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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10 | // Created On : Tue Jan 17 12:27:26 2017 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Mon Apr 9 16:11:46 2018 |
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13 | // Update Count : 24 |
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14 | // |
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15 | |
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16 | //C Includes |
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17 | #include <stddef.h> |
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18 | #include <errno.h> |
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19 | #include <string.h> |
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20 | extern "C" { |
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21 | #include <stdio.h> |
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22 | #include <fenv.h> |
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23 | #include <sys/resource.h> |
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24 | #include <signal.h> |
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25 | #include <unistd.h> |
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26 | } |
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27 | |
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28 | //CFA Includes |
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29 | #include "time.hfa" |
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30 | #include "kernel_private.hfa" |
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31 | #include "preemption.hfa" |
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32 | #include "startup.hfa" |
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33 | |
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34 | //Private includes |
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35 | #define __CFA_INVOKE_PRIVATE__ |
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36 | #include "invoke.h" |
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37 | |
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38 | //Start and stop routine for the kernel, declared first to make sure they run first |
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39 | static void kernel_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) )); |
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40 | static void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) )); |
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41 | |
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42 | //----------------------------------------------------------------------------- |
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43 | // Kernel storage |
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44 | KERNEL_STORAGE(cluster, mainCluster); |
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45 | KERNEL_STORAGE(processor, mainProcessor); |
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46 | KERNEL_STORAGE(thread_desc, mainThread); |
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47 | KERNEL_STORAGE(__stack_t, mainThreadCtx); |
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48 | |
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49 | cluster * mainCluster; |
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50 | processor * mainProcessor; |
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51 | thread_desc * mainThread; |
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52 | |
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53 | extern "C" { |
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54 | struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters; |
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55 | } |
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56 | |
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57 | size_t __page_size = 0; |
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58 | |
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59 | //----------------------------------------------------------------------------- |
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60 | // Global state |
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61 | thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = { |
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62 | NULL, |
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63 | NULL, |
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64 | { 1, false, false } |
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65 | }; |
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66 | |
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67 | //----------------------------------------------------------------------------- |
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68 | // Struct to steal stack |
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69 | struct current_stack_info_t { |
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70 | __stack_t * storage; // pointer to stack object |
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71 | void *base; // base of 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 | }; |
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75 | |
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76 | void ?{}( current_stack_info_t & this ) { |
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77 | __stack_context_t ctx; |
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78 | CtxGet( ctx ); |
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79 | this.base = ctx.FP; |
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80 | |
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81 | rlimit r; |
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82 | getrlimit( RLIMIT_STACK, &r); |
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83 | size_t size = r.rlim_cur; |
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84 | |
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85 | this.limit = (void *)(((intptr_t)this.base) - size); |
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86 | this.context = &storage_mainThreadCtx; |
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87 | } |
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88 | |
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89 | //----------------------------------------------------------------------------- |
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90 | // Main thread construction |
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91 | |
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92 | void ?{}( coroutine_desc & this, current_stack_info_t * info) with( this ) { |
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93 | context.errno_ = 0; |
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94 | stack.storage = info->storage; |
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95 | with(*stack.storage) { |
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96 | limit = info->limit; |
