[f07e037] | 1 | // -*- Mode: CFA -*- |
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| 2 | // |
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| 3 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 4 | // |
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| 5 | // The contents of this file are covered under the licence agreement in the |
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| 6 | // file "LICENCE" distributed with Cforall. |
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| 7 | // |
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[84c52a8] | 8 | // monitor_desc.c -- |
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[f07e037] | 9 | // |
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| 10 | // Author : Thierry Delisle |
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| 11 | // Created On : Thd Feb 23 12:27:26 2017 |
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| 12 | // Last Modified By : Thierry Delisle |
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| 13 | // Last Modified On : -- |
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| 14 | // Update Count : 0 |
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| 15 | // |
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| 16 | |
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| 17 | #include "monitor" |
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| 18 | |
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[a933dcf4] | 19 | #include <stdlib> |
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| 20 | |
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[f07e037] | 21 | #include "kernel_private.h" |
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[5ea06d6] | 22 | #include "libhdr.h" |
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[f07e037] | 23 | |
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[0c78741] | 24 | //----------------------------------------------------------------------------- |
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| 25 | // Forward declarations |
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| 26 | static inline void set_owner( monitor_desc * this, thread_desc * owner ); |
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| 27 | static inline thread_desc * next_thread( monitor_desc * this ); |
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| 28 | |
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| 29 | static inline void lock_all( spinlock ** locks, unsigned short count ); |
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| 30 | static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count ); |
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| 31 | static inline void unlock_all( spinlock ** locks, unsigned short count ); |
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| 32 | static inline void unlock_all( monitor_desc ** locks, unsigned short count ); |
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| 33 | |
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| 34 | static inline void save_recursion ( monitor_desc ** ctx, unsigned int * /*out*/ recursions, unsigned short count ); |
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| 35 | static inline void restore_recursion( monitor_desc ** ctx, unsigned int * /*in */ recursions, unsigned short count ); |
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| 36 | |
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| 37 | static inline thread_desc * check_condition( __condition_criterion_t * ); |
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| 38 | static inline void brand_condition( condition * ); |
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| 39 | static inline unsigned short insert_unique( thread_desc ** thrds, unsigned short end, thread_desc * val ); |
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| 40 | |
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| 41 | //----------------------------------------------------------------------------- |
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| 42 | // Enter/Leave routines |
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[690f13c] | 43 | |
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| 44 | |
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[cb0e6de] | 45 | extern "C" { |
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[0c78741] | 46 | void __enter_monitor_desc(monitor_desc * this) { |
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[cb0e6de] | 47 | lock( &this->lock ); |
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| 48 | thread_desc * thrd = this_thread(); |
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[f07e037] | 49 | |
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[0c78741] | 50 | LIB_DEBUG_PRINT_SAFE("%p Entering %p (o: %p, r: %i)\n", thrd, this, this->owner, this->recursion); |
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[5ea06d6] | 51 | |
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[cb0e6de] | 52 | if( !this->owner ) { |
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| 53 | //No one has the monitor, just take it |
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[cd348e7] | 54 | set_owner( this, thrd ); |
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[cb0e6de] | 55 | } |
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| 56 | else if( this->owner == thrd) { |
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| 57 | //We already have the monitor, just not how many times we took it |
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| 58 | assert( this->recursion > 0 ); |
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| 59 | this->recursion += 1; |
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| 60 | } |
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| 61 | else { |
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| 62 | //Some one else has the monitor, wait in line for it |
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| 63 | append( &this->entry_queue, thrd ); |
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| 64 | ScheduleInternal( &this->lock ); |
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[cc7f4b1] | 65 | |
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[cb0e6de] | 66 | //ScheduleInternal will unlock spinlock, no need to unlock ourselves |
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| 67 | return; |
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| 68 | } |
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[f07e037] | 69 | |
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[cb0e6de] | 70 | unlock( &this->lock ); |
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[5ea06d6] | 71 | return; |
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[cb0e6de] | 72 | } |
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[f07e037] | 73 | |
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[690f13c] | 74 | // leave pseudo code : |
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[0c78741] | 75 | // TODO |
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| 76 | void __leave_monitor_desc(monitor_desc * this) { |
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[cb0e6de] | 77 | lock( &this->lock ); |
