[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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[231b18f] | 12 | // Last Modified On : Fri Nov 6 07:42:13 2020
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| 13 | // Update Count : 54
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[c81ebf9] | 14 | //
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| 15 |
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[2026bb6] | 16 | #define __cforall_thread__
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[1c6e1ec] | 17 | // #define __CFA_DEBUG_PRINT_PREEMPTION__
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[2026bb6] | 18 |
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[73abe95] | 19 | #include "preemption.hfa"
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[a83ffa4] | 20 | #include <assert.h>
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[c81ebf9] | 21 |
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[82ff5845] | 22 | #include <errno.h>
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| 23 | #include <stdio.h>
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| 24 | #include <string.h>
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| 25 | #include <unistd.h>
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[27f5f71] | 26 | #include <limits.h> // PTHREAD_STACK_MIN
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[c81ebf9] | 27 |
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[73abe95] | 28 | #include "bits/signal.hfa"
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[e660761] | 29 | #include "kernel_private.hfa"
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[82ff5845] | 30 |
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[1c6e1ec] | 31 |
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[d8548e2] | 32 | #if !defined(__CFA_DEFAULT_PREEMPTION__)
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[2a84d06d] | 33 | #define __CFA_DEFAULT_PREEMPTION__ 10`ms
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[d8548e2] | 34 | #endif
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[c81ebf9] | 35 |
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[1c6e1ec] | 36 | __attribute__((weak)) Duration default_preemption() {
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[357fae8] | 37 | const char * preempt_rate_s = getenv("CFA_DEFAULT_PREEMPTION");
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[1c6e1ec] | 38 | if(!preempt_rate_s) {
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[357fae8] | 39 | __cfadbg_print_safe(preemption, "No CFA_DEFAULT_PREEMPTION in ENV\n");
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[1c6e1ec] | 40 | return __CFA_DEFAULT_PREEMPTION__;
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| 41 | }
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| 42 |
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| 43 | char * endptr = 0p;
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| 44 | long int preempt_rate_l = strtol(preempt_rate_s, &endptr, 10);
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| 45 | if(preempt_rate_l < 0 || preempt_rate_l > 65535) {
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[357fae8] | 46 | __cfadbg_print_safe(preemption, "CFA_DEFAULT_PREEMPTION out of range : %ld\n", preempt_rate_l);
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[1c6e1ec] | 47 | return __CFA_DEFAULT_PREEMPTION__;
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| 48 | }
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| 49 | if('\0' != *endptr) {
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[357fae8] | 50 | __cfadbg_print_safe(preemption, "CFA_DEFAULT_PREEMPTION not a decimal number : %s\n", preempt_rate_s);
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[1c6e1ec] | 51 | return __CFA_DEFAULT_PREEMPTION__;
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| 52 | }
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| 53 |
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| 54 | return preempt_rate_l`ms;
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[c81ebf9] | 55 | }
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| 56 |
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[969b3fe] | 57 | // FwdDeclarations : timeout handlers
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[c81ebf9] | 58 | static void preempt( processor * this );
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[e873838] | 59 | static void timeout( $thread * this );
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[c81ebf9] | 60 |
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[969b3fe] | 61 | // FwdDeclarations : Signal handlers
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[c29c342] | 62 | static void sigHandler_ctxSwitch( __CFA_SIGPARMS__ );
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[c59a346] | 63 | static void sigHandler_alarm ( __CFA_SIGPARMS__ );
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[c29c342] | 64 | static void sigHandler_segv ( __CFA_SIGPARMS__ );
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| 65 | static void sigHandler_ill ( __CFA_SIGPARMS__ );
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| 66 | static void sigHandler_fpe ( __CFA_SIGPARMS__ );
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| 67 | static void sigHandler_abort ( __CFA_SIGPARMS__ );
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[82ff5845] | 68 |
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[969b3fe] | 69 | // FwdDeclarations : alarm thread main
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[c29c342] | 70 | static void * alarm_loop( __attribute__((unused)) void * args );
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[969b3fe] | 71 |
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| 72 | // Machine specific register name
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[381fdee] | 73 | #if defined( __i386 )
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[b2b44d8] | 74 | #define CFA_REG_IP gregs[REG_EIP]
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[381fdee] | 75 | #elif defined( __x86_64 )
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| 76 | #define CFA_REG_IP gregs[REG_RIP]
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[e9b49379] | 77 | #elif defined( __arm__ )
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| 78 | #define CFA_REG_IP arm_pc
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| 79 | #elif defined( __aarch64__ )
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[482fa08] | 80 | #define CFA_REG_IP pc
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[381fdee] | 81 | #else
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[e9b49379] | 82 | #error unsupported hardware architecture
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[cd17862] | 83 | #endif
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| 84 |
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[969b3fe] | 85 | KERNEL_STORAGE(event_kernel_t, event_kernel); // private storage for event kernel
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| 86 | event_kernel_t * event_kernel; // kernel public handle to even kernel
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| 87 | static pthread_t alarm_thread; // pthread handle to alarm thread
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[09d4b22] | 88 | static void * alarm_stack; // pthread stack for alarm thread
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[969b3fe] | 89 |
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[c29c342] | 90 | static void ?{}(event_kernel_t & this) with( this ) {
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[65deb18] | 91 | alarms{};
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| 92 | lock{};
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[969b3fe] | 93 | }
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[82ff5845] | 94 |
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[4dad189] | 95 | enum {
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| 96 | PREEMPT_NORMAL = 0,
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| 97 | PREEMPT_TERMINATE = 1,
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| 98 | };
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| 99 |
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[c81ebf9] | 100 | //=============================================================================================
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| 101 | // Kernel Preemption logic
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| 102 | //=============================================================================================
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| 103 |
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[969b3fe] | 104 | // Get next expired node
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[2a84d06d] | 105 | static inline alarm_node_t * get_expired( alarm_list_t * alarms, Time currtime ) {
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[d3ab183] | 106 | if( ! & (*alarms)`first ) return 0p; // If no alarms return null
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| 107 | if( (*alarms)`first.alarm >= currtime ) return 0p; // If alarms head not expired return null
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[27f5f71] | 108 | return pop(alarms); // Otherwise just pop head
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[969b3fe] | 109 | }
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| 110 |
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| 111 | // Tick one frame of the Discrete Event Simulation for alarms
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[e873838] | 112 | static void tick_preemption(void) {
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[27f5f71] | 113 | alarm_node_t * node = 0p; // Used in the while loop but cannot be declared in the while condition
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| 114 | alarm_list_t * alarms = &event_kernel->alarms; // Local copy for ease of reading
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| 115 | Time currtime = __kernel_get_time(); // Check current time once so everything "happens at once"
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[8cb529e] | 116 |
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[969b3fe] | 117 | //Loop throught every thing expired
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| 118 | while( node = get_expired( alarms, currtime ) ) {
