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yap-6.3/OPTYap/alpha_locks.h

53 lines
2.1 KiB
C

/************************************************************************
** **
** The YapTab/YapOr/OPTYap systems **
** **
** YapTab extends the Yap Prolog engine to support sequential tabling **
** YapOr extends the Yap Prolog engine to support or-parallelism **
** OPTYap extends the Yap Prolog engine to support or-parallel tabling **
** **
** **
** Yap Prolog was developed at University of Porto, Portugal **
** **
************************************************************************/
/************************************************************************
** Atomic locks for ALPHA **
************************************************************************/
/* This code is stolen from the Linux kernel */
typedef struct { unsigned long a[100]; } __dummy_lock_t;
#define __dummy_lock(lock) (*(__dummy_lock_t *)(lock))
/*
Memory barrier in Alpha machines
*/
#define mb() \
__asm__ __volatile__("mb": : :"memory")
#define INIT_LOCK(LOCK_VAR) ((LOCK_VAR) = 0)
#define TRY_LOCK(LOCK_PTR) (!_test_and_set_bit(0,(volatile void *)(LOCK_PTR)))
#define LOCK(LOCK_VAR) _spin_lock((volatile void *)&(LOCK_VAR))
#define IS_LOCKED(LOCK_VAR) ((LOCK_VAR) != 0)
#define IS_UNLOCKED(LOCK_VAR) ((LOCK_VAR) == 0)
/* We need to support a memory barrier on Alphas */
#define UNLOCK(LOCK_VAR) { mb(); LOCK_VAR = 0; }
typedef struct {
volatile int write_lock:1, read_counter:31;
} /*__attribute__((aligned(32)))*/ rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
#define READ_LOCK(X) _read_lock(&(X))
#define READ_UNLOCK(X) _read_unlock(&(X))
#define WRITE_LOCK(X) _write_lock(&(X))
#define WRITE_UNLOCK(X) _write_unlock(&(X))
#define INIT_RWLOCK(RW) (RW) = RW_LOCK_UNLOCKED