[848439f] | 1 | #include "locks.hfa" |
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| 2 | #include "kernel_private.hfa" |
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| 3 | |
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| 4 | #include <kernel.hfa> |
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| 5 | #include <stdlib.hfa> |
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| 6 | |
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[ac5816d] | 7 | //----------------------------------------------------------------------------- |
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| 8 | // info_thread |
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[fd54fef] | 9 | forall(L & | is_blocking_lock(L)) { |
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[ac5816d] | 10 | struct info_thread { |
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| 11 | // used to put info_thread on a dl queue (aka sequence) |
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| 12 | inline Seqable; |
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| 13 | |
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| 14 | // waiting thread |
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| 15 | struct $thread * t; |
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| 16 | |
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| 17 | // shadow field |
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| 18 | uintptr_t info; |
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| 19 | |
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| 20 | // lock that is passed to wait() (if one is passed) |
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| 21 | L * lock; |
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| 22 | |
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| 23 | // true when signalled and false when timeout wakes thread |
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| 24 | bool signalled; |
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| 25 | }; |
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[848439f] | 26 | |
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[ac5816d] | 27 | void ?{}( info_thread(L) & this, $thread * t, uintptr_t info, L * l ) { |
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[cad1df1] | 28 | ((Seqable &) this){}; |
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[848439f] | 29 | this.t = t; |
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| 30 | this.info = info; |
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[ac5816d] | 31 | this.lock = l; |
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[848439f] | 32 | } |
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| 33 | |
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[ac5816d] | 34 | void ^?{}( info_thread(L) & this ) {} |
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[c131a02] | 35 | |
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| 36 | info_thread(L) *& Back( info_thread(L) * this ) { |
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| 37 | return (info_thread(L) *)Back( (Seqable *)this ); |
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| 38 | } |
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| 39 | |
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| 40 | info_thread(L) *& Next( info_thread(L) * this ) { |
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| 41 | return (info_thread(L) *)Next( (Colable *)this ); |
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| 42 | } |
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[848439f] | 43 | } |
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[cad1df1] | 44 | |
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[ac5816d] | 45 | //----------------------------------------------------------------------------- |
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| 46 | // Blocking Locks |
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[848439f] | 47 | void ?{}( blocking_lock & this, bool multi_acquisition, bool strict_owner ) { |
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| 48 | this.lock{}; |
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| 49 | this.blocked_threads{}; |
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| 50 | this.wait_count = 0; |
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| 51 | this.multi_acquisition = multi_acquisition; |
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| 52 | this.strict_owner = strict_owner; |
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| 53 | this.owner = 0p; |
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| 54 | this.recursion_count = 0; |
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| 55 | } |
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| 56 | |
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[cad1df1] | 57 | void ^?{}( blocking_lock & this ) {} |
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[ac5816d] | 58 | void ?{}( single_acquisition_lock & this ) {((blocking_lock &)this){ false, false };} |
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[cad1df1] | 59 | void ^?{}( single_acquisition_lock & this ) {} |
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[ac5816d] | 60 | void ?{}( owner_lock & this ) {((blocking_lock &)this){ true, true };} |
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[cad1df1] | 61 | void ^?{}( owner_lock & this ) {} |
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[ac5816d] | 62 | void ?{}( multiple_acquisition_lock & this ) {((blocking_lock &)this){ true, false };} |
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[cad1df1] | 63 | void ^?{}( multiple_acquisition_lock & this ) {} |
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[848439f] | 64 | |
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| 65 | void lock( blocking_lock & this ) with( this ) { |
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| 66 | lock( lock __cfaabi_dbg_ctx2 ); |
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[ac5816d] | 67 | $thread * thrd = active_thread(); |
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| 68 | |
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| 69 | // single acquisition lock is held by current thread |
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| 70 | /* paranoid */ verifyf( owner != thrd || multi_acquisition, "Single acquisition lock holder (%p) attempted to reacquire the lock %p resulting in a deadlock.", owner, &this ); |
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| 71 | |
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| 72 | // lock is held by some other thread |
