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