[8118303] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // kernel.c -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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[75f3522] | 10 | // Created On : Tue Jan 17 12:27:26 2017 |
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[6b0b624] | 11 | // Last Modified By : Peter A. Buhr |
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[0190480] | 12 | // Last Modified On : Mon Aug 31 07:08:20 2020 |
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| 13 | // Update Count : 71 |
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[8118303] | 14 | // |
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| 15 | |
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[2026bb6] | 16 | #define __cforall_thread__ |
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[4069faad] | 17 | // #define __CFA_DEBUG_PRINT_RUNTIME_CORE__ |
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[2026bb6] | 18 | |
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[8118303] | 19 | //C Includes |
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[214e8da] | 20 | #include <errno.h> |
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[9d944b2] | 21 | #include <stdio.h> |
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[58b6d1b] | 22 | #include <signal.h> |
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[9d944b2] | 23 | #include <unistd.h> |
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[8118303] | 24 | |
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| 25 | //CFA Includes |
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[73abe95] | 26 | #include "kernel_private.hfa" |
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| 27 | #include "preemption.hfa" |
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[8118303] | 28 | |
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| 29 | //Private includes |
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| 30 | #define __CFA_INVOKE_PRIVATE__ |
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| 31 | #include "invoke.h" |
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| 32 | |
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[4069faad] | 33 | |
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[deca0f5] | 34 | //----------------------------------------------------------------------------- |
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| 35 | // Some assembly required |
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[1805b1b] | 36 | #if defined( __i386 ) |
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[deca0f5] | 37 | // mxcr : SSE Status and Control bits (control bits are preserved across function calls) |
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| 38 | // fcw : X87 FPU control word (preserved across function calls) |
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| 39 | #define __x87_store \ |
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| 40 | uint32_t __mxcr; \ |
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| 41 | uint16_t __fcw; \ |
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| 42 | __asm__ volatile ( \ |
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| 43 | "stmxcsr %0\n" \ |
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| 44 | "fnstcw %1\n" \ |
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| 45 | : "=m" (__mxcr),\ |
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| 46 | "=m" (__fcw) \ |
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| 47 | ) |
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| 48 | |
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| 49 | #define __x87_load \ |
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| 50 | __asm__ volatile ( \ |
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| 51 | "fldcw %1\n" \ |
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| 52 | "ldmxcsr %0\n" \ |
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| 53 | ::"m" (__mxcr),\ |
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| 54 | "m" (__fcw) \ |
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| 55 | ) |
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| 56 | |
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| 57 | #elif defined( __x86_64 ) |
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| 58 | #define __x87_store \ |
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| 59 | uint32_t __mxcr; \ |
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| 60 | uint16_t __fcw; \ |
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| 61 | __asm__ volatile ( \ |
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| 62 | "stmxcsr %0\n" \ |
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| 63 | "fnstcw %1\n" \ |
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| 64 | : "=m" (__mxcr),\ |
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| 65 | "=m" (__fcw) \ |
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| 66 | ) |
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| 67 | |
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| 68 | #define __x87_load \ |
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| 69 | __asm__ volatile ( \ |
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| 70 | "fldcw %1\n" \ |
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| 71 | "ldmxcsr %0\n" \ |
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| 72 | :: "m" (__mxcr),\ |
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| 73 | "m" (__fcw) \ |
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| 74 | ) |
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| 75 | |
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[0190480] | 76 | #elif defined( __arm__ ) |
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| 77 | #define __x87_store |
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| 78 | #define __x87_load |
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| 79 | |
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| 80 | #elif defined( __aarch64__ ) |
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[74f5c83] | 81 | #define __x87_store \ |
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| 82 | uint32_t __fpcntl[2]; \ |
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| 83 | __asm__ volatile ( \ |
