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_unlock — unlock a spin lock object

SYNOPSIS

       #include <pthread.h>

       int pthread_spin_unlock(pthread_spinlock_t *lock);

DESCRIPTION

       The  pthread_spin_unlock()  function  shall release the spin lock referenced by lock which was locked via
       the pthread_spin_lock() or pthread_spin_trylock() functions.

       The results are undefined if the lock is not held by the calling thread.

       If there are threads spinning on  the  lock  when  pthread_spin_unlock()  is  called,  the  lock  becomes
       available and an unspecified spinning thread shall acquire the lock.

       The results are undefined if this function is called with an uninitialized thread spin lock.

RETURN VALUE

       Upon  successful  completion,  the  pthread_spin_unlock() function shall return zero; otherwise, an error
       number shall be returned to indicate the error.

ERRORS

       This function 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_unlock()  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_unlock()
       refers  to a spin lock object for which the current thread does not hold the lock, it is recommended that
       the function should fail and report an [EPERM] error.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_spin_destroy(), pthread_spin_lock()

       The Base Definitions volume of POSIX.1‐2017, Section 4.12, Memory Synchronization, <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_UNLOCK(3POSIX)