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97 | base = info->base; |
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98 | } |
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99 | *((intptr_t*)&stack.storage) |= 0x1; |
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100 | name = "Main Thread"; |
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101 | state = Start; |
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102 | starter = NULL; |
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103 | last = NULL; |
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104 | cancellation = NULL; |
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105 | } |
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106 | |
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107 | void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) { |
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108 | self_cor{ info }; |
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109 | curr_cor = &self_cor; |
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110 | curr_cluster = mainCluster; |
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111 | self_mon.owner = &this; |
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112 | self_mon.recursion = 1; |
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113 | self_mon_p = &self_mon; |
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114 | next = NULL; |
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115 | |
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116 | node.next = NULL; |
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117 | node.prev = NULL; |
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118 | doregister(curr_cluster, this); |
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119 | |
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120 | monitors{ &self_mon_p, 1, (fptr_t)0 }; |
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121 | } |
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122 | |
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123 | //----------------------------------------------------------------------------- |
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124 | // Processor coroutine |
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125 | void ?{}(processorCtx_t & this) { |
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126 | |
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127 | } |
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128 | |
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129 | // Construct the processor context of non-main processors |
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130 | static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) { |
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131 | (this.__cor){ info }; |
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132 | this.proc = proc; |
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133 | } |
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134 | |
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135 | static void start(processor * this); |
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136 | void ?{}(processor & this, const char * name, cluster & cltr) with( this ) { |
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137 | this.name = name; |
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138 | this.cltr = &cltr; |
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139 | terminated{ 0 }; |
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140 | do_terminate = false; |
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141 | preemption_alarm = NULL; |
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142 | pending_preemption = false; |
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143 | runner.proc = &this; |
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144 | |
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145 | idleLock{}; |
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146 | |
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147 | start( &this ); |
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148 | } |
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149 | |
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150 | void ^?{}(processor & this) with( this ){ |
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151 | if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) { |
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152 | __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this); |
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153 | |
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154 | __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED); |
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155 | wake( &this ); |
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156 | |
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157 | P( terminated ); |
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158 | verify( kernelTLS.this_processor != &this); |
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159 | } |
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160 | |
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161 | pthread_join( kernel_thread, NULL ); |
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162 | } |
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163 | |
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164 | void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) { |
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165 | this.name = name; |
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166 | this.preemption_rate = preemption_rate; |
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167 | ready_queue{}; |
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168 | ready_queue_lock{}; |
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169 | |
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170 | procs{ __get }; |
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171 | idles{ __get }; |
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172 | threads{ __get }; |
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173 | |
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174 | doregister(this); |
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175 | } |
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176 | |
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177 | void ^?{}(cluster & this) { |
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178 | unregister(this); |
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179 | } |
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180 | |
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181 | //============================================================================================= |
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182 | // Kernel Scheduling logic |
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183 | //============================================================================================= |
