pthread_spin_unlock

PTHREAD_SPIN_LOCK(3)       Linux Programmer's Manual      PTHREAD_SPIN_LOCK(3)

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 ac-
       quires the lock immediately.  If the spin lock is currently  locked  by
       another thread, the calling thread spins, testing the lock until it be-
       comes 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  uninitial-
       ized 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)