[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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[690f13c] | 22 | void set_owner( monitor_desc * this, thread_desc * owner ) { |
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| 23 | //Pass the monitor appropriately |
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| 24 | this->owner = owner; |
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| 25 | |
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| 26 | //We are passing the monitor to someone else, which means recursion level is not 0 |
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| 27 | this->recursion = owner ? 1 : 0; |
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| 28 | } |
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| 29 | |
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[cb0e6de] | 30 | extern "C" { |
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[5ea06d6] | 31 | void __enter_monitor_desc(monitor_desc * this, monitor_desc * leader) { |
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[cb0e6de] | 32 | lock( &this->lock ); |
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| 33 | thread_desc * thrd = this_thread(); |
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[f07e037] | 34 | |
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[cd348e7] | 35 | // //Update the stack owner |
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| 36 | // this->stack_owner = leader; |
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| 37 | |
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| 38 | LIB_DEBUG_PRINT_SAFE("Entering %p (o: %p, r: %i)\n", this, this->owner, this->recursion); |
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[5ea06d6] | 39 | |
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[cb0e6de] | 40 | if( !this->owner ) { |
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| 41 | //No one has the monitor, just take it |
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[cd348e7] | 42 | set_owner( this, thrd ); |
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[cb0e6de] | 43 | } |
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| 44 | else if( this->owner == thrd) { |
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| 45 | //We already have the monitor, just not how many times we took it |
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| 46 | assert( this->recursion > 0 ); |
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| 47 | this->recursion += 1; |
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| 48 | } |
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| 49 | else { |
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| 50 | //Some one else has the monitor, wait in line for it |
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| 51 | append( &this->entry_queue, thrd ); |
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| 52 | ScheduleInternal( &this->lock ); |
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[cc7f4b1] | 53 | |
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[cb0e6de] | 54 | //ScheduleInternal will unlock spinlock, no need to unlock ourselves |
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| 55 | return; |
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| 56 | } |
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[f07e037] | 57 | |
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[cb0e6de] | 58 | unlock( &this->lock ); |
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[5ea06d6] | 59 | return; |
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[cb0e6de] | 60 | } |
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[f07e037] | 61 | |
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[690f13c] | 62 | // leave pseudo code : |
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| 63 | // decrement level |
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| 64 | // leve == 0 ? |
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| 65 | // no : done |
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| 66 | // yes : |
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| 67 | // signal stack empty ? |
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| 68 | // has leader : |
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| 69 | // bulk acquiring means we don't own the signal stack |
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| 70 | // ignore it but don't release the monitor |
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| 71 | // yes : |
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| 72 | // next in entry queue is new owner |
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| 73 | // no : |
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| 74 | // top of the signal stack is the owner |
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| 75 | // context switch to him right away |
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| 76 | // |
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[5ea06d6] | 77 | void __leave_monitor_desc(monitor_desc * this, monitor_desc * leader) { |
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[cb0e6de] | 78 | lock( &this->lock ); |
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[f07e037] | 79 | |
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[cd348e7] | 80 | LIB_DEBUG_PRINT_SAFE("Leaving %p (o: %p, r: %i)\n", this, this->owner, this->recursion); |
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| 81 | |
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[cb0e6de] | 82 | thread_desc * thrd = this_thread(); |
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[cd348e7] | 83 | assertf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i)", this->owner, thrd, this->recursion ); |
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[cc7f4b1] | 84 | |
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[cb0e6de] | 85 | //Leaving a recursion level, decrement the counter |
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| 86 | this->recursion -= 1; |
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[f07e037] | 87 | |
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[690f13c] | 88 | //If we haven't left the last level of recursion |
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| 89 | //it means we don't need to do anything |
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| 90 | if( this->recursion != 0) { |
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[cd348e7] | 91 | // this->stack_owner = leader; |
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[690f13c] | 92 | unlock( &this->lock ); |
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| 93 | return; |
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| 94 | } |
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| 95 | |
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[cd348e7] | 96 | // //If we don't own the signal stack then just leave it to the owner |
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| 97 | // if( this->stack_owner ) { |
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| 98 | // this->stack_owner = leader; |
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| 99 | // unlock( &this->lock ); |
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| 100 | // return; |