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[b1a4300] | 119 | // __cfaabi_dbg_print_buffer_decl( " KERNEL: preemption tick.\n" );
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[185efe6] | 120 | Duration period = node->period;
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| 121 | if( period == 0) {
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| 122 | node->set = false; // Node is one-shot, just mark it as not pending
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| 123 | }
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[1c273d0] | 124 |
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[969b3fe] | 125 | // Check if this is a kernel
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[4b30e8cc] | 126 | if( node->type == Kernel ) {
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[c81ebf9] | 127 | preempt( node->proc );
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| 128 | }
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[4b30e8cc] | 129 | else if( node->type == User ) {
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[e873838] | 130 | timeout( node->thrd );
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[c81ebf9] | 131 | }
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[4b30e8cc] | 132 | else {
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[eeb5023] | 133 | node->callback(*node);
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[4b30e8cc] | 134 | }
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[c81ebf9] | 135 |
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[969b3fe] | 136 | // Check if this is a periodic alarm
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[8cb529e] | 137 | if( period > 0 ) {
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[b1a4300] | 138 | // __cfaabi_dbg_print_buffer_local( " KERNEL: alarm period is %lu.\n", period.tv );
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[969b3fe] | 139 | node->alarm = currtime + period; // Alarm is periodic, add currtime to it (used cached current time)
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| 140 | insert( alarms, node ); // Reinsert the node for the next time it triggers
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[c81ebf9] | 141 | }
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| 142 | }
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| 143 |
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[969b3fe] | 144 | // If there are still alarms pending, reset the timer
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[d3ab183] | 145 | if( & (*alarms)`first ) {
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| 146 | Duration delta = (*alarms)`first.alarm - currtime;
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| 147 | Duration capped = max(delta, 50`us);
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| 148 | __kernel_set_timer( capped );
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[b1a4300] | 149 | }
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[c81ebf9] | 150 | }
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| 151 |
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[969b3fe] | 152 | // Update the preemption of a processor and notify interested parties
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[2a84d06d] | 153 | void update_preemption( processor * this, Duration duration ) {
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[c81ebf9] | 154 | alarm_node_t * alarm = this->preemption_alarm;
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| 155 |
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| 156 | // Alarms need to be enabled
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[2a84d06d] | 157 | if ( duration > 0 && ! alarm->set ) {
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[c81ebf9] | 158 | alarm->alarm = __kernel_get_time() + duration;
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| 159 | alarm->period = duration;
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| 160 | register_self( alarm );
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| 161 | }
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[8ad6533] | 162 | // Zero duration but alarm is set
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[c81ebf9] | 163 | else if ( duration == 0 && alarm->set ) {
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| 164 | unregister_self( alarm );
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| 165 | alarm->alarm = 0;
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| 166 | alarm->period = 0;
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| 167 | }
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| 168 | // If alarm is different from previous, change it
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| 169 | else if ( duration > 0 && alarm->period != duration ) {
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| 170 | unregister_self( alarm );
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| 171 | alarm->alarm = __kernel_get_time() + duration;
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| 172 | alarm->period = duration;
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| 173 | register_self( alarm );
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| 174 | }
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| 175 | }
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| 176 |
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| 177 | //=============================================================================================
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[cd17862] | 178 | // Kernel Signal Tools
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[c81ebf9] | 179 | //=============================================================================================
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[231b18f] | 180 | // In a user-level threading system, there are handful of thread-local variables where this problem occurs on the ARM.
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[54dcab1] | 181 | //
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[231b18f] | 182 | // For each kernel thread running user-level threads, there is a flag variable to indicate if interrupts are
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| 183 | // enabled/disabled for that kernel thread. Therefore, this variable is made thread local.
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[54dcab1] | 184 | //
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[231b18f] | 185 | // For example, this code fragment sets the state of the "interrupt" variable in thread-local memory.
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[54dcab1] | 186 | //
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[231b18f] | 187 | // _Thread_local volatile int interrupts;
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| 188 | // int main() {
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| 189 | // interrupts = 0; // disable interrupts }
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[54dcab1] | 190 | //
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[231b18f] | 191 | // which generates the following code on the ARM
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[54dcab1] | 192 | //
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[231b18f] | 193 | // (gdb) disassemble main
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| 194 | // Dump of assembler code for function main:
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| 195 | // 0x0000000000000610 <+0>: mrs x1, tpidr_el0
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| 196 | // 0x0000000000000614 <+4>: mov w0, #0x0 // #0
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| 197 | // 0x0000000000000618 <+8>: add x1, x1, #0x0, lsl #12
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| 198 | // 0x000000000000061c <+12>: add x1, x1, #0x10
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| 199 | // 0x0000000000000620 <+16>: str wzr, [x1]
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| 200 | // 0x0000000000000624 <+20>: ret
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[54dcab1] | 201 | //
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[231b18f] | 202 | // The mrs moves a pointer from coprocessor register tpidr_el0 into register x1. Register w0 is set to 0. The two adds
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| 203 | // increase the TLS pointer with the displacement (offset) 0x10, which is the location in the TSL of variable
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| 204 | // "interrupts". Finally, 0 is stored into "interrupts" through the pointer in register x1 that points into the
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| 205 | // TSL. Now once x1 has the pointer to the location of the TSL for kernel thread N, it can be be preempted at a
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| 206 | // user-level and the user thread is put on the user-level ready-queue. When the preempted thread gets to the front of
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| 207 | // the user-level ready-queue it is run on kernel thread M. It now stores 0 into "interrupts" back on kernel thread N,
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| 208 | // turning off interrupt on the wrong kernel thread.
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[54dcab1] | 209 | //
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[231b18f] | 210 | // On the x86, the following code is generated for the same code fragment.
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[54dcab1] | 211 | //
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[231b18f] | 212 | // (gdb) disassemble main
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| 213 | // Dump of assembler code for function main:
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| 214 | // 0x0000000000400420 <+0>: movl $0x0,%fs:0xfffffffffffffffc
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| 215 | // 0x000000000040042c <+12>: xor %eax,%eax
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[54dcab1] | 216 | // 0x000000000040042e <+14>: retq
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| 217 | //
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[231b18f] | 218 | // and there is base-displacement addressing used to atomically reset variable "interrupts" off of the TSL pointer in
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| 219 | // register "fs".
