[c81ebf9] | 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 | // signal.c -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Mon Jun 5 14:20:42 2017 |
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[6b0b624] | 11 | // Last Modified By : Peter A. Buhr |
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[8ad6533] | 12 | // Last Modified On : Mon Apr 9 13:52:39 2018 |
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| 13 | // Update Count : 36 |
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[c81ebf9] | 14 | // |
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| 15 | |
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| 16 | #include "preemption.h" |
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[a83ffa4] | 17 | #include <assert.h> |
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[c81ebf9] | 18 | |
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| 19 | extern "C" { |
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[82ff5845] | 20 | #include <errno.h> |
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| 21 | #include <stdio.h> |
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| 22 | #include <string.h> |
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| 23 | #include <unistd.h> |
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[c81ebf9] | 24 | } |
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| 25 | |
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[dbe9b08] | 26 | #include "bits/signal.h" |
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[82ff5845] | 27 | |
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[d8548e2] | 28 | #if !defined(__CFA_DEFAULT_PREEMPTION__) |
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[2a84d06d] | 29 | #define __CFA_DEFAULT_PREEMPTION__ 10`ms |
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[d8548e2] | 30 | #endif |
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[c81ebf9] | 31 | |
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[2a84d06d] | 32 | Duration default_preemption() __attribute__((weak)) { |
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[c81ebf9] | 33 | return __CFA_DEFAULT_PREEMPTION__; |
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| 34 | } |
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| 35 | |
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[969b3fe] | 36 | // FwdDeclarations : timeout handlers |
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[c81ebf9] | 37 | static void preempt( processor * this ); |
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| 38 | static void timeout( thread_desc * this ); |
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| 39 | |
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[969b3fe] | 40 | // FwdDeclarations : Signal handlers |
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[82ff5845] | 41 | void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ); |
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[1c273d0] | 42 | void sigHandler_segv ( __CFA_SIGPARMS__ ); |
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[2b8bc41] | 43 | void sigHandler_ill ( __CFA_SIGPARMS__ ); |
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| 44 | void sigHandler_fpe ( __CFA_SIGPARMS__ ); |
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[1c273d0] | 45 | void sigHandler_abort ( __CFA_SIGPARMS__ ); |
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[82ff5845] | 46 | |
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[969b3fe] | 47 | // FwdDeclarations : alarm thread main |
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| 48 | void * alarm_loop( __attribute__((unused)) void * args ); |
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| 49 | |
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| 50 | // Machine specific register name |
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[381fdee] | 51 | #if defined( __i386 ) |
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[b2b44d8] | 52 | #define CFA_REG_IP gregs[REG_EIP] |
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[381fdee] | 53 | #elif defined( __x86_64 ) |
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| 54 | #define CFA_REG_IP gregs[REG_RIP] |
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| 55 | #elif defined( __ARM_ARCH ) |
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[b2b44d8] | 56 | #define CFA_REG_IP arm_pc |
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[381fdee] | 57 | #else |
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| 58 | #error unknown hardware architecture |
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[cd17862] | 59 | #endif |
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| 60 | |
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[969b3fe] | 61 | KERNEL_STORAGE(event_kernel_t, event_kernel); // private storage for event kernel |
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| 62 | event_kernel_t * event_kernel; // kernel public handle to even kernel |
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| 63 | static pthread_t alarm_thread; // pthread handle to alarm thread |
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| 64 | |
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[65deb18] | 65 | void ?{}(event_kernel_t & this) with( this ) { |
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| 66 | alarms{}; |
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| 67 | lock{}; |
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[969b3fe] | 68 | } |
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[82ff5845] | 69 | |
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[4dad189] | 70 | enum { |
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| 71 | PREEMPT_NORMAL = 0, |
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| 72 | PREEMPT_TERMINATE = 1, |
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| 73 | }; |
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| 74 | |
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[c81ebf9] | 75 | //============================================================================================= |
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| 76 | // Kernel Preemption logic |
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| 77 | //============================================================================================= |
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| 78 | |
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[969b3fe] | 79 | // Get next expired node |
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[2a84d06d] | 80 | static inline alarm_node_t * get_expired( alarm_list_t * alarms, Time currtime ) { |
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[969b3fe] | 81 | if( !alarms->head ) return NULL; // If no alarms return null |
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| 82 | if( alarms->head->alarm >= currtime ) return NULL; // If alarms head not expired return null |
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| 83 | return pop(alarms); // Otherwise just pop head |
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| 84 | } |
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| 85 | |
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| 86 | // Tick one frame of the Discrete Event Simulation for alarms |
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[c81ebf9] | 87 | void tick_preemption() { |
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[969b3fe] | 88 | alarm_node_t * node = NULL; // Used in the while loop but cannot be declared in the while condition |
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| 89 | alarm_list_t * alarms = &event_kernel->alarms; // Local copy for ease of reading |
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[2a84d06d] | 90 | Time currtime = __kernel_get_time(); // Check current time once so we everything "happens at once" |
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[8cb529e] | 91 | |
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[969b3fe] | 92 | //Loop throught every thing expired |
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| 93 | while( node = get_expired( alarms, currtime ) ) { |
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[b1a4300] | 94 | // __cfaabi_dbg_print_buffer_decl( " KERNEL: preemption tick.\n" ); |
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[1c273d0] | 95 | |
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[969b3fe] | 96 | // Check if this is a kernel |
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[c81ebf9] | 97 | if( node->kernel_alarm ) { |
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| 98 | preempt( node->proc ); |
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| 99 | } |
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| 100 | else { |
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| 101 | timeout( node->thrd ); |
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| 102 | } |
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| 103 | |
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[969b3fe] | 104 | // Check if this is a periodic alarm |
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[2a84d06d] | 105 | Duration period = node->period; |
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[8cb529e] | 106 | if( period > 0 ) { |
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[b1a4300] | 107 | // __cfaabi_dbg_print_buffer_local( " KERNEL: alarm period is %lu.\n", period.tv ); |
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[969b3fe] | 108 | node->alarm = currtime + period; // Alarm is periodic, add currtime to it (used cached current time) |
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| 109 | insert( alarms, node ); // Reinsert the node for the next time it triggers |
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[c81ebf9] | 110 | } |
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| 111 | else { |
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[969b3fe] | 112 | node->set = false; // Node is one-shot, just mark it as not pending |
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[c81ebf9] | 113 | } |
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| 114 | } |
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| 115 | |
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[969b3fe] | 116 | // If there are still alarms pending, reset the timer |
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[b1a4300] | 117 | if( alarms->head ) { |
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| 118 | __cfaabi_dbg_print_buffer_decl( " KERNEL: @%lu(%lu) resetting alarm to %lu.\n", currtime.tv, __kernel_get_time().tv, (alarms->head->alarm - currtime).tv); |
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| 119 | Duration delta = alarms->head->alarm - currtime; |
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| 120 | Duration caped = max(delta, 50`us); |
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| 121 | // itimerval tim = { caped }; |
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| 122 | // __cfaabi_dbg_print_buffer_local( " Values are %lu, %lu, %lu %lu.\n", delta.tv, caped.tv, tim.it_value.tv_sec, tim.it_value.tv_usec); |
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| 123 | |
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| 124 | __kernel_set_timer( caped ); |
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| 125 | } |
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[c81ebf9] | 126 | } |
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| 127 | |
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[969b3fe] | 128 | // Update the preemption of a processor and notify interested parties |
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[2a84d06d] | 129 | void update_preemption( processor * this, Duration duration ) { |
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[c81ebf9] | 130 | alarm_node_t * alarm = this->preemption_alarm; |
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| 131 | |
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| 132 | // Alarms need to be enabled |
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[2a84d06d] | 133 | if ( duration > 0 && ! alarm->set ) { |
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[c81ebf9] | 134 | alarm->alarm = __kernel_get_time() + duration; |
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| 135 | alarm->period = duration; |
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| 136 | register_self( alarm ); |
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| 137 | } |
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[8ad6533] | 138 | // Zero duration but alarm is set |
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[c81ebf9] | 139 | else if ( duration == 0 && alarm->set ) { |
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| 140 | unregister_self( alarm ); |
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| 141 | alarm->alarm = 0; |
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| 142 | alarm->period = 0; |
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| 143 | } |
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| 144 | // If alarm is different from previous, change it |
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| 145 | else if ( duration > 0 && alarm->period != duration ) { |
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| 146 | unregister_self( alarm ); |
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| 147 | alarm->alarm = __kernel_get_time() + duration; |
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| 148 | alarm->period = duration; |
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| 149 | register_self( alarm ); |
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| 150 | } |
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| 151 | } |
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| 152 | |
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| 153 | //============================================================================================= |
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[cd17862] | 154 | // Kernel Signal Tools |
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[c81ebf9] | 155 | //============================================================================================= |
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| 156 | |
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[36982fc] | 157 | __cfaabi_dbg_debug_do( static thread_local void * last_interrupt = 0; ) |
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[b227f68] | 158 | |
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[82ff5845] | 159 | extern "C" { |
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[969b3fe] | 160 | // Disable interrupts by incrementing the counter |
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[82ff5845] | 161 | void disable_interrupts() { |
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[afd550c] | 162 | with( kernelTLS.preemption_state ) { |
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[1f81d61] | 163 | #if GCC_VERSION > 50000 |
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[13073be] | 164 | static_assert(__atomic_always_lock_free(sizeof(enabled), &enabled), "Must be lock-free"); |
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[1f81d61] | 165 | #endif |
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[13073be] | 166 | |
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| 167 | // Set enabled flag to false |
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| 168 | // should be atomic to avoid preemption in the middle of the operation. |
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| 169 | // use memory order RELAXED since there is no inter-thread on this variable requirements |
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| 170 | __atomic_store_n(&enabled, false, __ATOMIC_RELAXED); |
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| 171 | |
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| 172 | // Signal the compiler that a fence is needed but only for signal handlers |
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| 173 | __atomic_signal_fence(__ATOMIC_ACQUIRE); |
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| 174 | |
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[de6319f] | 175 | __attribute__((unused)) unsigned short new_val = disable_count + 1; |
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| 176 | disable_count = new_val; |
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| 177 | verify( new_val < 65_000u ); // If this triggers someone is disabling interrupts without enabling them |
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| 178 | } |
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[82ff5845] | 179 | } |
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| 180 | |
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[969b3fe] | 181 | // Enable interrupts by decrementing the counter |
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| 182 | // If counter reaches 0, execute any pending CtxSwitch |
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[36982fc] | 183 | void enable_interrupts( __cfaabi_dbg_ctx_param ) { |
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[13073be] | 184 | processor * proc = kernelTLS.this_processor; // Cache the processor now since interrupts can start happening after the atomic store |
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| 185 | thread_desc * thrd = kernelTLS.this_thread; // Cache the thread now since interrupts can start happening after the atomic store |
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[969b3fe] | 186 | |
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[afd550c] | 187 | with( kernelTLS.preemption_state ){ |
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[de6319f] | 188 | unsigned short prev = disable_count; |
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| 189 | disable_count -= 1; |
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| 190 | verify( prev != 0u ); // If this triggers someone is enabled already enabled interruptsverify( prev != 0u ); |
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| 191 | |
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| 192 | // Check if we need to prempt the thread because an interrupt was missed |
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| 193 | if( prev == 1 ) { |
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[1f81d61] | 194 | #if GCC_VERSION > 50000 |
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[13073be] | 195 | static_assert(__atomic_always_lock_free(sizeof(enabled), &enabled), "Must be lock-free"); |
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[1f81d61] | 196 | #endif |
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[13073be] | 197 | |
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| 198 | // Set enabled flag to true |
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| 199 | // should be atomic to avoid preemption in the middle of the operation. |
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| 200 | // use memory order RELAXED since there is no inter-thread on this variable requirements |
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| 201 | __atomic_store_n(&enabled, true, __ATOMIC_RELAXED); |
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| 202 | |
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| 203 | // Signal the compiler that a fence is needed but only for signal handlers |
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| 204 | __atomic_signal_fence(__ATOMIC_RELEASE); |
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[de6319f] | 205 | if( proc->pending_preemption ) { |
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| 206 | proc->pending_preemption = false; |
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| 207 | BlockInternal( thrd ); |
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| 208 | } |
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[d0a045c7] | 209 | } |
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[82ff5845] | 210 | } |
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[4e6fb8e] | 211 | |
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[969b3fe] | 212 | // For debugging purposes : keep track of the last person to enable the interrupts |
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[36982fc] | 213 | __cfaabi_dbg_debug_do( proc->last_enable = caller; ) |
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[82ff5845] | 214 | } |
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[969b3fe] | 215 | |
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| 216 | // Disable interrupts by incrementint the counter |
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| 217 | // Don't execute any pending CtxSwitch even if counter reaches 0 |
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| 218 | void enable_interrupts_noPoll() { |
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[afd550c] | 219 | unsigned short prev = kernelTLS.preemption_state.disable_count; |
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| 220 | kernelTLS.preemption_state.disable_count -= 1; |
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[2e9aed4] | 221 | verifyf( prev != 0u, "Incremented from %u\n", prev ); // If this triggers someone is enabled already enabled interrupts |
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[d0a045c7] | 222 | if( prev == 1 ) { |
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[1f81d61] | 223 | #if GCC_VERSION > 50000 |
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[13073be] | 224 | static_assert(__atomic_always_lock_free(sizeof(kernelTLS.preemption_state.enabled), &kernelTLS.preemption_state.enabled), "Must be lock-free"); |
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[1f81d61] | 225 | #endif |
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[13073be] | 226 | // Set enabled flag to true |
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| 227 | // should be atomic to avoid preemption in the middle of the operation. |
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| 228 | // use memory order RELAXED since there is no inter-thread on this variable requirements |
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| 229 | __atomic_store_n(&kernelTLS.preemption_state.enabled, true, __ATOMIC_RELAXED); |
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| 230 | |
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| 231 | // Signal the compiler that a fence is needed but only for signal handlers |
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| 232 | __atomic_signal_fence(__ATOMIC_RELEASE); |
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[d0a045c7] | 233 | } |
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[969b3fe] | 234 | } |
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[82ff5845] | 235 | } |
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| 236 | |
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[969b3fe] | 237 | // sigprocmask wrapper : unblock a single signal |
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[1c273d0] | 238 | static inline void signal_unblock( int sig ) { |
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[82ff5845] | 239 | sigset_t mask; |
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| 240 | sigemptyset( &mask ); |
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[1c273d0] | 241 | sigaddset( &mask, sig ); |
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[82ff5845] | 242 | |
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[47ecf2b] | 243 | if ( pthread_sigmask( SIG_UNBLOCK, &mask, NULL ) == -1 ) { |
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[169d944] | 244 | abort( "internal error, pthread_sigmask" ); |
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[cd17862] | 245 | } |
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[82ff5845] | 246 | } |
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| 247 | |
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[969b3fe] | 248 | // sigprocmask wrapper : block a single signal |
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[cd17862] | 249 | static inline void signal_block( int sig ) { |
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| 250 | sigset_t mask; |
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| 251 | sigemptyset( &mask ); |
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| 252 | sigaddset( &mask, sig ); |
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[47ecf2b] | 253 | |
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[cd17862] | 254 | if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) { |
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[169d944] | 255 | abort( "internal error, pthread_sigmask" ); |
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[cd17862] | 256 | } |
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| 257 | } |
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[47ecf2b] | 258 | |
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[969b3fe] | 259 | // kill wrapper : signal a processor |
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[cd17862] | 260 | static void preempt( processor * this ) { |
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[4dad189] | 261 | sigval_t value = { PREEMPT_NORMAL }; |
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| 262 | pthread_sigqueue( this->kernel_thread, SIGUSR1, value ); |
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| 263 | } |
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| 264 | |
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| 265 | // kill wrapper : signal a processor |
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| 266 | void terminate(processor * this) { |
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| 267 | this->do_terminate = true; |
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| 268 | sigval_t value = { PREEMPT_TERMINATE }; |
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| 269 | pthread_sigqueue( this->kernel_thread, SIGUSR1, value ); |
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[1c273d0] | 270 | } |
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[82ff5845] | 271 | |
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[969b3fe] | 272 | // reserved for future use |
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[cd17862] | 273 | static void timeout( thread_desc * this ) { |
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| 274 | //TODO : implement waking threads |
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| 275 | } |
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| 276 | |
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[14a61b5] | 277 | // KERNEL ONLY |
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[969b3fe] | 278 | // Check if a CtxSwitch signal handler shoud defer |
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| 279 | // If true : preemption is safe |
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| 280 | // If false : preemption is unsafe and marked as pending |
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| 281 | static inline bool preemption_ready() { |
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[14a61b5] | 282 | // Check if preemption is safe |
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| 283 | bool ready = kernelTLS.preemption_state.enabled && ! kernelTLS.preemption_state.in_progress; |
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| 284 | |
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| 285 | // Adjust the pending flag accordingly |
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| 286 | kernelTLS.this_processor->pending_preemption = !ready; |
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[969b3fe] | 287 | return ready; |
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| 288 | } |
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| 289 | |
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[cd17862] | 290 | //============================================================================================= |
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| 291 | // Kernel Signal Startup/Shutdown logic |
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| 292 | //============================================================================================= |
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| 293 | |
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[969b3fe] | 294 | // Startup routine to activate preemption |
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| 295 | // Called from kernel_startup |
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[cd17862] | 296 | void kernel_start_preemption() { |
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[169d944] | 297 | __cfaabi_dbg_print_safe( "Kernel : Starting preemption\n" ); |
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[969b3fe] | 298 | |
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| 299 | // Start with preemption disabled until ready |
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[14a61b5] | 300 | kernelTLS.preemption_state.enabled = false; |
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| 301 | kernelTLS.preemption_state.disable_count = 1; |
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[969b3fe] | 302 | |
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| 303 | // Initialize the event kernel |
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| 304 | event_kernel = (event_kernel_t *)&storage_event_kernel; |
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[9236060] | 305 | (*event_kernel){}; |
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[969b3fe] | 306 | |
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| 307 | // Setup proper signal handlers |
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[2b8bc41] | 308 | __cfaabi_sigaction( SIGUSR1, sigHandler_ctxSwitch, SA_SIGINFO | SA_RESTART ); // CtxSwitch handler |
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[cd17862] | 309 | |
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| 310 | signal_block( SIGALRM ); |
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| 311 | |
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| 312 | pthread_create( &alarm_thread, NULL, alarm_loop, NULL ); |
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| 313 | } |
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| 314 | |
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[969b3fe] | 315 | // Shutdown routine to deactivate preemption |
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| 316 | // Called from kernel_shutdown |
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[cd17862] | 317 | void kernel_stop_preemption() { |
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[169d944] | 318 | __cfaabi_dbg_print_safe( "Kernel : Preemption stopping\n" ); |
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[d6ff3ff] | 319 | |
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[969b3fe] | 320 | // Block all signals since we are already shutting down |
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[cd17862] | 321 | sigset_t mask; |
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| 322 | sigfillset( &mask ); |
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| 323 | sigprocmask( SIG_BLOCK, &mask, NULL ); |
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| 324 | |
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[969b3fe] | 325 | // Notify the alarm thread of the shutdown |
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[a0b3e32] | 326 | sigval val = { 1 }; |
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| 327 | pthread_sigqueue( alarm_thread, SIGALRM, val ); |
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[969b3fe] | 328 | |
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| 329 | // Wait for the preemption thread to finish |
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[cd17862] | 330 | pthread_join( alarm_thread, NULL ); |
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[969b3fe] | 331 | |
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| 332 | // Preemption is now fully stopped |
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| 333 | |
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[169d944] | 334 | __cfaabi_dbg_print_safe( "Kernel : Preemption stopped\n" ); |
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[cd17862] | 335 | } |
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| 336 | |
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[969b3fe] | 337 | // Raii ctor/dtor for the preemption_scope |
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| 338 | // Used by thread to control when they want to receive preemption signals |
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[242a902] | 339 | void ?{}( preemption_scope & this, processor * proc ) { |
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[2a84d06d] | 340 | (this.alarm){ proc, (Time){ 0 }, 0`s }; |
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[242a902] | 341 | this.proc = proc; |
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| 342 | this.proc->preemption_alarm = &this.alarm; |
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[969b3fe] | 343 | |
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[d8548e2] | 344 | update_preemption( this.proc, this.proc->cltr->preemption_rate ); |
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[cd17862] | 345 | } |
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| 346 | |
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[242a902] | 347 | void ^?{}( preemption_scope & this ) { |
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[cd17862] | 348 | disable_interrupts(); |
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| 349 | |
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[2a84d06d] | 350 | update_preemption( this.proc, 0`s ); |
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[cd17862] | 351 | } |
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| 352 | |
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| 353 | //============================================================================================= |
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| 354 | // Kernel Signal Handlers |
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| 355 | //============================================================================================= |
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[47ecf2b] | 356 | |
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[969b3fe] | 357 | // Context switch signal handler |
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| 358 | // Receives SIGUSR1 signal and causes the current thread to yield |
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[1c273d0] | 359 | void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ) { |
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[b2b44d8] | 360 | __cfaabi_dbg_debug_do( last_interrupt = (void *)(cxt->uc_mcontext.CFA_REG_IP); ) |
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[969b3fe] | 361 | |
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[4dad189] | 362 | // SKULLDUGGERY: if a thread creates a processor and the immediately deletes it, |
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| 363 | // the interrupt that is supposed to force the kernel thread to preempt might arrive |
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| 364 | // before the kernel thread has even started running. When that happens an iterrupt |
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| 365 | // we a null 'this_processor' will be caught, just ignore it. |
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[14a61b5] | 366 | if(! kernelTLS.this_processor ) return; |
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[4dad189] | 367 | |
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| 368 | choose(sfp->si_value.sival_int) { |
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| 369 | case PREEMPT_NORMAL : ;// Normal case, nothing to do here |
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[14a61b5] | 370 | case PREEMPT_TERMINATE: verify( kernelTLS.this_processor->do_terminate); |
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[4dad189] | 371 | default: |
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[ff878b7] | 372 | abort( "internal error, signal value is %d", sfp->si_value.sival_int ); |
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[4dad189] | 373 | } |
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| 374 | |
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[b2b44d8] | 375 | // Check if it is safe to preempt here |
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[969b3fe] | 376 | if( !preemption_ready() ) { return; } |
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| 377 | |
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[b1a4300] | 378 | __cfaabi_dbg_print_buffer_decl( " KERNEL: preempting core %p (%p @ %p).\n", kernelTLS.this_processor, kernelTLS.this_thread, (void *)(cxt->uc_mcontext.CFA_REG_IP) ); |
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[14a61b5] | 379 | |
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| 380 | // Sync flag : prevent recursive calls to the signal handler |
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| 381 | kernelTLS.preemption_state.in_progress = true; |
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| 382 | |
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[a83ffa4] | 383 | // Clear sighandler mask before context switching. |
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[1f81d61] | 384 | #if GCC_VERSION > 50000 |
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[a83ffa4] | 385 | static_assert( sizeof( sigset_t ) == sizeof( cxt->uc_sigmask ), "Expected cxt->uc_sigmask to be of sigset_t" ); |
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[1f81d61] | 386 | #endif |
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[a83ffa4] | 387 | if ( pthread_sigmask( SIG_SETMASK, (sigset_t *)&(cxt->uc_sigmask), NULL ) == -1 ) { |
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| 388 | abort( "internal error, sigprocmask" ); |
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| 389 | } |
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[05615ba] | 390 | |
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[14a61b5] | 391 | // TODO: this should go in finish action |
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| 392 | // Clear the in progress flag |
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| 393 | kernelTLS.preemption_state.in_progress = false; |
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[969b3fe] | 394 | |
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| 395 | // Preemption can occur here |
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| 396 | |
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[14a61b5] | 397 | BlockInternal( kernelTLS.this_thread ); // Do the actual CtxSwitch |
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[c81ebf9] | 398 | } |
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| 399 | |
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[969b3fe] | 400 | // Main of the alarm thread |
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| 401 | // Waits on SIGALRM and send SIGUSR1 to whom ever needs it |
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[cd17862] | 402 | void * alarm_loop( __attribute__((unused)) void * args ) { |
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[969b3fe] | 403 | // Block sigalrms to control when they arrive |
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[cd17862] | 404 | sigset_t mask; |
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[ade5272] | 405 | sigfillset(&mask); |
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[cd17862] | 406 | if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) { |
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[169d944] | 407 | abort( "internal error, pthread_sigmask" ); |
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[82ff5845] | 408 | } |
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[c81ebf9] | 409 | |
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[ade5272] | 410 | sigemptyset( &mask ); |
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| 411 | sigaddset( &mask, SIGALRM ); |
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| 412 | |
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[969b3fe] | 413 | // Main loop |
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[cd17862] | 414 | while( true ) { |
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[969b3fe] | 415 | // Wait for a sigalrm |
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[a0b3e32] | 416 | siginfo_t info; |
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| 417 | int sig = sigwaitinfo( &mask, &info ); |
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[969b3fe] | 418 | |
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[e2f7bc3] | 419 | if( sig < 0 ) { |
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| 420 | //Error! |
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| 421 | int err = errno; |
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| 422 | switch( err ) { |
