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.1‐2008,  Section  4.11,  Memory  Synchronization,
       <pthread.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2013 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX),  The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical  Corrigendum  1  applied.)  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.unix.org/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 .