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1 #ifndef CYGONCE_KERNEL_THREAD_HXX |
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2 #define CYGONCE_KERNEL_THREAD_HXX |
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3 |
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4 //========================================================================== |
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5 // |
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6 // thread.hxx |
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7 // |
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8 // Thread class declarations |
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9 // |
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10 //========================================================================== |
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11 //####COPYRIGHTBEGIN#### |
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12 // |
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13 // ------------------------------------------- |
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14 // The contents of this file are subject to the Cygnus eCos Public License |
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15 // Version 1.0 (the "License"); you may not use this file except in |
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16 // compliance with the License. You may obtain a copy of the License at |
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17 // http://sourceware.cygnus.com/ecos |
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18 // |
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19 // Software distributed under the License is distributed on an "AS IS" |
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20 // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the |
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21 // License for the specific language governing rights and limitations under |
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22 // the License. |
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23 // |
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24 // The Original Code is eCos - Embedded Cygnus Operating System, released |
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25 // September 30, 1998. |
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26 // |
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27 // The Initial Developer of the Original Code is Cygnus. Portions created |
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28 // by Cygnus are Copyright (C) 1998,1999 Cygnus Solutions. All Rights Reserved. |
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29 // ------------------------------------------- |
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30 // |
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31 //####COPYRIGHTEND#### |
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32 //========================================================================== |
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33 //#####DESCRIPTIONBEGIN#### |
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34 // |
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35 // Author(s): nickg |
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36 // Contributors: nickg |
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37 // Date: 1997-09-09 |
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38 // Purpose: Define Thread class interfaces |
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39 // Description: The classes defined here collectively implement the |
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40 // internal API used to create, configure and manage threads. |
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41 // Usage: #include <cyg/kernel/thread.hxx> |
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42 // |
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43 //####DESCRIPTIONEND#### |
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44 // |
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45 //========================================================================== |
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46 |
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47 #include <cyg/kernel/ktypes.h> |
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48 #include <cyg/infra/cyg_ass.h> // assertion macros |
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49 #include <cyg/kernel/sched.hxx> |
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50 #include <cyg/kernel/clock.hxx> |
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51 #include <cyg/kernel/except.hxx> |
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52 |
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53 #include <cyg/hal/hal_arch.h> |
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54 |
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55 // ------------------------------------------------------------------------- |
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56 // Miscellaneous types |
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57 |
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58 typedef void cyg_thread_entry(CYG_ADDRWORD data);// Thread entry point function |
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59 |
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60 // ------------------------------------------------------------------------- |
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61 // Hardware thread interface. |
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62 // The implementation of this class is provided by the HAL. |
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63 |
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64 class Cyg_HardwareThread |
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65 { |
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66 friend class Cyg_Scheduler; |
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67 |
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68 protected: |
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69 |
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70 CYG_ADDRESS stack_base; // pointer to base of stack area |
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71 |
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72 cyg_uint32 stack_size; // size of stack area in bytes |
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73 |
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74 #ifdef CYGFUN_KERNEL_THREADS_STACK_LIMIT |
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75 CYG_ADDRESS stack_limit; // movable stack limit |
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76 #endif |
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77 |
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78 CYG_ADDRESS stack_ptr; // pointer to saved state on stack |
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79 |
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80 cyg_thread_entry *entry_point; // main entry point (code pointer!) |
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81 |
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82 CYG_ADDRWORD entry_data; // entry point argument |
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83 |
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84 #ifdef CYGDBG_KERNEL_DEBUG_GDB_THREAD_SUPPORT |
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85 |
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86 HAL_SavedRegisters *saved_context; // If non-zero, this points at a more |
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87 // interesting context than stack_ptr. |
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88 #endif |
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89 |
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90 Cyg_HardwareThread( |
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91 cyg_thread_entry *entry_point, // entry point function |
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92 CYG_ADDRWORD entry_data, // entry data |
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93 cyg_ucount32 stack_size = 0, // stack size, 0 = use default |
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94 CYG_ADDRESS stack_base = 0 // stack base, NULL = allocate |
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95 ); |
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96 |
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97 // Thread entry point. This is where all threads begin execution. |
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98 // This routine does a little housekeeping and then call the main |
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99 // entry_point specified above. |
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100 static void thread_entry(Cyg_Thread *thread); |
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101 |