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| 101 | // } |
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[690f13c] | 102 | |
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| 103 | //We are the stack owner and have left the last recursion level. |
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| 104 | //We are in charge of passing the monitor |
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[cb0e6de] | 105 | thread_desc * new_owner = 0; |
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[cc7f4b1] | 106 | |
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[690f13c] | 107 | //Check the signaller stack |
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| 108 | new_owner = pop( &this->signal_stack ); |
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| 109 | if( new_owner ) { |
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| 110 | //The signaller stack is not empty, |
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| 111 | //transfer control immediately |
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| 112 | set_owner( this, new_owner ); |
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[cd348e7] | 113 | // this->stack_owner = leader; |
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[690f13c] | 114 | ScheduleInternal( &this->lock, new_owner ); |
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| 115 | return; |
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| 116 | } |
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| 117 | |
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| 118 | // No signaller thread |
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| 119 | // Get the next thread in the entry_queue |
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| 120 | new_owner = pop_head( &this->entry_queue ); |
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| 121 | set_owner( this, new_owner ); |
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[f07e037] | 122 | |
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[cd348e7] | 123 | // //Update the stack owner |
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| 124 | // this->stack_owner = leader; |
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[5ea06d6] | 125 | |
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[690f13c] | 126 | //We can now let other threads in safely |
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[cb0e6de] | 127 | unlock( &this->lock ); |
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[51f3798] | 128 | |
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[690f13c] | 129 | //We need to wake-up the thread |
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| 130 | ScheduleThread( new_owner ); |
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[cc7f4b1] | 131 | } |
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[2781e65] | 132 | } |
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| 133 | |
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[5ea06d6] | 134 | static inline void enter(monitor_desc ** monitors, int count) { |
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| 135 | __enter_monitor_desc( monitors[0], NULL ); |
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| 136 | for(int i = 1; i < count; i++) { |
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| 137 | __enter_monitor_desc( monitors[i], monitors[0] ); |
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[2781e65] | 138 | } |
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| 139 | } |
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| 140 | |
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[5ea06d6] | 141 | static inline void leave(monitor_desc ** monitors, int count) { |
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| 142 | __leave_monitor_desc( monitors[0], NULL ); |
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[cd348e7] | 143 | for(int i = count - 1; i >= 1; i--) { |
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[5ea06d6] | 144 | __leave_monitor_desc( monitors[i], monitors[0] ); |
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[2781e65] | 145 | } |
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[5ea06d6] | 146 | } |
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| 147 | |
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| 148 | void ?{}( monitor_guard_t * this, monitor_desc ** m, int count ) { |
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| 149 | this->m = m; |
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| 150 | this->count = count; |
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| 151 | qsort(this->m, count); |
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| 152 | enter( this->m, this->count ); |
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| 153 | |
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| 154 | this->prev_mntrs = this_thread()->current_monitors; |
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| 155 | this->prev_count = this_thread()->current_monitor_count; |
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| 156 | |
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| 157 | this_thread()->current_monitors = m; |
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| 158 | this_thread()->current_monitor_count = count; |
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| 159 | } |
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| 160 | |
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| 161 | void ^?{}( monitor_guard_t * this ) { |
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| 162 | leave( this->m, this->count ); |
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| 163 | |
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| 164 | this_thread()->current_monitors = this->prev_mntrs; |
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| 165 | this_thread()->current_monitor_count = this->prev_count; |
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| 166 | } |
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| 167 | |
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| 168 | //----------------------------------------------------------------------------- |
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| 169 | // Internal scheduling |
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| 170 | void wait( condition * this ) { |
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[cd348e7] | 171 | assertf(false, "NO SUPPORTED"); |
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[5ea06d6] | 172 | // LIB_DEBUG_FPRINTF("Waiting\n"); |
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| 173 | thread_desc * this_thrd = this_thread(); |
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| 174 | |
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| 175 | if( !this->monitors ) { |
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| 176 | this->monitors = this_thrd->current_monitors; |
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| 177 | this->monitor_count = this_thrd->current_monitor_count; |
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| 178 | } |
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| 179 | |
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| 180 | unsigned short count = this->monitor_count; |
