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

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       pthread_spin_destroy, pthread_spin_init - destroy or initialize a  spin
       lock object (ADVANCED REALTIME THREADS)
SYNOPSIS
       #include <pthread.h>
       int pthread_spin_destroy(pthread_spinlock_t *lock);
       int pthread_spin_init(pthread_spinlock_t *lock, int pshared);

DESCRIPTION
       The  pthread_spin_destroy() function shall destroy the spin lock refer-
       enced by lock and release any resources used by the lock. The effect of
       subsequent use of the lock is undefined until the lock is reinitialized
       by another call to pthread_spin_init(). The results  are  undefined  if
       pthread_spin_destroy()  is  called  when a thread holds the lock, or if
       this function is called with an uninitialized thread spin lock.
       The pthread_spin_init() function shall allocate any resources  required
       to  use  the spin lock referenced by lock and initialize the lock to an
       unlocked state.
       If the Thread Process-Shared Synchronization option  is  supported  and
       the  value  of  pshared  is  PTHREAD_PROCESS_SHARED, the implementation
       shall permit the spin lock to be operated upon by any thread  that  has
       access  to  the  memory where the spin lock is allocated, even if it is
       allocated in memory that is shared by multiple processes.
       If the Thread Process-Shared Synchronization option  is  supported  and
       the  value  of  pshared is PTHREAD_PROCESS_PRIVATE, or if the option is
       not supported, the spin lock shall only be  operated  upon  by  threads
       created within the same process as the thread that initialized the spin
       lock. If threads of differing processes attempt to operate  on  such  a
       spin lock, the behavior is undefined.
       The  results  are undefined if pthread_spin_init() is called specifying
       an already initialized spin lock. The results are undefined if  a  spin
       lock is used without first being initialized.
       If  the pthread_spin_init() function fails, the lock is not initialized
       and the contents of lock are undefined.
       Only the object referenced by lock may be used for performing  synchro-
       nization.
       The  result  of  referring  to  copies  of  that  object  in  calls  to
       pthread_spin_destroy(), pthread_spin_lock(), pthread_spin_trylock(), or
       pthread_spin_unlock() is undefined.
RETURN VALUE
       Upon  successful  completion, these functions shall return zero; other-
       wise, an error number shall be returned to indicate the error.
ERRORS
       These functions may fail if:
       EBUSY  The implementation has detected  an  attempt  to  initialize  or
              destroy a spin lock while it is in use (for example, while being
              used in a pthread_spin_lock() call) by another thread.
       EINVAL The value specified by lock is invalid.

       The pthread_spin_init() function shall fail if:
       EAGAIN The system lacks the necessary resources to  initialize  another
              spin lock.
       ENOMEM Insufficient memory exists to initialize the lock.

       These functions shall not return an error code of [EINTR].
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       The  pthread_spin_destroy()  and pthread_spin_init() functions are part
       of the Spin Locks option and need not be provided  on  all  implementa-
       tions.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       pthread_spin_lock(), 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 .

IEEE/The Open Group                  2003             PTHREAD_SPIN_DESTROY(3P)