[8118303] | 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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[0c92c9f] | 17 | //Start and stop routine for the kernel, declared first to make sure they run first |
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| 18 | void kernel_startup(void) __attribute__((constructor(101))); |
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| 19 | void kernel_shutdown(void) __attribute__((destructor(101))); |
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| 20 | |
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[8118303] | 21 | //Header |
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| 22 | #include "kernel" |
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| 23 | |
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| 24 | //C Includes |
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[c84e80a] | 25 | #include <stddef.h> |
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[eb2e723] | 26 | extern "C" { |
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| 27 | #include <sys/resource.h> |
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| 28 | } |
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[8118303] | 29 | |
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| 30 | //CFA Includes |
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| 31 | #include "libhdr.h" |
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| 32 | #include "threads" |
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| 33 | |
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| 34 | //Private includes |
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| 35 | #define __CFA_INVOKE_PRIVATE__ |
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| 36 | #include "invoke.h" |
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| 37 | |
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[8def349] | 38 | //----------------------------------------------------------------------------- |
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| 39 | // Kernel storage |
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| 40 | struct processorCtx_t { |
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| 41 | processor * proc; |
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| 42 | coroutine c; |
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| 43 | }; |
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| 44 | |
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| 45 | DECL_COROUTINE(processorCtx_t) |
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| 46 | |
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| 47 | #define KERNEL_STORAGE(T,X) static char X##_storage[sizeof(T)] |
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| 48 | |
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| 49 | KERNEL_STORAGE(processorCtx_t, systemProcessorCtx); |
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| 50 | KERNEL_STORAGE(cluster, systemCluster); |
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| 51 | KERNEL_STORAGE(processor, systemProcessor); |
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[e15df4c] | 52 | KERNEL_STORAGE(thread, mainThread); |
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[8def349] | 53 | KERNEL_STORAGE(machine_context_t, mainThread_context); |
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| 54 | |
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[bd98b58] | 55 | cluster * systemCluster; |
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[eb2e723] | 56 | processor * systemProcessor; |
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[e15df4c] | 57 | thread * mainThread; |
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[eb2e723] | 58 | |
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[bd98b58] | 59 | //----------------------------------------------------------------------------- |
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| 60 | // Global state |
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| 61 | |
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[8def349] | 62 | thread_local processor * this_processor; |
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| 63 | |
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| 64 | processor * get_this_processor() { |
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| 65 | return this_processor; |
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| 66 | } |
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[c84e80a] | 67 | |
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[bd98b58] | 68 | coroutine * this_coroutine(void) { |
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| 69 | return this_processor->current_coroutine; |
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| 70 | } |
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| 71 | |
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[e15df4c] | 72 | thread * this_thread(void) { |
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[bd98b58] | 73 | return this_processor->current_thread; |
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[c84e80a] | 74 | } |
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| 75 | |
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| 76 | //----------------------------------------------------------------------------- |
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[8def349] | 77 | // Main thread construction |
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| 78 | struct current_stack_info_t { |
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| 79 | machine_context_t ctx; |
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| 80 | unsigned int size; // size of stack |
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| 81 | void *base; // base of stack |
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| 82 | void *storage; // pointer to stack |
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| 83 | void *limit; // stack grows towards stack limit |
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| 84 | void *context; // address of cfa_context_t |
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| 85 | void *top; // address of top of storage |
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[c84e80a] | 86 | }; |
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| 87 | |
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[8def349] | 88 | void ?{}( current_stack_info_t * this ) { |
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| 89 | CtxGet( &this->ctx ); |
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| 90 | this->base = this->ctx.FP; |
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| 91 | this->storage = this->ctx.SP; |
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| 92 | |
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| 93 | rlimit r; |
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| 94 | int ret = getrlimit( RLIMIT_STACK, &r); |
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| 95 | this->size = r.rlim_cur; |
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| 96 | |
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| 97 | this->limit = (void *)(((intptr_t)this->base) - this->size); |
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| 98 | this->context = &mainThread_context_storage; |
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| 99 | this->top = this->base; |
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| 100 | } |
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| 101 | |
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| 102 | void ?{}( coStack_t * this, current_stack_info_t * info) { |
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| 103 | this->size = info->size; |
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| 104 | this->storage = info->storage; |
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| 105 | this->limit = info->limit; |
