forked from KolibriOS/kolibrios
111 lines
2.1 KiB
C
111 lines
2.1 KiB
C
#ifndef __LBSYNC_H__
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#define __LBSYNC_H__
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#define FUTEX_INIT 0
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#define FUTEX_DESTROY 1
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#define FUTEX_WAIT 2
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#define FUTEX_WAKE 3
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#define exchange_acquire(ptr, new) \
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__atomic_exchange_4((ptr), (new), __ATOMIC_ACQUIRE)
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#define exchange_release(ptr, new) \
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__atomic_exchange_4((ptr), (new), __ATOMIC_RELEASE)
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typedef struct
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{
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volatile int lock;
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int handle;
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}mutex_t;
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static inline int mutex_init(mutex_t *mutex)
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{
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int handle;
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mutex->lock = 0;
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asm volatile(
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"int $0x40\t"
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:"=a"(handle)
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:"a"(77),"b"(FUTEX_INIT),"c"(mutex));
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mutex->handle = handle;
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return handle;
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};
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static inline int mutex_destroy(mutex_t *mutex)
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{
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int retval;
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asm volatile(
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"int $0x40\t"
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:"=a"(retval)
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:"a"(77),"b"(FUTEX_DESTROY),"c"(mutex->handle));
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return retval;
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};
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static inline void mutex_lock(mutex_t *mutex)
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{
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int tmp;
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if( __sync_fetch_and_add(&mutex->lock, 1) == 0)
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return;
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while (exchange_acquire (&mutex->lock, 2) != 0)
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{
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asm volatile(
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"int $0x40\t\n"
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:"=a"(tmp)
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:"a"(77),"b"(FUTEX_WAIT),
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"c"(mutex->handle),"d"(2),"S"(0));
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}
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};
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static inline int mutex_lock_timeout(mutex_t *mutex, int timeout)
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{
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int tmp = 0;
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if( __sync_fetch_and_add(&mutex->lock, 1) == 0)
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return 1;
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while (exchange_acquire (&mutex->lock, 2) != 0)
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{
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asm volatile(
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"int $0x40\t"
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:"=a"(tmp)
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:"a"(77),"b"(FUTEX_WAIT),
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"c"(mutex->handle),"d"(2),"S"(timeout));
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if(++tmp == 0)
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break;
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}
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return tmp ;
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};
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static inline int mutex_trylock (mutex_t *mutex)
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{
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int zero = 0;
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return __atomic_compare_exchange_4(&mutex->lock, &zero, 1,0,__ATOMIC_ACQUIRE,__ATOMIC_RELAXED);
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};
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static inline void mutex_unlock(mutex_t *mutex)
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{
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int prev;
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prev = exchange_release (&mutex->lock, 0);
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if (prev != 1)
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{
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asm volatile(
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"int $0x40\t"
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:"=a"(prev)
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:"a"(77),"b"(FUTEX_WAKE),
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"c"(mutex->handle),"d"(1));
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};
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};
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#endif
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