NAME
pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock - lock and unlock a spin lock
LIBRARY
POSIX threads library (libpthread, -lpthread)
SYNOPSIS
#include <pthread.h>int pthread_spin_lock(pthread_spinlock_t *\nlock\n);\n
\nint pthread_spin_trylock(pthread_spinlock_t *\nlock\n);\n
\nint pthread_spin_unlock(pthread_spinlock_t *\nlock\n);pthread_spin_lock(), pthread_spin_trylock():
\n
_POSIX_C_SOURCE >= 200112LDESCRIPTION
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.
RETURN VALUE
On success, these functions return zero. On failure, they return an error number.
ERRORS
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.
STANDARDS
POSIX.1-2008.
HISTORY
glibc 2.2. POSIX.1-2001.
CAVEATS
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).
SEE ALSO
pthread_spin_destroy(3), pthread_spin_init(3), pthreads(7)