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184 | static void runThread(processor * this, thread_desc * dst); |
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185 | static void finishRunning(processor * this); |
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186 | static void halt(processor * this); |
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187 | |
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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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191 | verify(this); |
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192 | |
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193 | __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this); |
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194 | |
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195 | doregister(this->cltr, this); |
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196 | |
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197 | { |
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198 | // Setup preemption data |
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199 | preemption_scope scope = { this }; |
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200 | |
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201 | __cfaabi_dbg_print_safe("Kernel : core %p started\n", this); |
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202 | |
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203 | thread_desc * readyThread = NULL; |
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204 | for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ ) |
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205 | { |
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206 | readyThread = nextThread( this->cltr ); |
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207 | |
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208 | if(readyThread) |
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209 | { |
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210 | verify( ! kernelTLS.preemption_state.enabled ); |
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211 | |
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212 | runThread(this, readyThread); |
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213 | |
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214 | verify( ! kernelTLS.preemption_state.enabled ); |
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215 | |
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216 | //Some actions need to be taken from the kernel |
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217 | finishRunning(this); |
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218 | |
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219 | spin_count = 0; |
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220 | } |
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221 | else |
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222 | { |
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223 | // spin(this, &spin_count); |
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224 | halt(this); |
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225 | } |
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226 | } |
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227 | |
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228 | __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this); |
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229 | } |
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230 | |
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231 | unregister(this->cltr, this); |
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232 | |
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233 | V( this->terminated ); |
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234 | |
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235 | __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this); |
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236 | } |
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237 | |
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238 | // KERNEL ONLY |
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239 | // runThread runs a thread by context switching |
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240 | // from the processor coroutine to the target thread |
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241 | static void runThread(processor * this, thread_desc * dst) { |
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242 | assert(dst->curr_cor); |
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243 | coroutine_desc * proc_cor = get_coroutine(this->runner); |
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244 | coroutine_desc * thrd_cor = dst->curr_cor; |
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245 | |
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246 | // Reset the terminating actions here |
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247 | this->finish.action_code = No_Action; |
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248 | |
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249 | // Update global state |
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250 | kernelTLS.this_thread = dst; |
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251 | |
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252 | // Context Switch to the thread |
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253 | ThreadCtxSwitch(proc_cor, thrd_cor); |
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254 | // when ThreadCtxSwitch returns we are back in the processor coroutine |
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255 | } |
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256 | |
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257 | // KERNEL_ONLY |
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258 | static void returnToKernel() { |
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259 | coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner); |
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260 | coroutine_desc * thrd_cor = kernelTLS.this_thread->curr_cor; |
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261 | ThreadCtxSwitch(thrd_cor, proc_cor); |
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262 | } |
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263 | |
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264 | // KERNEL_ONLY |
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265 | // Once a thread has finished running, some of |
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266 | // its final actions must be executed from the kernel |
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267 | static void finishRunning(processor * this) with( this->finish ) { |
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268 | verify( ! kernelTLS.preemption_state.enabled ); |
