/*------------------------------------------------------------------------- * * spin . h * API for spinlocks . * * * The interface to spinlocks is defined by the typedef " slock_t " and * these macros : * * void SpinLockInit ( volatile slock_t * lock ) * Initialize a spinlock ( to the unlocked state ) . * * void SpinLockAcquire ( volatile 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 . * * void SpinLockRelease ( volatile slock_t * lock ) * Unlock a previously acquired lock . * * 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 ! * * Load and store operations in calling code are guaranteed not to be * reordered with respect to these operations , because they include a * compiler barrier . ( Before PostgreSQL 9 . 5 , callers needed to use a * volatile qualifier to access data protected by spinlocks . ) * * Keep in mind the coding rule that spinlocks must not be held for more * than a few instructions . In particular , we assume it is not possible * for a CHECK_FOR_INTERRUPTS ( ) to occur while holding a spinlock , and so * it is not necessary to do HOLD / RESUME_INTERRUPTS ( ) in these macros . * * These macros are implemented in terms of hardware - dependent macros * supplied by s_lock . h . There is not currently any extra functionality * added by this header , but there has been in the past and may someday * be again . * * * Portions Copyright ( c ) 1996 - 2025 , PostgreSQL Global Development Group * Portions Copyright ( c ) 1994 , Regents of the University of California * * src / include / storage / spin . h * * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #ifndef SPIN_H#define SPIN_H#include "storage/s_lock.h" #define SpinLockInit(lock) S_INIT_LOCK(lock)#define SpinLockAcquire(lock) S_LOCK(lock)#define SpinLockRelease(lock) S_UNLOCK(lock)#define SpinLockFree(lock) S_LOCK_FREE(lock)#endif /* SPIN_H */
Messung V0.5 in Prozent C=88 H=99 G=93
¤ Dauer der Verarbeitung: 0.10 Sekunden
(vorverarbeitet am 2026-08-08)
¤ *© Formatika GbR, Deutschland
