|PTHREAD_SPIN_INIT(3)||FreeBSD Library Functions Manual||PTHREAD_SPIN_INIT(3)|
NAMEpthread_spin_init, pthread_spin_destroy — initialize or destroy a spin lock
LIBRARYPOSIX Threads Library (libpthread, -lpthread)
SYNOPSIS#include < pthread.h>
pthread_spin_init( pthread_spinlock_t *lock, int pshared);
pthread_spin_destroy( pthread_spinlock_t *lock);
DESCRIPTIONThe 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 VALUESIf 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.
ERRORSThe 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.
HISTORYThe 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.
BUGSThe implementation of pthread_spin_init() does not fully conform to IEEE Std 1003.2 (“POSIX.2”) because the pshared argument is ignored in 1:1 Threading Library (libthr, -lthr), and in N:M Threading Library (libkse, -lkse) if any value other than PTHREAD_PROCESSES_PRIVATE is specified, it returns EINVAL.
|January 22, 2004||FreeBSD|