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[f07e037] | 78 | |
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[cb0e6de] | 79 | thread_desc * thrd = this_thread(); |
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[0c78741] | 80 | |
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| 81 | LIB_DEBUG_PRINT_SAFE("%p Leaving %p (o: %p, r: %i)\n", thrd, this, this->owner, this->recursion); |
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| 82 | assertf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i)", thrd, this->owner, this->recursion ); |
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[cc7f4b1] | 83 | |
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[cb0e6de] | 84 | //Leaving a recursion level, decrement the counter |
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| 85 | this->recursion -= 1; |
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[f07e037] | 86 | |
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[690f13c] | 87 | //If we haven't left the last level of recursion |
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| 88 | //it means we don't need to do anything |
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| 89 | if( this->recursion != 0) { |
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| 90 | unlock( &this->lock ); |
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| 91 | return; |
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| 92 | } |
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[f07e037] | 93 | |
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[0c78741] | 94 | thread_desc * new_owner = next_thread( this ); |
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[5ea06d6] | 95 | |
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[690f13c] | 96 | //We can now let other threads in safely |
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[cb0e6de] | 97 | unlock( &this->lock ); |
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[51f3798] | 98 | |
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[690f13c] | 99 | //We need to wake-up the thread |
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| 100 | ScheduleThread( new_owner ); |
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[cc7f4b1] | 101 | } |
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[2781e65] | 102 | } |
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| 103 | |
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[5ea06d6] | 104 | static inline void enter(monitor_desc ** monitors, int count) { |
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[0c78741] | 105 | for(int i = 0; i < count; i++) { |
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| 106 | __enter_monitor_desc( monitors[i] ); |
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[2781e65] | 107 | } |
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| 108 | } |
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| 109 | |
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[5ea06d6] | 110 | static inline void leave(monitor_desc ** monitors, int count) { |
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[0c78741] | 111 | for(int i = count - 1; i >= 0; i--) { |
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| 112 | __leave_monitor_desc( monitors[i] ); |
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[2781e65] | 113 | } |
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[5ea06d6] | 114 | } |
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| 115 | |
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| 116 | void ?{}( monitor_guard_t * this, monitor_desc ** m, int count ) { |
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| 117 | this->m = m; |
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| 118 | this->count = count; |
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| 119 | qsort(this->m, count); |
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| 120 | enter( this->m, this->count ); |
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| 121 | |
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| 122 | this->prev_mntrs = this_thread()->current_monitors; |
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| 123 | this->prev_count = this_thread()->current_monitor_count; |
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| 124 | |
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| 125 | this_thread()->current_monitors = m; |
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| 126 | this_thread()->current_monitor_count = count; |
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| 127 | } |
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| 128 | |
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| 129 | void ^?{}( monitor_guard_t * this ) { |
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| 130 | leave( this->m, this->count ); |
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| 131 | |
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| 132 | this_thread()->current_monitors = this->prev_mntrs; |
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| 133 | this_thread()->current_monitor_count = this->prev_count; |
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| 134 | } |
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| 135 | |
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[ad1a8dd] | 136 | void debug_break() __attribute__(( noinline )) |
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| 137 | { |
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| 138 | |
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| 139 | } |
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| 140 | |
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[5ea06d6] | 141 | //----------------------------------------------------------------------------- |
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| 142 | // Internal scheduling |
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| 143 | void wait( condition * this ) { |
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[0c78741] | 144 | LIB_DEBUG_PRINT_SAFE("Waiting\n"); |
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[5ea06d6] | 145 | |
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[0c78741] | 146 | brand_condition( this ); |
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[5ea06d6] | 147 | |
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| 148 | //Check that everything is as expected |
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[0c78741] | 149 | assertf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors ); |
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| 150 | assertf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count ); |
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[5ea06d6] | 151 | |
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[0c78741] | 152 | unsigned short count = this->monitor_count; |
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[9c59cd4] | 153 | unsigned int recursions[ count ]; //Save the current recursion levels to restore them later |
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| 154 | spinlock * locks [ count ]; //We need to pass-in an array of locks to ScheduleInternal |
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[0c78741] | 155 | |
