[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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[ae66348] | 248 | __cfaabi_dbg_debug_do( |
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[276ae57e] | 249 | thrd_dst->park_stale = true; |
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| 250 | thrd_dst->unpark_stale = true; |
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[ae66348] | 251 | ) |
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[58d64a4] | 252 | // Update global state |
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| 253 | kernelTLS.this_thread = thrd_dst; |
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[75f3522] | 254 | |
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[3381ed7] | 255 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[a7b486b] | 256 | /* paranoid */ verify( kernelTLS.this_thread == thrd_dst ); |
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[210b8b3] | 257 | /* 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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| 258 | /* 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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[3381ed7] | 259 | |
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[58d64a4] | 260 | |
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[9f575ea] | 261 | // set context switch to the thread that the processor is executing |
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| 262 | verify( thrd_dst->context.SP ); |
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[c7a900a] | 263 | __cfactx_switch( &proc_cor->context, &thrd_dst->context ); |
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| 264 | // when __cfactx_switch returns we are back in the processor coroutine |
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[9f575ea] | 265 | |
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[210b8b3] | 266 | /* 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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| 267 | /* 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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[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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| 290 | unpark( this->destroyer __cfaabi_dbg_ctx2 ); |
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| 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 | __cfaabi_dbg_debug_do( thrd_dst->park_result = old_ticket; ) |
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| 301 | switch(old_ticket) { |
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| 302 | case 1: |
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[3381ed7] | 303 | // This is case 1, the regular case, nothing more is needed |
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| 304 | break RUNNING; |
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[ff79d5e] | 305 | case 2: |
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[3381ed7] | 306 | // This is case 2, the racy case, someone tried to run this thread before it finished blocking |
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| 307 | // In this case, just run it again. |
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| 308 | continue RUNNING; |
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| 309 | default: |
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| 310 | // This makes no sense, something is wrong abort |
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[ff79d5e] | 311 | abort(); |
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[3381ed7] | 312 | } |
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[9f575ea] | 313 | } |
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[e8e457e] | 314 | |
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[9f575ea] | 315 | // Just before returning to the processor, set the processor coroutine to active |
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[e8e457e] | 316 | proc_cor->state = Active; |
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[1eb239e4] | 317 | |
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| 318 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[82c948c] | 319 | } |
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| 320 | |
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[14a61b5] | 321 | // KERNEL_ONLY |
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[b0c7419] | 322 | void returnToKernel() { |