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[54dcab1] | 220 | //
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[231b18f] | 221 | // Hence, the ARM has base-displacement address for the general purpose registers, BUT not to the coprocessor
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| 222 | // registers. As a result, generating the address for the write into variable "interrupts" is no longer atomic.
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[54dcab1] | 223 | //
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[231b18f] | 224 | // Note this problem does NOT occur when just using multiple kernel threads because the preemption ALWAYS restarts the
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| 225 | // thread on the same kernel thread.
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[54dcab1] | 226 | //
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[231b18f] | 227 | // The obvious question is why does ARM use a coprocessor register to store the TSL pointer given that coprocessor
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| 228 | // registers are second-class registers with respect to the instruction set. One possible answer is that they did not
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| 229 | // want to dedicate one of the general registers to hold the TLS pointer and there was a free coprocessor register
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| 230 | // available.
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[c81ebf9] | 231 |
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[ead174a] | 232 | //-----------------------------------------------------------------------------
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| 233 | // Some assembly required
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| 234 | #define __cfaasm_label(label, when) when: asm volatile goto(".global __cfaasm_" #label "_" #when "\n" "__cfaasm_" #label "_" #when ":":::"memory":when)
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| 235 |
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[8fc652e0] | 236 | //----------
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| 237 | // special case for preemption since used often
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| 238 | bool __preemption_enabled() {
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| 239 | // create a assembler label before
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| 240 | // marked as clobber all to avoid movement
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[ead174a] | 241 | __cfaasm_label(check, before);
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[8fc652e0] | 242 |
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| 243 | // access tls as normal
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| 244 | bool enabled = __cfaabi_tls.preemption_state.enabled;
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| 245 |
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| 246 | // create a assembler label after
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| 247 | // marked as clobber all to avoid movement
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[ead174a] | 248 | __cfaasm_label(check, after);
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[8fc652e0] | 249 | return enabled;
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| 250 | }
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| 251 |
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[82a2fed] | 252 | struct asm_region {
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| 253 | void * before;
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| 254 | void * after;
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| 255 | };
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| 256 |
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| 257 | static inline bool __cfaasm_in( void * ip, struct asm_region & region ) {
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| 258 | return ip >= region.before && ip <= region.after;
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| 259 | }
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| 260 |
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| 261 |
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[8fc652e0] | 262 | //----------
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| 263 | // Get data from the TLS block
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[82a2fed] | 264 | // struct asm_region __cfaasm_get;
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[8fc652e0] | 265 | uintptr_t __cfatls_get( unsigned long int offset ) __attribute__((__noinline__)); //no inline to avoid problems
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| 266 | uintptr_t __cfatls_get( unsigned long int offset ) {
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| 267 | // create a assembler label before
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| 268 | // marked as clobber all to avoid movement
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[ead174a] | 269 | __cfaasm_label(get, before);
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[8fc652e0] | 270 |
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| 271 | // access tls as normal (except for pointer arithmetic)
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| 272 | uintptr_t val = *(uintptr_t*)((uintptr_t)&__cfaabi_tls + offset);
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| 273 |
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| 274 | // create a assembler label after
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| 275 | // marked as clobber all to avoid movement
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[ead174a] | 276 | __cfaasm_label(get, after);
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[8fc652e0] | 277 | return val;
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| 278 | }
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| 279 |
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[82ff5845] | 280 | extern "C" {
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[969b3fe] | 281 | // Disable interrupts by incrementing the counter
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[82ff5845] | 282 | void disable_interrupts() {
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[8fc652e0] | 283 | // create a assembler label before
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| 284 | // marked as clobber all to avoid movement
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[ead174a] | 285 | __cfaasm_label(dsable, before);
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[8fc652e0] | 286 |
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| 287 | with( __cfaabi_tls.preemption_state ) {
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[1f81d61] | 288 | #if GCC_VERSION > 50000
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[13073be] | 289 | static_assert(__atomic_always_lock_free(sizeof(enabled), &enabled), "Must be lock-free");
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[1f81d61] | 290 | #endif
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[13073be] | 291 |
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| 292 | // Set enabled flag to false
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| 293 | // should be atomic to avoid preemption in the middle of the operation.
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| 294 | // use memory order RELAXED since there is no inter-thread on this variable requirements
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| 295 | __atomic_store_n(&enabled, false, __ATOMIC_RELAXED);
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| 296 |
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| 297 | // Signal the compiler that a fence is needed but only for signal handlers
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| 298 | __atomic_signal_fence(__ATOMIC_ACQUIRE);
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| 299 |
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[de6319f] | 300 | __attribute__((unused)) unsigned short new_val = disable_count + 1;
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| 301 | disable_count = new_val;
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| 302 | verify( new_val < 65_000u ); // If this triggers someone is disabling interrupts without enabling them
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| 303 | }
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[8fc652e0] | 304 |
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| 305 | // create a assembler label after
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| 306 | // marked as clobber all to avoid movement
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[ead174a] | 307 | __cfaasm_label(dsable, after);
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| 308 |
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[82ff5845] | 309 | }
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| 310 |
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[969b3fe] | 311 | // Enable interrupts by decrementing the counter
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[c7a900a] | 312 | // If counter reaches 0, execute any pending __cfactx_switch
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[36982fc] | 313 | void enable_interrupts( __cfaabi_dbg_ctx_param ) {
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[ead174a] | 314 | // Cache the processor now since interrupts can start happening after the atomic store
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| 315 | processor * proc = __cfaabi_tls.this_processor;
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[8e9e9a2] | 316 | /* paranoid */ verify( proc );
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[969b3fe] | 317 |
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[8fc652e0] | 318 | with( __cfaabi_tls.preemption_state ){
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[de6319f] | 319 | unsigned short prev = disable_count;
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| 320 | disable_count -= 1;
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[ead174a] | 321 |
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| 322 | // If this triggers someone is enabled already enabled interruptsverify( prev != 0u );
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| 323 | /* paranoid */ verify( prev != 0u );
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[de6319f] | 324 |
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| 325 | // Check if we need to prempt the thread because an interrupt was missed
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| 326 | if( prev == 1 ) {
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[1f81d61] | 327 | #if GCC_VERSION > 50000
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[ead174a] | 328 | static_assert(__atomic_always_lock_free(sizeof(enabled), &enabled), "Must be lock-free");
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[1f81d61] | 329 | #endif
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[13073be] | 330 |
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| 331 | // Set enabled flag to true
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| 332 | // should be atomic to avoid preemption in the middle of the operation.