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| 84 | "mrs x9, FPCR\n" \ |
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| 85 | "mrs x10, FPSR\n" \ |
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| 86 | "stp x9, x10, %0\n" \ |
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| 87 | : "=m" (__fpcntl) : : "x9", "x10" \ |
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| 88 | ) |
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| 89 | |
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| 90 | #define __x87_load \ |
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| 91 | __asm__ volatile ( \ |
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| 92 | "ldp x9, x10, %0\n" \ |
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| 93 | "msr FPSR, x10\n" \ |
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| 94 | "msr FPCR, x9\n" \ |
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| 95 | : "=m" (__fpcntl) : : "x9", "x10" \ |
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| 96 | ) |
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| 97 | |
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[deca0f5] | 98 | #else |
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[0190480] | 99 | #error unsupported hardware architecture |
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[deca0f5] | 100 | #endif |
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| 101 | |
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[e660761] | 102 | extern $thread * mainThread; |
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| 103 | extern processor * mainProcessor; |
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[2ac095d] | 104 | |
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[92e7631] | 105 | //----------------------------------------------------------------------------- |
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| 106 | // Kernel Scheduling logic |
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| 107 | static $thread * __next_thread(cluster * this); |
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[1eb239e4] | 108 | static $thread * __next_thread_slow(cluster * this); |
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[92e7631] | 109 | static void __run_thread(processor * this, $thread * dst); |
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[1eb239e4] | 110 | static void __wake_one(struct __processor_id_t * id, cluster * cltr); |
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| 111 | |
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| 112 | static void push (__cluster_idles & idles, processor & proc); |
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| 113 | static void remove(__cluster_idles & idles, processor & proc); |
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| 114 | static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles ); |
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| 115 | |
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[c84e80a] | 116 | |
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[75f3522] | 117 | //============================================================================================= |
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| 118 | // Kernel Scheduling logic |
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| 119 | //============================================================================================= |
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[8fcbb4c] | 120 | //Main of the processor contexts |
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[83a071f9] | 121 | void main(processorCtx_t & runner) { |
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[21184e3] | 122 | // Because of a bug, we couldn't initialized the seed on construction |
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| 123 | // Do it here |
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[7768b8d] | 124 | kernelTLS.rand_seed ^= rdtscl(); |
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[f2384c9a] | 125 | kernelTLS.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner); |
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| 126 | __tls_rand_advance_bck(); |
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[21184e3] | 127 | |
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[83a071f9] | 128 | processor * this = runner.proc; |
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[094476d] | 129 | verify(this); |
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[c81ebf9] | 130 | |
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[4069faad] | 131 | __cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this); |
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[28d73c1] | 132 | #if !defined(__CFA_NO_STATISTICS__) |
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| 133 | if( this->print_halts ) { |
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| 134 | __cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this); |
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| 135 | } |
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| 136 | #endif |
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[b798713] | 137 | |
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[75f3522] | 138 | { |
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[c81ebf9] | 139 | // Setup preemption data |
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| 140 | preemption_scope scope = { this }; |
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| 141 | |
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[4069faad] | 142 | __cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this); |
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[8118303] | 143 | |
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[ac2b598] | 144 | $thread * readyThread = 0p; |
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[1eb239e4] | 145 | MAIN_LOOP: |
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| 146 | for() { |
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[92e7631] | 147 | // Try to get the next thread |
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[8c50aed] | 148 | readyThread = __next_thread( this->cltr ); |
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[75f3522] | 149 | |
