PTHREAD_SPIN_LOCK(3P)                               POSIX Programmer's Manual                              PTHREAD_SPIN_LOCK(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

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, Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                         PTHREAD_SPIN_LOCK(3P)