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| 333 | // use memory order RELAXED since there is no inter-thread on this variable requirements
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| 334 | __atomic_store_n(&enabled, true, __ATOMIC_RELAXED);
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| 335 |
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| 336 | // Signal the compiler that a fence is needed but only for signal handlers
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| 337 | __atomic_signal_fence(__ATOMIC_RELEASE);
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[de6319f] | 338 | if( proc->pending_preemption ) {
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| 339 | proc->pending_preemption = false;
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[3381ed7] | 340 | force_yield( __POLL_PREEMPTION );
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[de6319f] | 341 | }
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[d0a045c7] | 342 | }
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[82ff5845] | 343 | }
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[4e6fb8e] | 344 |
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[969b3fe] | 345 | // For debugging purposes : keep track of the last person to enable the interrupts
|
---|
[36982fc] | 346 | __cfaabi_dbg_debug_do( proc->last_enable = caller; )
|
---|
[82ff5845] | 347 | }
|
---|
[969b3fe] | 348 |
|
---|
| 349 | // Disable interrupts by incrementint the counter
|
---|
[c7a900a] | 350 | // Don't execute any pending __cfactx_switch even if counter reaches 0
|
---|
[969b3fe] | 351 | void enable_interrupts_noPoll() {
|
---|
[8fc652e0] | 352 | unsigned short prev = __cfaabi_tls.preemption_state.disable_count;
|
---|
| 353 | __cfaabi_tls.preemption_state.disable_count -= 1;
|
---|
[ead174a] | 354 | // If this triggers someone is enabled already enabled interrupts
|
---|
| 355 | /* paranoid */ verifyf( prev != 0u, "Incremented from %u\n", prev );
|
---|
[d0a045c7] | 356 | if( prev == 1 ) {
|
---|
[1f81d61] | 357 | #if GCC_VERSION > 50000
|
---|
[ead174a] | 358 | static_assert(__atomic_always_lock_free(sizeof(__cfaabi_tls.preemption_state.enabled), &__cfaabi_tls.preemption_state.enabled), "Must be lock-free");
|
---|
[1f81d61] | 359 | #endif
|
---|
[13073be] | 360 | // Set enabled flag to true
|
---|
| 361 | // should be atomic to avoid preemption in the middle of the operation.
|
---|
| 362 | // use memory order RELAXED since there is no inter-thread on this variable requirements
|
---|
[8fc652e0] | 363 | __atomic_store_n(&__cfaabi_tls.preemption_state.enabled, true, __ATOMIC_RELAXED);
|
---|
[13073be] | 364 |
|
---|
| 365 | // Signal the compiler that a fence is needed but only for signal handlers
|
---|
| 366 | __atomic_signal_fence(__ATOMIC_RELEASE);
|
---|
[d0a045c7] | 367 | }
|
---|
[969b3fe] | 368 | }
|
---|
[82ff5845] | 369 | }
|
---|
| 370 |
|
---|
[adf34b3] | 371 | //-----------------------------------------------------------------------------
|
---|
| 372 | // Kernel Signal Debug
|
---|
| 373 | void __cfaabi_check_preemption() {
|
---|
| 374 | bool ready = __preemption_enabled();
|
---|
| 375 | if(!ready) { abort("Preemption should be ready"); }
|
---|
| 376 |
|
---|
| 377 | __cfaasm_label(debug, before);
|
---|
| 378 |
|
---|
| 379 | sigset_t oldset;
|
---|
| 380 | int ret;
|
---|
| 381 | ret = pthread_sigmask(0, ( const sigset_t * ) 0p, &oldset); // workaround trac#208: cast should be unnecessary
|
---|
| 382 | if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); }
|
---|
| 383 |
|
---|
| 384 | ret = sigismember(&oldset, SIGUSR1);
|
---|
| 385 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 386 | if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); }
|
---|
| 387 |
|
---|
| 388 | ret = sigismember(&oldset, SIGALRM);
|
---|
| 389 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 390 | if(ret == 0) { abort("ERROR SIGALRM is enabled"); }
|
---|
| 391 |
|
---|
| 392 | ret = sigismember(&oldset, SIGTERM);
|
---|
| 393 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 394 | if(ret == 1) { abort("ERROR SIGTERM is disabled"); }
|
---|
| 395 |
|
---|
| 396 | __cfaasm_label(debug, after);
|
---|
| 397 | }
|
---|
| 398 |
|
---|
| 399 | #ifdef __CFA_WITH_VERIFY__
|
---|
| 400 | bool __cfaabi_dbg_in_kernel() {
|
---|
| 401 | return !__preemption_enabled();
|
---|
| 402 | }
|
---|
| 403 | #endif
|
---|
| 404 |
|
---|
[ead174a] | 405 | #undef __cfaasm_label
|
---|
| 406 |
|
---|
[adf34b3] | 407 | //-----------------------------------------------------------------------------
|
---|
| 408 | // Signal handling
|
---|
| 409 |
|
---|
[969b3fe] | 410 | // sigprocmask wrapper : unblock a single signal
|
---|