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| 73 | if ( owner != 0p && owner != thrd ) { |
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| 74 | addTail( blocked_threads, *thrd ); |
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[848439f] | 75 | wait_count++; |
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| 76 | unlock( lock ); |
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[eeb5023] | 77 | park( ); |
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[ac5816d] | 78 | } |
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| 79 | // multi acquisition lock is held by current thread |
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| 80 | else if ( owner == thrd && multi_acquisition ) { |
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[848439f] | 81 | recursion_count++; |
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| 82 | unlock( lock ); |
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[ac5816d] | 83 | } |
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| 84 | // lock isn't held |
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| 85 | else { |
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| 86 | owner = thrd; |
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[848439f] | 87 | recursion_count = 1; |
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| 88 | unlock( lock ); |
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| 89 | } |
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| 90 | } |
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| 91 | |
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| 92 | bool try_lock( blocking_lock & this ) with( this ) { |
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| 93 | bool ret = false; |
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| 94 | lock( lock __cfaabi_dbg_ctx2 ); |
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[ac5816d] | 95 | |
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| 96 | // lock isn't held |
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| 97 | if ( owner == 0p ) { |
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[6a8882c] | 98 | owner = active_thread(); |
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| 99 | recursion_count = 1; |
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[848439f] | 100 | ret = true; |
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[ac5816d] | 101 | } |
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| 102 | // multi acquisition lock is held by current thread |
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| 103 | else if ( owner == active_thread() && multi_acquisition ) { |
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[848439f] | 104 | recursion_count++; |
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| 105 | ret = true; |
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| 106 | } |
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[ac5816d] | 107 | |
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[848439f] | 108 | unlock( lock ); |
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| 109 | return ret; |
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| 110 | } |
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| 111 | |
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[cad1df1] | 112 | void pop_and_set_new_owner( blocking_lock & this ) with( this ) { |
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[c131a02] | 113 | $thread * t = &dropHead( blocked_threads ); |
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[cad1df1] | 114 | owner = t; |
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| 115 | recursion_count = ( t ? 1 : 0 ); |
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| 116 | wait_count--; |
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| 117 | unpark( t ); |
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| 118 | } |
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| 119 | |
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| 120 | void unlock( blocking_lock & this ) with( this ) { |
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| 121 | lock( lock __cfaabi_dbg_ctx2 ); |
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[ac5816d] | 122 | /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this ); |
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| 123 | /* paranoid */ verifyf( owner == active_thread() || !strict_owner, "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this ); |
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| 124 | |
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| 125 | // if recursion count is zero release lock and set new owner if one is waiting |
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[848439f] | 126 | recursion_count--; |
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[ac5816d] | 127 | if ( recursion_count == 0 ) { |
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[cad1df1] | 128 | pop_and_set_new_owner( this ); |
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[848439f] | 129 | } |
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| 130 | unlock( lock ); |
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| 131 | } |
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| 132 | |
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| 133 | size_t wait_count( blocking_lock & this ) with( this ) { |
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| 134 | return wait_count; |
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| 135 | } |
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| 136 | |
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| 137 | void set_recursion_count( blocking_lock & this, size_t recursion ) with( this ) { |
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| 138 | recursion_count = recursion; |
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| 139 | } |
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| 140 | |
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| 141 | size_t get_recursion_count( blocking_lock & this ) with( this ) { |
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| 142 | return recursion_count; |
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| 143 | } |
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| 144 | |
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[797a193] | 145 | void on_notify( blocking_lock & this, $thread * t ) with( this ) { |
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[ac5816d] | 146 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 147 | // lock held |
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| 148 | if ( owner != 0p ) { |