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102 // Initialize the context of the thread to start execution at thread_entry |
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103 void init_context( Cyg_Thread *thread ); |
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104 |
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105 // Save current thread's context and load that of the given next thread. |
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106 void switch_context(Cyg_HardwareThread *next); |
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107 |
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108 // load this thread's context without saving current context |
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109 void load_context(); |
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110 |
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111 // attach a stack to this thread |
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112 void attach_stack(CYG_ADDRESS stack, cyg_uint32 stack_size); |
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113 |
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114 // detach the stack from this thread |
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115 CYG_ADDRESS detach_stack(); |
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116 |
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117 // Adjust the thread's saved state to call the exception |
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118 // handler when next executed. |
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119 void prepare_exception ( |
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120 cyg_exception_handler *exception_handler, |
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121 CYG_ADDRWORD exception_data, |
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122 cyg_code exception_number, |
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123 CYG_ADDRWORD exception_info |
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124 ); |
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125 |
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126 public: |
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127 |
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128 CYGDBG_DEFINE_CHECK_THIS |
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129 |
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130 // Get and set entry_data. |
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131 |
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132 void set_entry_data( CYG_ADDRWORD data ); |
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133 |
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134 CYG_ADDRWORD get_entry_data(); |
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135 |
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136 #ifdef CYGDBG_KERNEL_DEBUG_GDB_THREAD_SUPPORT |
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137 // Return the current saved state for this thread. |
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138 HAL_SavedRegisters *get_saved_context(); |
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139 |
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140 // Set the saved context pointer. |
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141 void set_saved_context(HAL_SavedRegisters *ctx); |
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142 #endif |
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143 |
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144 // get the size/base of this thread's stack |
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145 CYG_ADDRESS get_stack_base(); |
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146 |
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147 cyg_uint32 get_stack_size(); |
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148 |
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149 #ifdef CYGFUN_KERNEL_THREADS_STACK_LIMIT |
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150 // Allocate some memory at the lower end of the stack |
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151 // by moving the stack limit pointer. |
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152 |
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153 void *increment_stack_limit( cyg_ucount32 size); |
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154 |
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155 CYG_ADDRESS get_stack_limit(); |
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156 #endif |
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157 }; |
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158 |
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159 // ------------------------------------------------------------------------- |
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160 // Per-thread timer support class. |
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161 // This is only included when required. |
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162 |
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163 #ifdef CYGFUN_KERNEL_THREADS_TIMER |
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164 |
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165 class Cyg_ThreadTimer |
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166 : public Cyg_Alarm |
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167 { |
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168 friend class Cyg_Thread; |
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169 |
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170 // Pointer to current thread |
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171 Cyg_Thread *thread; |
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172 |
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173 // Constructor |
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174 Cyg_ThreadTimer( |
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175 Cyg_Thread *thread |
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176 ); |
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177 |
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178 // Alarm function |
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179 static void alarm( Cyg_Alarm *alarm, CYG_ADDRWORD data); |
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180 |
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181 CYGDBG_DEFINE_CHECK_THIS |
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182 |
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183 }; |
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184 |
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185 #endif |
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186 |
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187 // ------------------------------------------------------------------------- |
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188 // Main Thread class. |
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189 // This provides the public API for controlling threads. |
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190 |
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191 class Cyg_Thread |
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192 : public Cyg_HardwareThread, // provides hardware abstractions |
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193 public Cyg_SchedThread // provides scheduling abstractions |
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194 { |
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195 friend class Cyg_Scheduler; |
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196 friend void deliver_exception( CYG_WORD code, CYG_ADDRWORD data ); |
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197 |
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198 // The following definitions are used by all variants of the |
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199 // basic thread object. |
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200 |
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201 public: |
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202 enum { // Thread state values |
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203 |
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204 RUNNING = 0, // Thread is runnable or running |
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205 SLEEPING = 1, // Thread is waiting for something to happen |
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206 COUNTSLEEP = 2, // Sleep in counted manner |
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207 SUSPENDED = 4, // Suspend count is non-zero |
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208 CREATING = 8, // Thread is being created |
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209 EXITED = 16, // Thread has exited |
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210 |
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211 // This is the set of bits that must be cleared by a generic |