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| 156 | LIB_DEBUG_PRINT_SAFE("count %i\n", count); |
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| 157 | |
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| 158 | __condition_node_t waiter; |
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| 159 | waiter.waiting_thread = this_thread(); |
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| 160 | waiter.count = count; |
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| 161 | waiter.next = NULL; |
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| 162 | |
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| 163 | __condition_criterion_t criteria[count]; |
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| 164 | for(int i = 0; i < count; i++) { |
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| 165 | criteria[i].ready = false; |
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| 166 | criteria[i].target = this->monitors[i]; |
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| 167 | criteria[i].owner = &waiter; |
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| 168 | criteria[i].next = NULL; |
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| 169 | LIB_DEBUG_PRINT_SAFE( "Criterion %p\n", &criteria[i] ); |
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| 170 | } |
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[5ea06d6] | 171 | |
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[0c78741] | 172 | waiter.criteria = criteria; |
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| 173 | append( &this->blocked, &waiter ); |
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[5ea06d6] | 174 | |
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[9c59cd4] | 175 | lock_all( this->monitors, locks, count ); |
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| 176 | save_recursion( this->monitors, recursions, count ); |
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[0c78741] | 177 | //DON'T unlock, ask the kernel to do it |
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[5ea06d6] | 178 | |
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[0c78741] | 179 | //Find the next thread(s) to run |
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[ad1a8dd] | 180 | unsigned short thread_count = 0; |
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[0c78741] | 181 | thread_desc * threads[ count ]; |
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[ad1a8dd] | 182 | for(int i = 0; i < count; i++) { |
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| 183 | threads[i] = 0; |
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| 184 | } |
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| 185 | |
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| 186 | debug_break(); |
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[5ea06d6] | 187 | |
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[0c78741] | 188 | for( int i = 0; i < count; i++) { |
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| 189 | thread_desc * new_owner = next_thread( this->monitors[i] ); |
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[ad1a8dd] | 190 | thread_count = insert_unique( threads, thread_count, new_owner ); |
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[5ea06d6] | 191 | } |
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| 192 | |
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[ad1a8dd] | 193 | debug_break(); |
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| 194 | |
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[0c78741] | 195 | LIB_DEBUG_PRINT_SAFE("Will unblock: "); |
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| 196 | for(int i = 0; i < thread_count; i++) { |
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| 197 | LIB_DEBUG_PRINT_SAFE("%p ", threads[i]); |
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| 198 | } |
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| 199 | LIB_DEBUG_PRINT_SAFE("\n"); |
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[5ea06d6] | 200 | |
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[9c59cd4] | 201 | // Everything is ready to go to sleep |
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| 202 | ScheduleInternal( locks, count, threads, thread_count ); |
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[5ea06d6] | 203 | |
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| 204 | |
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| 205 | //WE WOKE UP |
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| 206 | |
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| 207 | |
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| 208 | //We are back, restore the owners and recursions |
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[9c59cd4] | 209 | lock_all( locks, count ); |
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| 210 | restore_recursion( this->monitors, recursions, count ); |
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| 211 | unlock_all( locks, count ); |
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[5ea06d6] | 212 | } |
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| 213 | |
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[0c78741] | 214 | void signal( condition * this ) { |
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| 215 | if( !this->blocked.head ) { |
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| 216 | LIB_DEBUG_PRINT_SAFE("Nothing to signal\n"); |
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| 217 | return; |
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| 218 | } |
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[5ea06d6] | 219 | |
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| 220 | //Check that everything is as expected |
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| 221 | assert( this->monitors ); |
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| 222 | assert( this->monitor_count != 0 ); |
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[0c78741] | 223 | |
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| 224 | unsigned short count = this->monitor_count; |
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[5ea06d6] | 225 | |
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| 226 | LIB_DEBUG_DO( |
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[0c78741] | 227 | thread_desc * this_thrd = this_thread(); |
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| 228 | if ( this->monitor_count != this_thrd->current_monitor_count ) { |
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| 229 | abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", this, this->monitor_count, this_thrd->current_monitor_count ); |
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[5ea06d6] | 230 | } // if |
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[0c78741] | 231 | |
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| 232 | for(int i = 0; i < this->monitor_count; i++) { |
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| 233 | if ( this->monitors[i] != this_thrd->current_monitors[i] ) { |
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| 234 | abortf( "Signal on condition %p made with different monitor, expected %p got %i", this, this->monitors[i], this_thrd->current_monitors[i] ); |