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[1eb239e4] | 150 | if( !readyThread ) { |
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| 151 | readyThread = __next_thread_slow( this->cltr ); |
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| 152 | } |
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[4e6fb8e] | 153 | |
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[1eb239e4] | 154 | HALT: |
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| 155 | if( !readyThread ) { |
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| 156 | // Don't block if we are done |
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| 157 | if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP; |
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[c81ebf9] | 158 | |
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[1eb239e4] | 159 | #if !defined(__CFA_NO_STATISTICS__) |
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| 160 | __tls_stats()->ready.sleep.halts++; |
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| 161 | #endif |
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[398e8e9] | 162 | |
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[1eb239e4] | 163 | // Push self to idle stack |
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| 164 | push(this->cltr->idles, * this); |
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[398e8e9] | 165 | |
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[1eb239e4] | 166 | // Confirm the ready-queue is empty |
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| 167 | readyThread = __next_thread_slow( this->cltr ); |
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| 168 | if( readyThread ) { |
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| 169 | // A thread was found, cancel the halt |
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| 170 | remove(this->cltr->idles, * this); |
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| 171 | |
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| 172 | #if !defined(__CFA_NO_STATISTICS__) |
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| 173 | __tls_stats()->ready.sleep.cancels++; |
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| 174 | #endif |
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| 175 | |
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| 176 | // continue the mai loop |
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| 177 | break HALT; |
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| 178 | } |
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| 179 | |
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| 180 | #if !defined(__CFA_NO_STATISTICS__) |
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| 181 | if(this->print_halts) { |
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| 182 | __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl()); |
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| 183 | } |
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| 184 | #endif |
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| 185 | |
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| 186 | wait( this->idle ); |
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| 187 | |
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| 188 | #if !defined(__CFA_NO_STATISTICS__) |
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| 189 | if(this->print_halts) { |
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| 190 | __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl()); |
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| 191 | } |
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| 192 | #endif |
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| 193 | |
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| 194 | // We were woken up, remove self from idle |
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| 195 | remove(this->cltr->idles, * this); |
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| 196 | |
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| 197 | // DON'T just proceed, start looking again |
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| 198 | continue MAIN_LOOP; |
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[64a7146] | 199 | } |
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[1eb239e4] | 200 | |
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| 201 | /* paranoid */ verify( readyThread ); |
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| 202 | |
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| 203 | // We found a thread run it |
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| 204 | __run_thread(this, readyThread); |
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| 205 | |
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| 206 | // Are we done? |
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| 207 | if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP; |
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[c81ebf9] | 208 | } |
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| 209 | |
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[4069faad] | 210 | __cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this); |
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[c84e80a] | 211 | } |
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[8118303] | 212 | |
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[4cedd9f] | 213 | V( this->terminated ); |
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[bdeba0b] | 214 | |
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[28d73c1] | 215 | if(this == mainProcessor) { |
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[6a490b2] | 216 | // HACK : the coroutine context switch expects this_thread to be set |
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| 217 | // and it make sense for it to be set in all other cases except here |
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| 218 | // fake it |
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| 219 | kernelTLS.this_thread = mainThread; |
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| 220 | } |
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[7768b8d] | 221 | |
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[4069faad] | 222 | __cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this); |