[7222630] | 411 | static inline void signal_unblock( int sig ) {
|
---|
[82ff5845] | 412 | sigset_t mask;
|
---|
| 413 | sigemptyset( &mask );
|
---|
[1c273d0] | 414 | sigaddset( &mask, sig );
|
---|
[82ff5845] | 415 |
|
---|
[27f5f71] | 416 | if ( pthread_sigmask( SIG_UNBLOCK, &mask, 0p ) == -1 ) {
|
---|
[169d944] | 417 | abort( "internal error, pthread_sigmask" );
|
---|
[cd17862] | 418 | }
|
---|
[82ff5845] | 419 | }
|
---|
| 420 |
|
---|
[969b3fe] | 421 | // sigprocmask wrapper : block a single signal
|
---|
[7222630] | 422 | static inline void signal_block( int sig ) {
|
---|
[cd17862] | 423 | sigset_t mask;
|
---|
| 424 | sigemptyset( &mask );
|
---|
| 425 | sigaddset( &mask, sig );
|
---|
[47ecf2b] | 426 |
|
---|
[27f5f71] | 427 | if ( pthread_sigmask( SIG_BLOCK, &mask, 0p ) == -1 ) {
|
---|
[c59a346] | 428 | abort( "internal error, pthread_sigmask" );
|
---|
[cd17862] | 429 | }
|
---|
| 430 | }
|
---|
[47ecf2b] | 431 |
|
---|
[969b3fe] | 432 | // kill wrapper : signal a processor
|
---|
[cd17862] | 433 | static void preempt( processor * this ) {
|
---|
[4dad189] | 434 | sigval_t value = { PREEMPT_NORMAL };
|
---|
| 435 | pthread_sigqueue( this->kernel_thread, SIGUSR1, value );
|
---|
| 436 | }
|
---|
| 437 |
|
---|
[969b3fe] | 438 | // reserved for future use
|
---|
[e873838] | 439 | static void timeout( $thread * this ) {
|
---|
| 440 | unpark( this );
|
---|
[cd17862] | 441 | }
|
---|
| 442 |
|
---|
[7222630] | 443 | void __disable_interrupts_hard() {
|
---|
| 444 | sigset_t oldset;
|
---|
| 445 | int ret;
|
---|
| 446 | ret = pthread_sigmask(0, ( const sigset_t * ) 0p, &oldset); // workaround trac#208: cast should be unnecessary
|
---|
| 447 | if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); }
|
---|
| 448 |
|
---|
| 449 | ret = sigismember(&oldset, SIGUSR1);
|
---|
| 450 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 451 | if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); }
|
---|
| 452 |
|
---|
| 453 | ret = sigismember(&oldset, SIGALRM);
|
---|
| 454 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 455 | if(ret == 0) { abort("ERROR SIGALRM is enabled"); }
|
---|
| 456 |
|
---|
| 457 | signal_block( SIGUSR1 );
|
---|
| 458 | }
|
---|
| 459 |
|
---|
| 460 | void __enable_interrupts_hard() {
|
---|
| 461 | signal_unblock( SIGUSR1 );
|
---|
| 462 |
|
---|
| 463 | sigset_t oldset;
|
---|
| 464 | int ret;
|
---|
| 465 | ret = pthread_sigmask(0, ( const sigset_t * ) 0p, &oldset); // workaround trac#208: cast should be unnecessary
|
---|
| 466 | if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); }
|
---|
| 467 |
|
---|
| 468 | ret = sigismember(&oldset, SIGUSR1);
|
---|
| 469 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 470 | if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); }
|
---|
| 471 |
|
---|
| 472 | ret = sigismember(&oldset, SIGALRM);
|
---|
| 473 | if(ret < 0) { abort("ERROR sigismember returned %d", ret); }
|
---|
| 474 | if(ret == 0) { abort("ERROR SIGALRM is enabled"); }
|
---|
| 475 | }
|
---|
| 476 |
|
---|
[82a2fed] | 477 | //-----------------------------------------------------------------------------
|
---|
| 478 | // Some assembly required
|
---|
| 479 | #if defined( __i386 )
|
---|
| 480 | #ifdef __PIC__
|
---|
| 481 | #define RELOC_PRELUDE( label ) \
|
---|
| 482 | "calll .Lcfaasm_prelude_" #label "$pb\n\t" \
|
---|
| 483 | ".Lcfaasm_prelude_" #label "$pb:\n\t" \
|
---|
| 484 | "popl %%eax\n\t" \
|
---|
| 485 | ".Lcfaasm_prelude_" #label "_end:\n\t" \
|
---|
| 486 | "addl $_GLOBAL_OFFSET_TABLE_+(.Lcfaasm_prelude_" #label "_end-.Lcfaasm_prelude_" #label "$pb), %%eax\n\t"
|
---|
| 487 | #define RELOC_PREFIX ""
|
---|
| 488 | #define RELOC_SUFFIX "@GOT(%%eax)"
|
---|
| 489 | #else
|
---|
| 490 | #define RELOC_PREFIX "$"
|
---|
| 491 | #define RELOC_SUFFIX ""
|
---|
| 492 | #endif
|
---|
[a12810d] | 493 | #define __cfaasm_label( label ) struct asm_region label = \
|
---|
[82a2fed] | 494 | ({ \
|
---|
| 495 | struct asm_region region; \
|
---|
| 496 | asm( \
|
---|
| 497 | RELOC_PRELUDE( label ) \
|
---|
| 498 | "movl " RELOC_PREFIX "__cfaasm_" #label "_before" RELOC_SUFFIX ", %[vb]\n\t" \
|
---|
| 499 | "movl " RELOC_PREFIX "__cfaasm_" #label "_after" RELOC_SUFFIX ", %[va]\n\t" \
|
---|
| 500 | : [vb]"=r"(region.before), [va]"=r"(region.after) \
|
---|
| 501 | ); \
|
---|
| 502 | region; \
|
---|
| 503 | });
|
---|
| 504 | #elif defined( __x86_64 )
|
---|
| 505 | #ifdef __PIC__
|
---|
| 506 | #define RELOC_PREFIX ""
|
---|
| 507 | #define RELOC_SUFFIX "@GOTPCREL(%%rip)"
|
---|
| 508 | #else
|
---|
| 509 | #define RELOC_PREFIX "$"
|
---|
| 510 | #define RELOC_SUFFIX ""
|
---|
| 511 | #endif
|
---|
[a12810d] | 512 | #define __cfaasm_label( label ) struct asm_region label = \