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| 235 | } // if |
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| 236 | } |
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[5ea06d6] | 237 | ); |
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| 238 | |
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[0c78741] | 239 | lock_all( this->monitors, NULL, count ); |
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| 240 | LIB_DEBUG_PRINT_SAFE("Signalling"); |
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| 241 | |
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| 242 | __condition_node_t * node = pop_head( &this->blocked ); |
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| 243 | for(int i = 0; i < count; i++) { |
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| 244 | __condition_criterion_t * crit = &node->criteria[i]; |
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| 245 | LIB_DEBUG_PRINT_SAFE(" %p", crit->target); |
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| 246 | assert( !crit->ready ); |
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| 247 | push( &crit->target->signal_stack, crit ); |
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[5ea06d6] | 248 | } |
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[0c78741] | 249 | |
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| 250 | LIB_DEBUG_PRINT_SAFE("\n"); |
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| 251 | |
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| 252 | unlock_all( this->monitors, count ); |
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[5ea06d6] | 253 | } |
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| 254 | |
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[0c78741] | 255 | //----------------------------------------------------------------------------- |
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| 256 | // Utilities |
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| 257 | |
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| 258 | static inline void set_owner( monitor_desc * this, thread_desc * owner ) { |
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| 259 | //Pass the monitor appropriately |
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| 260 | this->owner = owner; |
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| 261 | |
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| 262 | //We are passing the monitor to someone else, which means recursion level is not 0 |
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| 263 | this->recursion = owner ? 1 : 0; |
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| 264 | } |
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| 265 | |
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| 266 | static inline thread_desc * next_thread( monitor_desc * this ) { |
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| 267 | //Check the signaller stack |
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| 268 | __condition_criterion_t * urgent = pop( &this->signal_stack ); |
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| 269 | if( urgent ) { |
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| 270 | //The signaller stack is not empty, |
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| 271 | //regardless of if we are ready to baton pass, |
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| 272 | //we need to set the monitor as in use |
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| 273 | set_owner( this, urgent->owner->waiting_thread ); |
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| 274 | |
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| 275 | return check_condition( urgent ); |
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| 276 | } |
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| 277 | |
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| 278 | // No signaller thread |
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| 279 | // Get the next thread in the entry_queue |
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| 280 | thread_desc * new_owner = pop_head( &this->entry_queue ); |
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| 281 | set_owner( this, new_owner ); |
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| 282 | |
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| 283 | return new_owner; |
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| 284 | } |
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| 285 | |
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| 286 | static inline void lock_all( spinlock ** locks, unsigned short count ) { |
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| 287 | for( int i = 0; i < count; i++ ) { |
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| 288 | lock( locks[i] ); |
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| 289 | } |
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| 290 | } |
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| 291 | |
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| 292 | static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count ) { |
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| 293 | for( int i = 0; i < count; i++ ) { |
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| 294 | spinlock * l = &source[i]->lock; |
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| 295 | lock( l ); |
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| 296 | if(locks) locks[i] = l; |
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| 297 | } |
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| 298 | } |
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| 299 | |
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| 300 | static inline void unlock_all( spinlock ** locks, unsigned short count ) { |
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| 301 | for( int i = 0; i < count; i++ ) { |
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| 302 | unlock( locks[i] ); |
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| 303 | } |
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| 304 | } |
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| 305 | |
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| 306 | static inline void unlock_all( monitor_desc ** locks, unsigned short count ) { |
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| 307 | for( int i = 0; i < count; i++ ) { |
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| 308 | unlock( &locks[i]->lock ); |
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| 309 | } |
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| 310 | } |
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| 311 | |
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| 312 | |
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| 313 | static inline void save_recursion ( monitor_desc ** ctx, unsigned int * /*out*/ recursions, unsigned short count ) { |
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| 314 | for( int i = 0; i < count; i++ ) { |
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| 315 | recursions[i] = ctx[i]->recursion; |