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269 | choose( action_code ) { |
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270 | case No_Action: |
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271 | break; |
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272 | case Release: |
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273 | unlock( *lock ); |
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274 | case Schedule: |
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275 | ScheduleThread( thrd ); |
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276 | case Release_Schedule: |
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277 | unlock( *lock ); |
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278 | ScheduleThread( thrd ); |
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279 | case Release_Multi: |
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280 | for(int i = 0; i < lock_count; i++) { |
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281 | unlock( *locks[i] ); |
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282 | } |
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283 | case Release_Multi_Schedule: |
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284 | for(int i = 0; i < lock_count; i++) { |
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285 | unlock( *locks[i] ); |
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286 | } |
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287 | for(int i = 0; i < thrd_count; i++) { |
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288 | ScheduleThread( thrds[i] ); |
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289 | } |
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290 | case Callback: |
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291 | callback(); |
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292 | default: |
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293 | abort("KERNEL ERROR: Unexpected action to run after thread"); |
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294 | } |
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295 | } |
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296 | |
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297 | // KERNEL_ONLY |
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298 | // Context invoker for processors |
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299 | // This is the entry point for processors (kernel threads) |
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300 | // It effectively constructs a coroutine by stealing the pthread stack |
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301 | static void * CtxInvokeProcessor(void * arg) { |
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302 | processor * proc = (processor *) arg; |
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303 | kernelTLS.this_processor = proc; |
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304 | kernelTLS.this_thread = NULL; |
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305 | kernelTLS.preemption_state.[enabled, disable_count] = [false, 1]; |
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306 | // SKULLDUGGERY: We want to create a context for the processor coroutine |
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307 | // which is needed for the 2-step context switch. However, there is no reason |
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308 | // to waste the perfectly valid stack create by pthread. |
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309 | current_stack_info_t info; |
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310 | __stack_t ctx; |
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311 | info.storage = &ctx; |
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312 | (proc->runner){ proc, &info }; |
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313 | |
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314 | __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage); |
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315 | |
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316 | //Set global state |
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317 | kernelTLS.this_thread = NULL; |
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318 | |
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319 | //We now have a proper context from which to schedule threads |
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320 | __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx); |
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321 | |
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322 | // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't |
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323 | // resume it to start it like it normally would, it will just context switch |
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324 | // back to here. Instead directly call the main since we already are on the |
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325 | // appropriate stack. |
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326 | get_coroutine(proc->runner)->state = Active; |
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327 | main( proc->runner ); |
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328 | get_coroutine(proc->runner)->state = Halted; |
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329 | |
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330 | // Main routine of the core returned, the core is now fully terminated |
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331 | __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner); |
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332 | |
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333 | return NULL; |
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334 | } |
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335 | |
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336 | static void start(processor * this) { |
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337 | __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this); |
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338 | |
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339 | pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this ); |
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340 | |
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341 | __cfaabi_dbg_print_safe("Kernel : core %p started\n", this); |
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342 | } |
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343 | |
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344 | // KERNEL_ONLY |
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345 | void kernel_first_resume(processor * this) { |
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346 | coroutine_desc * src = mainThread->curr_cor; |
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347 | coroutine_desc * dst = get_coroutine(this->runner); |