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[3381ed7] | 323 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[ac2b598] | 324 | $coroutine * proc_cor = get_coroutine(kernelTLS.this_processor->runner); |
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| 325 | $thread * thrd_src = kernelTLS.this_thread; |
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[e8e457e] | 326 | |
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[29cb302] | 327 | #if !defined(__CFA_NO_STATISTICS__) |
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| 328 | struct processor * last_proc = kernelTLS.this_processor; |
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| 329 | #endif |
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| 330 | |
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[9f575ea] | 331 | // Run the thread on this processor |
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| 332 | { |
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| 333 | int local_errno = *__volatile_errno(); |
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| 334 | #if defined( __i386 ) || defined( __x86_64 ) |
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| 335 | __x87_store; |
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| 336 | #endif |
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| 337 | verify( proc_cor->context.SP ); |
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[c7a900a] | 338 | __cfactx_switch( &thrd_src->context, &proc_cor->context ); |
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[9f575ea] | 339 | #if defined( __i386 ) || defined( __x86_64 ) |
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| 340 | __x87_load; |
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| 341 | #endif |
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| 342 | *__volatile_errno() = local_errno; |
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[8fcbb4c] | 343 | } |
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[deca0f5] | 344 | |
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[29cb302] | 345 | #if !defined(__CFA_NO_STATISTICS__) |
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| 346 | if(last_proc != kernelTLS.this_processor) { |
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| 347 | __tls_stats()->ready.threads.migration++; |
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| 348 | } |
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| 349 | #endif |
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| 350 | |
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[3381ed7] | 351 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[210b8b3] | 352 | /* 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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| 353 | /* 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] | 354 | } |
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| 355 | |
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[8def349] | 356 | //----------------------------------------------------------------------------- |
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| 357 | // Scheduler routines |
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[14a61b5] | 358 | // KERNEL ONLY |
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[9b1dcc2] | 359 | void __schedule_thread( struct __processor_id_t * id, $thread * thrd ) { |
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[6a490b2] | 360 | /* paranoid */ verify( thrd ); |
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| 361 | /* paranoid */ verify( thrd->state != Halted ); |
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[9f575ea] | 362 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
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[3381ed7] | 363 | /* paranoid */ #if defined( __CFA_WITH_VERIFY__ ) |
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[504a7dc] | 364 | /* paranoid */ if( thrd->state == Blocked || thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION, |
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| 365 | "Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted ); |
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[ff79d5e] | 366 | /* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active, |
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[504a7dc] | 367 | "Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted ); |
