NAME

       pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock - lock and unlock a spin lock

SYNOPSIS

       #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

DESCRIPTION

       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.

VERSIONS

       These functions first appeared in glibc in version 2.2.

CONFORMING TO

       POSIX.1-2001.

NOTES

       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)

COLOPHON

       This page is part of release 5.05 of the Linux man-pages project.  A description of the project,
       information about reporting bugs, and the latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

Linux                                              2017-09-30                               PTHREAD_SPIN_LOCK(3)