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[c84e80a] | 223 | } |
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| 224 | |
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[5c1a531] | 225 | static int * __volatile_errno() __attribute__((noinline)); |
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| 226 | static int * __volatile_errno() { asm(""); return &errno; } |
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| 227 | |
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[14a61b5] | 228 | // KERNEL ONLY |
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[1c273d0] | 229 | // runThread runs a thread by context switching |
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| 230 | // from the processor coroutine to the target thread |
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[ac2b598] | 231 | static void __run_thread(processor * this, $thread * thrd_dst) { |
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[1eb239e4] | 232 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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| 233 | /* paranoid */ verifyf( thrd_dst->state == Ready || thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted); |
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| 234 | /* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next ); |
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| 235 | __builtin_prefetch( thrd_dst->context.SP ); |
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| 236 | |
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[ac2b598] | 237 | $coroutine * proc_cor = get_coroutine(this->runner); |
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[8fcbb4c] | 238 | |
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[9f575ea] | 239 | // set state of processor coroutine to inactive |
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| 240 | verify(proc_cor->state == Active); |
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[ae7be7a] | 241 | proc_cor->state = Blocked; |
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[e8e457e] | 242 | |
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[9f575ea] | 243 | // Actually run the thread |
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[3381ed7] | 244 | RUNNING: while(true) { |
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[ff79d5e] | 245 | thrd_dst->preempted = __NO_PREEMPTION; |
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| 246 | thrd_dst->state = Active; |
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[e8e457e] | 247 | |
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[58d64a4] | 248 | // Update global state |
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| 249 | kernelTLS.this_thread = thrd_dst; |
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[75f3522] | 250 | |
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[3381ed7] | 251 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[a7b486b] | 252 | /* paranoid */ verify( kernelTLS.this_thread == thrd_dst ); |
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[b4b63e8] | 253 | /* paranoid */ verify( thrd_dst->context.SP ); |
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[210b8b3] | 254 | /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor |
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| 255 | /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor |
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[b4b63e8] | 256 | /* paranoid */ verify( 0x0D15EA5E0D15EA5E == thrd_dst->canary ); |
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| 257 | |
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[3381ed7] | 258 | |
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[58d64a4] | 259 | |
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[9f575ea] | 260 | // set context switch to the thread that the processor is executing |
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[c7a900a] | 261 | __cfactx_switch( &proc_cor->context, &thrd_dst->context ); |
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| 262 | // when __cfactx_switch returns we are back in the processor coroutine |
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[9f575ea] | 263 | |
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[b4b63e8] | 264 | /* paranoid */ verify( 0x0D15EA5E0D15EA5E == thrd_dst->canary ); |
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[210b8b3] | 265 | /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); |
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| 266 | /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); |
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[b4b63e8] | 267 | /* paranoid */ verify( thrd_dst->context.SP ); |
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[a7b486b] | 268 | /* paranoid */ verify( kernelTLS.this_thread == thrd_dst ); |
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[3381ed7] | 269 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[75f3522] | 270 | |
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[58d64a4] | 271 | // Reset global state |
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| 272 | kernelTLS.this_thread = 0p; |
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[3381ed7] | 273 | |
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| 274 | // We just finished running a thread, there are a few things that could have happened. |
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| 275 | // 1 - Regular case : the thread has blocked and now one has scheduled it yet. |
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| 276 | // 2 - Racy case : the thread has blocked but someone has already tried to schedule it. |
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| 277 | // 4 - Preempted |
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| 278 | // In case 1, we may have won a race so we can't write to the state again. |
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| 279 | // In case 2, we lost the race so we now own the thread. |
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| 280 | |
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| 281 | if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) { |
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| 282 | // The thread was preempted, reschedule it and reset the flag |