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[3381ed7] | 368 | /* paranoid */ #endif |
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[6a490b2] | 369 | /* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next ); |
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[9f575ea] | 370 | |
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[ae7be7a] | 371 | if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready; |
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[6b4cdd3] | 372 | |
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[9b1dcc2] | 373 | ready_schedule_lock ( id ); |
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[504a7dc] | 374 | push( thrd->curr_cluster, thrd ); |
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[1eb239e4] | 375 | __wake_one(id, thrd->curr_cluster); |
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[9b1dcc2] | 376 | ready_schedule_unlock( id ); |
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[1c273d0] | 377 | |
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[9f575ea] | 378 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[db6f06a] | 379 | } |
---|
| 380 | |
---|
[14a61b5] | 381 | // KERNEL ONLY |
---|
[1eb239e4] | 382 | static inline $thread * __next_thread(cluster * this) with( *this ) { |
---|
[3381ed7] | 383 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[7768b8d] | 384 | |
---|
[9b1dcc2] | 385 | ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[1eb239e4] | 386 | $thread * thrd = pop( this ); |
---|
[9b1dcc2] | 387 | ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[7768b8d] | 388 | |
---|
[3381ed7] | 389 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[1eb239e4] | 390 | return thrd; |
---|
[eb2e723] | 391 | } |
---|
| 392 | |
---|
[64a7146] | 393 | // KERNEL ONLY |
---|
[1eb239e4] | 394 | static inline $thread * __next_thread_slow(cluster * this) with( *this ) { |
---|
[64a7146] | 395 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 396 | |
---|
| 397 | ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor ); |
---|
[1eb239e4] | 398 | $thread * thrd = pop_slow( this ); |
---|
[64a7146] | 399 | ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor ); |
---|
| 400 | |
---|
| 401 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[1eb239e4] | 402 | return thrd; |
---|
[64a7146] | 403 | } |
---|
| 404 | |
---|
[2d8f7b0] | 405 | // KERNEL ONLY unpark with out disabling interrupts |
---|
[9b1dcc2] | 406 | void __unpark( struct __processor_id_t * id, $thread * thrd __cfaabi_dbg_ctx_param2 ) { |
---|
[ae66348] | 407 | // record activity |
---|
| 408 | __cfaabi_dbg_record_thrd( *thrd, false, caller ); |
---|
| 409 | |
---|
[ff79d5e] | 410 | int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST); |
---|
| 411 | __cfaabi_dbg_debug_do( thrd->unpark_result = old_ticket; thrd->unpark_state = thrd->state; ) |
---|
| 412 | switch(old_ticket) { |
---|
| 413 | case 1: |
---|
[3381ed7] | 414 | // Wake won the race, the thread will reschedule/rerun itself |
---|
| 415 | break; |
---|
[ff79d5e] | 416 | case 0: |
---|
[3381ed7] | 417 | /* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION ); |
---|
[ff79d5e] | 418 | /* paranoid */ verify( thrd->state == Blocked ); |
---|
[0b33412] | 419 | |
---|
[3381ed7] | 420 | // Wake lost the race, |
---|
[9b1dcc2] | 421 | __schedule_thread( id, thrd ); |
---|
[3381ed7] | 422 | break; |
---|
| 423 | default: |
---|
| 424 | // This makes no sense, something is wrong abort |
---|
| 425 | abort(); |
---|
[de6319f] | 426 | } |
---|
[db6f06a] | 427 | } |
---|
| 428 | |
---|
[2d8f7b0] | 429 | void unpark( $thread * thrd __cfaabi_dbg_ctx_param2 ) { |
---|
| 430 | if( !thrd ) return; |
---|
[db6f06a] | 431 | |
---|
[82ff5845] | 432 | disable_interrupts(); |
---|
[9b1dcc2] | 433 | __unpark( (__processor_id_t*)kernelTLS.this_processor, thrd __cfaabi_dbg_ctx_fwd2 ); |
---|
[36982fc] | 434 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[eb2e723] | 435 | } |
---|
| 436 | |
---|
[ae66348] | 437 | void park( __cfaabi_dbg_ctx_param ) { |
---|
[3381ed7] | 438 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[82ff5845] | 439 | disable_interrupts(); |
---|
[3381ed7] | 440 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 441 | /* paranoid */ verify( kernelTLS.this_thread->preempted == __NO_PREEMPTION ); |
---|
[0b33412] | 442 | |
---|
[ae66348] | 443 | // record activity |
---|
