pthread_spin_init() Syntax

int  pthread_spin_init(pthread_spinlock_t *lock, int pshared);

#include <pthread.h>

pthread_spinlock_t lock;
int pshared;
int ret;

/* initialize a spin lock */
ret = pthread_spin_init(&lock, pshared); 

The pshared attribute has one of the following values:

PTHREAD_PROCESS_SHARED

Description:

Permits a spin lock to be operated on by any thread that has access to the memory where the spin lock is allocated. Operation on the lock is permitted even if the lock is allocated in memory that is shared by multiple processes.

PTHREAD_PROCESS_PRIVATE

Description:

Permits a spin lock to be operated upon only by threads created within the same process as the thread that initialized the spin lock. If threads of differing processes attempt to operate on such a spin lock, the behavior is undefined. The default value of the process-shared attribute is PTHREAD_PROCESS_PRIVATE.