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[9b1dcc2] | 283 | __schedule_thread( (__processor_id_t*)this, thrd_dst ); |
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[3381ed7] | 284 | break RUNNING; |
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| 285 | } |
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[75f3522] | 286 | |
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[ff79d5e] | 287 | if(unlikely(thrd_dst->state == Halted)) { |
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| 288 | // The thread has halted, it should never be scheduled/run again |
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| 289 | // We may need to wake someone up here since |
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[e235429] | 290 | unpark( this->destroyer ); |
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[ff79d5e] | 291 | this->destroyer = 0p; |
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| 292 | break RUNNING; |
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| 293 | } |
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| 294 | |
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| 295 | /* paranoid */ verify( thrd_dst->state == Active ); |
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| 296 | thrd_dst->state = Blocked; |
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| 297 | |
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[3381ed7] | 298 | // set state of processor coroutine to active and the thread to inactive |
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[ff79d5e] | 299 | int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST); |
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| 300 | switch(old_ticket) { |
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| 301 | case 1: |
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[3381ed7] | 302 | // This is case 1, the regular case, nothing more is needed |
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| 303 | break RUNNING; |
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[ff79d5e] | 304 | case 2: |
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[3381ed7] | 305 | // This is case 2, the racy case, someone tried to run this thread before it finished blocking |
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| 306 | // In this case, just run it again. |
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| 307 | continue RUNNING; |
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| 308 | default: |
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| 309 | // This makes no sense, something is wrong abort |
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[ff79d5e] | 310 | abort(); |
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[3381ed7] | 311 | } |
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[9f575ea] | 312 | } |
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[e8e457e] | 313 | |
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[9f575ea] | 314 | // Just before returning to the processor, set the processor coroutine to active |
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[e8e457e] | 315 | proc_cor->state = Active; |
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[1eb239e4] | 316 | |
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| 317 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[82c948c] | 318 | } |
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| 319 | |
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[14a61b5] | 320 | // KERNEL_ONLY |
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[b0c7419] | 321 | void returnToKernel() { |
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[3381ed7] | 322 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[ac2b598] | 323 | $coroutine * proc_cor = get_coroutine(kernelTLS.this_processor->runner); |
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| 324 | $thread * thrd_src = kernelTLS.this_thread; |
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[e8e457e] | 325 | |
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[29cb302] | 326 | #if !defined(__CFA_NO_STATISTICS__) |
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| 327 | struct processor * last_proc = kernelTLS.this_processor; |
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| 328 | #endif |
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| 329 | |
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[9f575ea] | 330 | // Run the thread on this processor |
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| 331 | { |
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| 332 | int local_errno = *__volatile_errno(); |
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| 333 | #if defined( __i386 ) || defined( __x86_64 ) |
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| 334 | __x87_store; |
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| 335 | #endif |
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[b4b63e8] | 336 | /* paranoid */ verify( proc_cor->context.SP ); |
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| 337 | /* paranoid */ verify( 0x0D15EA5E0D15EA5E == thrd_src->canary ); |
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[c7a900a] | 338 | __cfactx_switch( &thrd_src->context, &proc_cor->context ); |
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[b4b63e8] | 339 | /* paranoid */ verify( 0x0D15EA5E0D15EA5E == thrd_src->canary ); |
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[9f575ea] | 340 | #if defined( __i386 ) || defined( __x86_64 ) |
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| 341 | __x87_load; |
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| 342 | #endif |
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| 343 | *__volatile_errno() = local_errno; |
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[8fcbb4c] | 344 | } |
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[deca0f5] | 345 | |
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[29cb302] | 346 | #if !defined(__CFA_NO_STATISTICS__) |
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| 347 | if(last_proc != kernelTLS.this_processor) { |
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| 348 | __tls_stats()->ready.threads.migration++; |
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| 349 | } |
