[8118303] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // kernel.c -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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[75f3522] | 10 | // Created On : Tue Jan 17 12:27:26 2017 |
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[6b0b624] | 11 | // Last Modified By : Peter A. Buhr |
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| 12 | // Last Modified On : Fri Jul 21 22:33:18 2017 |
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| 13 | // Update Count : 2 |
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[8118303] | 14 | // |
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| 15 | |
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[2ac095d] | 16 | #include "libhdr.h" |
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[8118303] | 17 | |
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| 18 | //C Includes |
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[c84e80a] | 19 | #include <stddef.h> |
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[eb2e723] | 20 | extern "C" { |
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[9d944b2] | 21 | #include <stdio.h> |
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[8fcbb4c] | 22 | #include <fenv.h> |
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[eb2e723] | 23 | #include <sys/resource.h> |
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[9d944b2] | 24 | #include <signal.h> |
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| 25 | #include <unistd.h> |
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[eb2e723] | 26 | } |
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[8118303] | 27 | |
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| 28 | //CFA Includes |
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[2ac095d] | 29 | #include "kernel_private.h" |
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[c81ebf9] | 30 | #include "preemption.h" |
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[2ac095d] | 31 | #include "startup.h" |
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[8118303] | 32 | |
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| 33 | //Private includes |
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| 34 | #define __CFA_INVOKE_PRIVATE__ |
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| 35 | #include "invoke.h" |
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| 36 | |
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[2ac095d] | 37 | //Start and stop routine for the kernel, declared first to make sure they run first |
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| 38 | void kernel_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) )); |
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| 39 | void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) )); |
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| 40 | |
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[8def349] | 41 | //----------------------------------------------------------------------------- |
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| 42 | // Kernel storage |
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[969b3fe] | 43 | KERNEL_STORAGE(cluster, mainCluster); |
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| 44 | KERNEL_STORAGE(processor, mainProcessor); |
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| 45 | KERNEL_STORAGE(processorCtx_t, mainProcessorCtx); |
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| 46 | KERNEL_STORAGE(thread_desc, mainThread); |
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[f2b12406] | 47 | KERNEL_STORAGE(machine_context_t, mainThreadCtx); |
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[8def349] | 48 | |
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[969b3fe] | 49 | cluster * mainCluster; |
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| 50 | processor * mainProcessor; |
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[348006f] | 51 | thread_desc * mainThread; |
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[eb2e723] | 52 | |
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[bd98b58] | 53 | //----------------------------------------------------------------------------- |
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| 54 | // Global state |
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| 55 | |
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[9cc0472] | 56 | thread_local coroutine_desc * volatile this_coroutine; |
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| 57 | thread_local thread_desc * volatile this_thread; |
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| 58 | thread_local processor * volatile this_processor; |
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[969b3fe] | 59 | |
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[d6ff3ff] | 60 | volatile thread_local bool preemption_in_progress = 0; |
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[1c273d0] | 61 | volatile thread_local unsigned short disable_preempt_count = 1; |
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[c84e80a] | 62 | |
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| 63 | //----------------------------------------------------------------------------- |
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[8def349] | 64 | // Main thread construction |
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| 65 | struct current_stack_info_t { |
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[1c273d0] | 66 | machine_context_t ctx; |
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[8def349] | 67 | unsigned int size; // size of stack |
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| 68 | void *base; // base of stack |
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| 69 | void *storage; // pointer to stack |
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| 70 | void *limit; // stack grows towards stack limit |
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| 71 | void *context; // address of cfa_context_t |
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| 72 | void *top; // address of top of storage |
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[c84e80a] | 73 | }; |
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| 74 | |
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[242a902] | 75 | void ?{}( current_stack_info_t & this ) { |
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| 76 | CtxGet( this.ctx ); |
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| 77 | this.base = this.ctx.FP; |
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| 78 | this.storage = this.ctx.SP; |
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[8def349] | 79 | |
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| 80 | rlimit r; |
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[132fad4] | 81 | getrlimit( RLIMIT_STACK, &r); |
