1 | // -*- Mode: CFA -*- |
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2 | // |
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3 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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4 | // |
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5 | // The contents of this file are covered under the licence agreement in the |
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6 | // file "LICENCE" distributed with Cforall. |
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7 | // |
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8 | // kernel.c -- |
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9 | // |
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10 | // Author : Thierry Delisle |
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11 | // Created On : Tue Jan 17 12:27:26 2016 |
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12 | // Last Modified By : Thierry Delisle |
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13 | // Last Modified On : -- |
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14 | // Update Count : 0 |
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15 | // |
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16 | |
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17 | //Header |
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18 | #include "kernel" |
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19 | |
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20 | //C Includes |
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21 | #include <stddef.h> |
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22 | extern "C" { |
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23 | #include <sys/resource.h> |
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24 | } |
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25 | |
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26 | //CFA Includes |
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27 | #include "libhdr.h" |
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28 | #include "threads" |
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29 | |
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30 | //Private includes |
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31 | #define __CFA_INVOKE_PRIVATE__ |
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32 | #include "invoke.h" |
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33 | |
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34 | cluster * systemCluster; |
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35 | processor * systemProcessor; |
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36 | thread_h * mainThread; |
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37 | |
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38 | void kernel_startup(void) __attribute__((constructor(101))); |
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39 | void kernel_shutdown(void) __attribute__((destructor(101))); |
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40 | |
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41 | void ?{}(processor * this, cluster * cltr) { |
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42 | this->ctx = NULL; |
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43 | this->cltr = cltr; |
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44 | this->terminated = false; |
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45 | } |
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46 | |
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47 | void ^?{}(processor * this) {} |
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48 | |
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49 | void ?{}(cluster * this) { |
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50 | ( &this->ready_queue ){}; |
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51 | } |
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52 | |
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53 | void ^?{}(cluster * this) {} |
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54 | |
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55 | //----------------------------------------------------------------------------- |
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56 | // Global state |
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57 | |
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58 | /*thread_local*/ processor * this_processor; |
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59 | |
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60 | coroutine * this_coroutine(void) { |
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61 | return this_processor->current_coroutine; |
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62 | } |
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63 | |
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64 | thread_h * this_thread(void) { |
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65 | return this_processor->current_thread; |
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66 | } |
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67 | |
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68 | //----------------------------------------------------------------------------- |
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69 | // Processor coroutine |
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70 | struct processorCtx_t { |
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71 | processor * proc; |
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72 | coroutine c; |
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73 | }; |
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74 | |
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75 | DECL_COROUTINE(processorCtx_t) |
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76 | |
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77 | void ?{}(processorCtx_t * this, processor * proc) { |
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78 | (&this->c){}; |
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79 | this->proc = proc; |
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80 | } |
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81 | |
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82 | void CtxInvokeProcessor(processor * proc) { |
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83 | processorCtx_t proc_cor_storage = {proc}; |
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84 | resume( &proc_cor_storage ); |
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85 | } |
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86 | |
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87 | //----------------------------------------------------------------------------- |
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88 | // Processor running routines |
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89 | void main(processorCtx_t * ctx); |
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90 | thread_h * nextThread(cluster * this); |
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91 | void runThread(processor * this, thread_h * dst); |
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92 | void spin(processor * this, unsigned int * spin_count); |
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93 | |
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94 | void main(processorCtx_t * ctx) { |
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95 | processor * this = ctx->proc; |
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96 | LIB_DEBUG_PRINTF("Kernel : core %p starting\n", this); |
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97 | |
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98 | thread_h * readyThread = NULL; |
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99 | for( unsigned int spin_count = 0; ! this->terminated; spin_count++ ) { |
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100 | |
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101 | readyThread = nextThread( this->cltr ); |
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102 | |
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103 | if(readyThread) { |
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104 | runThread(this, readyThread); |
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105 | spin_count = 0; |
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106 | } else { |
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107 | spin(this, &spin_count); |
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108 | } |
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109 | } |
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110 | |
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111 | LIB_DEBUG_PRINTF("Kernel : core %p terminated\n", this); |
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112 | } |
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113 | |
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114 | void runThread(processor * this, thread_h * dst) { |
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115 | coroutine * proc_ctx = get_coroutine(this->ctx); |
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116 | coroutine * thrd_ctx = get_coroutine(dst); |
