[ab1b971] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2021 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // locks.hfa -- PUBLIC |
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| 8 | // Runtime locks that used with the runtime thread system. |
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| 9 | // |
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| 10 | // Author : Colby Alexander Parsons |
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| 11 | // Created On : Thu Jan 21 19:46:50 2021 |
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| 12 | // Last Modified By : |
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| 13 | // Last Modified On : |
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| 14 | // Update Count : |
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| 15 | // |
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| 16 | |
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[f4e35326] | 17 | #pragma once |
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| 18 | |
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[848439f] | 19 | #include <stdbool.h> |
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[5a46e09] | 20 | #include <stdio.h> |
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[848439f] | 21 | |
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[ab1b971] | 22 | #include "bits/weakso_locks.hfa" |
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[f4ec5e45] | 23 | #include "containers/queueLockFree.hfa" |
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[82f4063] | 24 | #include "containers/list.hfa" |
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[f4ec5e45] | 25 | |
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[07033ce] | 26 | #include "limits.hfa" |
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[f4ec5e45] | 27 | #include "thread.hfa" |
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[848439f] | 28 | |
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| 29 | #include "time_t.hfa" |
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| 30 | #include "time.hfa" |
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| 31 | |
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[f4ec5e45] | 32 | //----------------------------------------------------------------------------- |
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| 33 | // Semaphore |
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| 34 | struct semaphore { |
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| 35 | __spinlock_t lock; |
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| 36 | int count; |
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[e84ab3d] | 37 | __queue_t(thread$) waiting; |
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[f4ec5e45] | 38 | }; |
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| 39 | |
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| 40 | void ?{}(semaphore & this, int count = 1); |
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| 41 | void ^?{}(semaphore & this); |
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| 42 | bool P (semaphore & this); |
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| 43 | bool V (semaphore & this); |
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| 44 | bool V (semaphore & this, unsigned count); |
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[e84ab3d] | 45 | thread$ * V (semaphore & this, bool ); |
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[f4ec5e45] | 46 | |
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[ab1b971] | 47 | //---------- |
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| 48 | struct single_acquisition_lock { |
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| 49 | inline blocking_lock; |
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| 50 | }; |
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| 51 | |
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| 52 | static inline void ?{}( single_acquisition_lock & this ) {((blocking_lock &)this){ false, false };} |
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| 53 | static inline void ^?{}( single_acquisition_lock & this ) {} |
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[22b7579] | 54 | static inline void lock ( single_acquisition_lock & this ) { lock ( (blocking_lock &)this ); } |
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| 55 | static inline bool try_lock ( single_acquisition_lock & this ) { return try_lock( (blocking_lock &)this ); } |
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| 56 | static inline void unlock ( single_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); } |
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| 57 | static inline size_t on_wait ( single_acquisition_lock & this ) { return on_wait ( (blocking_lock &)this ); } |
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| 58 | static inline void on_wakeup( single_acquisition_lock & this, size_t v ) { on_wakeup ( (blocking_lock &)this, v ); } |
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[e84ab3d] | 59 | static inline void on_notify( single_acquisition_lock & this, struct thread$ * t ) { on_notify( (blocking_lock &)this, t ); } |
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[ab1b971] | 60 | |
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| 61 | //---------- |
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| 62 | struct owner_lock { |
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| 63 | inline blocking_lock; |
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| 64 | }; |
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| 65 | |
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| 66 | static inline void ?{}( owner_lock & this ) {((blocking_lock &)this){ true, true };} |
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| 67 | static inline void ^?{}( owner_lock & this ) {} |
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[f19497c] | 68 | static inline void lock ( owner_lock & this ) { lock ( (blocking_lock &)this ); } |
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[d27b6be] | 69 | static inline bool try_lock ( owner_lock & this ) { return try_lock( (blocking_lock &)this ); } |
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[f19497c] | 70 | static inline void unlock ( owner_lock & this ) { unlock ( (blocking_lock &)this ); } |
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[22b7579] | 71 | static inline size_t on_wait ( owner_lock & this ) { return on_wait ( (blocking_lock &)this ); } |
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| 72 | static inline void on_wakeup( owner_lock & this, size_t v ) { on_wakeup ( (blocking_lock &)this, v ); } |