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[242a902] | 82 | this.size = r.rlim_cur; |
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[8def349] | 83 | |
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[242a902] | 84 | this.limit = (void *)(((intptr_t)this.base) - this.size); |
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[9236060] | 85 | this.context = &storage_mainThreadCtx; |
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[242a902] | 86 | this.top = this.base; |
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[8def349] | 87 | } |
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| 88 | |
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[242a902] | 89 | void ?{}( coStack_t & this, current_stack_info_t * info) { |
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| 90 | this.size = info->size; |
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| 91 | this.storage = info->storage; |
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| 92 | this.limit = info->limit; |
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| 93 | this.base = info->base; |
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| 94 | this.context = info->context; |
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| 95 | this.top = info->top; |
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| 96 | this.userStack = true; |
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[8def349] | 97 | } |
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| 98 | |
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[242a902] | 99 | void ?{}( coroutine_desc & this, current_stack_info_t * info) { |
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| 100 | (this.stack){ info }; |
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| 101 | this.name = "Main Thread"; |
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| 102 | this.errno_ = 0; |
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| 103 | this.state = Start; |
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[39fea2f] | 104 | this.starter = NULL; |
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[8def349] | 105 | } |
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| 106 | |
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[242a902] | 107 | void ?{}( thread_desc & this, current_stack_info_t * info) { |
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[b18830e] | 108 | (this.self_cor){ info }; |
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[8def349] | 109 | } |
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[c84e80a] | 110 | |
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[8def349] | 111 | //----------------------------------------------------------------------------- |
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| 112 | // Processor coroutine |
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[39fea2f] | 113 | |
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| 114 | // Construct the processor context of the main processor |
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[242a902] | 115 | void ?{}(processorCtx_t & this, processor * proc) { |
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| 116 | (this.__cor){ "Processor" }; |
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[b462670] | 117 | this.__cor.starter = NULL; |
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[242a902] | 118 | this.proc = proc; |
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| 119 | proc->runner = &this; |
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[8def349] | 120 | } |
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| 121 | |
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[39fea2f] | 122 | // Construct the processor context of non-main processors |
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[242a902] | 123 | void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) { |
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| 124 | (this.__cor){ info }; |
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| 125 | this.proc = proc; |
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| 126 | proc->runner = &this; |
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[8def349] | 127 | } |
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| 128 | |
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[242a902] | 129 | void ?{}(processor & this) { |
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[969b3fe] | 130 | this{ mainCluster }; |
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[8def349] | 131 | } |
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| 132 | |
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[242a902] | 133 | void ?{}(processor & this, cluster * cltr) { |
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| 134 | this.cltr = cltr; |
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| 135 | (this.terminated){ 0 }; |
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[9236060] | 136 | this.do_terminate = false; |
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[242a902] | 137 | this.preemption_alarm = NULL; |
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| 138 | this.pending_preemption = false; |
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[8def349] | 139 | |
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[242a902] | 140 | start( &this ); |
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[c84e80a] | 141 | } |
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| 142 | |
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[83a071f9] | 143 | void ?{}(processor & this, cluster * cltr, processorCtx_t & runner) { |
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[242a902] | 144 | this.cltr = cltr; |
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| 145 | (this.terminated){ 0 }; |
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[9236060] | 146 | this.do_terminate = false; |
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[242a902] | 147 | this.preemption_alarm = NULL; |
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| 148 | this.pending_preemption = false; |
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| 149 | this.kernel_thread = pthread_self(); |
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[8def349] | 150 | |
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[83a071f9] | 151 | this.runner = &runner; |
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[9236060] | 152 | LIB_DEBUG_PRINT_SAFE("Kernel : constructing main processor context %p\n", &runner); |
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[83a071f9] | 153 | runner{ &this }; |
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[8def349] | 154 | } |
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| 155 | |
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[242a902] | 156 | void ^?{}(processor & this) { |