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212 // wake() or release(). |
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213 SLEEPSET = (SLEEPING | COUNTSLEEP) |
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214 }; |
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215 |
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216 private: |
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217 // Current thread state, a logical OR of the above values. |
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218 // Only if this word is zero can the thread execute. |
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219 cyg_uint32 state; |
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220 |
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221 // Suspension counter, if > 0, the thread is suspended |
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222 cyg_ucount32 suspend_count; |
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223 |
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224 // Wakeup counter, if > 0, sleep will not sleep, just decrement |
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225 cyg_ucount32 wakeup_count; |
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226 |
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227 // A word of data used in syncronization object to communicate |
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228 // information between sleepers and wakers. |
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229 CYG_ADDRWORD wait_info; |
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230 |
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231 // Unique thread id assigned on creation |
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232 cyg_uint16 unique_id; |
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233 |
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234 #ifdef CYGPKG_KERNEL_EXCEPTIONS |
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235 |
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236 // If exceptions are supported, define an exception control |
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237 // object that will be used to manage and deliver them. If |
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238 // exceptions are global there is a single static instance |
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239 // of this object, if they are per-thread then there is one |
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240 // for each thread. |
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241 private: |
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242 |
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243 #ifdef CYGSEM_KERNEL_EXCEPTIONS_GLOBAL |
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244 static |
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245 #endif |
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246 Cyg_Exception_Control exception_control; |
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247 |
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248 public: |
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249 |
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250 static void register_exception( |
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251 cyg_code exception_number, // exception number |
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252 cyg_exception_handler handler, // handler function |
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253 CYG_ADDRWORD data, // data argument |
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254 cyg_exception_handler **old_handler, // handler function |
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255 CYG_ADDRWORD *old_data // data argument |
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256 ); |
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257 |
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258 static void deregister_exception( |
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259 cyg_code exception_number // exception number |
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260 ); |
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261 |
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262 void deliver_exception( |
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263 cyg_code exception_number, // exception being raised |
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264 CYG_ADDRWORD exception_info // exception specific info |
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265 ); |
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266 |
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267 #endif |
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268 |
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269 |
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270 public: |
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271 |
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272 CYGDBG_DEFINE_CHECK_THIS |
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273 |
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274 // Constructor, Initialize the thread structure. The thread is |
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275 // created in suspended state, and needs to be resumed to execute. |
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276 // It is also started at some (configurable) default priority, which |
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277 // may need to be changed before calling resume. |
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278 |
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279 Cyg_Thread ( |
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280 cyg_thread_entry *entry, // entry point function |
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281 CYG_ADDRWORD entry_data, // entry data |
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282 cyg_ucount32 stack_size = 0, // stack size, 0 = use default |
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283 CYG_ADDRESS stack_base = 0 // stack base, NULL = allocate |
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284 ); |
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285 |
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286 Cyg_Thread ( |
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287 CYG_ADDRWORD sched_info, // Scheduling parameter(s) |
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288 cyg_thread_entry *entry, // entry point function |
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289 CYG_ADDRWORD entry_data, // entry data |
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290 char *name, // thread name |
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291 CYG_ADDRESS stack_base = 0, // stack base, NULL = allocate |
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292 cyg_ucount32 stack_size = 0 // stack size, 0 = use default |
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293 ); |
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294 |
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295 // Re-initialize the thread back to it's initial state. |
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296 void Cyg_Thread::reinitialize(); |
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297 |
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298 ~Cyg_Thread(); |
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299 |
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300 // The following are invoked implicitly on the current thread, |
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301 // hence they are static member functions. |
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302 |
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303 static void sleep(); // Put thread to sleep |
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304 |
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305 static void counted_sleep();// Decrement counter or put |
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306 // thread to sleep |
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307 #ifdef CYGFUN_KERNEL_THREADS_TIMER |
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308 static void counted_sleep( cyg_tick_count delay ); |
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309 // ...for delay ticks |
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310 #endif |
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311 |
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312 static void exit(); // Terminate thread |
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313 |
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314 static void yield(); // Yield CPU to another thread |
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315 |
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316 static void rotate_queue( cyg_priority pri ); |
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317 // Rotate that run queue |