|
---|
[82a2fed] | 513 | ({ \
|
---|
| 514 | struct asm_region region; \
|
---|
| 515 | asm( \
|
---|
| 516 | "movq " RELOC_PREFIX "__cfaasm_" #label "_before" RELOC_SUFFIX ", %[vb]\n\t" \
|
---|
| 517 | "movq " RELOC_PREFIX "__cfaasm_" #label "_after" RELOC_SUFFIX ", %[va]\n\t" \
|
---|
| 518 | : [vb]"=r"(region.before), [va]"=r"(region.after) \
|
---|
| 519 | ); \
|
---|
| 520 | region; \
|
---|
| 521 | });
|
---|
| 522 | #elif defined( __aarch64__ )
|
---|
| 523 | #ifdef __PIC__
|
---|
[ead174a] | 524 | // Note that this works only for gcc
|
---|
[a12810d] | 525 | #define __cfaasm_label( label ) struct asm_region label = \
|
---|
[82a2fed] | 526 | ({ \
|
---|
| 527 | struct asm_region region; \
|
---|
| 528 | asm( \
|
---|
[ead174a] | 529 | "adrp %[vb], _GLOBAL_OFFSET_TABLE_" "\n\t" \
|
---|
| 530 | "ldr %[vb], [%[vb], #:gotpage_lo15:__cfaasm_" #label "_before]" "\n\t" \
|
---|
| 531 | "adrp %[va], _GLOBAL_OFFSET_TABLE_" "\n\t" \
|
---|
| 532 | "ldr %[va], [%[va], #:gotpage_lo15:__cfaasm_" #label "_after]" "\n\t" \
|
---|
[82a2fed] | 533 | : [vb]"=r"(region.before), [va]"=r"(region.after) \
|
---|
| 534 | ); \
|
---|
| 535 | region; \
|
---|
| 536 | });
|
---|
| 537 | #else
|
---|
[ead174a] | 538 | #error this is not the right thing to do
|
---|
[b5344a3] | 539 | /*
|
---|
[a12810d] | 540 | #define __cfaasm_label( label ) struct asm_region label = \
|
---|
[82a2fed] | 541 | ({ \
|
---|
| 542 | struct asm_region region; \
|
---|
| 543 | asm( \
|
---|
[b5344a3] | 544 | "adrp %[vb], __cfaasm_" #label "_before" "\n\t" \
|
---|
| 545 | "add %[vb], %[vb], :lo12:__cfaasm_" #label "_before" "\n\t" \
|
---|
| 546 | "adrp %[va], :got:__cfaasm_" #label "_after" "\n\t" \
|
---|
| 547 | "add %[va], %[va], :lo12:__cfaasm_" #label "_after" "\n\t" \
|
---|
[82a2fed] | 548 | : [vb]"=r"(region.before), [va]"=r"(region.after) \
|
---|
| 549 | ); \
|
---|
| 550 | region; \
|
---|
| 551 | });
|
---|
[b5344a3] | 552 | */
|
---|
[ead174a] | 553 | #endif
|
---|
[82a2fed] | 554 | #else
|
---|
| 555 | #error unknown hardware architecture
|
---|
| 556 | #endif
|
---|
| 557 |
|
---|
[14a61b5] | 558 | // KERNEL ONLY
|
---|
[c7a900a] | 559 | // Check if a __cfactx_switch signal handler shoud defer
|
---|
[969b3fe] | 560 | // If true : preemption is safe
|
---|
| 561 | // If false : preemption is unsafe and marked as pending
|
---|
[82a2fed] | 562 | static inline bool preemption_ready( void * ip ) {
|
---|
| 563 | // Get all the region for which it is not safe to preempt
|
---|
| 564 | __cfaasm_label( get );
|
---|
| 565 | __cfaasm_label( check );
|
---|
| 566 | __cfaasm_label( dsable );
|
---|
[adf34b3] | 567 | __cfaasm_label( debug );
|
---|
[14a61b5] | 568 |
|
---|
[82a2fed] | 569 | // Check if preemption is safe
|
---|
| 570 | bool ready = true;
|
---|
| 571 | if( __cfaasm_in( ip, get ) ) { ready = false; goto EXIT; };
|
---|
| 572 | if( __cfaasm_in( ip, check ) ) { ready = false; goto EXIT; };
|
---|
| 573 | if( __cfaasm_in( ip, dsable ) ) { ready = false; goto EXIT; };
|
---|
[adf34b3] | 574 | if( __cfaasm_in( ip, debug ) ) { ready = false; goto EXIT; };
|
---|
[82a2fed] | 575 | if( !__cfaabi_tls.preemption_state.enabled) { ready = false; goto EXIT; };
|
---|
| 576 | if( __cfaabi_tls.preemption_state.in_progress ) { ready = false; goto EXIT; };
|
---|
| 577 |
|
---|
| 578 | EXIT:
|
---|
[14a61b5] | 579 | // Adjust the pending flag accordingly
|
---|
[8fc652e0] | 580 | __cfaabi_tls.this_processor->pending_preemption = !ready;
|
---|
[969b3fe] | 581 | return ready;
|
---|
| 582 | }
|
---|
| 583 |
|
---|
[cd17862] | 584 | //=============================================================================================
|
---|
| 585 | // Kernel Signal Startup/Shutdown logic
|
---|
| 586 | //=============================================================================================
|
---|
| 587 |
|
---|
[969b3fe] | 588 | // Startup routine to activate preemption
|
---|
| 589 | // Called from kernel_startup
|
---|
[e660761] | 590 | void __kernel_alarm_startup() {
|
---|
[169d944] | 591 | __cfaabi_dbg_print_safe( "Kernel : Starting preemption\n" );
|
---|
[969b3fe] | 592 |
|
---|
| 593 | // Start with preemption disabled until ready
|
---|
[8fc652e0] | 594 | __cfaabi_tls.preemption_state.enabled = false;
|
---|
| 595 | __cfaabi_tls.preemption_state.disable_count = 1;
|
---|
[969b3fe] | 596 |
|
---|
| 597 | // Initialize the event kernel
|
---|
| 598 | event_kernel = (event_kernel_t *)&storage_event_kernel;
|
---|
[9236060] | 599 | (*event_kernel){};
|
---|
[969b3fe] | 600 |
|
---|
| 601 | // Setup proper signal handlers
|
---|
[6047b00] | 602 | __cfaabi_sigaction( SIGUSR1, sigHandler_ctxSwitch, SA_SIGINFO ); // __cfactx_switch handler
|
---|