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[e84ab3d] | 73 | static inline void on_notify( owner_lock & this, struct thread$ * t ) { on_notify( (blocking_lock &)this, t ); } |
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[ab1b971] | 74 | |
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[7f958c4] | 75 | //----------------------------------------------------------------------------- |
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| 76 | // MCS Lock |
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[f4ec5e45] | 77 | struct mcs_node { |
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| 78 | mcs_node * volatile next; |
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| 79 | single_sem sem; |
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| 80 | }; |
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| 81 | |
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[8f5576d5] | 82 | static inline void ?{}(mcs_node & this) { this.next = 0p; } |
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[f4ec5e45] | 83 | |
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| 84 | static inline mcs_node * volatile & ?`next ( mcs_node * node ) { |
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| 85 | return node->next; |
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| 86 | } |
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| 87 | |
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| 88 | struct mcs_lock { |
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| 89 | mcs_queue(mcs_node) queue; |
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| 90 | }; |
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| 91 | |
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| 92 | static inline void lock(mcs_lock & l, mcs_node & n) { |
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| 93 | if(push(l.queue, &n)) |
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| 94 | wait(n.sem); |
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| 95 | } |
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| 96 | |
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| 97 | static inline void unlock(mcs_lock & l, mcs_node & n) { |
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| 98 | mcs_node * next = advance(l.queue, &n); |
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| 99 | if(next) post(next->sem); |
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| 100 | } |
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| 101 | |
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[7f958c4] | 102 | //----------------------------------------------------------------------------- |
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| 103 | // Linear backoff Spinlock |
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[5a46e09] | 104 | struct linear_backoff_then_block_lock { |
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| 105 | // Spin lock used for mutual exclusion |
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| 106 | __spinlock_t spinlock; |
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| 107 | |
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| 108 | // Current thread owning the lock |
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[e84ab3d] | 109 | struct thread$ * owner; |
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[5a46e09] | 110 | |
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| 111 | // List of blocked threads |
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[e84ab3d] | 112 | dlist( thread$ ) blocked_threads; |
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[5a46e09] | 113 | |
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| 114 | // Used for comparing and exchanging |
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| 115 | volatile size_t lock_value; |
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| 116 | |
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| 117 | // used for linear backoff spinning |
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| 118 | int spin_start; |
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| 119 | int spin_end; |
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| 120 | int spin_count; |
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| 121 | |
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| 122 | // after unsuccessful linear backoff yield this many times |
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| 123 | int yield_count; |
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| 124 | }; |
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| 125 | |
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| 126 | static inline void ?{}( linear_backoff_then_block_lock & this, int spin_start, int spin_end, int spin_count, int yield_count ) { |
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| 127 | this.spinlock{}; |
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| 128 | this.blocked_threads{}; |
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| 129 | this.lock_value = 0; |
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| 130 | this.spin_start = spin_start; |
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| 131 | this.spin_end = spin_end; |
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| 132 | this.spin_count = spin_count; |
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| 133 | this.yield_count = yield_count; |
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| 134 | } |
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[55ad35c] | 135 | static inline void ?{}( linear_backoff_then_block_lock & this ) { this{4, 1024, 16, 0}; } |
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[5a46e09] | 136 | static inline void ^?{}( linear_backoff_then_block_lock & this ) {} |
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[eba9d27] | 137 | static inline void ?{}( linear_backoff_then_block_lock & this, linear_backoff_then_block_lock this2 ) = void; |
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| 138 | static inline void ?=?( linear_backoff_then_block_lock & this, linear_backoff_then_block_lock this2 ) = void; |
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[5a46e09] | 139 | |
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| 140 | static inline bool internal_try_lock(linear_backoff_then_block_lock & this, size_t & compare_val) with(this) { |
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| 141 | if (__atomic_compare_exchange_n(&lock_value, &compare_val, 1, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) { |
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| 142 | owner = active_thread(); |
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| 143 | return true; |
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| 144 | } |