| 444 | __cfaabi_dbg_record_thrd( *kernelTLS.this_thread, true, caller ); |
---|
[0b33412] | 445 | |
---|
[82c948c] | 446 | returnToKernel(); |
---|
[0b33412] | 447 | |
---|
[3381ed7] | 448 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[36982fc] | 449 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[3381ed7] | 450 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[0c78741] | 451 | |
---|
| 452 | } |
---|
[09800e9] | 453 | |
---|
[3381ed7] | 454 | // KERNEL ONLY |
---|
[b0c7419] | 455 | void __leave_thread() { |
---|
[3381ed7] | 456 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 457 | returnToKernel(); |
---|
[b0c7419] | 458 | abort(); |
---|
[09800e9] | 459 | } |
---|
| 460 | |
---|
[14a61b5] | 461 | // KERNEL ONLY |
---|
[3381ed7] | 462 | bool force_yield( __Preemption_Reason reason ) { |
---|
| 463 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 464 | disable_interrupts(); |
---|
[3381ed7] | 465 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[09800e9] | 466 | |
---|
[ac2b598] | 467 | $thread * thrd = kernelTLS.this_thread; |
---|
[ff79d5e] | 468 | /* paranoid */ verify(thrd->state == Active); |
---|
[3381ed7] | 469 | |
---|
| 470 | // SKULLDUGGERY: It is possible that we are preempting this thread just before |
---|
| 471 | // it was going to park itself. If that is the case and it is already using the |
---|
| 472 | // intrusive fields then we can't use them to preempt the thread |
---|
| 473 | // If that is the case, abandon the preemption. |
---|
| 474 | bool preempted = false; |
---|
[504a7dc] | 475 | if(thrd->link.next == 0p) { |
---|
[3381ed7] | 476 | preempted = true; |
---|
| 477 | thrd->preempted = reason; |
---|
| 478 | returnToKernel(); |
---|
[de6319f] | 479 | } |
---|
[f2b12406] | 480 | |
---|
[3381ed7] | 481 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 482 | enable_interrupts_noPoll(); |
---|
| 483 | /* paranoid */ verify( kernelTLS.preemption_state.enabled ); |
---|
[f2b12406] | 484 | |
---|
[3381ed7] | 485 | return preempted; |
---|
[f2b12406] | 486 | } |
---|
| 487 | |
---|
[14a61b5] | 488 | //============================================================================================= |
---|
[92e7631] | 489 | // Kernel Idle Sleep |
---|
[14a61b5] | 490 | //============================================================================================= |
---|
[64a7146] | 491 | // Wake a thread from the front if there are any |
---|
[1eb239e4] | 492 | static void __wake_one(struct __processor_id_t * id, cluster * this) { |
---|
| 493 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[64a7146] | 494 | /* paranoid */ verify( ready_schedule_islocked( id ) ); |
---|
[14a61b5] | 495 | |
---|
[64a7146] | 496 | // Check if there is a sleeping processor |
---|
[1eb239e4] | 497 | processor * p; |
---|
| 498 | unsigned idle; |
---|
| 499 | unsigned total; |
---|
| 500 | [idle, total, p] = query(this->idles); |
---|
[14a61b5] | 501 | |
---|
[64a7146] | 502 | // If no one is sleeping, we are done |
---|
[1eb239e4] | 503 | if( idle == 0 ) return; |
---|
[14a61b5] | 504 | |
---|
[64a7146] | 505 | // We found a processor, wake it up |
---|
| 506 | post( p->idle ); |
---|
[14a61b5] | 507 | |
---|
[1eb239e4] | 508 | #if !defined(__CFA_NO_STATISTICS__) |
---|
| 509 | __tls_stats()->ready.sleep.wakes++; |
---|
| 510 | #endif |
---|
| 511 | |
---|
| 512 | /* paranoid */ verify( ready_schedule_islocked( id ) ); |
---|
| 513 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 514 | |
---|
| 515 | return; |
---|
[64a7146] | 516 | } |
---|
[14a61b5] | 517 | |
---|
[64a7146] | 518 | // Unconditionnaly wake a thread |
---|
[1eb239e4] | 519 | void __wake_proc(processor * this) { |
---|
[64a7146] | 520 | __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this); |
---|
[14a61b5] | 521 | |
---|
[64a7146] | 522 | disable_interrupts(); |
---|
| 523 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
[58d64a4] | 524 | post( this->idle ); |
---|
[64a7146] | 525 | enable_interrupts( __cfaabi_dbg_ctx ); |
---|
[92e7631] | 526 | } |
---|
| 527 | |
---|
[1eb239e4] | 528 | static void push (__cluster_idles & this, processor & proc) { |
---|
| 529 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 530 | lock( this ); |
---|
| 531 | this.idle++; |
---|
| 532 | /* paranoid */ verify( this.idle <= this.total ); |
---|
[8e16177] | 533 | |
---|
[1eb239e4] | 534 | insert_first(this.list, proc); |
---|
| 535 | unlock( this ); |
---|