| 603 | __cfaabi_sigaction( SIGALRM, sigHandler_alarm , SA_SIGINFO ); // debug handler
|
---|
[cd17862] | 604 |
|
---|
| 605 | signal_block( SIGALRM );
|
---|
| 606 |
|
---|
[8c50aed] | 607 | alarm_stack = __create_pthread( &alarm_thread, alarm_loop, 0p );
|
---|
[cd17862] | 608 | }
|
---|
| 609 |
|
---|
[969b3fe] | 610 | // Shutdown routine to deactivate preemption
|
---|
| 611 | // Called from kernel_shutdown
|
---|
[e660761] | 612 | void __kernel_alarm_shutdown() {
|
---|
[169d944] | 613 | __cfaabi_dbg_print_safe( "Kernel : Preemption stopping\n" );
|
---|
[d6ff3ff] | 614 |
|
---|
[969b3fe] | 615 | // Block all signals since we are already shutting down
|
---|
[cd17862] | 616 | sigset_t mask;
|
---|
| 617 | sigfillset( &mask );
|
---|
[27f5f71] | 618 | sigprocmask( SIG_BLOCK, &mask, 0p );
|
---|
[cd17862] | 619 |
|
---|
[969b3fe] | 620 | // Notify the alarm thread of the shutdown
|
---|
[a0b3e32] | 621 | sigval val = { 1 };
|
---|
| 622 | pthread_sigqueue( alarm_thread, SIGALRM, val );
|
---|
[969b3fe] | 623 |
|
---|
| 624 | // Wait for the preemption thread to finish
|
---|
[27f5f71] | 625 |
|
---|
[bfcf6b9] | 626 | __destroy_pthread( alarm_thread, alarm_stack, 0p );
|
---|
[969b3fe] | 627 |
|
---|
| 628 | // Preemption is now fully stopped
|
---|
| 629 |
|
---|
[169d944] | 630 | __cfaabi_dbg_print_safe( "Kernel : Preemption stopped\n" );
|
---|
[cd17862] | 631 | }
|
---|
| 632 |
|
---|
[92bfda0] | 633 | // Prevent preemption since we are about to start terminating things
|
---|
| 634 | void __kernel_abort_lock(void) {
|
---|
| 635 | signal_block( SIGUSR1 );
|
---|
| 636 | }
|
---|
| 637 |
|
---|
[969b3fe] | 638 | // Raii ctor/dtor for the preemption_scope
|
---|
| 639 | // Used by thread to control when they want to receive preemption signals
|
---|
[242a902] | 640 | void ?{}( preemption_scope & this, processor * proc ) {
|
---|
[2a84d06d] | 641 | (this.alarm){ proc, (Time){ 0 }, 0`s };
|
---|
[242a902] | 642 | this.proc = proc;
|
---|
| 643 | this.proc->preemption_alarm = &this.alarm;
|
---|
[969b3fe] | 644 |
|
---|
[d8548e2] | 645 | update_preemption( this.proc, this.proc->cltr->preemption_rate );
|
---|
[cd17862] | 646 | }
|
---|
| 647 |
|
---|
[242a902] | 648 | void ^?{}( preemption_scope & this ) {
|
---|
[cd17862] | 649 | disable_interrupts();
|
---|
| 650 |
|
---|
[2a84d06d] | 651 | update_preemption( this.proc, 0`s );
|
---|
[cd17862] | 652 | }
|
---|
| 653 |
|
---|
| 654 | //=============================================================================================
|
---|
| 655 | // Kernel Signal Handlers
|
---|
| 656 | //=============================================================================================
|
---|
[54dcab1] | 657 | __cfaabi_dbg_debug_do( static thread_local void * last_interrupt = 0; )
|
---|
[47ecf2b] | 658 |
|
---|
[969b3fe] | 659 | // Context switch signal handler
|
---|
| 660 | // Receives SIGUSR1 signal and causes the current thread to yield
|
---|
[c29c342] | 661 | static void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ) {
|
---|
[8fc652e0] | 662 | void * ip = (void *)(cxt->uc_mcontext.CFA_REG_IP);
|
---|
| 663 | __cfaabi_dbg_debug_do( last_interrupt = ip; )
|
---|
[969b3fe] | 664 |
|
---|
[4dad189] | 665 | // SKULLDUGGERY: if a thread creates a processor and the immediately deletes it,
|
---|
| 666 | // the interrupt that is supposed to force the kernel thread to preempt might arrive
|
---|
[482fa08] | 667 | // before the kernel thread has even started running. When that happens, an interrupt
|
---|
[97cba9f] | 668 | // with a null 'this_processor' will be caught, just ignore it.
|
---|
[8fc652e0] | 669 | if(! __cfaabi_tls.this_processor ) return;
|
---|
[4dad189] | 670 |
|
---|
| 671 | choose(sfp->si_value.sival_int) {
|
---|
| 672 | case PREEMPT_NORMAL : ;// Normal case, nothing to do here
|
---|
[8fc652e0] | 673 | case PREEMPT_TERMINATE: verify( __atomic_load_n( &__cfaabi_tls.this_processor->do_terminate, __ATOMIC_SEQ_CST ) );
|
---|
[4dad189] | 674 | default:
|
---|
[ff878b7] | 675 | abort( "internal error, signal value is %d", sfp->si_value.sival_int );
|
---|
[4dad189] | 676 | }
|
---|
| 677 |
|
---|
[b2b44d8] | 678 | // Check if it is safe to preempt here
|
---|
[82a2fed] | 679 | if( !preemption_ready( ip ) ) { return; }
|
---|
[8fc652e0] | 680 |
|
---|
| 681 | __cfaabi_dbg_print_buffer_decl( " KERNEL: preempting core %p (%p @ %p).\n", __cfaabi_tls.this_processor, __cfaabi_tls.this_thread, (void *)(cxt->uc_mcontext.CFA_REG_IP) );
|
---|
[14a61b5] | 682 |
|
---|
| 683 | // Sync flag : prevent recursive calls to the signal handler
|
---|
[8fc652e0] | 684 | __cfaabi_tls.preemption_state.in_progress = true;
|
---|
[14a61b5] | 685 |
|
---|
[a83ffa4] | 686 | // Clear sighandler mask before context switching.