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[c131a02] | 149 | addTail( blocked_threads, *t ); |
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[848439f] | 150 | wait_count++; |
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| 151 | unlock( lock ); |
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[ac5816d] | 152 | } |
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| 153 | // lock not held |
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| 154 | else { |
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[848439f] | 155 | owner = t; |
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[6a8882c] | 156 | recursion_count = 1; |
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[eeb5023] | 157 | unpark( t ); |
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[848439f] | 158 | unlock( lock ); |
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| 159 | } |
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| 160 | } |
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| 161 | |
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[797a193] | 162 | void on_wait( blocking_lock & this ) with( this ) { |
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[ac5816d] | 163 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 164 | /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this ); |
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| 165 | /* paranoid */ verifyf( owner == active_thread() || !strict_owner, "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this ); |
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| 166 | |
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[cad1df1] | 167 | pop_and_set_new_owner( this ); |
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[848439f] | 168 | unlock( lock ); |
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| 169 | } |
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| 170 | |
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[ac5816d] | 171 | //----------------------------------------------------------------------------- |
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| 172 | // Overloaded routines for traits |
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[797a193] | 173 | // These routines are temporary until an inheritance bug is fixed |
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[ac5816d] | 174 | void lock ( single_acquisition_lock & this ) { lock ( (blocking_lock &)this ); } |
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| 175 | void unlock ( single_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); } |
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| 176 | void on_wait ( single_acquisition_lock & this ) { on_wait( (blocking_lock &)this ); } |
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| 177 | void on_notify ( single_acquisition_lock & this, struct $thread * t ) { on_notify( (blocking_lock &)this, t ); } |
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| 178 | void set_recursion_count( single_acquisition_lock & this, size_t recursion ) { set_recursion_count( (blocking_lock &)this, recursion ); } |
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| 179 | size_t get_recursion_count( single_acquisition_lock & this ) { return get_recursion_count( (blocking_lock &)this ); } |
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| 180 | |
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| 181 | void lock ( owner_lock & this ) { lock ( (blocking_lock &)this ); } |
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| 182 | void unlock ( owner_lock & this ) { unlock ( (blocking_lock &)this ); } |
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| 183 | void on_wait ( owner_lock & this ) { on_wait( (blocking_lock &)this ); } |
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| 184 | void on_notify( owner_lock & this, struct $thread * t ) { on_notify( (blocking_lock &)this, t ); } |
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| 185 | void set_recursion_count( owner_lock & this, size_t recursion ) { set_recursion_count( (blocking_lock &)this, recursion ); } |
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| 186 | size_t get_recursion_count( owner_lock & this ) { return get_recursion_count( (blocking_lock &)this ); } |
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| 187 | |
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| 188 | void lock ( multiple_acquisition_lock & this ) { lock ( (blocking_lock &)this ); } |
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| 189 | void unlock ( multiple_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); } |
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| 190 | void on_wait ( multiple_acquisition_lock & this ) { on_wait( (blocking_lock &)this ); } |
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| 191 | void on_notify( multiple_acquisition_lock & this, struct $thread * t ){ on_notify( (blocking_lock &)this, t ); } |
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| 192 | void set_recursion_count( multiple_acquisition_lock & this, size_t recursion ){ set_recursion_count( (blocking_lock &)this, recursion ); } |
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[cad1df1] | 193 | size_t get_recursion_count( multiple_acquisition_lock & this ){ return get_recursion_count( (blocking_lock &)this ); } |
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[848439f] | 194 | |
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[ac5816d] | 195 | //----------------------------------------------------------------------------- |
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| 196 | // alarm node wrapper |
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[fd54fef] | 197 | forall(L & | is_blocking_lock(L)) { |
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[c20533ea] | 198 | struct alarm_node_wrap { |
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| 199 | alarm_node_t alarm_node; |
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| 200 | condition_variable(L) * cond; |
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| 201 | info_thread(L) * i; |
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| 202 | }; |
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| 203 | |
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[ac5816d] | 204 | void ?{}( alarm_node_wrap(L) & this, Time alarm, Duration period, Alarm_Callback callback, condition_variable(L) * c, info_thread(L) * i ) { |
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[c20533ea] | 205 | this.alarm_node{ callback, alarm, period }; |