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| 145 | return false; |
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| 146 | } |
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| 147 | |
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| 148 | static inline bool try_lock(linear_backoff_then_block_lock & this) { size_t compare_val = 0; return internal_try_lock(this, compare_val); } |
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| 149 | |
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| 150 | static inline bool try_lock_contention(linear_backoff_then_block_lock & this) with(this) { |
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| 151 | if (__atomic_exchange_n(&lock_value, 2, __ATOMIC_ACQUIRE) == 0) { |
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| 152 | owner = active_thread(); |
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| 153 | return true; |
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| 154 | } |
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| 155 | return false; |
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| 156 | } |
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| 157 | |
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| 158 | static inline bool block(linear_backoff_then_block_lock & this) with(this) { |
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| 159 | lock( spinlock __cfaabi_dbg_ctx2 ); |
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| 160 | if (lock_value != 2) { |
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| 161 | unlock( spinlock ); |
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| 162 | return true; |
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| 163 | } |
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| 164 | insert_last( blocked_threads, *active_thread() ); |
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| 165 | unlock( spinlock ); |
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| 166 | park( ); |
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| 167 | return true; |
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| 168 | } |
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| 169 | |
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[0d4f954] | 170 | static inline void lock(linear_backoff_then_block_lock & this) with(this) { |
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[5a46e09] | 171 | // if owner just return |
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[0d4f954] | 172 | if (active_thread() == owner) return; |
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[5a46e09] | 173 | size_t compare_val = 0; |
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| 174 | int spin = spin_start; |
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| 175 | // linear backoff |
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| 176 | for( ;; ) { |
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| 177 | compare_val = 0; |
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[0d4f954] | 178 | if (internal_try_lock(this, compare_val)) return; |
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[5a46e09] | 179 | if (2 == compare_val) break; |
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| 180 | for (int i = 0; i < spin; i++) Pause(); |
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| 181 | if (spin >= spin_end) break; |
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| 182 | spin += spin; |
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| 183 | } |
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| 184 | |
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[0d4f954] | 185 | if(2 != compare_val && try_lock_contention(this)) return; |
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[b7763da] | 186 | // block until signalled |
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[0d4f954] | 187 | while (block(this)) if(try_lock_contention(this)) return; |
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[b7763da] | 188 | } |
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| 189 | |
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[5a46e09] | 190 | static inline void unlock(linear_backoff_then_block_lock & this) with(this) { |
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| 191 | verify(lock_value > 0); |
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| 192 | owner = 0p; |
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| 193 | if (__atomic_exchange_n(&lock_value, 0, __ATOMIC_RELEASE) == 1) return; |
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| 194 | lock( spinlock __cfaabi_dbg_ctx2 ); |
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[e84ab3d] | 195 | thread$ * t = &try_pop_front( blocked_threads ); |
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[5a46e09] | 196 | unlock( spinlock ); |
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| 197 | unpark( t ); |
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| 198 | } |
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| 199 | |
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[e84ab3d] | 200 | static inline void on_notify(linear_backoff_then_block_lock & this, struct thread$ * t ) { unpark(t); } |
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[dcad80a] | 201 | static inline size_t on_wait(linear_backoff_then_block_lock & this) { unlock(this); return 0; } |
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[bbe3719] | 202 | static inline void on_wakeup(linear_backoff_then_block_lock & this, size_t recursion ) { lock(this); } |
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[5a46e09] | 203 | |
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[7f958c4] | 204 | //----------------------------------------------------------------------------- |
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| 205 | // Fast Block Lock |
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| 206 | |
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| 207 | // High efficiency minimal blocking lock |
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| 208 | // - No reacquire for cond var |
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| 209 | // - No recursive acquisition |
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| 210 | // - No ownership |
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| 211 | struct fast_block_lock { |
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| 212 | // Spin lock used for mutual exclusion |
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| 213 | __spinlock_t lock; |
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| 214 | |
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| 215 | // List of blocked threads |