| 536 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 537 | } |
---|
[8e16177] | 538 | |
---|
[1eb239e4] | 539 | static void remove(__cluster_idles & this, processor & proc) { |
---|
| 540 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 541 | lock( this ); |
---|
| 542 | this.idle--; |
---|
| 543 | /* paranoid */ verify( this.idle >= 0 ); |
---|
[c34ebf2] | 544 | |
---|
[1eb239e4] | 545 | remove(proc); |
---|
| 546 | unlock( this ); |
---|
| 547 | /* paranoid */ verify( ! kernelTLS.preemption_state.enabled ); |
---|
| 548 | } |
---|
[c34ebf2] | 549 | |
---|
[1eb239e4] | 550 | static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) { |
---|
| 551 | for() { |
---|
| 552 | uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST); |
---|
| 553 | if( 1 == (l % 2) ) { Pause(); continue; } |
---|
| 554 | unsigned idle = this.idle; |
---|
| 555 | unsigned total = this.total; |
---|
| 556 | processor * proc = &this.list`first; |
---|
[7fdae38] | 557 | // Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it |
---|
| 558 | asm volatile("": : :"memory"); |
---|
[1eb239e4] | 559 | if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; } |
---|
| 560 | return [idle, total, proc]; |
---|
| 561 | } |
---|
[6b4cdd3] | 562 | } |
---|
| 563 | |
---|
[dbe9b08] | 564 | //============================================================================================= |
---|
| 565 | // Unexpected Terminating logic |
---|
| 566 | //============================================================================================= |
---|
[ea7d2b0] | 567 | static __spinlock_t kernel_abort_lock; |
---|
[9d944b2] | 568 | static bool kernel_abort_called = false; |
---|
| 569 | |
---|
[afd550c] | 570 | void * kernel_abort(void) __attribute__ ((__nothrow__)) { |
---|
[9d944b2] | 571 | // abort cannot be recursively entered by the same or different processors because all signal handlers return when |
---|
| 572 | // the globalAbort flag is true. |
---|
[36982fc] | 573 | lock( kernel_abort_lock __cfaabi_dbg_ctx2 ); |
---|
[9d944b2] | 574 | |
---|
| 575 | // first task to abort ? |
---|
[de94a60] | 576 | if ( kernel_abort_called ) { // not first task to abort ? |
---|
[ea7d2b0] | 577 | unlock( kernel_abort_lock ); |
---|
[1c273d0] | 578 | |
---|
[9d944b2] | 579 | sigset_t mask; |
---|
| 580 | sigemptyset( &mask ); |
---|
[de94a60] | 581 | sigaddset( &mask, SIGALRM ); // block SIGALRM signals |
---|
[8a13c47] | 582 | sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals |
---|
| 583 | sigsuspend( &mask ); // block the processor to prevent further damage during abort |
---|
| 584 | _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it |
---|
[de94a60] | 585 | } |
---|
| 586 | else { |
---|
| 587 | kernel_abort_called = true; |
---|
| 588 | unlock( kernel_abort_lock ); |
---|
[9d944b2] | 589 | } |
---|
| 590 | |
---|
[14a61b5] | 591 | return kernelTLS.this_thread; |
---|
[9d944b2] | 592 | } |
---|
| 593 | |
---|
| 594 | void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) { |
---|
[b81fd95] | 595 | $thread * thrd = ( $thread * ) kernel_data; |
---|
[9d944b2] | 596 | |
---|
[de94a60] | 597 | if(thrd) { |
---|
| 598 | int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd ); |
---|
[1c40091] | 599 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[de94a60] | 600 | |
---|
[212c2187] | 601 | if ( &thrd->self_cor != thrd->curr_cor ) { |
---|
| 602 | len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor ); |
---|
[1c40091] | 603 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[de94a60] | 604 | } |
---|
| 605 | else { |
---|
[1c40091] | 606 | __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 ); |
---|
[de94a60] | 607 | } |
---|
[1c273d0] | 608 | } |
---|
[9d944b2] | 609 | else { |
---|
[de94a60] | 610 | int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" ); |
---|
[1c40091] | 611 | __cfaabi_bits_write( STDERR_FILENO, abort_text, len ); |
---|
[9d944b2] | 612 | } |
---|
| 613 | } |
---|
| 614 | |
---|
[2b8bc41] | 615 | int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) { |
---|
[14a61b5] | 616 | return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2; |
---|
[2b8bc41] | 617 | } |
---|
| 618 | |
---|
[de94a60] | 619 | static __spinlock_t kernel_debug_lock; |
---|
| 620 | |
---|
[9d944b2] | 621 | extern "C" { |
---|
[1c40091] | 622 | void __cfaabi_bits_acquire() { |
---|
[36982fc] | 623 | lock( kernel_debug_lock __cfaabi_dbg_ctx2 ); |
---|
