Manual Pages  — PTHREAD_SPIN_INIT

pthread_spin_init – initialize or destroy a spin lock

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO HISTORY

POSIX Threads Library (libpthread, -lpthread)

#include <pthread.h>

int
pthread_spin_init(pthread_spinlock_t *lock, int pshared);

int
pthread_spin_destroy(pthread_spinlock_t *lock);

The pthread_spin_init() function will initialize lock to an unlocked state and allocate any resources necessary to begin using it. If pshared is set to PTHREAD_PROCESS_SHARED, any thread, whether belonging to the process in which the spinlock was created or not, that has access to the memory area where lock resides, can use lock. If it is set to PTHREAD_PROCESS_PRIVATE, it can only be used by threads within the same process.

The pthread_spin_destroy() function will destroy lock and release any resources that may have been allocated on its behalf.

If successful, both pthread_spin_init() and pthread_spin_destroy() will return zero. Otherwise, an error number will be returned to indicate the error.

Neither of these functions will return EINTR.

The pthread_spin_init() and pthread_spin_destroy() functions will fail if:

[EBUSY]
	An attempt to initialize or destroy lock while it is in use.
[EINVAL]
	The value specified by lock is invalid.

The pthread_spin_init() function will fail if:

[EAGAIN]
	Insufficient resources, other than memory, to initialize lock.
[ENOMEM]
	Insufficient memory to initialize lock.

The pthread_spin_init() and pthread_spin_destroy() functions first appeared in N:M Threading Library (libkse, -lkse)in FreeBSD 5.2, and in 1:1 Threading Library (libthr, -lthr)in FreeBSD 5.3 . Support for process-shared spinlocks appeared in FreeBSD 11.0 .