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[ac5816d] | 206 | this.cond = c; |
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| 207 | this.i = i; |
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[c20533ea] | 208 | } |
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| 209 | |
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| 210 | void ^?{}( alarm_node_wrap(L) & this ) { } |
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[848439f] | 211 | |
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[c5bbb9b] | 212 | void timeout_handler ( alarm_node_wrap(L) & this ) with( this ) { |
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[ac5816d] | 213 | // This condition_variable member is called from the kernel, and therefore, cannot block, but it can spin. |
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| 214 | lock( cond->lock __cfaabi_dbg_ctx2 ); |
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| 215 | |
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| 216 | // this check is necessary to avoid a race condition since this timeout handler |
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| 217 | // may still be called after a thread has been removed from the queue but |
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| 218 | // before the alarm is unregistered |
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| 219 | if ( listed(i) ) { // is thread on queue |
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| 220 | i->signalled = false; |
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| 221 | // remove this thread O(1) |
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| 222 | remove( cond->blocked_threads, *i ); |
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[6a8882c] | 223 | cond->count--; |
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[797a193] | 224 | if( i->lock ) { |
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[ac5816d] | 225 | // call lock's on_notify if a lock was passed |
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| 226 | on_notify(*i->lock, i->t); |
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| 227 | } else { |
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| 228 | // otherwise wake thread |
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| 229 | unpark( i->t ); |
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| 230 | } |
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| 231 | } |
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| 232 | unlock( cond->lock ); |
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[848439f] | 233 | } |
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| 234 | |
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[797a193] | 235 | // this casts the alarm node to our wrapped type since we used type erasure |
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[cad1df1] | 236 | void alarm_node_wrap_cast( alarm_node_t & a ) { timeout_handler( (alarm_node_wrap(L) &)a ); } |
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[c20533ea] | 237 | } |
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| 238 | |
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[ac5816d] | 239 | //----------------------------------------------------------------------------- |
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| 240 | // condition variable |
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[fd54fef] | 241 | forall(L & | is_blocking_lock(L)) { |
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[c20533ea] | 242 | |
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[848439f] | 243 | void ?{}( condition_variable(L) & this ){ |
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[eeb5023] | 244 | this.lock{}; |
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| 245 | this.blocked_threads{}; |
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| 246 | this.count = 0; |
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[848439f] | 247 | } |
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| 248 | |
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[cad1df1] | 249 | void ^?{}( condition_variable(L) & this ){ } |
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[848439f] | 250 | |
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[cad1df1] | 251 | void process_popped( condition_variable(L) & this, info_thread(L) & popped ) with( this ) { |
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| 252 | if(&popped != 0p) { |
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[dff1fd1] | 253 | popped.signalled = true; |
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[eeb5023] | 254 | count--; |
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[cad1df1] | 255 | if (popped.lock) { |
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[ac5816d] | 256 | // if lock passed call on_notify |
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| 257 | on_notify(*popped.lock, popped.t); |
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[848439f] | 258 | } else { |
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[ac5816d] | 259 | // otherwise wake thread |
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| 260 | unpark(popped.t); |
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[848439f] | 261 | } |
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| 262 | } |
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[cad1df1] | 263 | } |
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| 264 | |
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| 265 | bool notify_one( condition_variable(L) & this ) with( this ) { |
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| 266 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 267 | bool ret = !empty(blocked_threads); |
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| 268 | process_popped(this, dropHead( blocked_threads )); |
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[848439f] | 269 | unlock( lock ); |
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| 270 | return ret; |
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| 271 | } |
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| 272 | |
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[eeb5023] | 273 | bool notify_all( condition_variable(L) & this ) with(this) { |
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[848439f] | 274 | lock( lock __cfaabi_dbg_ctx2 ); |
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[cad1df1] | 275 | bool ret = !empty(blocked_threads); |
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| 276 | while( !empty(blocked_threads) ) { |
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| 277 | process_popped(this, dropHead( blocked_threads )); |
