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



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

NAME
       pthread_spin_destroy, pthread_spin_init -- destroy or initialize a spin
       lock object

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
       referenced 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.

       See Section 2.9.9, Synchronization Object Copies and Alternative
       Mappings for further requirements.

       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
       synchronization.

       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;
       otherwise, an error number shall be returned to indicate the error.

ERRORS
       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
       None.

RATIONALE
       If an implementation detects that the value specified by the lock
       argument to pthread__spin__destroy() does not refer to an initialized
       spin lock object, it is recommended that the function should fail and
       report an [EINVAL] error.

       If an implementation detects that the value specified by the lock
       argument to pthread__spin__destroy() or pthread__spin__init() refers to a
       locked spin lock object, or detects that the value specified by the
       lock argument to pthread__spin__init() refers to an already initialized
       spin lock object, it is recommended that the function should fail and
       report an [EBUSY] error.

FUTURE DIRECTIONS
       None.

SEE ALSO
       pthread__spin__lock(), pthread__spin__unlock()

       The Base Definitions volume of POSIX.1-2017, <pthread.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017              PTHREAD_SPIN_DESTROY(3)