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| 106 | this->base = info->base; |
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| 107 | this->context = info->context; |
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| 108 | this->top = info->top; |
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| 109 | this->userStack = true; |
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| 110 | } |
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| 111 | |
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| 112 | void ?{}( coroutine * this, current_stack_info_t * info) { |
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| 113 | (&this->stack){ info }; |
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| 114 | this->name = "Main Thread"; |
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| 115 | this->errno_ = 0; |
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| 116 | this->state = Inactive; |
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| 117 | this->notHalted = true; |
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| 118 | } |
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| 119 | |
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[e15df4c] | 120 | void ?{}( thread * this, current_stack_info_t * info) { |
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[8def349] | 121 | (&this->c){ info }; |
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| 122 | } |
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[c84e80a] | 123 | |
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[8def349] | 124 | //----------------------------------------------------------------------------- |
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| 125 | // Processor coroutine |
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[eb2e723] | 126 | void ?{}(processorCtx_t * this, processor * proc) { |
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| 127 | (&this->c){}; |
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[c84e80a] | 128 | this->proc = proc; |
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[8def349] | 129 | proc->ctx = this; |
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| 130 | } |
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| 131 | |
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| 132 | void ?{}(processorCtx_t * this, processor * proc, current_stack_info_t * info) { |
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| 133 | (&this->c){ info }; |
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| 134 | this->proc = proc; |
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| 135 | proc->ctx = this; |
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| 136 | } |
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| 137 | |
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| 138 | void start(processor * this); |
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| 139 | |
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| 140 | void ?{}(processor * this) { |
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| 141 | this{ systemCluster }; |
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| 142 | } |
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| 143 | |
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| 144 | void ?{}(processor * this, cluster * cltr) { |
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| 145 | this->cltr = cltr; |
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| 146 | this->current_coroutine = NULL; |
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| 147 | this->current_thread = NULL; |
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| 148 | (&this->lock){}; |
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| 149 | this->terminated = false; |
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| 150 | |
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| 151 | start( this ); |
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[c84e80a] | 152 | } |
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| 153 | |
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[8def349] | 154 | void ?{}(processor * this, cluster * cltr, processorCtx_t * ctx) { |
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| 155 | this->cltr = cltr; |
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| 156 | this->current_coroutine = NULL; |
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| 157 | this->current_thread = NULL; |
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| 158 | (&this->lock){}; |
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| 159 | this->terminated = false; |
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| 160 | |
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| 161 | this->ctx = ctx; |
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| 162 | LIB_DEBUG_PRINTF("Kernel : constructing processor context %p\n", ctx); |
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| 163 | ctx{ this }; |
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| 164 | } |
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| 165 | |
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| 166 | void ^?{}(processor * this) { |
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| 167 | if( ! this->terminated ) { |
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| 168 | LIB_DEBUG_PRINTF("Kernel : core %p signaling termination\n", this); |
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| 169 | this->terminated = true; |
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| 170 | lock( &this->lock ); |
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| 171 | } |
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| 172 | } |
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| 173 | |
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| 174 | void ?{}(cluster * this) { |
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| 175 | ( &this->ready_queue ){}; |
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| 176 | pthread_spin_init( &this->lock, PTHREAD_PROCESS_PRIVATE ); |
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| 177 | } |
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| 178 | |
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| 179 | void ^?{}(cluster * this) { |
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| 180 | pthread_spin_destroy( &this->lock ); |
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[c84e80a] | 181 | } |
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| 182 | |
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| 183 | //----------------------------------------------------------------------------- |
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| 184 | // Processor running routines |
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[eb2e723] | 185 | void main(processorCtx_t * ctx); |
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[e15df4c] | 186 | thread * nextThread(cluster * this); |
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[0c92c9f] | 187 | void scheduleInternal(processor * this, thread * dst); |
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[c84e80a] | 188 | void spin(processor * this, unsigned int * spin_count); |
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[8118303] | 189 | |
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[eb2e723] | 190 | void main(processorCtx_t * ctx) { |
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| 191 | processor * this = ctx->proc; |
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| 192 | LIB_DEBUG_PRINTF("Kernel : core %p starting\n", this); |
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[8118303] | 193 | |
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[e15df4c] | 194 | thread * readyThread = NULL; |
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[c84e80a] | 195 | for( unsigned int spin_count = 0; ! this->terminated; spin_count++ ) { |
