pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock - lock and unlock a
spin lock
#include <pthread.h>
int pthread_spin_lock(pthread_spinlock_t *lock);
int pthread_spin_trylock(pthread_spinlock_t *lock);
int pthread_spin_unlock(pthread_spinlock_t *lock);
Compile and link with
-pthread.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
pthread_spin_lock(),
pthread_spin_trylock():
_POSIX_C_SOURCE >= 200112L
The
pthread_spin_lock() function locks the spin lock referred to by
lock. If the spin lock is currently unlocked, the calling thread
acquires the lock immediately. If the spin lock is currently locked by another
thread, the calling thread spins, testing the lock until it becomes available,
at which point the calling thread acquires the lock.
Calling
pthread_spin_lock() on a lock that is already held by the caller
or a lock that has not been initialized with
pthread_spin_init(3)
results in undefined behavior.
The
pthread_spin_trylock() function is like
pthread_spin_lock(),
except that if the spin lock referred to by
lock is currently locked,
then, instead of spinning, the call returns immediately with the error
EBUSY.
The
pthread_spin_unlock() function unlocks the spin lock referred to
lock. If any threads are spinning on the lock, one of those threads
will then acquire the lock.
Calling
pthread_spin_unlock() on a lock that is not held by the caller
results in undefined behavior.
On success, these functions return zero. On failure, they return an error
number.
pthread_spin_lock() may fail with the following errors:
- EDEADLOCK
- The system detected a deadlock condition.
pthread_spin_trylock() fails with the following errors:
- EBUSY
- The spin lock is currently locked by another thread.
These functions first appeared in glibc in version 2.2.
POSIX.1-2001.
Applying any of the functions described on this page to an uninitialized spin
lock results in undefined behavior.
Carefully read NOTES in
pthread_spin_init(3).
pthread_spin_destroy(3),
pthread_spin_init(3),
pthreads(7)