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348 | |
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349 | verify( ! kernelTLS.preemption_state.enabled ); |
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350 | |
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351 | __stack_prepare( &dst->stack, 65000 ); |
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352 | CtxStart(&this->runner, CtxInvokeCoroutine); |
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353 | |
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354 | verify( ! kernelTLS.preemption_state.enabled ); |
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355 | |
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356 | dst->last = src; |
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357 | dst->starter = dst->starter ? dst->starter : src; |
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358 | |
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359 | // set state of current coroutine to inactive |
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360 | src->state = src->state == Halted ? Halted : Inactive; |
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361 | |
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362 | // SKULLDUGGERY normally interrupts are enable before leaving a coroutine ctxswitch. |
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363 | // Therefore, when first creating a coroutine, interrupts are enable before calling the main. |
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364 | // This is consistent with thread creation. However, when creating the main processor coroutine, |
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365 | // we wan't interrupts to be disabled. Therefore, we double-disable interrupts here so they will |
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366 | // stay disabled. |
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367 | disable_interrupts(); |
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368 | |
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369 | // context switch to specified coroutine |
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370 | verify( dst->context.SP ); |
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371 | CtxSwitch( &src->context, &dst->context ); |
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372 | // when CtxSwitch returns we are back in the src coroutine |
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373 | |
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374 | // set state of new coroutine to active |
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375 | src->state = Active; |
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376 | |
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377 | verify( ! kernelTLS.preemption_state.enabled ); |
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378 | } |
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379 | |
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380 | //----------------------------------------------------------------------------- |
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381 | // Scheduler routines |
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382 | |
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383 | // KERNEL ONLY |
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384 | void ScheduleThread( thread_desc * thrd ) { |
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385 | verify( thrd ); |
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386 | verify( thrd->self_cor.state != Halted ); |
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387 | |
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388 | verify( ! kernelTLS.preemption_state.enabled ); |
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389 | |
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390 | verifyf( thrd->next == NULL, "Expected null got %p", thrd->next ); |
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391 | |
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392 | with( *thrd->curr_cluster ) { |
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393 | lock ( ready_queue_lock __cfaabi_dbg_ctx2 ); |
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394 | bool was_empty = !(ready_queue != 0); |
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395 | append( ready_queue, thrd ); |
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396 | unlock( ready_queue_lock ); |
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397 | |
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398 | if(was_empty) { |
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399 | lock (proc_list_lock __cfaabi_dbg_ctx2); |
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400 | if(idles) { |
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401 | wake_fast(idles.head); |
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402 | } |
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403 | unlock (proc_list_lock); |
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404 | } |
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405 | else if( struct processor * idle = idles.head ) { |
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406 | wake_fast(idle); |
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407 | } |
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408 | |
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409 | } |
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410 | |
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411 | verify( ! kernelTLS.preemption_state.enabled ); |
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412 | } |
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413 | |
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414 | // KERNEL ONLY |
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415 | thread_desc * nextThread(cluster * this) with( *this ) { |
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416 | verify( ! kernelTLS.preemption_state.enabled ); |
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417 | lock( ready_queue_lock __cfaabi_dbg_ctx2 ); |
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418 | thread_desc * head = pop_head( ready_queue ); |
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419 | unlock( ready_queue_lock ); |
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420 | verify( ! kernelTLS.preemption_state.enabled ); |
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421 | return head; |
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422 | } |
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423 | |
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424 | void BlockInternal() { |
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425 | disable_interrupts(); |
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426 | verify( ! kernelTLS.preemption_state.enabled ); |
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427 | returnToKernel(); |
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428 | verify( ! kernelTLS.preemption_state.enabled ); |