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[9236060] | 157 | if( ! this.do_terminate ) { |
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[242a902] | 158 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p signaling termination\n", &this); |
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[9236060] | 159 | this.do_terminate = true; |
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[53a8e68] | 160 | P( &this.terminated ); |
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[242a902] | 161 | pthread_join( this.kernel_thread, NULL ); |
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[8def349] | 162 | } |
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| 163 | } |
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| 164 | |
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[242a902] | 165 | void ?{}(cluster & this) { |
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| 166 | ( this.ready_queue ){}; |
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[9236060] | 167 | ( this.ready_queue_lock ){}; |
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[e60e0dc] | 168 | |
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[9236060] | 169 | this.preemption = default_preemption(); |
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[8def349] | 170 | } |
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| 171 | |
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[242a902] | 172 | void ^?{}(cluster & this) { |
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[1c273d0] | 173 | |
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[c84e80a] | 174 | } |
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| 175 | |
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[75f3522] | 176 | //============================================================================================= |
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| 177 | // Kernel Scheduling logic |
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| 178 | //============================================================================================= |
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[8fcbb4c] | 179 | //Main of the processor contexts |
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[83a071f9] | 180 | void main(processorCtx_t & runner) { |
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| 181 | processor * this = runner.proc; |
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[c81ebf9] | 182 | |
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[9d944b2] | 183 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p starting\n", this); |
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[8118303] | 184 | |
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[75f3522] | 185 | { |
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[c81ebf9] | 186 | // Setup preemption data |
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| 187 | preemption_scope scope = { this }; |
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| 188 | |
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| 189 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p started\n", this); |
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[8118303] | 190 | |
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[c81ebf9] | 191 | thread_desc * readyThread = NULL; |
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[e60e0dc] | 192 | for( unsigned int spin_count = 0; ! this->do_terminate; spin_count++ ) |
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[75f3522] | 193 | { |
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[c81ebf9] | 194 | readyThread = nextThread( this->cltr ); |
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[75f3522] | 195 | |
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[c81ebf9] | 196 | if(readyThread) |
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| 197 | { |
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[0b33412] | 198 | verify( disable_preempt_count > 0 ); |
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[4e6fb8e] | 199 | |
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[c81ebf9] | 200 | runThread(this, readyThread); |
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[75f3522] | 201 | |
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[0b33412] | 202 | verify( disable_preempt_count > 0 ); |
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[4e6fb8e] | 203 | |
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[c81ebf9] | 204 | //Some actions need to be taken from the kernel |
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| 205 | finishRunning(this); |
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| 206 | |
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| 207 | spin_count = 0; |
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| 208 | } |
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| 209 | else |
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| 210 | { |
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| 211 | spin(this, &spin_count); |
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| 212 | } |
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| 213 | } |
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| 214 | |
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| 215 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p stopping\n", this); |
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[c84e80a] | 216 | } |
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[8118303] | 217 | |
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[bdeba0b] | 218 | V( &this->terminated ); |
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| 219 | |
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[9d944b2] | 220 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p terminated\n", this); |
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[c84e80a] | 221 | } |
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| 222 | |
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[1c273d0] | 223 | // runThread runs a thread by context switching |
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| 224 | // from the processor coroutine to the target thread |
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[348006f] | 225 | void runThread(processor * this, thread_desc * dst) { |
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[83a071f9] | 226 | coroutine_desc * proc_cor = get_coroutine(*this->runner); |
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[c3acb841] | 227 | coroutine_desc * thrd_cor = get_coroutine(dst); |
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[1c273d0] | 228 | |
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[75f3522] | 229 | //Reset the terminating actions here |
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[db6f06a] | 230 | this->finish.action_code = No_Action; |