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[848439f] | 278 | } |
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| 279 | unlock( lock ); |
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| 280 | return ret; |
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| 281 | } |
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| 282 | |
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[eeb5023] | 283 | uintptr_t front( condition_variable(L) & this ) with(this) { |
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[cad1df1] | 284 | return empty(blocked_threads) ? NULL : head(blocked_threads).info; |
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[848439f] | 285 | } |
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| 286 | |
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[cad1df1] | 287 | bool empty( condition_variable(L) & this ) with(this) { return empty(blocked_threads); } |
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| 288 | |
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| 289 | int counter( condition_variable(L) & this ) with(this) { return count; } |
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[848439f] | 290 | |
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[cad1df1] | 291 | size_t queue_and_get_recursion( condition_variable(L) & this, info_thread(L) * i ) with(this) { |
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[ac5816d] | 292 | // add info_thread to waiting queue |
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| 293 | addTail( blocked_threads, *i ); |
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[cad1df1] | 294 | count++; |
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| 295 | size_t recursion_count = 0; |
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[ac5816d] | 296 | if (i->lock) { |
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| 297 | // if lock was passed get recursion count to reset to after waking thread |
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[cad1df1] | 298 | recursion_count = get_recursion_count(*i->lock); |
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[797a193] | 299 | on_wait( *i->lock ); |
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[cad1df1] | 300 | } |
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| 301 | return recursion_count; |
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[848439f] | 302 | } |
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| 303 | |
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[cad1df1] | 304 | // helper for wait()'s' with no timeout |
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[eeb5023] | 305 | void queue_info_thread( condition_variable(L) & this, info_thread(L) & i ) with(this) { |
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[848439f] | 306 | lock( lock __cfaabi_dbg_ctx2 ); |
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[cad1df1] | 307 | size_t recursion_count = queue_and_get_recursion(this, &i); |
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[848439f] | 308 | unlock( lock ); |
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[ac5816d] | 309 | |
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| 310 | // blocks here |
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| 311 | park( ); |
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| 312 | |
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| 313 | // resets recursion count here after waking |
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| 314 | if (i.lock) set_recursion_count(*i.lock, recursion_count); |
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[848439f] | 315 | } |
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| 316 | |
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[ac5816d] | 317 | #define WAIT( u, l ) \ |
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| 318 | info_thread( L ) i = { active_thread(), u, l }; \ |
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| 319 | queue_info_thread( this, i ); |
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| 320 | |
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[eeb5023] | 321 | // helper for wait()'s' with a timeout |
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| 322 | void queue_info_thread_timeout( condition_variable(L) & this, info_thread(L) & info, Time t ) with(this) { |
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| 323 | lock( lock __cfaabi_dbg_ctx2 ); |
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[cad1df1] | 324 | size_t recursion_count = queue_and_get_recursion(this, &info); |
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[ac5816d] | 325 | alarm_node_wrap(L) node_wrap = { t, 0`s, alarm_node_wrap_cast, &this, &info }; |
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[eeb5023] | 326 | register_self( &node_wrap.alarm_node ); |
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[848439f] | 327 | unlock( lock ); |
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| 328 | |
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[ac5816d] | 329 | // blocks here |
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| 330 | park(); |
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[848439f] | 331 | |
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[ac5816d] | 332 | // unregisters alarm so it doesn't go off if this happens first |
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| 333 | unregister_self( &node_wrap.alarm_node ); |
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[848439f] | 334 | |
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[ac5816d] | 335 | // resets recursion count here after waking |
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| 336 | if (info.lock) set_recursion_count(*info.lock, recursion_count); |
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[848439f] | 337 | } |
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| 338 | |
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[ac5816d] | 339 | #define WAIT_TIME( u, l, t ) \ |
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| 340 | info_thread( L ) i = { active_thread(), u, l }; \ |
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| 341 | queue_info_thread_timeout(this, i, t ); \ |
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[dff1fd1] | 342 | return i.signalled; |
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[848439f] | 343 | |
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[ac5816d] | 344 | void wait( condition_variable(L) & this ) with(this) { WAIT( 0, 0p ) } |