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429 | enable_interrupts( __cfaabi_dbg_ctx ); |
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430 | } |
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431 | |
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432 | void BlockInternal( __spinlock_t * lock ) { |
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433 | disable_interrupts(); |
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434 | with( *kernelTLS.this_processor ) { |
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435 | finish.action_code = Release; |
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436 | finish.lock = lock; |
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437 | } |
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438 | |
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439 | verify( ! kernelTLS.preemption_state.enabled ); |
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440 | returnToKernel(); |
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441 | verify( ! kernelTLS.preemption_state.enabled ); |
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442 | |
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443 | enable_interrupts( __cfaabi_dbg_ctx ); |
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444 | } |
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445 | |
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446 | void BlockInternal( thread_desc * thrd ) { |
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447 | disable_interrupts(); |
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448 | with( * kernelTLS.this_processor ) { |
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449 | finish.action_code = Schedule; |
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450 | finish.thrd = thrd; |
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451 | } |
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452 | |
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453 | verify( ! kernelTLS.preemption_state.enabled ); |
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454 | returnToKernel(); |
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455 | verify( ! kernelTLS.preemption_state.enabled ); |
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456 | |
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457 | enable_interrupts( __cfaabi_dbg_ctx ); |
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458 | } |
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459 | |
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460 | void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) { |
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461 | assert(thrd); |
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462 | disable_interrupts(); |
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463 | with( * kernelTLS.this_processor ) { |
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464 | finish.action_code = Release_Schedule; |
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465 | finish.lock = lock; |
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466 | finish.thrd = thrd; |
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467 | } |
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468 | |
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469 | verify( ! kernelTLS.preemption_state.enabled ); |
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470 | returnToKernel(); |
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471 | verify( ! kernelTLS.preemption_state.enabled ); |
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472 | |
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473 | enable_interrupts( __cfaabi_dbg_ctx ); |
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474 | } |
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475 | |
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476 | void BlockInternal(__spinlock_t * locks [], unsigned short count) { |
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477 | disable_interrupts(); |
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478 | with( * kernelTLS.this_processor ) { |
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479 | finish.action_code = Release_Multi; |
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480 | finish.locks = locks; |
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481 | finish.lock_count = count; |
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482 | } |
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483 | |
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484 | verify( ! kernelTLS.preemption_state.enabled ); |
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485 | returnToKernel(); |
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486 | verify( ! kernelTLS.preemption_state.enabled ); |
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487 | |
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488 | enable_interrupts( __cfaabi_dbg_ctx ); |
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489 | } |
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490 | |
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491 | void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) { |
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492 | disable_interrupts(); |
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493 | with( *kernelTLS.this_processor ) { |
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494 | finish.action_code = Release_Multi_Schedule; |
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495 | finish.locks = locks; |
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496 | finish.lock_count = lock_count; |
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497 | finish.thrds = thrds; |
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498 | finish.thrd_count = thrd_count; |
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499 | } |
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500 | |
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501 | verify( ! kernelTLS.preemption_state.enabled ); |
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502 | returnToKernel(); |
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503 | verify( ! kernelTLS.preemption_state.enabled ); |
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504 | |
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505 | enable_interrupts( __cfaabi_dbg_ctx ); |
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506 | } |
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507 | |
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508 | void BlockInternal(__finish_callback_fptr_t callback) { |
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509 | disable_interrupts(); |
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510 | with( *kernelTLS.this_processor ) { |
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511 | finish.action_code = Callback; |
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512 | finish.callback = callback; |
