PTHREAD_SPIN_INIT(3)   FreeBSD Library Functions Manual   PTHREAD_SPIN_INIT(3)

NAME
     pthread_spin_init, pthread_spin_destroy - initialize or destroy a spin
     lock

LIBRARY
     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS
     #include <pthread.h>

     int
     pthread_spin_init(pthread_spinlock_t *lock, int pshared);

     int
     pthread_spin_destroy(pthread_spinlock_t *lock);

DESCRIPTION
     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.

RETURN VALUES
     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.

ERRORS
     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.

SEE ALSO
     pthread_spin_lock(3), pthread_spin_unlock(3)

HISTORY
     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.

FreeBSD 13.1-RELEASE-p6          May 31, 2016          FreeBSD 13.1-RELEASE-p6