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318 |
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319 void to_queue_head( void ); |
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320 // Move to the head of its queue |
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321 // (not necessarily a scheduler q) |
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322 |
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323 static Cyg_Thread *self(); // Return current thread |
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324 |
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325 |
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326 // The following are called on threads other than the current one. |
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327 |
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328 void wake(); // Wake this thread from sleep. |
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329 |
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330 void counted_wake(); // Increment counter or wake thread |
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331 cyg_uint32 cancel_counted_wake(); |
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332 // Cancel counted wakeups for this |
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333 // thread and return how many were |
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334 // pending |
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335 |
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336 void suspend(); // Suspend this thread: increment counter and |
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337 // deschedule. |
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338 |
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339 void resume(); // Resume this thread: decrement counter and |
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340 // reschedule if counter is zero. |
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341 |
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342 void release(); // Release thread from sleep with BREAK |
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343 // wake_reason. |
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344 |
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345 void kill(); // Kill this thread |
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346 |
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347 void force_resume(); // Resume this thread: set counter to zero. |
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348 |
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349 cyg_uint32 get_state(); // Return current thread state. |
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350 |
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351 |
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352 // Accessor functions to set and get wait_info. |
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353 |
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354 void set_wait_info(CYG_ADDRWORD data); |
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355 |
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356 CYG_ADDRWORD get_wait_info(); |
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357 |
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358 // This part of the API is used if we have a clock and want |
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359 // per-thread timers for doing delays and timeouts. |
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360 |
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361 // delay the given number of ticks |
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362 void delay( cyg_tick_count delay ); |
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363 |
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364 |
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365 enum cyg_reason // sleep/wakeup reason codes |
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366 { |
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367 NONE, // No recorded reason |
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368 WAIT, // Wait with no timeout |
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369 DELAY, // Simple time delay |
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370 TIMEOUT, // Wait with timeout/timeout expired |
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371 BREAK, // forced break out of sleep |
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372 DESTRUCT, // wait object destroyed[note] |
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373 EXIT, // forced termination |
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374 DONE // Wait/delay complete |
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375 }; |
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376 // [note] NOT the thread, some object it was waiting on. |
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377 // Thread destruction would first involve EXITing it. |
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378 |
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379 private: |
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380 |
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381 #ifdef CYGFUN_KERNEL_THREADS_TIMER |
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382 Cyg_ThreadTimer timer; // per-thread timer |
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383 #endif |
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384 |
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385 cyg_reason sleep_reason; // reason for sleeping |
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386 |
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387 cyg_reason wake_reason; // reason for waking |
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388 |
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389 #ifdef CYGIMP_THREAD_PRIORITY |
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390 |
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391 public: |
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392 |
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393 // If the scheduler implements priorities, provide |
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394 // functions to set and get it. |
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395 |
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396 void set_priority( cyg_priority pri ); |
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397 |
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398 cyg_priority get_priority(); |
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399 |
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400 // This returns the current dispatching priority of the |
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401 // thread. This may differ from the result of get_priority() |
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402 // in the presence of priority inheritance or certain |
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403 // scheduling algorithms. |
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404 cyg_priority get_current_priority(); |
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405 |
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406 #endif |
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407 |
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408 #ifdef CYGVAR_KERNEL_THREADS_DATA |
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409 |
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410 private: |
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411 // Array of single word entries for each index. |
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412 CYG_ADDRWORD thread_data[CYGNUM_KERNEL_THREADS_DATA_MAX]; |
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413 |
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414 // Map of free thread_data indexes. Each bit represents an index |
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415 // and is 1 if that index is free, and 0 if it is in use. |
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416 static cyg_ucount32 thread_data_map; |
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417 |
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418 public: |
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419 |
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420 static CYG_ADDRWORD get_data( cyg_ucount32 index ); |
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421 |
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422 static CYG_ADDRWORD *get_data_ptr( cyg_ucount32 index ); |
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423 |
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424 void set_data( cyg_ucount32 index, CYG_ADDRWORD data ); |
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425 |
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426 static cyg_ucount32 new_data_index(); |
