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