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| 196 | |
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[bd98b58] | 197 | readyThread = nextThread( this->cltr ); |
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[8118303] | 198 | |
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[c84e80a] | 199 | if(readyThread) { |
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[0c92c9f] | 200 | scheduleInternal(this, readyThread); |
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[c84e80a] | 201 | spin_count = 0; |
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| 202 | } else { |
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| 203 | spin(this, &spin_count); |
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| 204 | } |
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| 205 | } |
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[8118303] | 206 | |
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[8def349] | 207 | LIB_DEBUG_PRINTF("Kernel : core %p unlocking thread\n", this); |
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| 208 | unlock( &this->lock ); |
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[c84e80a] | 209 | LIB_DEBUG_PRINTF("Kernel : core %p terminated\n", this); |
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| 210 | } |
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| 211 | |
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[0c92c9f] | 212 | //Declarations for scheduleInternal |
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| 213 | extern void ThreadCtxSwitch(coroutine * src, coroutine * dst); |
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| 214 | |
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| 215 | // scheduleInternal runs a thread by context switching |
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| 216 | // from the processor coroutine to the target thread |
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| 217 | void scheduleInternal(processor * this, thread * dst) { |
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| 218 | // coroutine * proc_ctx = get_coroutine(this->ctx); |
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| 219 | // coroutine * thrd_ctx = get_coroutine(dst); |
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| 220 | |
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| 221 | // //Update global state |
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| 222 | // this->current_thread = dst; |
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| 223 | |
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| 224 | // // Context Switch to the thread |
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| 225 | // ThreadCtxSwitch(proc_ctx, thrd_ctx); |
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| 226 | // // when ThreadCtxSwitch returns we are back in the processor coroutine |
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| 227 | |
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[eb2e723] | 228 | coroutine * proc_ctx = get_coroutine(this->ctx); |
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[c84e80a] | 229 | coroutine * thrd_ctx = get_coroutine(dst); |
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[0c92c9f] | 230 | thrd_ctx->last = proc_ctx; |
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| 231 | |
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| 232 | // context switch to specified coroutine |
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| 233 | // Which is now the current_coroutine |
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| 234 | LIB_DEBUG_PRINTF("Kernel : switching to ctx %p (from %p, current %p)\n", thrd_ctx, proc_ctx, this->current_coroutine); |
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| 235 | this->current_thread = dst; |
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| 236 | this->current_coroutine = thrd_ctx; |
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| 237 | CtxSwitch( proc_ctx->stack.context, thrd_ctx->stack.context ); |
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| 238 | this->current_coroutine = proc_ctx; |
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| 239 | LIB_DEBUG_PRINTF("Kernel : returned from ctx %p (to %p, current %p)\n", thrd_ctx, proc_ctx, this->current_coroutine); |
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| 240 | |
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| 241 | // when CtxSwitch returns we are back in the processor coroutine |
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[c84e80a] | 242 | } |
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| 243 | |
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[0c92c9f] | 244 | // Handles spinning logic |
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| 245 | // TODO : find some strategy to put cores to sleep after some time |
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[c84e80a] | 246 | void spin(processor * this, unsigned int * spin_count) { |
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| 247 | (*spin_count)++; |
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| 248 | } |
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| 249 | |
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[0c92c9f] | 250 | // Context invoker for processors |
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| 251 | // This is the entry point for processors (kernel threads) |
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| 252 | // It effectively constructs a coroutine by stealing the pthread stack |
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[8def349] | 253 | void * CtxInvokeProcessor(void * arg) { |
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| 254 | processor * proc = (processor *) arg; |
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| 255 | this_processor = proc; |
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| 256 | // SKULLDUGGERY: We want to create a context for the processor coroutine |
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| 257 | // which is needed for the 2-step context switch. However, there is no reason |
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| 258 | // to waste the perfectly valid stack create by pthread. |
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| 259 | current_stack_info_t info; |
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| 260 | machine_context_t ctx; |
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| 261 | info.context = &ctx; |
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| 262 | processorCtx_t proc_cor_storage = { proc, &info }; |
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| 263 | |
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[0c92c9f] | 264 | //Set global state |
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[8def349] | 265 | proc->current_coroutine = &proc->ctx->c; |
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| 266 | proc->current_thread = NULL; |
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| 267 | |
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| 268 | //We now have a proper context from which to schedule threads |
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[0c92c9f] | 269 | LIB_DEBUG_PRINTF("Kernel : core %p created (%p)\n", proc, proc->ctx); |
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[8def349] | 270 | |
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| 271 | // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't |
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| 272 | // resume it to start it like it normally would, it will just context switch |
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| 273 | // back to here. Instead directly call the main since we already are on the |
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| 274 | // appropriate stack. |
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| 275 | proc_cor_storage.c.state = Active; |