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| 350 | #endif |
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| 351 | |
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[3381ed7] | 352 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[210b8b3] | 353 | /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too small.\n", thrd_src ); |
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| 354 | /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) > ((uintptr_t)__get_stack(thrd_src->curr_cor)->limit), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too large.\n", thrd_src ); |
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[c84e80a] | 355 | } |
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| 356 | |
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[8def349] | 357 | //----------------------------------------------------------------------------- |
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| 358 | // Scheduler routines |
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[14a61b5] | 359 | // KERNEL ONLY |
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[9b1dcc2] | 360 | void __schedule_thread( struct __processor_id_t * id, $thread * thrd ) { |
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[6a490b2] | 361 | /* paranoid */ verify( thrd ); |
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| 362 | /* paranoid */ verify( thrd->state != Halted ); |
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[9f575ea] | 363 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[3381ed7] | 364 | /* paranoid */ #if defined( __CFA_WITH_VERIFY__ ) |
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[504a7dc] | 365 | /* paranoid */ if( thrd->state == Blocked || thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION, |
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| 366 | "Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted ); |
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[ff79d5e] | 367 | /* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active, |
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[504a7dc] | 368 | "Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted ); |
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[3381ed7] | 369 | /* paranoid */ #endif |
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[6a490b2] | 370 | /* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next ); |
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[b4b63e8] | 371 | /* paranoid */ verify( 0x0D15EA5E0D15EA5E == thrd->canary ); |
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| 372 | |
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[9f575ea] | 373 | |
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[ae7be7a] | 374 | if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready; |
---|
[6b4cdd3] | 375 | |
---|
[9b1dcc2] | 376 | ready_schedule_lock ( id ); |
---|
[504a7dc] | 377 | push( thrd->curr_cluster, thrd ); |
---|
[1eb239e4] | 378 | __wake_one(id, thrd->curr_cluster); |
---|
[9b1dcc2] | 379 | ready_schedule_unlock( id ); |
---|
[1c273d0] | 380 | |
---|
[9f575ea] | 381 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[db6f06a] | 382 | } |
---|
| 383 | |
---|
[14a61b5] | 384 | // KERNEL ONLY |
---|
[1eb239e4] | 385 | static inline $thread * __next_thread(cluster * this) with( *this ) { |
---|
[3381ed7] | 386 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[7768b8d] | 387 | |
---|
[9b1dcc2] | 388 | ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[1eb239e4] | 389 | $thread * thrd = pop( this ); |
---|
[9b1dcc2] | 390 | ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[7768b8d] | 391 | |
---|
[3381ed7] | 392 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[1eb239e4] | 393 | return thrd; |
---|
[eb2e723] | 394 | } |
---|
| 395 | |
---|
[64a7146] | 396 | // KERNEL ONLY |
---|
[1eb239e4] | 397 | static inline $thread * __next_thread_slow(cluster * this) with( *this ) { |
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[64a7146] | 398 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 399 | |
---|
| 400 | ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[1eb239e4] | 401 | $thread * thrd = pop_slow( this ); |
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[64a7146] | 402 | ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor ); |
---|
| 403 | |
---|
| 404 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[1eb239e4] | 405 | return thrd; |
---|
[64a7146] | 406 | } |
---|
| 407 | |
---|
[2d8f7b0] | 408 | // KERNEL ONLY unpark with out disabling interrupts |
---|
[e235429] | 409 | void __unpark( struct __processor_id_t * id, $thread * thrd ) { |
---|
[ff79d5e] | 410 | int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST); |
---|
| 411 | switch(old_ticket) { |
---|
| 412 | case 1: |
---|
[3381ed7] | 413 | // Wake won the race, the thread will reschedule/rerun itself |
---|
| 414 | break; |
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[ff79d5e] | 415 | case 0: |
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[3381ed7] | 416 | /* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION ); |
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[ff79d5e] | 417 | /* paranoid */ verify( thrd->state == Blocked ); |
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[0b33412] | 418 | |
---|
[3381ed7] | 419 | // Wake lost the race, |
---|
[9b1dcc2] | 420 | __schedule_thread( id, thrd ); |
---|
[3381ed7] | 421 | break; |
---|
| 422 | default: |
---|
| 423 | // This makes no sense, something is wrong abort |
---|
| 424 | abort(); |
---|
[de6319f] | 425 | } |
---|
[db6f06a] | 426 | } |
---|
| 427 | |
---|
[e235429] | 428 | void unpark( $thread * thrd ) { |
---|
[2d8f7b0] | 429 | if( !thrd ) return; |
---|
[db6f06a] | 430 | |
---|
[82ff5845] | 431 | disable_interrupts(); |
---|
[e235429] | 432 | __unpark( (__processor_id_t*)kernelTLS.this_processor, thrd ); |
---|
[36982fc] | 433 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[eb2e723] | 434 | } |
---|
| 435 | |
---|
[e235429] | 436 | void park( void ) { |
---|
[3381ed7] | 437 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[82ff5845] | 438 | disable_interrupts(); |
---|
[3381ed7] | 439 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 440 | /* paranoid */ verify( kernelTLS.this_thread->preempted == __NO_PREEMPTION ); |