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| 216 | dlist( thread$ ) blocked_threads; |
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| 217 | |
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| 218 | bool held:1; |
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| 219 | }; |
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| 220 | |
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| 221 | static inline void ?{}( fast_block_lock & this ) with(this) { |
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| 222 | lock{}; |
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| 223 | blocked_threads{}; |
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| 224 | held = false; |
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| 225 | } |
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| 226 | static inline void ^?{}( fast_block_lock & this ) {} |
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| 227 | static inline void ?{}( fast_block_lock & this, fast_block_lock this2 ) = void; |
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| 228 | static inline void ?=?( fast_block_lock & this, fast_block_lock this2 ) = void; |
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| 229 | |
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| 230 | // if this is called recursively IT WILL DEADLOCK!!!!! |
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| 231 | static inline void lock(fast_block_lock & this) with(this) { |
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| 232 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 233 | if (held) { |
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| 234 | insert_last( blocked_threads, *active_thread() ); |
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| 235 | unlock( lock ); |
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| 236 | park( ); |
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| 237 | return; |
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| 238 | } |
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| 239 | held = true; |
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| 240 | unlock( lock ); |
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| 241 | } |
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| 242 | |
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| 243 | static inline void unlock(fast_block_lock & this) with(this) { |
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| 244 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 245 | /* paranoid */ verifyf( held != false, "Attempt to release lock %p that isn't held", &this ); |
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| 246 | thread$ * t = &try_pop_front( blocked_threads ); |
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| 247 | held = ( t ? true : false ); |
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| 248 | unpark( t ); |
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| 249 | unlock( lock ); |
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| 250 | } |
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| 251 | |
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| 252 | static inline void on_notify(fast_block_lock & this, struct thread$ * t ) { unpark(t); } |
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| 253 | static inline size_t on_wait(fast_block_lock & this) { unlock(this); return 0; } |
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| 254 | static inline void on_wakeup(fast_block_lock & this, size_t recursion ) { } |
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| 255 | |
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[ac5816d] | 256 | //----------------------------------------------------------------------------- |
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| 257 | // is_blocking_lock |
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[fd54fef] | 258 | trait is_blocking_lock(L & | sized(L)) { |
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[ac5816d] | 259 | // For synchronization locks to use when acquiring |
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[e84ab3d] | 260 | void on_notify( L &, struct thread$ * ); |
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[ac5816d] | 261 | |
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| 262 | // For synchronization locks to use when releasing |
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[22b7579] | 263 | size_t on_wait( L & ); |
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[ac5816d] | 264 | |
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| 265 | // to set recursion count after getting signalled; |
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[22b7579] | 266 | void on_wakeup( L &, size_t recursion ); |
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[ac5816d] | 267 | }; |
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[848439f] | 268 | |
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[ac5816d] | 269 | //----------------------------------------------------------------------------- |
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[82f4063] | 270 | // // info_thread |
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| 271 | // // the info thread is a wrapper around a thread used |
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| 272 | // // to store extra data for use in the condition variable |
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[fd54fef] | 273 | forall(L & | is_blocking_lock(L)) { |
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[ac5816d] | 274 | struct info_thread; |
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[c131a02] | 275 | |
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[82f4063] | 276 | // // for use by sequence |
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| 277 | // info_thread(L) *& Back( info_thread(L) * this ); |
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| 278 | // info_thread(L) *& Next( info_thread(L) * this ); |
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[848439f] | 279 | } |
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| 280 | |
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[ac5816d] | 281 | //----------------------------------------------------------------------------- |
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| 282 | // Synchronization Locks |
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[fd54fef] | 283 | forall(L & | is_blocking_lock(L)) { |
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[7f958c4] | 284 | |
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| 285 | //----------------------------------------------------------------------------- |
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| 286 | // condition_variable |
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| 287 | |