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| 276 | main( &proc_cor_storage ); |
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| 277 | proc_cor_storage.c.state = Halt; |
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| 278 | proc_cor_storage.c.notHalted = false; |
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| 279 | |
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[0c92c9f] | 280 | // Main routine of the core returned, the core is now fully terminated |
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[8def349] | 281 | LIB_DEBUG_PRINTF("Kernel : core %p main ended (%p)\n", proc, proc->ctx); |
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| 282 | |
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| 283 | return NULL; |
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[c84e80a] | 284 | } |
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| 285 | |
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[8def349] | 286 | void start(processor * this) { |
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| 287 | LIB_DEBUG_PRINTF("Kernel : Starting core %p\n", this); |
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| 288 | |
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| 289 | pthread_attr_t attributes; |
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| 290 | pthread_attr_init( &attributes ); |
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[eb2e723] | 291 | |
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[8def349] | 292 | pthread_create( &this->kernel_thread, &attributes, CtxInvokeProcessor, (void*)this ); |
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[eb2e723] | 293 | |
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[8def349] | 294 | pthread_attr_destroy( &attributes ); |
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[eb2e723] | 295 | |
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[8def349] | 296 | LIB_DEBUG_PRINTF("Kernel : core %p started\n", this); |
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[eb2e723] | 297 | } |
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| 298 | |
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[8def349] | 299 | //----------------------------------------------------------------------------- |
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| 300 | // Scheduler routines |
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[e15df4c] | 301 | void thread_schedule( thread * thrd ) { |
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[8def349] | 302 | assertf( thrd->next == NULL, "Expected null got %p", thrd->next ); |
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| 303 | |
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| 304 | pthread_spinlock_guard guard = { &systemProcessor->cltr->lock }; |
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| 305 | append( &systemProcessor->cltr->ready_queue, thrd ); |
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[eb2e723] | 306 | } |
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| 307 | |
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[e15df4c] | 308 | thread * nextThread(cluster * this) { |
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[8def349] | 309 | pthread_spinlock_guard guard = { &this->lock }; |
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| 310 | return pop_head( &this->ready_queue ); |
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[eb2e723] | 311 | } |
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| 312 | |
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| 313 | //----------------------------------------------------------------------------- |
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| 314 | // Kernel boot procedures |
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| 315 | void kernel_startup(void) { |
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| 316 | |
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| 317 | // SKULLDUGGERY: the mainThread steals the process main thread |
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| 318 | // which will then be scheduled by the systemProcessor normally |
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| 319 | LIB_DEBUG_PRINTF("Kernel : Starting\n"); |
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| 320 | |
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[8def349] | 321 | current_stack_info_t info; |
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| 322 | |
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| 323 | // LIB_DEBUG_PRINTF("Kernel : core base : %p \n", info.base ); |
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| 324 | // LIB_DEBUG_PRINTF("Kernel : core storage : %p \n", info.storage ); |
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| 325 | // LIB_DEBUG_PRINTF("Kernel : core size : %x \n", info.size ); |
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| 326 | // LIB_DEBUG_PRINTF("Kernel : core limit : %p \n", info.limit ); |
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| 327 | // LIB_DEBUG_PRINTF("Kernel : core context : %p \n", info.context ); |
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| 328 | // LIB_DEBUG_PRINTF("Kernel : core top : %p \n", info.top ); |
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[eb2e723] | 329 | |
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| 330 | // Start by initializing the main thread |
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[e15df4c] | 331 | mainThread = (thread *)&mainThread_storage; |
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[8def349] | 332 | mainThread{ &info }; |
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[eb2e723] | 333 | |
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[bd98b58] | 334 | // Initialize the system cluster |
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| 335 | systemCluster = (cluster *)&systemCluster_storage; |
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| 336 | systemCluster{}; |
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| 337 | |
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[8def349] | 338 | // Initialize the system processor and the system processor ctx |
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[eb2e723] | 339 | // (the coroutine that contains the processing control flow) |
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[8def349] | 340 | systemProcessor = (processor *)&systemProcessor_storage; |
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| 341 | systemProcessor{ systemCluster, (processorCtx_t *)&systemProcessorCtx_storage }; |
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[eb2e723] | 342 | |
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[dcb42b8] | 343 | // Add the main thread to the ready queue |
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| 344 | // once resume is called on systemProcessor->ctx the mainThread needs to be scheduled like any normal thread |
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[bd98b58] | 345 | thread_schedule(mainThread); |
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[eb2e723] | 346 | |
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[dcb42b8] | 347 | //initialize the global state variables |
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[bd98b58] | 348 | this_processor = systemProcessor; |
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| 349 | this_processor->current_thread = mainThread; |
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| 350 | this_processor->current_coroutine = &mainThread->c; |
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[eb2e723] | 351 | |
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[dcb42b8] | 352 | // SKULLDUGGERY: Force a context switch to the system processor to set the main thread's context to the current UNIX |
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| 353 | // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that |
