mirror of
https://github.com/postgres/postgres.git
synced 2025-06-26 12:21:12 +03:00
78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* spin.h
|
|
* Hardware-independent implementation of spinlocks.
|
|
*
|
|
*
|
|
* The hardware-independent interface to spinlocks is defined by the
|
|
* typedef "slock_t" and these macros:
|
|
*
|
|
* void SpinLockInit(slock_t *lock)
|
|
* Initialize a spinlock (to the unlocked state).
|
|
*
|
|
* void SpinLockAcquire(slock_t *lock)
|
|
* Acquire a spinlock, waiting if necessary.
|
|
* Time out and abort() if unable to acquire the lock in a
|
|
* "reasonable" amount of time --- typically ~ 1 minute.
|
|
* Cancel/die interrupts are held off until the lock is released.
|
|
*
|
|
* void SpinLockRelease(slock_t *lock)
|
|
* Unlock a previously acquired lock.
|
|
* Release the cancel/die interrupt holdoff.
|
|
*
|
|
* void SpinLockAcquire_NoHoldoff(slock_t *lock)
|
|
* void SpinLockRelease_NoHoldoff(slock_t *lock)
|
|
* Same as above, except no interrupt holdoff processing is done.
|
|
* This pair of macros may be used when there is a surrounding
|
|
* interrupt holdoff.
|
|
*
|
|
* bool SpinLockFree(slock_t *lock)
|
|
* Tests if the lock is free. Returns TRUE if free, FALSE if locked.
|
|
* This does *not* change the state of the lock.
|
|
*
|
|
* Callers must beware that the macro argument may be evaluated multiple
|
|
* times!
|
|
*
|
|
* The macros are implemented in terms of hardware-dependent macros
|
|
* supplied by s_lock.h.
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* $Id: spin.h,v 1.22 2003/08/04 02:40:15 momjian Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef SPIN_H
|
|
#define SPIN_H
|
|
|
|
#include "storage/s_lock.h"
|
|
#include "miscadmin.h"
|
|
|
|
|
|
#define SpinLockInit(lock) S_INIT_LOCK(lock)
|
|
|
|
#define SpinLockAcquire(lock) \
|
|
do { \
|
|
HOLD_INTERRUPTS(); \
|
|
S_LOCK(lock); \
|
|
} while (0)
|
|
|
|
#define SpinLockAcquire_NoHoldoff(lock) S_LOCK(lock)
|
|
|
|
#define SpinLockRelease(lock) \
|
|
do { \
|
|
S_UNLOCK(lock); \
|
|
RESUME_INTERRUPTS(); \
|
|
} while (0)
|
|
|
|
#define SpinLockRelease_NoHoldoff(lock) S_UNLOCK(lock)
|
|
|
|
#define SpinLockFree(lock) S_LOCK_FREE(lock)
|
|
|
|
|
|
extern int SpinlockSemas(void);
|
|
|
|
#endif /* SPIN_H */
|