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| 288 | // The multi-tool condition variable |
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| 289 | // - can pass timeouts to wait for either a signal or timeout |
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| 290 | // - can wait without passing a lock |
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| 291 | // - can have waiters reacquire different locks while waiting on the same cond var |
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| 292 | // - has shadow queue |
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| 293 | // - can be signalled outside of critical sections with no locks held |
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[eeb5023] | 294 | struct condition_variable { |
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[848439f] | 295 | // Spin lock used for mutual exclusion |
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| 296 | __spinlock_t lock; |
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| 297 | |
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| 298 | // List of blocked threads |
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[82f4063] | 299 | dlist( info_thread(L) ) blocked_threads; |
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[848439f] | 300 | |
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| 301 | // Count of current blocked threads |
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| 302 | int count; |
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| 303 | }; |
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[e84ab3d] | 304 | |
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[848439f] | 305 | |
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[ac5816d] | 306 | void ?{}( condition_variable(L) & this ); |
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[848439f] | 307 | void ^?{}( condition_variable(L) & this ); |
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| 308 | |
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[eeb5023] | 309 | bool notify_one( condition_variable(L) & this ); |
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| 310 | bool notify_all( condition_variable(L) & this ); |
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[848439f] | 311 | |
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[eeb5023] | 312 | uintptr_t front( condition_variable(L) & this ); |
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[848439f] | 313 | |
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[ac5816d] | 314 | bool empty ( condition_variable(L) & this ); |
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| 315 | int counter( condition_variable(L) & this ); |
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[848439f] | 316 | |
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[eeb5023] | 317 | void wait( condition_variable(L) & this ); |
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| 318 | void wait( condition_variable(L) & this, uintptr_t info ); |
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[dff1fd1] | 319 | bool wait( condition_variable(L) & this, Duration duration ); |
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| 320 | bool wait( condition_variable(L) & this, uintptr_t info, Duration duration ); |
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[848439f] | 321 | |
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[eeb5023] | 322 | void wait( condition_variable(L) & this, L & l ); |
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| 323 | void wait( condition_variable(L) & this, L & l, uintptr_t info ); |
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[dff1fd1] | 324 | bool wait( condition_variable(L) & this, L & l, Duration duration ); |
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| 325 | bool wait( condition_variable(L) & this, L & l, uintptr_t info, Duration duration ); |
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[7f958c4] | 326 | |
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| 327 | //----------------------------------------------------------------------------- |
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| 328 | // fast_cond_var |
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| 329 | |
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| 330 | // The trimmed and slim condition variable |
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| 331 | // - no internal lock so you must hold a lock while using this cond var |
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| 332 | // - signalling without holding branded lock is UNSAFE! |
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| 333 | // - only allows usage of one lock, cond var is branded after usage |
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| 334 | struct fast_cond_var { |
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| 335 | // List of blocked threads |
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| 336 | dlist( info_thread(L) ) blocked_threads; |
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| 337 | |
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| 338 | #ifdef __CFA_DEBUG__ |
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| 339 | L * lock_used; |
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| 340 | #endif |
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| 341 | }; |
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| 342 | |
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| 343 | |
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| 344 | void ?{}( fast_cond_var(L) & this ); |
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| 345 | void ^?{}( fast_cond_var(L) & this ); |
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| 346 | |
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| 347 | bool notify_one( fast_cond_var(L) & this ); |
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| 348 | bool notify_all( fast_cond_var(L) & this ); |
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| 349 | |
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| 350 | uintptr_t front( fast_cond_var(L) & this ); |
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| 351 | |
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| 352 | bool empty ( fast_cond_var(L) & this ); |
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| 353 | |
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| 354 | void wait( fast_cond_var(L) & this, L & l ); |
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| 355 | void wait( fast_cond_var(L) & this, L & l, uintptr_t info ); |
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[f4ec5e45] | 356 | } |
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