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| 354 | // mainThread is on the ready queue when this call is made. |
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[eb2e723] | 355 | resume(systemProcessor->ctx); |
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| 356 | |
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[dcb42b8] | 357 | |
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| 358 | |
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| 359 | // THE SYSTEM IS NOW COMPLETELY RUNNING |
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| 360 | |
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| 361 | |
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| 362 | |
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[eb2e723] | 363 | LIB_DEBUG_PRINTF("Kernel : Started\n--------------------------------------------------\n\n"); |
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| 364 | } |
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| 365 | |
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[dcb42b8] | 366 | void kernel_shutdown(void) { |
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| 367 | LIB_DEBUG_PRINTF("\n--------------------------------------------------\nKernel : Shutting down\n"); |
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[eb2e723] | 368 | |
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[dcb42b8] | 369 | // SKULLDUGGERY: Notify the systemProcessor it needs to terminates. |
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| 370 | // When its coroutine terminates, it return control to the mainThread |
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| 371 | // which is currently here |
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[8f49a54] | 372 | systemProcessor->terminated = true; |
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[eb2e723] | 373 | suspend(); |
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| 374 | |
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[dcb42b8] | 375 | // THE SYSTEM IS NOW COMPLETELY STOPPED |
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[eb2e723] | 376 | |
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[dcb42b8] | 377 | // Destroy the system processor and its context in reverse order of construction |
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| 378 | // These were manually constructed so we need manually destroy them |
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[eb2e723] | 379 | ^(systemProcessor->ctx){}; |
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| 380 | ^(systemProcessor){}; |
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| 381 | |
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[dcb42b8] | 382 | // Final step, destroy the main thread since it is no longer needed |
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| 383 | // Since we provided a stack to this taxk it will not destroy anything |
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[eb2e723] | 384 | ^(mainThread){}; |
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| 385 | |
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| 386 | LIB_DEBUG_PRINTF("Kernel : Shutdown complete\n"); |
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[8118303] | 387 | } |
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| 388 | |
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[bd98b58] | 389 | //----------------------------------------------------------------------------- |
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| 390 | // Locks |
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| 391 | void ?{}( simple_lock * this ) { |
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| 392 | ( &this->blocked ){}; |
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| 393 | } |
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| 394 | |
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| 395 | void ^?{}( simple_lock * this ) { |
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| 396 | |
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| 397 | } |
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| 398 | |
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| 399 | void lock( simple_lock * this ) { |
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[8def349] | 400 | { |
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| 401 | pthread_spinlock_guard guard = { &systemCluster->lock }; //HUGE TEMP HACK which only works if we have a single cluster and is stupid |
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| 402 | append( &this->blocked, this_thread() ); |
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| 403 | } |
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[bd98b58] | 404 | suspend(); |
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| 405 | } |
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| 406 | |
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| 407 | void unlock( simple_lock * this ) { |
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[e15df4c] | 408 | thread * it; |
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[bd98b58] | 409 | while( it = pop_head( &this->blocked) ) { |
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| 410 | thread_schedule( it ); |
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| 411 | } |
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| 412 | } |
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| 413 | |
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| 414 | //----------------------------------------------------------------------------- |
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| 415 | // Queues |
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| 416 | void ?{}( simple_thread_list * this ) { |
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| 417 | this->head = NULL; |
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| 418 | this->tail = &this->head; |
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| 419 | } |
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| 420 | |
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[e15df4c] | 421 | void append( simple_thread_list * this, thread * t ) { |
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[bd98b58] | 422 | assert( t->next == NULL ); |
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| 423 | *this->tail = t; |
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| 424 | this->tail = &t->next; |
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| 425 | } |
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| 426 | |
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[e15df4c] | 427 | thread * pop_head( simple_thread_list * this ) { |
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| 428 | thread * head = this->head; |
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[bd98b58] | 429 | if( head ) { |
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| 430 | this->head = head->next; |
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| 431 | if( !head->next ) { |
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| 432 | this->tail = &this->head; |
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| 433 | } |
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| 434 | head->next = NULL; |
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| 435 | } |
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| 436 | |
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| 437 | return head; |
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| 438 | } |
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[8118303] | 439 | // Local Variables: // |
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| 440 | // mode: c // |
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| 441 | // tab-width: 4 // |
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| 442 | // End: // |
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