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427 |
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428 static void free_data_index( cyg_ucount32 index ); |
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429 |
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430 #endif |
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431 |
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432 #ifdef CYGVAR_KERNEL_THREADS_NAME |
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433 |
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434 private: |
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435 // An optional thread name string, for humans to read |
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436 char *name; |
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437 |
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438 public: |
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439 // function to get the name string |
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440 char *get_name(); |
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441 |
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442 #endif |
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443 |
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444 |
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445 #ifdef CYGVAR_KERNEL_THREADS_LIST |
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446 |
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447 // Housekeeping list that tracks all threads |
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448 private: |
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449 Cyg_Thread *list_next; |
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450 static Cyg_Thread *thread_list; |
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451 |
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452 void add_to_list( void ); |
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453 void remove_from_list( void ); |
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454 public: |
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455 |
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456 static Cyg_Thread *get_list_head(); |
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457 |
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458 Cyg_Thread *get_list_next(); |
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459 |
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460 #endif |
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461 |
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462 public: |
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463 |
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464 // Set sleep reason to reason and wake reason to NONE |
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465 static void set_sleep_reason( cyg_reason reason = WAIT); |
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466 |
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467 cyg_reason get_sleep_reason(); |
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468 |
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469 // Set the wakeup reason to the given value |
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470 void set_wake_reason( cyg_reason reason = DONE); |
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471 |
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472 // Get current wake reason |
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473 cyg_reason get_wake_reason(); |
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474 |
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475 static void set_timer( // Set timeout and sleep reason |
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476 cyg_tick_count trigger, // Absolute wakeup time |
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477 cyg_reason sleep_reason // reason for sleeping |
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478 ); |
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479 |
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480 static void clear_timer(); // disable thread timer |
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481 |
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482 // Get a 16 bit unique id for this thread. This is |
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483 // used in tracing and instrumentation to identify the |
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484 // current thread. |
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485 |
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486 cyg_uint16 get_unique_id(); |
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487 |
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488 }; |
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489 |
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490 // ------------------------------------------------------------------------- |
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491 // Thread Queue class. |
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492 // This defines the main API for manipulating queues of threads. |
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493 |
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494 class Cyg_ThreadQueue |
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495 : public Cyg_ThreadQueue_Implementation |
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0
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496 { |
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497 |
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498 public: |
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499 |
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500 CYGDBG_DEFINE_CHECK_THIS |
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501 |
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502 // API used by rest of kernel. |
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503 |
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504 // Add thread to queue |
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505 void enqueue(Cyg_Thread *thread); |
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506 |
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507 // return first thread on queue |
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508 Cyg_Thread *highpri(); |
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509 |
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510 // remove first thread on queue |
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511 Cyg_Thread *dequeue(); |
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512 |
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513 // remove specified thread from queue |
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514 void remove(Cyg_Thread *thread); |
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515 |
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516 // test if queue is empty |
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517 cyg_bool empty(); |
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518 |
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519 }; |
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520 |
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521 // ------------------------------------------------------------------------- |
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522 // Thread inlines |
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523 |
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524 // Return current thread state. |
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525 inline cyg_uint32 Cyg_Thread::get_state() |
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526 { |
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527 return state; |
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528 } |
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529 |
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530 inline void Cyg_Thread::set_wait_info(CYG_ADDRWORD data) |
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531 { |
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532 wait_info = data; |
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533 } |
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534 |
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535 inline CYG_ADDRWORD Cyg_Thread::get_wait_info() |
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536 { |
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537 return wait_info; |
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538 } |
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539 |
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540 // ------------------------------------------------------------------------- |
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541 #endif // ifndef CYGONCE_KERNEL_THREAD_HXX |
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542 // EOF thread.hxx |