---|
[0b33412] | 441 | |
---|
[82c948c] | 442 | returnToKernel(); |
---|
[0b33412] | 443 | |
---|
[3381ed7] | 444 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[36982fc] | 445 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[3381ed7] | 446 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[0c78741] | 447 | |
---|
| 448 | } |
---|
[09800e9] | 449 | |
---|
[3381ed7] | 450 | // KERNEL ONLY |
---|
[b0c7419] | 451 | void __leave_thread() { |
---|
[3381ed7] | 452 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 453 | returnToKernel(); |
---|
[b0c7419] | 454 | abort(); |
---|
[09800e9] | 455 | } |
---|
| 456 | |
---|
[14a61b5] | 457 | // KERNEL ONLY |
---|
[3381ed7] | 458 | bool force_yield( __Preemption_Reason reason ) { |
---|
| 459 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 460 | disable_interrupts(); |
---|
[3381ed7] | 461 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 462 | |
---|
[ac2b598] | 463 | $thread * thrd = kernelTLS.this_thread; |
---|
[ff79d5e] | 464 | /* paranoid */ verify(thrd->state == Active); |
---|
[3381ed7] | 465 | |
---|
| 466 | // SKULLDUGGERY: It is possible that we are preempting this thread just before |
---|
| 467 | // it was going to park itself. If that is the case and it is already using the |
---|
| 468 | // intrusive fields then we can't use them to preempt the thread |
---|
| 469 | // If that is the case, abandon the preemption. |
---|
| 470 | bool preempted = false; |
---|
[504a7dc] | 471 | if(thrd->link.next == 0p) { |
---|
[3381ed7] | 472 | preempted = true; |
---|
| 473 | thrd->preempted = reason; |
---|
| 474 | returnToKernel(); |
---|
[de6319f] | 475 | } |
---|
[f2b12406] | 476 | |
---|
[3381ed7] | 477 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 478 | enable_interrupts_noPoll(); |
---|
| 479 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[f2b12406] | 480 | |
---|
[3381ed7] | 481 | return preempted; |
---|
[f2b12406] | 482 | } |
---|
| 483 | |
---|
[14a61b5] | 484 | //============================================================================================= |
---|
[92e7631] | 485 | // Kernel Idle Sleep |
---|
[14a61b5] | 486 | //============================================================================================= |
---|
[64a7146] | 487 | // Wake a thread from the front if there are any |
---|
[1eb239e4] | 488 | static void __wake_one(struct __processor_id_t * id, cluster * this) { |
---|
| 489 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[64a7146] | 490 | /* paranoid */ verify( ready_schedule_islocked( id ) ); |
---|
[14a61b5] | 491 | |
---|
[64a7146] | 492 | // Check if there is a sleeping processor |
---|
[1eb239e4] | 493 | processor * p; |
---|
| 494 | unsigned idle; |
---|
| 495 | unsigned total; |
---|
| 496 | [idle, total, p] = query(this->idles); |
---|
[14a61b5] | 497 | |
---|
[64a7146] | 498 | // If no one is sleeping, we are done |
---|
[1eb239e4] | 499 | if( idle == 0 ) return; |
---|
[14a61b5] | 500 | |
---|
[64a7146] | 501 | // We found a processor, wake it up |
---|
| 502 | post( p->idle ); |
---|
[14a61b5] | 503 | |
---|
[1eb239e4] | 504 | #if !defined(__CFA_NO_STATISTICS__) |
---|
| 505 | __tls_stats()->ready.sleep.wakes++; |
---|
| 506 | #endif |
---|
| 507 | |
---|
| 508 | /* paranoid */ verify( ready_schedule_islocked( id ) ); |
---|
| 509 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 510 | |
---|
| 511 | return; |
---|
[64a7146] | 512 | } |
---|
[14a61b5] | 513 | |
---|
[64a7146] | 514 | // Unconditionnaly wake a thread |
---|
[1eb239e4] | 515 | void __wake_proc(processor * this) { |
---|
[64a7146] | 516 | __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this); |
---|
[14a61b5] | 517 | |
---|
[64a7146] | 518 | disable_interrupts(); |
---|
| 519 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[58d64a4] | 520 | post( this->idle ); |
---|
[64a7146] | 521 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[92e7631] | 522 | } |
---|
| 523 | |
---|
[1eb239e4] | 524 | static void push (__cluster_idles & this, processor & proc) { |
---|
| 525 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 526 | lock( this ); |
---|
| 527 | this.idle++; |
---|
| 528 | /* paranoid */ verify( this.idle <= this.total ); |
---|
[8e16177] | 529 | |
---|
[1eb239e4] | 530 | insert_first(this.list, proc); |
---|
| 531 | unlock( this ); |
---|
| 532 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 533 | } |
---|
[8e16177] | 534 | |
---|
[1eb239e4] | 535 | static void remove(__cluster_idles & this, processor & proc) { |
---|
| 536 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 537 | lock( this ); |
---|
| 538 | this.idle--; |
---|
| 539 | /* paranoid */ verify( this.idle >= 0 ); |
---|
[c34ebf2] | 540 | |
---|
[1eb239e4] | 541 | remove(proc); |
---|
| 542 | unlock( this ); |
---|
| 543 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 544 | } |
---|
[c34ebf2] | 545 | |
---|
[1eb239e4] | 546 | static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) { |
---|
| 547 | for() { |
---|
| 548 | uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST); |
---|
| 549 | if( 1 == (l % 2) ) { Pause(); continue; } |
---|
| 550 | unsigned idle = this.idle; |
---|
| 551 | unsigned total = this.total; |
---|
| 552 | processor * proc = &this.list`first; |
---|
[7fdae38] | 553 | // Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it |
---|
| 554 | asm volatile("": : :"memory"); |
---|
[1eb239e4] | 555 | if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; } |
---|
| 556 | return [idle, total, proc]; |
---|
| 557 | } |
---|
[6b4cdd3] | 558 | } |
---|
| 559 | |
---|
[dbe9b08] | 560 | //============================================================================================= |
---|
| 561 | // Unexpected Terminating logic |
---|
| 562 | //============================================================================================= |
---|
[ea7d2b0] | 563 | static __spinlock_t kernel_abort_lock; |
---|
[9d944b2] | 564 | static bool kernel_abort_called = false; |
---|
| 565 | |
---|
[afd550c] | 566 | void * kernel_abort(void) __attribute__ ((__nothrow__)) { |
---|
[9d944b2] | 567 | // abort cannot be recursively entered by the same or different processors because all signal handlers return when |
---|
| 568 | // the globalAbort flag is true. |
---|
[36982fc] | 569 | lock( kernel_abort_lock __cfaabi_dbg_ctx2 ); |
---|