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[8fcbb4c] | 231 | |
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[75f3522] | 232 | //Update global state |
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[1c273d0] | 233 | this_thread = dst; |
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[75f3522] | 234 | |
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| 235 | // Context Switch to the thread |
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| 236 | ThreadCtxSwitch(proc_cor, thrd_cor); |
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| 237 | // when ThreadCtxSwitch returns we are back in the processor coroutine |
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| 238 | } |
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| 239 | |
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[1c273d0] | 240 | // Once a thread has finished running, some of |
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[75f3522] | 241 | // its final actions must be executed from the kernel |
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[db6f06a] | 242 | void finishRunning(processor * this) { |
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| 243 | if( this->finish.action_code == Release ) { |
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| 244 | unlock( this->finish.lock ); |
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| 245 | } |
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| 246 | else if( this->finish.action_code == Schedule ) { |
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| 247 | ScheduleThread( this->finish.thrd ); |
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| 248 | } |
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| 249 | else if( this->finish.action_code == Release_Schedule ) { |
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[1c273d0] | 250 | unlock( this->finish.lock ); |
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[db6f06a] | 251 | ScheduleThread( this->finish.thrd ); |
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| 252 | } |
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[0c78741] | 253 | else if( this->finish.action_code == Release_Multi ) { |
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| 254 | for(int i = 0; i < this->finish.lock_count; i++) { |
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| 255 | unlock( this->finish.locks[i] ); |
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| 256 | } |
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| 257 | } |
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| 258 | else if( this->finish.action_code == Release_Multi_Schedule ) { |
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| 259 | for(int i = 0; i < this->finish.lock_count; i++) { |
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| 260 | unlock( this->finish.locks[i] ); |
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| 261 | } |
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| 262 | for(int i = 0; i < this->finish.thrd_count; i++) { |
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| 263 | ScheduleThread( this->finish.thrds[i] ); |
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| 264 | } |
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| 265 | } |
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[db6f06a] | 266 | else { |
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| 267 | assert(this->finish.action_code == No_Action); |
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[8fcbb4c] | 268 | } |
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[c84e80a] | 269 | } |
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| 270 | |
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[0c92c9f] | 271 | // Handles spinning logic |
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| 272 | // TODO : find some strategy to put cores to sleep after some time |
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[c84e80a] | 273 | void spin(processor * this, unsigned int * spin_count) { |
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| 274 | (*spin_count)++; |
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| 275 | } |
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| 276 | |
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[0c92c9f] | 277 | // Context invoker for processors |
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| 278 | // This is the entry point for processors (kernel threads) |
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| 279 | // It effectively constructs a coroutine by stealing the pthread stack |
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[8def349] | 280 | void * CtxInvokeProcessor(void * arg) { |
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| 281 | processor * proc = (processor *) arg; |
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| 282 | this_processor = proc; |
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[1c273d0] | 283 | this_coroutine = NULL; |
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| 284 | this_thread = NULL; |
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[4e6fb8e] | 285 | disable_preempt_count = 1; |
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[8def349] | 286 | // SKULLDUGGERY: We want to create a context for the processor coroutine |
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| 287 | // which is needed for the 2-step context switch. However, there is no reason |
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[1c273d0] | 288 | // to waste the perfectly valid stack create by pthread. |
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[8def349] | 289 | current_stack_info_t info; |
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| 290 | machine_context_t ctx; |
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| 291 | info.context = &ctx; |
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| 292 | processorCtx_t proc_cor_storage = { proc, &info }; |
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| 293 | |
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[9d944b2] | 294 | LIB_DEBUG_PRINT_SAFE("Coroutine : created stack %p\n", proc_cor_storage.__cor.stack.base); |
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[8fcbb4c] | 295 | |
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[0c92c9f] | 296 | //Set global state |
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[1c273d0] | 297 | this_coroutine = &proc->runner->__cor; |
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| 298 | this_thread = NULL; |
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[8def349] | 299 | |
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| 300 | //We now have a proper context from which to schedule threads |
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[9d944b2] | 301 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p created (%p, %p)\n", proc, proc->runner, &ctx); |