|
---|
[1f81d61] | 687 | #if GCC_VERSION > 50000
|
---|
[a83ffa4] | 688 | static_assert( sizeof( sigset_t ) == sizeof( cxt->uc_sigmask ), "Expected cxt->uc_sigmask to be of sigset_t" );
|
---|
[1f81d61] | 689 | #endif
|
---|
[27f5f71] | 690 | if ( pthread_sigmask( SIG_SETMASK, (sigset_t *)&(cxt->uc_sigmask), 0p ) == -1 ) {
|
---|
[a83ffa4] | 691 | abort( "internal error, sigprocmask" );
|
---|
| 692 | }
|
---|
[05615ba] | 693 |
|
---|
[14a61b5] | 694 | // Clear the in progress flag
|
---|
[8fc652e0] | 695 | __cfaabi_tls.preemption_state.in_progress = false;
|
---|
[969b3fe] | 696 |
|
---|
| 697 | // Preemption can occur here
|
---|
| 698 |
|
---|
[c7a900a] | 699 | force_yield( __ALARM_PREEMPTION ); // Do the actual __cfactx_switch
|
---|
[c81ebf9] | 700 | }
|
---|
| 701 |
|
---|
[c59a346] | 702 | static void sigHandler_alarm( __CFA_SIGPARMS__ ) {
|
---|
| 703 | abort("SIGALRM should never reach the signal handler");
|
---|
[c81ebf9] | 704 | }
|
---|
| 705 |
|
---|
[1b033b8] | 706 | #if !defined(__CFA_NO_STATISTICS__)
|
---|
| 707 | int __print_alarm_stats = 0;
|
---|
| 708 | #endif
|
---|
| 709 |
|
---|
[969b3fe] | 710 | // Main of the alarm thread
|
---|
| 711 | // Waits on SIGALRM and send SIGUSR1 to whom ever needs it
|
---|
[c29c342] | 712 | static void * alarm_loop( __attribute__((unused)) void * args ) {
|
---|
[9b1dcc2] | 713 | __processor_id_t id;
|
---|
[58d64a4] | 714 | id.full_proc = false;
|
---|
[9b1dcc2] | 715 | id.id = doregister(&id);
|
---|
[8fc652e0] | 716 | __cfaabi_tls.this_proc_id = &id;
|
---|
[9b1dcc2] | 717 |
|
---|
[1b033b8] | 718 | #if !defined(__CFA_NO_STATISTICS__)
|
---|
| 719 | struct __stats_t local_stats;
|
---|
| 720 | __cfaabi_tls.this_stats = &local_stats;
|
---|
| 721 | __init_stats( &local_stats );
|
---|
| 722 | #endif
|
---|
| 723 |
|
---|
[969b3fe] | 724 | // Block sigalrms to control when they arrive
|
---|
[cd17862] | 725 | sigset_t mask;
|
---|
[ade5272] | 726 | sigfillset(&mask);
|
---|
[27f5f71] | 727 | if ( pthread_sigmask( SIG_BLOCK, &mask, 0p ) == -1 ) {
|
---|
[169d944] | 728 | abort( "internal error, pthread_sigmask" );
|
---|
[82ff5845] | 729 | }
|
---|
[c81ebf9] | 730 |
|
---|
[ade5272] | 731 | sigemptyset( &mask );
|
---|
| 732 | sigaddset( &mask, SIGALRM );
|
---|
| 733 |
|
---|
[969b3fe] | 734 | // Main loop
|
---|
[cd17862] | 735 | while( true ) {
|
---|
[969b3fe] | 736 | // Wait for a sigalrm
|
---|
[a0b3e32] | 737 | siginfo_t info;
|
---|
| 738 | int sig = sigwaitinfo( &mask, &info );
|
---|
[969b3fe] | 739 |
|
---|
[e2f7bc3] | 740 | if( sig < 0 ) {
|
---|
| 741 | //Error!
|
---|
| 742 | int err = errno;
|
---|
| 743 | switch( err ) {
|
---|
| 744 | case EAGAIN :
|
---|
| 745 | case EINTR :
|
---|
[b1a4300] | 746 | {__cfaabi_dbg_print_buffer_decl( " KERNEL: Spurious wakeup %d.\n", err );}
|
---|
[e2f7bc3] | 747 | continue;
|
---|
[27f5f71] | 748 | case EINVAL :
|
---|
[169d944] | 749 | abort( "Timeout was invalid." );
|
---|
[e2f7bc3] | 750 | default:
|
---|
[169d944] | 751 | abort( "Unhandled error %d", err);
|
---|
[e2f7bc3] | 752 | }
|
---|
| 753 | }
|
---|
| 754 |
|
---|
[969b3fe] | 755 | // If another signal arrived something went wrong
|
---|
[8cb529e] | 756 | assertf(sig == SIGALRM, "Kernel Internal Error, sigwait: Unexpected signal %d (%d : %d)\n", sig, info.si_code, info.si_value.sival_int);
|
---|
| 757 |
|
---|
[169d944] | 758 | // __cfaabi_dbg_print_safe( "Kernel : Caught alarm from %d with %d\n", info.si_code, info.si_value.sival_int );
|
---|
[969b3fe] | 759 | // Switch on the code (a.k.a. the sender) to
|
---|
[8cb529e] | 760 | switch( info.si_code )
|
---|
[a0b3e32] | 761 | {
|
---|
[969b3fe] | 762 | // Timers can apparently be marked as sent for the kernel
|
---|
| 763 | // In either case, tick preemption
|
---|
[8cb529e] | 764 | case SI_TIMER:
|
---|
| 765 | case SI_KERNEL:
|
---|
[169d944] | 766 | // __cfaabi_dbg_print_safe( "Kernel : Preemption thread tick\n" );
|
---|
[36982fc] | 767 | lock( event_kernel->lock __cfaabi_dbg_ctx2 );
|
---|
[e873838] | 768 | tick_preemption();
|
---|
[ea7d2b0] | 769 | unlock( event_kernel->lock );
|
---|
[8cb529e] | 770 | break;
|
---|
[969b3fe] | 771 | // Signal was not sent by the kernel but by an other thread
|
---|
[8cb529e] | 772 | case SI_QUEUE:
|
---|
[969b3fe] | 773 | // For now, other thread only signal the alarm thread to shut it down
|
---|
| 774 | // If this needs to change use info.si_value and handle the case here
|
---|
[8cb529e] | 775 | goto EXIT;
|
---|
[cd17862] | 776 | }
|
---|
| 777 | }
|
---|
[a0b3e32] | 778 |
|
---|
[8cb529e] | 779 | EXIT:
|
---|
[169d944] | 780 | __cfaabi_dbg_print_safe( "Kernel : Preemption thread stopping\n" );
|
---|
[9b1dcc2] | 781 | unregister(&id);
|
---|
[1b033b8] | 782 |
|
---|
| 783 | #if !defined(__CFA_NO_STATISTICS__)
|
---|
| 784 | if( 0 != __print_alarm_stats ) {
|
---|
| 785 | __print_stats( &local_stats, __print_alarm_stats, "Alarm", "Thread", 0p );
|
---|
| 786 | }
|
---|
| 787 | #endif
|
---|
[27f5f71] | 788 | return 0p;
|
---|
[82ff5845] | 789 | }
|
---|
| 790 |
|
---|
[6b0b624] | 791 | // Local Variables: //
|
---|
| 792 | // mode: c //
|
---|
| 793 | // tab-width: 4 //
|
---|
| 794 | // End: //
|
---|