[9d944b2] | 570 | |
---|
| 571 | // first task to abort ? |
---|
[de94a60] | 572 | if ( kernel_abort_called ) { // not first task to abort ? |
---|
[ea7d2b0] | 573 | unlock( kernel_abort_lock ); |
---|
[1c273d0] | 574 | |
---|
[9d944b2] | 575 | sigset_t mask; |
---|
| 576 | sigemptyset( &mask ); |
---|
[de94a60] | 577 | sigaddset( &mask, SIGALRM ); // block SIGALRM signals |
---|
[8a13c47] | 578 | sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals |
---|
| 579 | sigsuspend( &mask ); // block the processor to prevent further damage during abort |
---|
| 580 | _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it |
---|
[de94a60] | 581 | } |
---|
| 582 | else { |
---|
| 583 | kernel_abort_called = true; |
---|
| 584 | unlock( kernel_abort_lock ); |
---|
[9d944b2] | 585 | } |
---|
| 586 | |
---|
[14a61b5] | 587 | return kernelTLS.this_thread; |
---|
[9d944b2] | 588 | } |
---|
| 589 | |
---|
| 590 | void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) { |
---|
[b81fd95] | 591 | $thread * thrd = ( $thread * ) kernel_data; |
---|
[9d944b2] | 592 | |
---|
[de94a60] | 593 | if(thrd) { |
---|
| 594 | int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd ); |
---|
[1c40091] | 595 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[de94a60] | 596 | |
---|
[212c2187] | 597 | if ( &thrd->self_cor != thrd->curr_cor ) { |
---|
| 598 | len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor ); |
---|
[1c40091] | 599 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[de94a60] | 600 | } |
---|
| 601 | else { |
---|
[1c40091] | 602 | __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 ); |
---|
[de94a60] | 603 | } |
---|
[1c273d0] | 604 | } |
---|
[9d944b2] | 605 | else { |
---|
[de94a60] | 606 | int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" ); |
---|
[1c40091] | 607 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[9d944b2] | 608 | } |
---|
| 609 | } |
---|
| 610 | |
---|
[2b8bc41] | 611 | int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) { |
---|
[14a61b5] | 612 | return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2; |
---|
[2b8bc41] | 613 | } |
---|
| 614 | |
---|
[de94a60] | 615 | static __spinlock_t kernel_debug_lock; |
---|
| 616 | |
---|
[9d944b2] | 617 | extern "C" { |
---|
[1c40091] | 618 | void __cfaabi_bits_acquire() { |
---|
[36982fc] | 619 | lock( kernel_debug_lock __cfaabi_dbg_ctx2 ); |
---|
[9d944b2] | 620 | } |
---|
| 621 | |
---|
[1c40091] | 622 | void __cfaabi_bits_release() { |
---|
[ea7d2b0] | 623 | unlock( kernel_debug_lock ); |
---|
[9d944b2] | 624 | } |
---|
[8118303] | 625 | } |
---|
| 626 | |
---|
[fa21ac9] | 627 | //============================================================================================= |
---|
| 628 | // Kernel Utilities |
---|
| 629 | //============================================================================================= |
---|
[bd98b58] | 630 | //----------------------------------------------------------------------------- |
---|
| 631 | // Locks |
---|
[242a902] | 632 | void ?{}( semaphore & this, int count = 1 ) { |
---|
| 633 | (this.lock){}; |
---|
| 634 | this.count = count; |
---|
| 635 | (this.waiting){}; |
---|
[db6f06a] | 636 | } |
---|
[242a902] | 637 | void ^?{}(semaphore & this) {} |
---|
[db6f06a] | 638 | |
---|
[71c8b7e] | 639 | bool P(semaphore & this) with( this ){ |
---|
[65deb18] | 640 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 641 | count -= 1; |
---|
| 642 | if ( count < 0 ) { |
---|
[bdeba0b] | 643 | // queue current task |
---|
[14a61b5] | 644 | append( waiting, kernelTLS.this_thread ); |
---|
[bdeba0b] | 645 | |
---|
| 646 | // atomically release spin lock and block |
---|
[3381ed7] | 647 | unlock( lock ); |
---|
[e235429] | 648 | park(); |
---|
[71c8b7e] | 649 | return true; |
---|
[8def349] | 650 | } |
---|
[4e6fb8e] | 651 | else { |
---|
[65deb18] | 652 | unlock( lock ); |
---|
[71c8b7e] | 653 | return false; |
---|
[4e6fb8e] | 654 | } |
---|
[bd98b58] | 655 | } |
---|
| 656 | |
---|
[f0ce5f4] | 657 | bool V(semaphore & this) with( this ) { |
---|
[ac2b598] | 658 | $thread * thrd = 0p; |
---|
[65deb18] | 659 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 660 | count += 1; |
---|
| 661 | if ( count <= 0 ) { |
---|
[bdeba0b] | 662 | // remove task at head of waiting list |
---|
[65deb18] | 663 | thrd = pop_head( waiting ); |
---|
[bd98b58] | 664 | } |
---|
[bdeba0b] | 665 | |
---|
[65deb18] | 666 | unlock( lock ); |
---|
[bdeba0b] | 667 | |
---|
| 668 | // make new owner |
---|
[e235429] | 669 | unpark( thrd ); |
---|
[f0ce5f4] | 670 | |
---|
[d384787] | 671 | return thrd != 0p; |
---|
| 672 | } |
---|
| 673 | |
---|
| 674 | bool V(semaphore & this, unsigned diff) with( this ) { |
---|
| 675 | $thread * thrd = 0p; |
---|
| 676 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 677 | int release = max(-count, (int)diff); |
---|
| 678 | count += diff; |
---|
| 679 | for(release) { |
---|
[e235429] | 680 | unpark( pop_head( waiting ) ); |
---|
[d384787] | 681 | } |
---|
| 682 | |
---|
| 683 | unlock( lock ); |
---|
| 684 | |
---|
[f0ce5f4] | 685 | return thrd != 0p; |
---|
[bd98b58] | 686 | } |
---|
| 687 | |
---|
[de94a60] | 688 | //----------------------------------------------------------------------------- |
---|
| 689 | // Debug |
---|
| 690 | __cfaabi_dbg_debug_do( |
---|
[1997b4e] | 691 | extern "C" { |
---|
[ae66348] | 692 | void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) { |
---|
[1997b4e] | 693 | this.prev_name = prev_name; |
---|
| 694 | this.prev_thrd = kernelTLS.this_thread; |
---|
| 695 | } |
---|
[9181f1d] | 696 | } |
---|
[f7d6bb0] | 697 | ) |
---|
[2026bb6] | 698 | |
---|
| 699 | //----------------------------------------------------------------------------- |
---|
| 700 | // Debug |
---|
[8c50aed] | 701 | bool threading_enabled(void) __attribute__((const)) { |
---|
[2026bb6] | 702 | return true; |
---|
| 703 | } |
---|
[c34ebf2] | 704 | |
---|
| 705 | //----------------------------------------------------------------------------- |
---|
| 706 | // Statistics |
---|
| 707 | #if !defined(__CFA_NO_STATISTICS__) |
---|
| 708 | void print_halts( processor & this ) { |
---|
| 709 | this.print_halts = true; |
---|
| 710 | } |
---|
| 711 | #endif |
---|
[8118303] | 712 | // Local Variables: // |
---|
| 713 | // mode: c // |
---|
| 714 | // tab-width: 4 // |
---|
| 715 | // End: // |
---|