control current_state; |
---|
697 | |
---|
698 | /** |
---|
699 | * @brief This field is the current priority state of this thread. |
---|
700 | * |
---|
701 | * Writes to this field are only allowed in _Thread_Initialize() or via |
---|
702 | * _Thread_Change_priority(). |
---|
703 | */ |
---|
704 | Priority_Control current_priority; |
---|
705 | |
---|
706 | /** |
---|
707 | * @brief This field is the base priority of this thread. |
---|
708 | * |
---|
709 | * Writes to this field are only allowed in _Thread_Initialize() or via |
---|
710 | * _Thread_Change_priority(). |
---|
711 | */ |
---|
712 | Priority_Control real_priority; |
---|
713 | |
---|
714 | /** |
---|
715 | * @brief Generation of the current priority value. |
---|
716 | * |
---|
717 | * It is used in _Thread_Change_priority() to serialize the update of |
---|
718 | * priority related data structures. |
---|
719 | */ |
---|
720 | uint32_t priority_generation; |
---|
721 | |
---|
722 | /** |
---|
723 | * @brief Hints if a priority restore is necessary once the resource count |
---|
724 | * changes from one to zero. |
---|
725 | * |
---|
726 | * This is an optimization to speed up the mutex surrender sequence in case |
---|
727 | * no attempt to change the priority was made during the mutex ownership. On |
---|
728 | * SMP configurations atomic fences must synchronize writes to |
---|
729 | * Thread_Control::priority_restore_hint and Thread_Control::resource_count. |
---|
730 | */ |
---|
731 | bool priority_restore_hint; |
---|
732 | |
---|
733 | /** This field is the number of mutexes currently held by this thread. */ |
---|
734 | uint32_t resource_count; |
---|
735 | /** This field is the blocking information for this thread. */ |
---|
736 | Thread_Wait_information Wait; |
---|
737 | /** This field is the Watchdog used to manage thread delays and timeouts. */ |
---|
738 | Watchdog_Control Timer; |
---|
739 | #if defined(RTEMS_MULTIPROCESSING) |
---|
740 | /** This field is the received response packet in an MP system. */ |
---|
741 | MP_packet_Prefix *receive_packet; |
---|
742 | #endif |
---|
743 | /*================= end of common block =================*/ |
---|
744 | |
---|
745 | #if defined(RTEMS_SMP) |
---|
746 | /** |
---|
747 | * @brief Thread lock control. |
---|
748 | */ |
---|
749 | Thread_Lock_control Lock; |
---|
750 | #endif |
---|
751 | |
---|
752 | #if defined(RTEMS_SMP) && defined(RTEMS_PROFILING) |
---|
753 | /** |
---|
754 | * @brief Potpourri lock statistics. |
---|
755 | * |
---|
756 | * These SMP lock statistics are used for all lock objects that lack a |
---|
757 | * storage space for the statistics. Examples are lock objects used in |
---|
758 | * external libraries which are independent of the actual RTEMS build |
---|
759 | * configuration. |
---|
760 | */ |
---|
761 | SMP_lock_Stats Potpourri_stats; |
---|
762 | #endif |
---|
763 | |
---|
764 | #ifdef __RTEMS_STRICT_ORDER_MUTEX__ |
---|
765 | /** This field is the head of queue of priority inheritance mutex |
---|
766 | * held by the thread. |
---|
767 | */ |
---|
768 | Chain_Control lock_mutex; |
---|
769 | #endif |
---|
770 | #if defined(RTEMS_SMP) |
---|
771 | /** |
---|
772 | * @brief Resource node to build a dependency tree in case this thread owns |
---|
773 | * resources or depends on a resource. |
---|
774 | */ |
---|
775 | Resource_Node Resource_node; |
---|
776 | #endif |
---|
777 | #if defined(RTEMS_MULTIPROCESSING) |
---|
778 | /** This field is true if the thread is offered globally */ |
---|
779 | bool is_global; |
---|
780 | #endif |
---|
781 | /** This field is true if the thread is preemptible. */ |
---|
782 | bool is_preemptible; |
---|
783 | /** This field is true if the thread uses the floating point unit. */ |
---|
784 | bool is_fp; |
---|
785 | |
---|
786 | /** |
---|
787 | * @brief Scheduler related control. |
---|
788 | */ |
---|
789 | Thread_Scheduler_control Scheduler; |
---|
790 | |
---|
791 | #if __RTEMS_ADA__ |
---|
792 | /** This field is the GNAT self context pointer. */ |
---|
793 | void *rtems_ada_self; |
---|
794 | #endif |
---|
795 | /** This field is the length of the time quantum that this thread is |
---|
796 | * allowed to consume. The algorithm used to manage limits on CPU usage |
---|
797 | * is specified by budget_algorithm. |
---|
798 | */ |
---|
799 | uint32_t cpu_time_budget; |
---|
800 | /** This field is the algorithm used to manage this thread's time |
---|
801 | * quantum. The algorithm may be specified as none which case, |
---|
802 | * no limit is in place. |
---|
803 | */ |
---|
804 | Thread_CPU_budget_algorithms budget_algorithm; |
---|
805 | /** This field is the method invoked with the budgeted time is consumed. */ |
---|
806 | Thread_CPU_budget_algorithm_callout budget_callout; |
---|
807 | /** This field is the amount of CPU time consumed by this thread |
---|
808 | * since it was created. |
---|
809 | */ |
---|
810 | Thread_CPU_usage_t cpu_time_used; |
---|
811 | |
---|
812 | /** This field contains information about the starting state of |
---|
813 | * this thread. |
---|
814 | */ |
---|