[9d944b2] | 624 | } |
---|
| 625 | |
---|
[1c40091] | 626 | void __cfaabi_bits_release() { |
---|
[ea7d2b0] | 627 | unlock( kernel_debug_lock ); |
---|
[9d944b2] | 628 | } |
---|
[8118303] | 629 | } |
---|
| 630 | |
---|
[fa21ac9] | 631 | //============================================================================================= |
---|
| 632 | // Kernel Utilities |
---|
| 633 | //============================================================================================= |
---|
[bd98b58] | 634 | //----------------------------------------------------------------------------- |
---|
| 635 | // Locks |
---|
[242a902] | 636 | void ?{}( semaphore & this, int count = 1 ) { |
---|
| 637 | (this.lock){}; |
---|
| 638 | this.count = count; |
---|
| 639 | (this.waiting){}; |
---|
[db6f06a] | 640 | } |
---|
[242a902] | 641 | void ^?{}(semaphore & this) {} |
---|
[db6f06a] | 642 | |
---|
[71c8b7e] | 643 | bool P(semaphore & this) with( this ){ |
---|
[65deb18] | 644 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 645 | count -= 1; |
---|
| 646 | if ( count < 0 ) { |
---|
[bdeba0b] | 647 | // queue current task |
---|
[14a61b5] | 648 | append( waiting, kernelTLS.this_thread ); |
---|
[bdeba0b] | 649 | |
---|
| 650 | // atomically release spin lock and block |
---|
[3381ed7] | 651 | unlock( lock ); |
---|
[ae66348] | 652 | park( __cfaabi_dbg_ctx ); |
---|
[71c8b7e] | 653 | return true; |
---|
[8def349] | 654 | } |
---|
[4e6fb8e] | 655 | else { |
---|
[65deb18] | 656 | unlock( lock ); |
---|
[71c8b7e] | 657 | return false; |
---|
[4e6fb8e] | 658 | } |
---|
[bd98b58] | 659 | } |
---|
| 660 | |
---|
[f0ce5f4] | 661 | bool V(semaphore & this) with( this ) { |
---|
[ac2b598] | 662 | $thread * thrd = 0p; |
---|
[65deb18] | 663 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 664 | count += 1; |
---|
| 665 | if ( count <= 0 ) { |
---|
[bdeba0b] | 666 | // remove task at head of waiting list |
---|
[65deb18] | 667 | thrd = pop_head( waiting ); |
---|
[bd98b58] | 668 | } |
---|
[bdeba0b] | 669 | |
---|
[65deb18] | 670 | unlock( lock ); |
---|
[bdeba0b] | 671 | |
---|
| 672 | // make new owner |
---|
[ae66348] | 673 | unpark( thrd __cfaabi_dbg_ctx2 ); |
---|
[f0ce5f4] | 674 | |
---|
[d384787] | 675 | return thrd != 0p; |
---|
| 676 | } |
---|
| 677 | |
---|
| 678 | bool V(semaphore & this, unsigned diff) with( this ) { |
---|
| 679 | $thread * thrd = 0p; |
---|
| 680 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
| 681 | int release = max(-count, (int)diff); |
---|
| 682 | count += diff; |
---|
| 683 | for(release) { |
---|
| 684 | unpark( pop_head( waiting ) __cfaabi_dbg_ctx2 ); |
---|
| 685 | } |
---|
| 686 | |
---|
| 687 | unlock( lock ); |
---|
| 688 | |
---|
[f0ce5f4] | 689 | return thrd != 0p; |
---|
[bd98b58] | 690 | } |
---|
| 691 | |
---|
[de94a60] | 692 | //----------------------------------------------------------------------------- |
---|
| 693 | // Debug |
---|
| 694 | __cfaabi_dbg_debug_do( |
---|
[1997b4e] | 695 | extern "C" { |
---|
[ae66348] | 696 | void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) { |
---|
[1997b4e] | 697 | this.prev_name = prev_name; |
---|
| 698 | this.prev_thrd = kernelTLS.this_thread; |
---|
| 699 | } |
---|
[ae66348] | 700 | |
---|
| 701 | void __cfaabi_dbg_record_thrd($thread & this, bool park, const char prev_name[]) { |
---|
| 702 | if(park) { |
---|
[f0ce5f4] | 703 | this.park_caller = prev_name; |
---|
| 704 | this.park_stale = false; |
---|
[ae66348] | 705 | } |
---|
| 706 | else { |
---|
[f0ce5f4] | 707 | this.unpark_caller = prev_name; |
---|
| 708 | this.unpark_stale = false; |
---|
[ae66348] | 709 | } |
---|
| 710 | } |
---|
[9181f1d] | 711 | } |
---|
[f7d6bb0] | 712 | ) |
---|
[2026bb6] | 713 | |
---|
| 714 | //----------------------------------------------------------------------------- |
---|
| 715 | // Debug |
---|
[8c50aed] | 716 | bool threading_enabled(void) __attribute__((const)) { |
---|
[2026bb6] | 717 | return true; |
---|
| 718 | } |
---|
[c34ebf2] | 719 | |
---|
| 720 | //----------------------------------------------------------------------------- |
---|
| 721 | // Statistics |
---|
| 722 | #if !defined(__CFA_NO_STATISTICS__) |
---|
| 723 | void print_halts( processor & this ) { |
---|
| 724 | this.print_halts = true; |
---|
| 725 | } |
---|
| 726 | #endif |
---|
[8118303] | 727 | // Local Variables: // |
---|
| 728 | // mode: c // |
---|
| 729 | // tab-width: 4 // |
---|
| 730 | // End: // |
---|