1 | /* mutex.h |
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2 | * |
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3 | * This include file contains all the constants and structures associated |
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4 | * with the Mutex Handler. A mutex is an enhanced version of the standard |
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5 | * Dijkstra binary semaphore used to provide synchronization and mutual |
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6 | * exclusion capabilities. |
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7 | * |
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8 | * COPYRIGHT (c) 1989-1997. |
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9 | * On-Line Applications Research Corporation (OAR). |
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10 | * Copyright assigned to U.S. Government, 1994. |
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11 | * |
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12 | * The license and distribution terms for this file may in |
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13 | * the file LICENSE in this distribution or at |
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14 | * http://www.OARcorp.com/rtems/license.html. |
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15 | * |
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16 | * $Id$ |
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17 | */ |
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18 | |
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19 | #ifndef __RTEMS_CORE_MUTEX_h |
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20 | #define __RTEMS_CORE_MUTEX_h |
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21 | |
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22 | #ifdef __cplusplus |
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23 | extern "C" { |
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24 | #endif |
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25 | |
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26 | #include <rtems/score/thread.h> |
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27 | #include <rtems/score/threadq.h> |
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28 | #include <rtems/score/priority.h> |
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29 | #include <rtems/score/watchdog.h> |
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30 | |
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31 | /* |
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32 | * The following type defines the callout which the API provides |
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33 | * to support global/multiprocessor operations on mutexes. |
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34 | */ |
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35 | |
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36 | typedef void ( *CORE_mutex_API_mp_support_callout )( |
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37 | Thread_Control *, |
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38 | Objects_Id |
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39 | ); |
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40 | |
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41 | /* |
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42 | * Blocking disciplines for a mutex. |
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43 | */ |
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44 | |
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45 | typedef enum { |
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46 | CORE_MUTEX_DISCIPLINES_FIFO, |
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47 | CORE_MUTEX_DISCIPLINES_PRIORITY, |
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48 | CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT, |
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49 | CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING |
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50 | } CORE_mutex_Disciplines; |
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51 | |
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52 | /* |
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53 | * Mutex handler return statuses. |
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54 | */ |
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55 | |
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56 | typedef enum { |
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57 | CORE_MUTEX_STATUS_SUCCESSFUL, |
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58 | CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT, |
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59 | CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED, |
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60 | CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE, |
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61 | CORE_MUTEX_WAS_DELETED, |
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62 | CORE_MUTEX_TIMEOUT, |
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63 | CORE_MUTEX_STATUS_CEILING_VIOLATED |
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64 | } CORE_mutex_Status; |
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65 | |
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66 | /* |
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67 | * Locked and unlocked values |
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68 | */ |
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69 | |
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70 | #define CORE_MUTEX_UNLOCKED 1 |
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71 | #define CORE_MUTEX_LOCKED 0 |
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72 | |
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73 | /* |
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74 | * The following defines the control block used to manage the |
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75 | * attributes of each mutex. |
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76 | */ |
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77 | |
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78 | typedef struct { |
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79 | boolean allow_nesting; |
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80 | CORE_mutex_Disciplines discipline; |
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81 | Priority_Control priority_ceiling; |
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82 | } CORE_mutex_Attributes; |
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83 | |
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84 | /* |
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85 | * The following defines the control block used to manage each mutex. |
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86 | */ |
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87 | |
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88 | typedef struct { |
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89 | Thread_queue_Control Wait_queue; |
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90 | CORE_mutex_Attributes Attributes; |
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91 | unsigned32 lock; |
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92 | unsigned32 nest_count; |
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93 | Thread_Control *holder; |
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94 | Objects_Id holder_id; |
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95 | } CORE_mutex_Control; |
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96 | |
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97 | /* |
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98 | * _CORE_mutex_Initialize |
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99 | * |
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100 | * DESCRIPTION: |
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101 | * |
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102 | * This routine initializes the mutex based on the parameters passed. |
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103 | */ |
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104 | |
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105 | void _CORE_mutex_Initialize( |
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106 | CORE_mutex_Control *the_mutex, |
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107 | Objects_Classes the_class, |
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108 | CORE_mutex_Attributes *the_mutex_attributes, |
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109 | unsigned32 initial_lock, |
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110 | Thread_queue_Extract_callout proxy_extract_callout |
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111 | ); |
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112 | |
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113 | /* |
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114 | * _CORE_mutex_Seize |
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115 | * |
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116 | * DESCRIPTION: |
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117 | * |
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118 | * This routine attempts to receive a unit from the_mutex. |
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119 | * If a unit is available or if the wait flag is FALSE, then the routine |
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120 | * returns. Otherwise, the calling task is blocked until a unit becomes |
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121 | * available. |
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122 | */ |
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123 | |
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124 | void _CORE_mutex_Seize( |
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125 | CORE_mutex_Control *the_mutex, |
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126 | Objects_Id id, |
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127 | boolean wait, |
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128 | Watchdog_Interval timeout |
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129 | ); |
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130 | |
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131 | /* |
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132 | * _CORE_mutex_Surrender |
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133 | * |
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134 | * DESCRIPTION: |
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135 | * |
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136 | * This routine frees a unit to the mutex. If a task was blocked waiting for |
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137 | * a unit from this mutex, then that task will be readied and the unit |
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138 | * given to that task. Otherwise, the unit will be returned to the mutex. |
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139 | */ |
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140 | |
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141 | CORE_mutex_Status _CORE_mutex_Surrender( |
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142 | CORE_mutex_Control *the_mutex, |
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143 | Objects_Id id, |
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144 | CORE_mutex_API_mp_support_callout api_mutex_mp_support |
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145 | ); |
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146 | |
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147 | /* |
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148 | * _CORE_mutex_Flush |
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149 | * |
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150 | * DESCRIPTION: |
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151 | * |
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152 | * This routine assists in the deletion of a mutex by flushing the associated |
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153 | * wait queue. |
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154 | */ |
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155 | |
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156 | void _CORE_mutex_Flush( |
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157 | CORE_mutex_Control *the_mutex, |
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158 | Thread_queue_Flush_callout remote_extract_callout, |
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159 | unsigned32 status |
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160 | ); |
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161 | |
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162 | #ifndef __RTEMS_APPLICATION__ |
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163 | #include <rtems/score/coremutex.inl> |
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164 | #endif |
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165 | |
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166 | #ifdef __cplusplus |
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167 | } |
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168 | #endif |
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169 | |
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170 | #endif |
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171 | /* end of include file */ |
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172 | |
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