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[8def349] | 302 | |
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[1c273d0] | 303 | // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't |
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| 304 | // resume it to start it like it normally would, it will just context switch |
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| 305 | // back to here. Instead directly call the main since we already are on the |
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[8def349] | 306 | // appropriate stack. |
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[17af7d1] | 307 | proc_cor_storage.__cor.state = Active; |
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[83a071f9] | 308 | main( proc_cor_storage ); |
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[4aa2fb2] | 309 | proc_cor_storage.__cor.state = Halted; |
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[8def349] | 310 | |
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[0c92c9f] | 311 | // Main routine of the core returned, the core is now fully terminated |
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[1c273d0] | 312 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p main ended (%p)\n", proc, proc->runner); |
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[8def349] | 313 | |
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| 314 | return NULL; |
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[c84e80a] | 315 | } |
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| 316 | |
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[8def349] | 317 | void start(processor * this) { |
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[9d944b2] | 318 | LIB_DEBUG_PRINT_SAFE("Kernel : Starting core %p\n", this); |
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[82ff5845] | 319 | |
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[8fcbb4c] | 320 | pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this ); |
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[eb2e723] | 321 | |
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[1c273d0] | 322 | LIB_DEBUG_PRINT_SAFE("Kernel : core %p started\n", this); |
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[eb2e723] | 323 | } |
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| 324 | |
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[8def349] | 325 | //----------------------------------------------------------------------------- |
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| 326 | // Scheduler routines |
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[348006f] | 327 | void ScheduleThread( thread_desc * thrd ) { |
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[1c273d0] | 328 | // if( !thrd ) return; |
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[135b431] | 329 | verify( thrd ); |
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[b18830e] | 330 | verify( thrd->self_cor.state != Halted ); |
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[1c273d0] | 331 | |
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| 332 | verify( disable_preempt_count > 0 ); |
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[690f13c] | 333 | |
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[4aa2fb2] | 334 | verifyf( thrd->next == NULL, "Expected null got %p", thrd->next ); |
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[1c273d0] | 335 | |
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[969b3fe] | 336 | lock( &this_processor->cltr->ready_queue_lock DEBUG_CTX2 ); |
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| 337 | append( &this_processor->cltr->ready_queue, thrd ); |
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| 338 | unlock( &this_processor->cltr->ready_queue_lock ); |
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[1c273d0] | 339 | |
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| 340 | verify( disable_preempt_count > 0 ); |
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[db6f06a] | 341 | } |
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| 342 | |
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[348006f] | 343 | thread_desc * nextThread(cluster * this) { |
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[1c273d0] | 344 | verify( disable_preempt_count > 0 ); |
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[e60e0dc] | 345 | lock( &this->ready_queue_lock DEBUG_CTX2 ); |
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[348006f] | 346 | thread_desc * head = pop_head( &this->ready_queue ); |
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[e60e0dc] | 347 | unlock( &this->ready_queue_lock ); |
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[1c273d0] | 348 | verify( disable_preempt_count > 0 ); |
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[db6f06a] | 349 | return head; |
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[eb2e723] | 350 | } |
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| 351 | |
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[82ff5845] | 352 | void BlockInternal() { |
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| 353 | disable_interrupts(); |
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[0b33412] | 354 | verify( disable_preempt_count > 0 ); |
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[75f3522] | 355 | suspend(); |
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[0b33412] | 356 | verify( disable_preempt_count > 0 ); |
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[2ac095d] | 357 | enable_interrupts( DEBUG_CTX ); |
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[75f3522] | 358 | } |
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| 359 | |
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[82ff5845] | 360 | void BlockInternal( spinlock * lock ) { |
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| 361 | disable_interrupts(); |
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[89a3df5] | 362 | this_processor->finish.action_code = Release; |
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| 363 | this_processor->finish.lock = lock; |
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[0b33412] | 364 | |
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| 365 | verify( disable_preempt_count > 0 ); |
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[db6f06a] | 366 | suspend(); |
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[0b33412] | 367 | verify( disable_preempt_count > 0 ); |
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| 368 | |
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[2ac095d] | 369 | enable_interrupts( DEBUG_CTX ); |
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[db6f06a] | 370 | } |
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| 371 | |
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[82ff5845] | 372 | void BlockInternal( thread_desc * thrd ) { |