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| 316 | } |
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| 317 | } |
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| 318 | |
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| 319 | static inline void restore_recursion( monitor_desc ** ctx, unsigned int * /*in */ recursions, unsigned short count ) { |
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| 320 | for( int i = 0; i < count; i++ ) { |
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| 321 | ctx[i]->recursion = recursions[i]; |
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| 322 | } |
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| 323 | } |
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| 324 | |
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| 325 | // Function has 2 different behavior |
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| 326 | // 1 - Marks a monitors as being ready to run |
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| 327 | // 2 - Checks if all the monitors are ready to run |
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| 328 | // if so return the thread to run |
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| 329 | static inline thread_desc * check_condition( __condition_criterion_t * target ) { |
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| 330 | __condition_node_t * node = target->owner; |
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| 331 | unsigned short count = node->count; |
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| 332 | __condition_criterion_t * criteria = node->criteria; |
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| 333 | |
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| 334 | bool ready2run = true; |
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| 335 | |
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| 336 | for( int i = 0; i < count; i++ ) { |
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| 337 | LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target ); |
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| 338 | if( &criteria[i] == target ) { |
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| 339 | criteria[i].ready = true; |
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| 340 | LIB_DEBUG_PRINT_SAFE( "True\n" ); |
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| 341 | } |
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| 342 | |
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| 343 | ready2run = criteria[i].ready && ready2run; |
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| 344 | } |
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| 345 | |
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| 346 | LIB_DEBUG_PRINT_SAFE( "Runing %i\n", ready2run ); |
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| 347 | return ready2run ? node->waiting_thread : NULL; |
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| 348 | } |
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| 349 | |
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| 350 | static inline void brand_condition( condition * this ) { |
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| 351 | thread_desc * thrd = this_thread(); |
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| 352 | if( !this->monitors ) { |
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| 353 | LIB_DEBUG_PRINT_SAFE("Branding\n"); |
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| 354 | assertf( thrd->current_monitors != NULL, "No current monitor to brand condition", thrd->current_monitors ); |
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| 355 | this->monitor_count = thrd->current_monitor_count; |
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[a933dcf4] | 356 | |
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| 357 | this->monitors = malloc( this->monitor_count * sizeof( *this->monitors ) ); |
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| 358 | for( int i = 0; i < this->monitor_count; i++ ) { |
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| 359 | this->monitors[i] = thrd->current_monitors[i]; |
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| 360 | } |
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[0c78741] | 361 | } |
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| 362 | } |
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| 363 | |
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| 364 | static inline unsigned short insert_unique( thread_desc ** thrds, unsigned short end, thread_desc * val ) { |
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[ad1a8dd] | 365 | if( !val ) return end; |
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| 366 | |
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| 367 | for(int i = 0; i <= end; i++) { |
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[0c78741] | 368 | if( thrds[i] == val ) return end; |
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| 369 | } |
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| 370 | |
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| 371 | thrds[end] = val; |
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| 372 | return end + 1; |
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| 373 | } |
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| 374 | |
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| 375 | void ?{}( __condition_blocked_queue_t * this ) { |
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| 376 | this->head = NULL; |
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| 377 | this->tail = &this->head; |
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| 378 | } |
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| 379 | |
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| 380 | void append( __condition_blocked_queue_t * this, __condition_node_t * c ) { |
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| 381 | assert(this->tail != NULL); |
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| 382 | *this->tail = c; |
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| 383 | this->tail = &c->next; |
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| 384 | } |
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| 385 | |
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| 386 | __condition_node_t * pop_head( __condition_blocked_queue_t * this ) { |
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| 387 | __condition_node_t * head = this->head; |
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| 388 | if( head ) { |
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| 389 | this->head = head->next; |
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| 390 | if( !head->next ) { |
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| 391 | this->tail = &this->head; |
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| 392 | } |
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| 393 | head->next = NULL; |
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| 394 | } |
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| 395 | return head; |
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[f07e037] | 396 | } |
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