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513 | } |
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514 | |
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515 | verify( ! kernelTLS.preemption_state.enabled ); |
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516 | returnToKernel(); |
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517 | verify( ! kernelTLS.preemption_state.enabled ); |
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518 | |
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519 | enable_interrupts( __cfaabi_dbg_ctx ); |
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520 | } |
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521 | |
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522 | // KERNEL ONLY |
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523 | void LeaveThread(__spinlock_t * lock, thread_desc * thrd) { |
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524 | verify( ! kernelTLS.preemption_state.enabled ); |
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525 | with( * kernelTLS.this_processor ) { |
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526 | finish.action_code = thrd ? Release_Schedule : Release; |
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527 | finish.lock = lock; |
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528 | finish.thrd = thrd; |
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529 | } |
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530 | |
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531 | returnToKernel(); |
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532 | } |
---|
533 | |
---|
534 | //============================================================================================= |
---|
535 | // Kernel Setup logic |
---|
536 | //============================================================================================= |
---|
537 | //----------------------------------------------------------------------------- |
---|
538 | // Kernel boot procedures |
---|
539 | static void kernel_startup(void) { |
---|
540 | verify( ! kernelTLS.preemption_state.enabled ); |
---|
541 | __cfaabi_dbg_print_safe("Kernel : Starting\n"); |
---|
542 | |
---|
543 | __page_size = sysconf( _SC_PAGESIZE ); |
---|
544 | |
---|
545 | __cfa_dbg_global_clusters.list{ __get }; |
---|
546 | __cfa_dbg_global_clusters.lock{}; |
---|
547 | |
---|
548 | // Initialize the main cluster |
---|
549 | mainCluster = (cluster *)&storage_mainCluster; |
---|
550 | (*mainCluster){"Main Cluster"}; |
---|
551 | |
---|
552 | __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n"); |
---|
553 | |
---|
554 | // Start by initializing the main thread |
---|
555 | // SKULLDUGGERY: the mainThread steals the process main thread |
---|
556 | // which will then be scheduled by the mainProcessor normally |
---|
557 | mainThread = (thread_desc *)&storage_mainThread; |
---|
558 | current_stack_info_t info; |
---|
559 | info.storage = (__stack_t*)&storage_mainThreadCtx; |
---|
560 | (*mainThread){ &info }; |
---|
561 | |
---|
562 | __cfaabi_dbg_print_safe("Kernel : Main thread ready\n"); |
---|
563 | |
---|
564 | |
---|
565 | |
---|
566 | // Construct the processor context of the main processor |
---|
567 | void ?{}(processorCtx_t & this, processor * proc) { |
---|
568 | (this.__cor){ "Processor" }; |
---|
569 | this.__cor.starter = NULL; |
---|
570 | this.proc = proc; |
---|
571 | } |
---|
572 | |
---|
573 | void ?{}(processor & this) with( this ) { |
---|
574 | name = "Main Processor"; |
---|
575 | cltr = mainCluster; |
---|
576 | terminated{ 0 }; |
---|
577 | do_terminate = false; |
---|
578 | preemption_alarm = NULL; |
---|
579 | pending_preemption = false; |
---|
580 | kernel_thread = pthread_self(); |
---|
581 | |
---|
582 | runner{ &this }; |
---|
583 | __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner); |
---|
584 | } |
---|
585 | |
---|
586 | // Initialize the main processor and the main processor ctx |
---|
587 | // (the coroutine that contains the processing control flow) |
---|
588 | mainProcessor = (processor *)&storage_mainProcessor; |
---|
589 | (*mainProcessor){}; |
---|
590 | |
---|
591 | //initialize the global state variables |
---|
592 | kernelTLS.this_processor = mainProcessor; |
---|
593 | kernelTLS.this_thread = mainThread; |
---|
594 | |
---|
595 | // Enable preemption |
---|
596 | kernel_start_preemption(); |
---|
597 | |
---|
598 | // Add the main thread to the ready queue |
---|
599 | // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread |
---|
600 | ScheduleThread(mainThread); |
---|
601 | |
---|
602 | // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX |
---|
603 | // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that |
---|
604 | // mainThread is on the ready queue when this call is made. |
---|
605 | kernel_first_resume( kernelTLS.this_processor ); |
---|
606 | |
---|
607 | |
---|
608 | |
---|
609 | // THE SYSTEM IS NOW COMPLETELY RUNNING |
---|
610 | __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n"); |
---|
611 | |
---|
612 | verify( ! kernelTLS.preemption_state.enabled ); |
---|
613 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
614 | verify( TL_GET( preemption_state.enabled ) ); |
---|
615 | } |
---|
616 | |
---|
617 | static void kernel_shutdown(void) { |
---|
618 | __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n"); |
---|
619 | |
---|
620 | verify( TL_GET( preemption_state.enabled ) ); |
---|
621 | disable_interrupts(); |
---|
622 | verify( ! kernelTLS.preemption_state.enabled ); |
---|
623 | |
---|
624 | // SKULLDUGGERY: Notify the mainProcessor it needs to terminates. |
---|
625 | // When its coroutine terminates, it return control to the mainThread |
---|
626 | // which is currently here |
---|
627 | __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE); |
---|
628 | returnToKernel(); |
---|
629 | mainThread->self_cor.state = Halted; |
---|
630 | |
---|
631 | // THE SYSTEM IS NOW COMPLETELY STOPPED |
---|
632 | |
---|
633 | // Disable preemption |
---|
634 | kernel_stop_preemption(); |
---|
635 | |
---|
636 | // Destroy the main processor and its context in reverse order of construction |
---|
637 | // These were manually constructed so we need manually destroy them |
---|
638 | ^(mainProcessor->runner){}; |
---|
639 | ^(mainProcessor){}; |
---|
640 | |
---|
641 | // Final step, destroy the main thread since it is no longer needed |
---|
642 | // Since we provided a stack to this taxk it will not destroy anything |
---|
643 | ^(mainThread){}; |
---|
644 | |
---|
645 | ^(__cfa_dbg_global_clusters.list){}; |
---|
646 | ^(__cfa_dbg_global_clusters.lock){}; |
---|
647 | |
---|
648 | __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n"); |
---|
649 | } |
---|
650 | |
---|
651 | //============================================================================================= |
---|
652 | // Kernel Quiescing |
---|
653 | //============================================================================================= |
---|
654 | static void halt(processor * this) with( *this ) { |
---|