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[97e3296] | 373 | assert(thrd); |
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[82ff5845] | 374 | disable_interrupts(); |
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[b18830e] | 375 | assert( thrd->self_cor.state != Halted ); |
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[89a3df5] | 376 | this_processor->finish.action_code = Schedule; |
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| 377 | this_processor->finish.thrd = thrd; |
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[0b33412] | 378 | |
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| 379 | verify( disable_preempt_count > 0 ); |
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[db6f06a] | 380 | suspend(); |
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[0b33412] | 381 | verify( disable_preempt_count > 0 ); |
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| 382 | |
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[2ac095d] | 383 | enable_interrupts( DEBUG_CTX ); |
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[db6f06a] | 384 | } |
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| 385 | |
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[82ff5845] | 386 | void BlockInternal( spinlock * lock, thread_desc * thrd ) { |
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[97e3296] | 387 | assert(thrd); |
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[82ff5845] | 388 | disable_interrupts(); |
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[89a3df5] | 389 | this_processor->finish.action_code = Release_Schedule; |
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| 390 | this_processor->finish.lock = lock; |
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| 391 | this_processor->finish.thrd = thrd; |
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[0b33412] | 392 | |
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| 393 | verify( disable_preempt_count > 0 ); |
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[db6f06a] | 394 | suspend(); |
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[0b33412] | 395 | verify( disable_preempt_count > 0 ); |
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| 396 | |
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[2ac095d] | 397 | enable_interrupts( DEBUG_CTX ); |
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[eb2e723] | 398 | } |
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| 399 | |
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[82ff5845] | 400 | void BlockInternal(spinlock ** locks, unsigned short count) { |
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| 401 | disable_interrupts(); |
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[0c78741] | 402 | this_processor->finish.action_code = Release_Multi; |
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| 403 | this_processor->finish.locks = locks; |
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| 404 | this_processor->finish.lock_count = count; |
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[0b33412] | 405 | |
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| 406 | verify( disable_preempt_count > 0 ); |
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[0c78741] | 407 | suspend(); |
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[0b33412] | 408 | verify( disable_preempt_count > 0 ); |
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| 409 | |
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[2ac095d] | 410 | enable_interrupts( DEBUG_CTX ); |
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[0c78741] | 411 | } |
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| 412 | |
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[82ff5845] | 413 | void BlockInternal(spinlock ** locks, unsigned short lock_count, thread_desc ** thrds, unsigned short thrd_count) { |
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| 414 | disable_interrupts(); |
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[0c78741] | 415 | this_processor->finish.action_code = Release_Multi_Schedule; |
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| 416 | this_processor->finish.locks = locks; |
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| 417 | this_processor->finish.lock_count = lock_count; |
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| 418 | this_processor->finish.thrds = thrds; |
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| 419 | this_processor->finish.thrd_count = thrd_count; |
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[0b33412] | 420 | |
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| 421 | verify( disable_preempt_count > 0 ); |
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[0c78741] | 422 | suspend(); |
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[0b33412] | 423 | verify( disable_preempt_count > 0 ); |
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| 424 | |
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[2ac095d] | 425 | enable_interrupts( DEBUG_CTX ); |
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[0c78741] | 426 | } |
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| 427 | |
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[f2b12406] | 428 | void LeaveThread(spinlock * lock, thread_desc * thrd) { |
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| 429 | verify( disable_preempt_count > 0 ); |
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| 430 | this_processor->finish.action_code = thrd ? Release_Schedule : Release; |
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| 431 | this_processor->finish.lock = lock; |
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| 432 | this_processor->finish.thrd = thrd; |
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| 433 | |
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| 434 | suspend(); |
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| 435 | } |
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| 436 | |
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[fa21ac9] | 437 | //============================================================================================= |
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| 438 | // Kernel Setup logic |
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| 439 | //============================================================================================= |
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[eb2e723] | 440 | //----------------------------------------------------------------------------- |
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| 441 | // Kernel boot procedures |
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| 442 | void kernel_startup(void) { |
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[1c273d0] | 443 | LIB_DEBUG_PRINT_SAFE("Kernel : Starting\n"); |