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| 345 | void wait( condition_variable(L) & this, uintptr_t info ) with(this) { WAIT( info, 0p ) } |
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| 346 | void wait( condition_variable(L) & this, L & l ) with(this) { WAIT( 0, &l ) } |
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| 347 | void wait( condition_variable(L) & this, L & l, uintptr_t info ) with(this) { WAIT( info, &l ) } |
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| 348 | |
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| 349 | bool wait( condition_variable(L) & this, Duration duration ) with(this) { WAIT_TIME( 0 , 0p , __kernel_get_time() + duration ) } |
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| 350 | bool wait( condition_variable(L) & this, uintptr_t info, Duration duration ) with(this) { WAIT_TIME( info, 0p , __kernel_get_time() + duration ) } |
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| 351 | bool wait( condition_variable(L) & this, Time time ) with(this) { WAIT_TIME( 0 , 0p , time ) } |
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| 352 | bool wait( condition_variable(L) & this, uintptr_t info, Time time ) with(this) { WAIT_TIME( info, 0p , time ) } |
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| 353 | bool wait( condition_variable(L) & this, L & l, Duration duration ) with(this) { WAIT_TIME( 0 , &l , __kernel_get_time() + duration ) } |
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| 354 | bool wait( condition_variable(L) & this, L & l, uintptr_t info, Duration duration ) with(this) { WAIT_TIME( info, &l , __kernel_get_time() + duration ) } |
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| 355 | bool wait( condition_variable(L) & this, L & l, Time time ) with(this) { WAIT_TIME( 0 , &l , time ) } |
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| 356 | bool wait( condition_variable(L) & this, L & l, uintptr_t info, Time time ) with(this) { WAIT_TIME( info, &l , time ) } |
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[848439f] | 357 | } |
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[454f478] | 358 | |
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| 359 | //----------------------------------------------------------------------------- |
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| 360 | // Semaphore |
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| 361 | void ?{}( semaphore & this, int count = 1 ) { |
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| 362 | (this.lock){}; |
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| 363 | this.count = count; |
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| 364 | (this.waiting){}; |
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| 365 | } |
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| 366 | void ^?{}(semaphore & this) {} |
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| 367 | |
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| 368 | bool P(semaphore & this) with( this ){ |
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| 369 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 370 | count -= 1; |
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| 371 | if ( count < 0 ) { |
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| 372 | // queue current task |
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| 373 | append( waiting, active_thread() ); |
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| 374 | |
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| 375 | // atomically release spin lock and block |
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| 376 | unlock( lock ); |
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| 377 | park(); |
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| 378 | return true; |
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| 379 | } |
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| 380 | else { |
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| 381 | unlock( lock ); |
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| 382 | return false; |
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| 383 | } |
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| 384 | } |
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| 385 | |
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| 386 | bool V(semaphore & this) with( this ) { |
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| 387 | $thread * thrd = 0p; |
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| 388 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 389 | count += 1; |
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| 390 | if ( count <= 0 ) { |
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| 391 | // remove task at head of waiting list |
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| 392 | thrd = pop_head( waiting ); |
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| 393 | } |
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| 394 | |
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| 395 | unlock( lock ); |
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| 396 | |
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| 397 | // make new owner |
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| 398 | unpark( thrd ); |
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| 399 | |
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| 400 | return thrd != 0p; |
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| 401 | } |
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| 402 | |
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| 403 | bool V(semaphore & this, unsigned diff) with( this ) { |
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| 404 | $thread * thrd = 0p; |
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| 405 | lock( lock __cfaabi_dbg_ctx2 ); |
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| 406 | int release = max(-count, (int)diff); |
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| 407 | count += diff; |
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| 408 | for(release) { |
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| 409 | unpark( pop_head( waiting ) ); |
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| 410 | } |
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| 411 | |
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| 412 | unlock( lock ); |
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| 413 | |
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| 414 | return thrd != 0p; |
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| 415 | } |
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