655 | // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) ); |
---|
656 | |
---|
657 | with( *cltr ) { |
---|
658 | lock (proc_list_lock __cfaabi_dbg_ctx2); |
---|
659 | remove (procs, *this); |
---|
660 | push_front(idles, *this); |
---|
661 | unlock (proc_list_lock); |
---|
662 | } |
---|
663 | |
---|
664 | __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this); |
---|
665 | |
---|
666 | wait( idleLock ); |
---|
667 | |
---|
668 | __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this); |
---|
669 | |
---|
670 | with( *cltr ) { |
---|
671 | lock (proc_list_lock __cfaabi_dbg_ctx2); |
---|
672 | remove (idles, *this); |
---|
673 | push_front(procs, *this); |
---|
674 | unlock (proc_list_lock); |
---|
675 | } |
---|
676 | } |
---|
677 | |
---|
678 | //============================================================================================= |
---|
679 | // Unexpected Terminating logic |
---|
680 | //============================================================================================= |
---|
681 | static __spinlock_t kernel_abort_lock; |
---|
682 | static bool kernel_abort_called = false; |
---|
683 | |
---|
684 | void * kernel_abort(void) __attribute__ ((__nothrow__)) { |
---|
685 | // abort cannot be recursively entered by the same or different processors because all signal handlers return when |
---|
686 | // the globalAbort flag is true. |
---|
687 | lock( kernel_abort_lock __cfaabi_dbg_ctx2 ); |
---|
688 | |
---|
689 | // first task to abort ? |
---|
690 | if ( kernel_abort_called ) { // not first task to abort ? |
---|
691 | unlock( kernel_abort_lock ); |
---|
692 | |
---|
693 | sigset_t mask; |
---|
694 | sigemptyset( &mask ); |
---|
695 | sigaddset( &mask, SIGALRM ); // block SIGALRM signals |
---|
696 | sigsuspend( &mask ); // block the processor to prevent further damage during abort |
---|
697 | _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it |
---|
698 | } |
---|
699 | else { |
---|
700 | kernel_abort_called = true; |
---|
701 | unlock( kernel_abort_lock ); |
---|
702 | } |
---|
703 | |
---|
704 | return kernelTLS.this_thread; |
---|
705 | } |
---|
706 | |
---|
707 | void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) { |
---|
708 | thread_desc * thrd = kernel_data; |
---|
709 | |
---|
710 | if(thrd) { |
---|
711 | int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd ); |
---|
712 | __cfaabi_dbg_bits_write( abort_text, len ); |
---|
713 | |
---|
714 | if ( &thrd->self_cor != thrd->curr_cor ) { |
---|
715 | len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor ); |
---|
716 | __cfaabi_dbg_bits_write( abort_text, len ); |
---|
717 | } |
---|
718 | else { |
---|
719 | __cfaabi_dbg_bits_write( ".\n", 2 ); |
---|
720 | } |
---|
721 | } |
---|
722 | else { |
---|
723 | int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" ); |
---|
724 | __cfaabi_dbg_bits_write( abort_text, len ); |
---|
725 | } |
---|
726 | } |
---|
727 | |
---|
728 | int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) { |
---|
729 | return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2; |
---|
730 | } |
---|
731 | |
---|
732 | static __spinlock_t kernel_debug_lock; |
---|
733 | |
---|
734 | extern "C" { |
---|
735 | void __cfaabi_dbg_bits_acquire() { |
---|
736 | lock( kernel_debug_lock __cfaabi_dbg_ctx2 ); |
---|
737 | } |
---|
738 | |
---|
739 | void __cfaabi_dbg_bits_release() { |
---|
740 | unlock( kernel_debug_lock ); |
---|
741 | } |
---|
742 | } |
---|
743 | |
---|
744 | //============================================================================================= |
---|
745 | // Kernel Utilities |
---|
746 | //============================================================================================= |
---|
747 | //----------------------------------------------------------------------------- |
---|
748 | // Locks |
---|
749 | void ?{}( semaphore & this, int count = 1 ) { |
---|
750 | (this.lock){}; |
---|
751 | this.count = count; |
---|
752 | (this.waiting){}; |
---|
753 | } |
---|
754 | void ^?{}(semaphore & this) {} |
---|
755 | |
---|
756 | void P(semaphore & this) with( this ){ |
---|
757 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
758 | count -= 1; |
---|
759 | if ( count < 0 ) { |
---|
760 | // queue current task |
---|
761 | append( waiting, kernelTLS.this_thread ); |
---|
762 | |
---|
763 | // atomically release spin lock and block |
---|
764 | BlockInternal( &lock ); |
---|
765 | } |
---|
766 | else { |
---|
767 | unlock( lock ); |
---|
768 | } |
---|
769 | } |
---|
770 | |
---|
771 | void V(semaphore & this) with( this ) { |
---|
772 | thread_desc * thrd = NULL; |
---|
773 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
774 | count += 1; |
---|
775 | if ( count <= 0 ) { |
---|
776 | // remove task at head of waiting list |
---|
777 | thrd = pop_head( waiting ); |
---|
778 | } |
---|
779 | |
---|
780 | unlock( lock ); |
---|
781 | |
---|
782 | // make new owner |
---|
783 | WakeThread( thrd ); |
---|
784 | } |
---|
785 | |
---|
786 | //----------------------------------------------------------------------------- |
---|
787 | // Global Queues |
---|
788 | void doregister( cluster & cltr ) { |
---|
789 | lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2); |
---|
790 | push_front( __cfa_dbg_global_clusters.list, cltr ); |
---|
791 | unlock ( __cfa_dbg_global_clusters.lock ); |
---|
792 | } |
---|
793 | |
---|
794 | void unregister( cluster & cltr ) { |
---|
795 | lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2); |
---|
796 | remove( __cfa_dbg_global_clusters.list, cltr ); |
---|
797 | unlock( __cfa_dbg_global_clusters.lock ); |
---|
798 | } |
---|
799 | |
---|
800 | void doregister( cluster * cltr, thread_desc & thrd ) { |
---|
801 | lock (cltr->thread_list_lock __cfaabi_dbg_ctx2); |
---|
802 | push_front(cltr->threads, thrd); |
---|
803 | unlock (cltr->thread_list_lock); |
---|
804 | } |
---|
805 | |
---|
806 | void unregister( cluster * cltr, thread_desc & thrd ) { |
---|
807 | lock (cltr->thread_list_lock __cfaabi_dbg_ctx2); |
---|
808 | remove(cltr->threads, thrd ); |
---|
809 | unlock(cltr->thread_list_lock); |
---|
810 | } |
---|
811 | |
---|
812 | void doregister( cluster * cltr, processor * proc ) { |
---|
813 | lock (cltr->proc_list_lock __cfaabi_dbg_ctx2); |
---|
814 | push_front(cltr->procs, *proc); |
---|
815 | unlock (cltr->proc_list_lock); |
---|
816 | } |
---|
817 | |
---|
818 | void unregister( cluster * cltr, processor * proc ) { |
---|
819 | lock (cltr->proc_list_lock __cfaabi_dbg_ctx2); |
---|
820 | remove(cltr->procs, *proc ); |
---|
821 | unlock(cltr->proc_list_lock); |
---|
822 | } |
---|
823 | |
---|
824 | //----------------------------------------------------------------------------- |
---|
825 | // Debug |
---|
826 | __cfaabi_dbg_debug_do( |
---|
827 | extern "C" { |
---|
828 | void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) { |
---|
829 | this.prev_name = prev_name; |
---|
830 | this.prev_thrd = kernelTLS.this_thread; |
---|
831 | } |
---|
832 | } |
---|
833 | ) |
---|
834 | // Local Variables: // |
---|
835 | // mode: c // |
---|
836 | // tab-width: 4 // |
---|
837 | // End: // |
---|