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[eb2e723] | 444 | |
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| 445 | // Start by initializing the main thread |
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[1c273d0] | 446 | // SKULLDUGGERY: the mainThread steals the process main thread |
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[969b3fe] | 447 | // which will then be scheduled by the mainProcessor normally |
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| 448 | mainThread = (thread_desc *)&storage_mainThread; |
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[8fcbb4c] | 449 | current_stack_info_t info; |
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[83a071f9] | 450 | (*mainThread){ &info }; |
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[eb2e723] | 451 | |
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[fa21ac9] | 452 | LIB_DEBUG_PRINT_SAFE("Kernel : Main thread ready\n"); |
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| 453 | |
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[969b3fe] | 454 | // Initialize the main cluster |
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| 455 | mainCluster = (cluster *)&storage_mainCluster; |
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[9236060] | 456 | (*mainCluster){}; |
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[bd98b58] | 457 | |
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[969b3fe] | 458 | LIB_DEBUG_PRINT_SAFE("Kernel : main cluster ready\n"); |
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[fa21ac9] | 459 | |
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[969b3fe] | 460 | // Initialize the main processor and the main processor ctx |
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[eb2e723] | 461 | // (the coroutine that contains the processing control flow) |
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[969b3fe] | 462 | mainProcessor = (processor *)&storage_mainProcessor; |
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[9236060] | 463 | (*mainProcessor){ mainCluster, *(processorCtx_t *)&storage_mainProcessorCtx }; |
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[eb2e723] | 464 | |
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[dcb42b8] | 465 | //initialize the global state variables |
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[969b3fe] | 466 | this_processor = mainProcessor; |
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[1c273d0] | 467 | this_thread = mainThread; |
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[b18830e] | 468 | this_coroutine = &mainThread->self_cor; |
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[eb2e723] | 469 | |
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[82ff5845] | 470 | // Enable preemption |
---|
| 471 | kernel_start_preemption(); |
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| 472 | |
---|
[969b3fe] | 473 | // Add the main thread to the ready queue |
---|
| 474 | // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread |
---|
| 475 | ScheduleThread(mainThread); |
---|
| 476 | |
---|
| 477 | // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX |
---|
[dcb42b8] | 478 | // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that |
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[1c273d0] | 479 | // mainThread is on the ready queue when this call is made. |
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[9236060] | 480 | resume( *mainProcessor->runner ); |
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[eb2e723] | 481 | |
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[dcb42b8] | 482 | |
---|
| 483 | |
---|
| 484 | // THE SYSTEM IS NOW COMPLETELY RUNNING |
---|
[9d944b2] | 485 | LIB_DEBUG_PRINT_SAFE("Kernel : Started\n--------------------------------------------------\n\n"); |
---|
[82ff5845] | 486 | |
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[2ac095d] | 487 | enable_interrupts( DEBUG_CTX ); |
---|
[eb2e723] | 488 | } |
---|
| 489 | |
---|
[dcb42b8] | 490 | void kernel_shutdown(void) { |
---|
[9d944b2] | 491 | LIB_DEBUG_PRINT_SAFE("\n--------------------------------------------------\nKernel : Shutting down\n"); |
---|
[eb2e723] | 492 | |
---|
[4e6fb8e] | 493 | disable_interrupts(); |
---|
| 494 | |
---|
[969b3fe] | 495 | // SKULLDUGGERY: Notify the mainProcessor it needs to terminates. |
---|
[dcb42b8] | 496 | // When its coroutine terminates, it return control to the mainThread |
---|
| 497 | // which is currently here |
---|
[969b3fe] | 498 | mainProcessor->do_terminate = true; |
---|
[eb2e723] | 499 | suspend(); |
---|
| 500 | |
---|
[dcb42b8] | 501 | // THE SYSTEM IS NOW COMPLETELY STOPPED |
---|
[eb2e723] | 502 | |
---|
[82ff5845] | 503 | // Disable preemption |
---|
| 504 | kernel_stop_preemption(); |
---|
| 505 | |
---|
[969b3fe] | 506 | // Destroy the main processor and its context in reverse order of construction |
---|
[dcb42b8] | 507 | // These were manually constructed so we need manually destroy them |
---|
[9236060] | 508 | ^(*mainProcessor->runner){}; |
---|
[969b3fe] | 509 | ^(mainProcessor){}; |
---|
[eb2e723] | 510 | |
---|
[dcb42b8] | 511 | // Final step, destroy the main thread since it is no longer needed |
---|
| 512 | // Since we provided a stack to this taxk it will not destroy anything |
---|
[eb2e723] | 513 | ^(mainThread){}; |
---|
| 514 | |
---|
[1c273d0] | 515 | LIB_DEBUG_PRINT_SAFE("Kernel : Shutdown complete\n"); |
---|
[9d944b2] | 516 | } |
---|
| 517 | |
---|
| 518 | static spinlock kernel_abort_lock; |
---|
| 519 | static spinlock kernel_debug_lock; |
---|
| 520 | static bool kernel_abort_called = false; |
---|
| 521 | |
---|
| 522 | void * kernel_abort (void) __attribute__ ((__nothrow__)) { |
---|
| 523 | // abort cannot be recursively entered by the same or different processors because all signal handlers return when |
---|
| 524 | // the globalAbort flag is true. |
---|
[2ac095d] | 525 | lock( &kernel_abort_lock DEBUG_CTX2 ); |
---|
[9d944b2] | 526 | |
---|
| 527 | // first task to abort ? |
---|
| 528 | if ( !kernel_abort_called ) { // not first task to abort ? |
---|
| 529 | kernel_abort_called = true; |
---|
| 530 | unlock( &kernel_abort_lock ); |
---|
[1c273d0] | 531 | } |
---|
[9d944b2] | 532 | else { |
---|
| 533 | unlock( &kernel_abort_lock ); |
---|
[1c273d0] | 534 | |
---|
[9d944b2] | 535 | sigset_t mask; |
---|
| 536 | sigemptyset( &mask ); |
---|
| 537 | sigaddset( &mask, SIGALRM ); // block SIGALRM signals |
---|
| 538 | sigaddset( &mask, SIGUSR1 ); // block SIGUSR1 signals |
---|
| 539 | sigsuspend( &mask ); // block the processor to prevent further damage during abort |
---|
[1c273d0] | 540 | _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it |
---|
[9d944b2] | 541 | } |
---|
| 542 | |
---|
[1c273d0] | 543 | return this_thread; |
---|
[9d944b2] | 544 | } |
---|
| 545 | |
---|
