NAME

       pthread_spin_lock,  pthread_spin_trylock  -  lock  a  spin  lock object (ADVANCED REALTIME
       THREADS)

SYNOPSIS

       #include <pthread.h>

       int pthread_spin_lock(pthread_spinlock_t *lock);
       int pthread_spin_trylock(pthread_spinlock_t *lock);

DESCRIPTION

       The pthread_spin_lock() function shall lock the spin lock referenced by lock. The  calling
       thread  shall  acquire the lock if it is not held by another thread. Otherwise, the thread
       shall spin (that is, shall not return from the pthread_spin_lock() call)  until  the  lock
       becomes  available.  The results are undefined if the calling thread holds the lock at the
       time the call is made. The  pthread_spin_trylock()  function  shall  lock  the  spin  lock
       referenced by lock if it is not held by any thread. Otherwise, the function shall fail.

       The  results  are undefined if any of these functions is called with an uninitialized spin
       lock.

RETURN VALUE

       Upon successful completion, these functions shall return zero; otherwise, an error  number
       shall be returned to indicate the error.

ERRORS

       These functions may fail if:

       EINVAL The value specified by lock does not refer to an initialized spin lock object.

       The pthread_spin_lock() function may fail if:

       EDEADLK
              The calling thread already holds the lock.

       The pthread_spin_trylock() function shall fail if:

       EBUSY  A thread currently holds the lock.

       These functions shall not return an error code of [EINTR].

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       Applications using this function may be subject to priority inversion, as discussed in the
       Base Definitions volume of IEEE Std 1003.1-2001, Section 3.285, Priority Inversion.

       The pthread_spin_lock() and pthread_spin_trylock() functions are part of  the  Spin  Locks
       option and need not be provided on all implementations.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_spin_destroy()   ,   pthread_spin_unlock()   ,  the  Base  Definitions  volume  of
       IEEE Std 1003.1-2001, <pthread.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .