kolibrios/contrib/sdk/sources/newlib/libc/include/libsync.h

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