spinlock

Spinlock

- is a mutual exclusion device that can have only two values: "locked" and "unlocked." 
 
 - is a lock which causes a thread trying to acquire it to simply wait in a loop ("spin") 
 while repeatedly checking if the lock is available. 
 Since the thread remains active but is not performing a useful task, 
 the use of such a lock is a kind of busy waiting.
 
 spin — вращение

Read/Write Spin Locks

These locks allow any number of readers into a critical section simultaneously, 
but writers must have exclusive access.  

API Pthread

#include <pthread.h>

int pthread_spin_lock(pthread_spinlock_t *lock);
int pthread_spin_trylock(pthread_spinlock_t *lock);

API

<linux/spinlock.h>

// Once you call spin_lock, you will spin until the lock becomes available.
void spin_lock(spinlock_t *lock);

// To release a lock that you have obtained, pass it to:    
void spin_unlock(spinlock_t *lock);