815 | Thread_Start_information Start; |
---|
816 | |
---|
817 | Thread_Action_control Post_switch_actions; |
---|
818 | |
---|
819 | /** This field contains the context of this thread. */ |
---|
820 | Context_Control Registers; |
---|
821 | #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE ) |
---|
822 | /** This field points to the floating point context for this thread. |
---|
823 | * If NULL, the thread is integer only. |
---|
824 | */ |
---|
825 | Context_Control_fp *fp_context; |
---|
826 | #endif |
---|
827 | /** This field points to the newlib reentrancy structure for this thread. */ |
---|
828 | struct _reent *libc_reent; |
---|
829 | /** This array contains the API extension area pointers. */ |
---|
830 | void *API_Extensions[ THREAD_API_LAST + 1 ]; |
---|
831 | |
---|
832 | #if !defined(RTEMS_SMP) |
---|
833 | /** This field points to the set of per task variables. */ |
---|
834 | rtems_task_variable_t *task_variables; |
---|
835 | #endif |
---|
836 | |
---|
837 | /** |
---|
838 | * This is the thread key value chain's control, which is used |
---|
839 | * to track all key value for specific thread, and when thread |
---|
840 | * exits, we can remove all key value for specific thread by |
---|
841 | * iterating this chain, or we have to search a whole rbtree, |
---|
842 | * which is inefficient. |
---|
843 | */ |
---|
844 | Chain_Control Key_Chain; |
---|
845 | |
---|
846 | /** |
---|
847 | * @brief Thread life-cycle control. |
---|
848 | * |
---|
849 | * Control state changes triggered by thread restart and delete requests. |
---|
850 | */ |
---|
851 | Thread_Life_control Life; |
---|
852 | |
---|
853 | Thread_Capture_control Capture; |
---|
854 | |
---|
855 | /** |
---|
856 | * @brief Variable length array of user extension pointers. |
---|
857 | * |
---|
858 | * The length is defined by the application via <rtems/confdefs.h>. |
---|
859 | */ |
---|
860 | void *extensions[ RTEMS_ZERO_LENGTH_ARRAY ]; |
---|
861 | }; |
---|
862 | |
---|
863 | #if (CPU_PROVIDES_IDLE_THREAD_BODY == FALSE) |
---|
864 | /** |
---|
865 | * This routine is the body of the system idle thread. |
---|
866 | * |
---|
867 | * NOTE: This routine is actually instantiated by confdefs.h when needed. |
---|
868 | */ |
---|
869 | void *_Thread_Idle_body( |
---|
870 | uintptr_t ignored |
---|
871 | ); |
---|
872 | #endif |
---|
873 | |
---|
874 | /** This defines the type for a method which operates on a single thread. |
---|
875 | */ |
---|
876 | typedef void (*rtems_per_thread_routine)( Thread_Control * ); |
---|
877 | |
---|
878 | /** |
---|
879 | * @brief Iterates over all threads. |
---|
880 | * This routine iterates over all threads regardless of API and |
---|
881 | * invokes the specified routine. |
---|
882 | */ |
---|
883 | void rtems_iterate_over_all_threads( |
---|
884 | rtems_per_thread_routine routine |
---|
885 | ); |
---|
886 | |
---|
887 | /** |
---|
888 | * @brief Thread control add-on. |
---|
889 | */ |
---|
890 | typedef struct { |
---|
891 | /** |
---|
892 | * @brief Offset of the pointer field in Thread_Control referencing an |
---|
893 | * application configuration dependent memory area in the thread control |
---|
894 | * block. |
---|
895 | */ |
---|
896 | size_t destination_offset; |
---|
897 | |
---|
898 | /** |
---|
899 | * @brief Offset relative to the thread control block begin to an application |
---|
900 | * configuration dependent memory area. |
---|
901 | */ |
---|
902 | size_t source_offset; |
---|
903 | } Thread_Control_add_on; |
---|
904 | |
---|
905 | /** |
---|
906 | * @brief Thread control add-ons. |
---|
907 | * |
---|
908 | * The thread control block contains fields that point to application |
---|
909 | * configuration dependent memory areas, like the scheduler information, the |
---|
910 | * API control blocks, the user extension context table, and the Newlib |
---|
911 | * re-entrancy support. Account for these areas in the configuration and |
---|
912 | * avoid extra workspace allocations for these areas. |
---|
913 | * |
---|
914 | * This array is provided via <rtems/confdefs.h>. |
---|
915 | * |
---|
916 | * @see _Thread_Control_add_on_count and _Thread_Control_size. |
---|
917 | */ |
---|
918 | extern const Thread_Control_add_on _Thread_Control_add_ons[]; |
---|
919 | |
---|
920 | /** |
---|
921 | * @brief Thread control add-on count. |
---|
922 | * |
---|
923 | * Count of entries in _Thread_Control_add_ons. |
---|
924 | * |
---|
925 | * This value is provided via <rtems/confdefs.h>. |
---|
926 | */ |
---|
927 | extern const size_t _Thread_Control_add_on_count; |
---|
928 | |
---|
929 | /** |
---|
930 | * @brief Size of the thread control block of a particular application. |
---|
931 | * |
---|
932 | * This value is provided via <rtems/confdefs.h>. |
---|
933 | * |
---|
934 | * @see _Thread_Control_add_ons. |
---|
935 | */ |
---|
936 | extern const size_t _Thread_Control_size; |
---|
937 | |
---|
938 | /**@}*/ |
---|
939 | |
---|
940 | #ifdef __cplusplus |
---|
941 | } |
---|
942 | #endif |
---|
943 | |
---|
944 | #endif |
---|
945 | /* end of include file */ |
---|