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| 423 | case EAGAIN : |
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| 424 | case EINTR : |
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[b1a4300] | 425 | {__cfaabi_dbg_print_buffer_decl( " KERNEL: Spurious wakeup %d.\n", err );} |
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[e2f7bc3] | 426 | continue; |
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| 427 | case EINVAL : |
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[169d944] | 428 | abort( "Timeout was invalid." ); |
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[e2f7bc3] | 429 | default: |
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[169d944] | 430 | abort( "Unhandled error %d", err); |
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[e2f7bc3] | 431 | } |
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| 432 | } |
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| 433 | |
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[969b3fe] | 434 | // If another signal arrived something went wrong |
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[8cb529e] | 435 | assertf(sig == SIGALRM, "Kernel Internal Error, sigwait: Unexpected signal %d (%d : %d)\n", sig, info.si_code, info.si_value.sival_int); |
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| 436 | |
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[169d944] | 437 | // __cfaabi_dbg_print_safe( "Kernel : Caught alarm from %d with %d\n", info.si_code, info.si_value.sival_int ); |
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[969b3fe] | 438 | // Switch on the code (a.k.a. the sender) to |
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[8cb529e] | 439 | switch( info.si_code ) |
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[a0b3e32] | 440 | { |
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[969b3fe] | 441 | // Timers can apparently be marked as sent for the kernel |
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| 442 | // In either case, tick preemption |
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[8cb529e] | 443 | case SI_TIMER: |
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| 444 | case SI_KERNEL: |
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[169d944] | 445 | // __cfaabi_dbg_print_safe( "Kernel : Preemption thread tick\n" ); |
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[36982fc] | 446 | lock( event_kernel->lock __cfaabi_dbg_ctx2 ); |
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[8cb529e] | 447 | tick_preemption(); |
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[ea7d2b0] | 448 | unlock( event_kernel->lock ); |
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[8cb529e] | 449 | break; |
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[969b3fe] | 450 | // Signal was not sent by the kernel but by an other thread |
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[8cb529e] | 451 | case SI_QUEUE: |
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[969b3fe] | 452 | // For now, other thread only signal the alarm thread to shut it down |
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| 453 | // If this needs to change use info.si_value and handle the case here |
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[8cb529e] | 454 | goto EXIT; |
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[cd17862] | 455 | } |
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| 456 | } |
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[a0b3e32] | 457 | |
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[8cb529e] | 458 | EXIT: |
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[169d944] | 459 | __cfaabi_dbg_print_safe( "Kernel : Preemption thread stopping\n" ); |
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[a0b3e32] | 460 | return NULL; |
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[82ff5845] | 461 | } |
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| 462 | |
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[b68fc85] | 463 | //============================================================================================= |
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| 464 | // Kernel Signal Debug |
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| 465 | //============================================================================================= |
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| 466 | |
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| 467 | void __cfaabi_check_preemption() { |
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[14a61b5] | 468 | bool ready = kernelTLS.preemption_state.enabled; |
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[b68fc85] | 469 | if(!ready) { abort("Preemption should be ready"); } |
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| 470 | |
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| 471 | sigset_t oldset; |
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| 472 | int ret; |
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[a83ffa4] | 473 | ret = pthread_sigmask(0, NULL, &oldset); |
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[b68fc85] | 474 | if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); } |
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| 475 | |
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| 476 | ret = sigismember(&oldset, SIGUSR1); |
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| 477 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); } |
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| 478 | if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); } |
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[a83ffa4] | 479 | |
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| 480 | ret = sigismember(&oldset, SIGALRM); |
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| 481 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); } |
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| 482 | if(ret == 0) { abort("ERROR SIGALRM is enabled"); } |
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| 483 | |
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| 484 | ret = sigismember(&oldset, SIGTERM); |
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| 485 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); } |
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| 486 | if(ret == 1) { abort("ERROR SIGTERM is disabled"); } |
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[b68fc85] | 487 | } |
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| 488 | |
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[6b0b624] | 489 | // Local Variables: // |
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| 490 | // mode: c // |
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| 491 | // tab-width: 4 // |
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| 492 | // End: // |
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