PTHREAD_SPIN_INIT(3) BSD Library Functions Manual PTHREAD_SPIN_INIT(3)NAME
pthread_spin_init, pthread_spin_destroy — initialize or destroy a spin
POSIX Threads Library (libpthread, -lpthread)
pthread_spin_init(pthread_spinlock_t *lock, int pshared);
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
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
Neither of these functions will return EINTR.
The pthread_spin_init() and pthread_spin_destroy() functions will fail
[EBUSY] An attempt to initialize or destroy lock while it is
[EINVAL] The value specified by lock is invalid.
The pthread_spin_init() function will fail if:
[EAGAIN] Insufficient resources, other than memory, to initial‐
[ENOMEM] Insufficient memory to initialize lock.
SEE ALSOpthread_spin_lock(3), pthread_spin_unlock(3)HISTORY
The pthread_spin_init() and pthread_spin_destroy() functions first
appeared in library “libkse” in FreeBSD 5.2, and in library “libthr” in
The implementation of pthread_spin_init() does not fully conform to IEEE
Std 1003.2 (“POSIX.2”) because the pshared argument is ignored in library
“libthr”, and in library “libkse” if any value other than
PTHREAD_PROCESSES_PRIVATE is specified, it returns EINVAL.
BSD January 22, 2004 BSD