| 546 | void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) { |
---|
| 547 | thread_desc * thrd = kernel_data; |
---|
| 548 | |
---|
[b18830e] | 549 | int len = snprintf( abort_text, abort_text_size, "Error occurred while executing task %.256s (%p)", thrd->self_cor.name, thrd ); |
---|
[9d944b2] | 550 | __lib_debug_write( STDERR_FILENO, abort_text, len ); |
---|
| 551 | |
---|
[1c273d0] | 552 | if ( thrd != this_coroutine ) { |
---|
| 553 | len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", this_coroutine->name, this_coroutine ); |
---|
[9d944b2] | 554 | __lib_debug_write( STDERR_FILENO, abort_text, len ); |
---|
[1c273d0] | 555 | } |
---|
[9d944b2] | 556 | else { |
---|
| 557 | __lib_debug_write( STDERR_FILENO, ".\n", 2 ); |
---|
| 558 | } |
---|
| 559 | } |
---|
| 560 | |
---|
| 561 | extern "C" { |
---|
| 562 | void __lib_debug_acquire() { |
---|
[2ac095d] | 563 | lock( &kernel_debug_lock DEBUG_CTX2 ); |
---|
[9d944b2] | 564 | } |
---|
| 565 | |
---|
| 566 | void __lib_debug_release() { |
---|
[2ac095d] | 567 | unlock( &kernel_debug_lock ); |
---|
[9d944b2] | 568 | } |
---|
[8118303] | 569 | } |
---|
| 570 | |
---|
[fa21ac9] | 571 | //============================================================================================= |
---|
| 572 | // Kernel Utilities |
---|
| 573 | //============================================================================================= |
---|
[bd98b58] | 574 | //----------------------------------------------------------------------------- |
---|
| 575 | // Locks |
---|
[242a902] | 576 | void ?{}( spinlock & this ) { |
---|
| 577 | this.lock = 0; |
---|
[bd98b58] | 578 | } |
---|
[242a902] | 579 | void ^?{}( spinlock & this ) { |
---|
[bd98b58] | 580 | |
---|
[db6f06a] | 581 | } |
---|
| 582 | |
---|
[2ac095d] | 583 | bool try_lock( spinlock * this DEBUG_CTX_PARAM2 ) { |
---|
[b227f68] | 584 | return this->lock == 0 && __sync_lock_test_and_set_4( &this->lock, 1 ) == 0; |
---|
[c81ebf9] | 585 | } |
---|
| 586 | |
---|
[2ac095d] | 587 | void lock( spinlock * this DEBUG_CTX_PARAM2 ) { |
---|
[db6f06a] | 588 | for ( unsigned int i = 1;; i += 1 ) { |
---|
[b227f68] | 589 | if ( this->lock == 0 && __sync_lock_test_and_set_4( &this->lock, 1 ) == 0 ) { break; } |
---|
[db6f06a] | 590 | } |
---|
[b227f68] | 591 | LIB_DEBUG_DO( |
---|
| 592 | this->prev_name = caller; |
---|
| 593 | this->prev_thrd = this_thread; |
---|
| 594 | ) |
---|
[db6f06a] | 595 | } |
---|
[bd98b58] | 596 | |
---|
[b227f68] | 597 | void lock_yield( spinlock * this DEBUG_CTX_PARAM2 ) { |
---|
| 598 | for ( unsigned int i = 1;; i += 1 ) { |
---|
| 599 | if ( this->lock == 0 && __sync_lock_test_and_set_4( &this->lock, 1 ) == 0 ) { break; } |
---|
| 600 | yield(); |
---|
| 601 | } |
---|
| 602 | LIB_DEBUG_DO( |
---|
| 603 | this->prev_name = caller; |
---|
| 604 | this->prev_thrd = this_thread; |
---|
| 605 | ) |
---|
| 606 | } |
---|
| 607 | |
---|
| 608 | |
---|
[db6f06a] | 609 | void unlock( spinlock * this ) { |
---|
| 610 | __sync_lock_release_4( &this->lock ); |
---|
[bd98b58] | 611 | } |
---|
| 612 | |
---|
[242a902] | 613 | void ?{}( semaphore & this, int count = 1 ) { |
---|
| 614 | (this.lock){}; |
---|
| 615 | this.count = count; |
---|
| 616 | (this.waiting){}; |
---|
[db6f06a] | 617 | } |
---|
[242a902] | 618 | void ^?{}(semaphore & this) {} |
---|
[db6f06a] | 619 | |
---|
[bdeba0b] | 620 | void P(semaphore * this) { |
---|
[2ac095d] | 621 | lock( &this->lock DEBUG_CTX2 ); |
---|
[bdeba0b] | 622 | this->count -= 1; |
---|
| 623 | if ( this->count < 0 ) { |
---|
| 624 | // queue current task |
---|
| 625 | append( &this->waiting, (thread_desc *)this_thread ); |
---|
| 626 | |
---|
| 627 | // atomically release spin lock and block |
---|
[82ff5845] | 628 | BlockInternal( &this->lock ); |
---|
[8def349] | 629 | } |
---|
[4e6fb8e] | 630 | else { |
---|
[bdeba0b] | 631 | unlock( &this->lock ); |
---|
[4e6fb8e] | 632 | } |
---|
[bd98b58] | 633 | } |
---|
| 634 | |
---|
[bdeba0b] | 635 | void V(semaphore * this) { |
---|
| 636 | thread_desc * thrd = NULL; |
---|
[2ac095d] | 637 | lock( &this->lock DEBUG_CTX2 ); |
---|
[bdeba0b] | 638 | this->count += 1; |
---|
| 639 | if ( this->count <= 0 ) { |
---|
| 640 | // remove task at head of waiting list |
---|
| 641 | thrd = pop_head( &this->waiting ); |
---|
[bd98b58] | 642 | } |
---|
[bdeba0b] | 643 | |
---|
[db6f06a] | 644 | unlock( &this->lock ); |
---|
[bdeba0b] | 645 | |
---|
| 646 | // make new owner |
---|
| 647 | WakeThread( thrd ); |
---|
[bd98b58] | 648 | } |
---|
| 649 | |
---|
| 650 | //----------------------------------------------------------------------------- |
---|
| 651 | // Queues |
---|
[242a902] | 652 | void ?{}( __thread_queue_t & this ) { |
---|
| 653 | this.head = NULL; |
---|
| 654 | this.tail = &this.head; |
---|
[bd98b58] | 655 | } |
---|
| 656 | |
---|
[5ea06d6] | 657 | void append( __thread_queue_t * this, thread_desc * t ) { |
---|
[4aa2fb2] | 658 | verify(this->tail != NULL); |
---|
[bd98b58] | 659 | *this->tail = t; |
---|
| 660 | this->tail = &t->next; |
---|
| 661 | } |
---|
| 662 | |
---|
[5ea06d6] | 663 | thread_desc * pop_head( __thread_queue_t * this ) { |
---|
[348006f] | 664 | thread_desc * head = this->head; |
---|
[bd98b58] | 665 | if( head ) { |
---|
| 666 | this->head = head->next; |
---|
| 667 | if( !head->next ) { |
---|
| 668 | this->tail = &this->head; |
---|
| 669 | } |
---|
| 670 | head->next = NULL; |
---|
[1c273d0] | 671 | } |
---|
[bd98b58] | 672 | return head; |
---|
| 673 | } |
---|
[690f13c] | 674 | |
---|
[90c4df0] | 675 | thread_desc * remove( __thread_queue_t * this, thread_desc ** it ) { |
---|
| 676 | thread_desc * thrd = *it; |
---|
| 677 | verify( thrd ); |
---|
| 678 | |
---|
| 679 | (*it) = thrd->next; |
---|
| 680 | |
---|
| 681 | if( this->tail == &thrd->next ) { |
---|
| 682 | this->tail = it; |
---|
| 683 | } |
---|
| 684 | |
---|
| 685 | thrd->next = NULL; |
---|
| 686 | |
---|
| 687 | verify( (this->head == NULL) == (&this->head == this->tail) ); |
---|
| 688 | verify( *this->tail == NULL ); |
---|
| 689 | return thrd; |
---|
| 690 | } |
---|
| 691 | |
---|
[242a902] | 692 | void ?{}( __condition_stack_t & this ) { |
---|
| 693 | this.top = NULL; |
---|
[690f13c] | 694 | } |
---|
| 695 | |
---|
[0c78741] | 696 | void push( __condition_stack_t * this, __condition_criterion_t * t ) { |
---|
[4aa2fb2] | 697 | verify( !t->next ); |
---|
[690f13c] | 698 | t->next = this->top; |
---|
| 699 | this->top = t; |
---|
| 700 | } |
---|
| 701 | |
---|
[0c78741] | 702 | __condition_criterion_t * pop( __condition_stack_t * this ) { |
---|
| 703 | __condition_criterion_t * top = this->top; |
---|
[690f13c] | 704 | if( top ) { |
---|
| 705 | this->top = top->next; |
---|
| 706 | top->next = NULL; |
---|
[1c273d0] | 707 | } |
---|
[690f13c] | 708 | return top; |
---|
| 709 | } |
---|
[6b0b624] | 710 | |
---|
[8118303] | 711 | // Local Variables: // |
---|
| 712 | // mode: c // |
---|
| 713 | // tab-width: 4 // |
---|
| 714 | // End: // |
---|