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117 | thrd_ctx->last = proc_ctx; |
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118 | |
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119 | // context switch to specified coroutine |
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120 | // Which is now the current_coroutine |
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121 | // LIB_DEBUG_PRINTF("Kernel : switching to ctx %p (from %p, current %p)\n", thrd_ctx, proc_ctx, current_coroutine); |
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122 | this->current_thread = dst; |
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123 | this->current_coroutine = thrd_ctx; |
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124 | CtxSwitch( proc_ctx->stack.context, thrd_ctx->stack.context ); |
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125 | this->current_coroutine = proc_ctx; |
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126 | // LIB_DEBUG_PRINTF("Kernel : returned from ctx %p (to %p, current %p)\n", thrd_ctx, proc_ctx, current_coroutine); |
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127 | |
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128 | // when CtxSwitch returns we are back in the processor coroutine |
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129 | } |
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130 | |
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131 | void spin(processor * this, unsigned int * spin_count) { |
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132 | (*spin_count)++; |
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133 | } |
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134 | |
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135 | //----------------------------------------------------------------------------- |
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136 | // Scheduler routines |
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137 | void thread_schedule( thread_h * thrd ) { |
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138 | assertf( thrd->next == NULL, "Expected null got %p", thrd->next ); |
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139 | append( &systemProcessor->cltr->ready_queue, thrd ); |
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140 | } |
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141 | |
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142 | thread_h * nextThread(cluster * this) { |
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143 | return pop_head( &this->ready_queue ); |
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144 | } |
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145 | |
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146 | //----------------------------------------------------------------------------- |
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147 | // Kernel storage |
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148 | #define KERNEL_STORAGE(T,X) static char X##_storage[sizeof(T)] |
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149 | |
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150 | KERNEL_STORAGE(processorCtx_t, systemProcessorCtx); |
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151 | KERNEL_STORAGE(cluster, systemCluster); |
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152 | KERNEL_STORAGE(processor, systemProcessor); |
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153 | KERNEL_STORAGE(thread_h, mainThread); |
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154 | KERNEL_STORAGE(machine_context_t, mainThread_context); |
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155 | |
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156 | //----------------------------------------------------------------------------- |
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157 | // Main thread construction |
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158 | struct mainThread_info_t { |
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159 | machine_context_t ctx; |
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160 | unsigned int size; // size of stack |
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161 | void *base; // base of stack |
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162 | void *storage; // pointer to stack |
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163 | void *limit; // stack grows towards stack limit |
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164 | void *context; // address of cfa_context_t |
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165 | void *top; // address of top of storage |
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166 | }; |
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167 | |
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168 | void ?{}( mainThread_info_t * this ) { |
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169 | CtxGet( &this->ctx ); |
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170 | this->base = this->ctx.FP; |
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171 | this->storage = this->ctx.SP; |
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172 | |
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173 | rlimit r; |
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174 | int ret = getrlimit( RLIMIT_STACK, &r); |
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175 | this->size = r.rlim_cur; |
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176 | |
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177 | this->limit = (void *)(((intptr_t)this->base) - this->size); |
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178 | this->context = &mainThread_context_storage; |
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179 | this->top = this->base; |
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180 | } |
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181 | |
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182 | void ?{}( coStack_t * this, mainThread_info_t * info) { |
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183 | this->size = info->size; |
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184 | this->storage = info->storage; |
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185 | this->limit = info->limit; |
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186 | this->base = info->base; |
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187 | this->context = info->context; |
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188 | this->top = info->top; |
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189 | this->userStack = true; |
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190 | } |
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191 | |
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192 | void ?{}( coroutine * this, mainThread_info_t * info) { |
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193 | (&this->stack){ info }; |
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194 | this->name = "Main Thread"; |
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195 | this->errno_ = 0; |
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196 | this->state = Inactive; |
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197 | this->notHalted = true; |
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198 | } |
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199 | |
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200 | void ?{}( thread_h * this, mainThread_info_t * info) { |
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201 | (&this->c){ info }; |
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202 | } |
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203 | |
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204 | //----------------------------------------------------------------------------- |
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205 | // Kernel boot procedures |
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206 | void kernel_startup(void) { |
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207 | |
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208 | // SKULLDUGGERY: the mainThread steals the process main thread |
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209 | // which will then be scheduled by the systemProcessor normally |
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210 | LIB_DEBUG_PRINTF("Kernel : Starting\n"); |
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211 | |
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212 | mainThread_info_t ctx; |
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213 | |
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214 | // Start by initializing the main thread |
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215 | mainThread = (thread_h *)&mainThread_storage; |
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216 | mainThread{ &ctx }; |
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217 | |
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218 | // Initialize the system cluster |
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219 | systemCluster = (cluster *)&systemCluster_storage; |
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220 | systemCluster{}; |