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| 181 | |
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| 182 | //Check that everything is as expected |
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| 183 | assert( this->monitors != NULL ); |
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| 184 | assert( this->monitor_count != 0 ); |
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| 185 | |
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| 186 | unsigned int recursions[ count ]; //Save the current recursion levels to restore them later |
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| 187 | spinlock * locks [ count ]; //We need to pass-in an array of locks to ScheduleInternal |
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| 188 | |
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| 189 | // LIB_DEBUG_FPRINTF("Getting ready to wait\n"); |
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| 190 | |
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| 191 | //Loop on all the monitors and release the owner |
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| 192 | for( unsigned int i = 0; i < count; i++ ) { |
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| 193 | monitor_desc * cur = this->monitors[i]; |
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| 194 | |
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| 195 | assert( cur ); |
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| 196 | |
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| 197 | // LIB_DEBUG_FPRINTF("cur %p lock %p\n", cur, &cur->lock); |
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| 198 | |
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| 199 | //Store the locks for later |
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| 200 | locks[i] = &cur->lock; |
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| 201 | |
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| 202 | //Protect the monitors |
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| 203 | lock( locks[i] ); |
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| 204 | { |
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| 205 | //Save the recursion levels |
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| 206 | recursions[i] = cur->recursion; |
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| 207 | |
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| 208 | //Release the owner |
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| 209 | cur->recursion = 0; |
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| 210 | cur->owner = NULL; |
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| 211 | } |
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| 212 | //Release the monitor |
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| 213 | unlock( locks[i] ); |
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| 214 | } |
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| 215 | |
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| 216 | // LIB_DEBUG_FPRINTF("Waiting now\n"); |
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| 217 | |
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| 218 | //Everything is ready to go to sleep |
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| 219 | ScheduleInternal( locks, count ); |
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| 220 | |
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| 221 | |
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| 222 | //WE WOKE UP |
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| 223 | |
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| 224 | |
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| 225 | //We are back, restore the owners and recursions |
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| 226 | for( unsigned int i = 0; i < count; i++ ) { |
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| 227 | monitor_desc * cur = this->monitors[i]; |
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| 228 | |
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| 229 | //Protect the monitors |
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| 230 | lock( locks[i] ); |
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| 231 | { |
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| 232 | //Release the owner |
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| 233 | cur->owner = this_thrd; |
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| 234 | cur->recursion = recursions[i]; |
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| 235 | } |
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| 236 | //Release the monitor |
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| 237 | unlock( locks[i] ); |
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| 238 | } |
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| 239 | } |
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| 240 | |
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| 241 | static void __signal_internal( condition * this ) { |
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[cd348e7] | 242 | assertf(false, "NO SUPPORTED"); |
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[5ea06d6] | 243 | if( !this->blocked.head ) return; |
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| 244 | |
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| 245 | //Check that everything is as expected |
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| 246 | assert( this->monitors ); |
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| 247 | assert( this->monitor_count != 0 ); |
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| 248 | |
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| 249 | LIB_DEBUG_DO( |
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| 250 | if ( this->monitors != this_thread()->current_monitors ) { |
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| 251 | abortf( "Signal on condition %p made outside of the correct monitor(s)", this ); |
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| 252 | } // if |
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| 253 | ); |
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| 254 | |
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| 255 | monitor_desc * owner = this->monitors[0]; |
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| 256 | lock( &owner->lock ); |
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| 257 | { |
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| 258 | thread_desc * unblock = pop_head( &this->blocked ); |
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| 259 | push( &owner->signal_stack, unblock ); |
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| 260 | } |
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| 261 | unlock( &owner->lock ); |
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| 262 | } |
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| 263 | |
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| 264 | void signal( condition * this ) { |
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| 265 | __signal_internal( this ); |
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[f07e037] | 266 | } |
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