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221 | |
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222 | // Initialize the system processor |
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223 | systemProcessor = (processor *)&systemProcessor_storage; |
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224 | systemProcessor{ systemCluster }; |
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225 | |
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226 | // Initialize the system processor ctx |
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227 | // (the coroutine that contains the processing control flow) |
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228 | systemProcessor->ctx = (processorCtx_t *)&systemProcessorCtx_storage; |
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229 | systemProcessor->ctx{ systemProcessor }; |
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230 | |
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231 | // Add the main thread to the ready queue |
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232 | // once resume is called on systemProcessor->ctx the mainThread needs to be scheduled like any normal thread |
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233 | thread_schedule(mainThread); |
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234 | |
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235 | //initialize the global state variables |
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236 | this_processor = systemProcessor; |
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237 | this_processor->current_thread = mainThread; |
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238 | this_processor->current_coroutine = &mainThread->c; |
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239 | |
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240 | // SKULLDUGGERY: Force a context switch to the system processor to set the main thread's context to the current UNIX |
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241 | // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that |
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242 | // mainThread is on the ready queue when this call is made. |
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243 | resume(systemProcessor->ctx); |
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244 | |
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245 | |
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246 | |
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247 | // THE SYSTEM IS NOW COMPLETELY RUNNING |
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248 | |
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249 | |
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250 | |
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251 | LIB_DEBUG_PRINTF("Kernel : Started\n--------------------------------------------------\n\n"); |
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252 | } |
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253 | |
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254 | void kernel_shutdown(void) { |
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255 | LIB_DEBUG_PRINTF("\n--------------------------------------------------\nKernel : Shutting down\n"); |
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256 | |
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257 | // SKULLDUGGERY: Notify the systemProcessor it needs to terminates. |
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258 | // When its coroutine terminates, it return control to the mainThread |
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259 | // which is currently here |
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260 | systemProcessor->terminated = true; |
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261 | suspend(); |
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262 | |
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263 | // THE SYSTEM IS NOW COMPLETELY STOPPED |
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264 | |
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265 | // Destroy the system processor and its context in reverse order of construction |
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266 | // These were manually constructed so we need manually destroy them |
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267 | ^(systemProcessor->ctx){}; |
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268 | ^(systemProcessor){}; |
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269 | |
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270 | // Final step, destroy the main thread since it is no longer needed |
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271 | // Since we provided a stack to this taxk it will not destroy anything |
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272 | ^(mainThread){}; |
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273 | |
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274 | LIB_DEBUG_PRINTF("Kernel : Shutdown complete\n"); |
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275 | } |
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276 | |
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277 | //----------------------------------------------------------------------------- |
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278 | // Locks |
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279 | void ?{}( simple_lock * this ) { |
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280 | ( &this->blocked ){}; |
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281 | } |
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282 | |
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283 | void ^?{}( simple_lock * this ) { |
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284 | |
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285 | } |
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286 | |
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287 | void lock( simple_lock * this ) { |
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288 | append( &this->blocked, this_thread() ); |
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289 | suspend(); |
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290 | } |
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291 | |
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292 | void unlock( simple_lock * this ) { |
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293 | thread_h * it; |
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294 | while( it = pop_head( &this->blocked) ) { |
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295 | thread_schedule( it ); |
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296 | } |
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297 | } |
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298 | |
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299 | //----------------------------------------------------------------------------- |
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300 | // Queues |
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301 | void ?{}( simple_thread_list * this ) { |
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302 | this->head = NULL; |
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303 | this->tail = &this->head; |
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304 | } |
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305 | |
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306 | void append( simple_thread_list * this, thread_h * t ) { |
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307 | assert( t->next == NULL ); |
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308 | *this->tail = t; |
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309 | this->tail = &t->next; |
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310 | } |
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311 | |
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312 | thread_h * pop_head( simple_thread_list * this ) { |
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313 | thread_h * head = this->head; |
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314 | if( head ) { |
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315 | this->head = head->next; |
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316 | if( !head->next ) { |
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317 | this->tail = &this->head; |
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318 | } |
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319 | head->next = NULL; |
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320 | } |
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321 | |
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322 | return head; |
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323 | } |
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324 | // Local Variables: // |
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325 | // mode: c // |
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326 | // tab-width: 4 // |
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327 | // End: // |
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