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  • Committer: Bazaar Package Importer
  • Author(s): Kees Cook
  • Date: 2007-02-20 10:33:44 UTC
  • mto: This revision was merged to the branch mainline in revision 16.
  • Revision ID: james.westby@ubuntu.com-20070220103344-zgcu2psnx9d98fpa
Tags: upstream-0.90
Import upstream version 0.90

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win32/3rdparty/pthreads/pthread_spin_destroy.c
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/*
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 * pthread_spin_destroy.c
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 *
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 * Description:
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 * This translation unit implements spin lock primitives.
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 *
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 * --------------------------------------------------------------------------
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 *
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 *      Pthreads-win32 - POSIX Threads Library for Win32
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 *      Copyright(C) 1998 John E. Bossom
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 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
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 * 
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 *      Contact Email: rpj@callisto.canberra.edu.au
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 * 
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 *      The current list of contributors is contained
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 *      in the file CONTRIBUTORS included with the source
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 *      code distribution. The list can also be seen at the
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 *      following World Wide Web location:
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 *      http://sources.redhat.com/pthreads-win32/contributors.html
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 * 
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 *      This library is free software; you can redistribute it and/or
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 *      modify it under the terms of the GNU Lesser General Public
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 *      License as published by the Free Software Foundation; either
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 *      version 2 of the License, or (at your option) any later version.
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 * 
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 *      This library is distributed in the hope that it will be useful,
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 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 *      Lesser General Public License for more details.
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 * 
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 *      You should have received a copy of the GNU Lesser General Public
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 *      License along with this library in the file COPYING.LIB;
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 *      if not, write to the Free Software Foundation, Inc.,
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 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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 */
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#include "pthread.h"
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#include "implement.h"
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int
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pthread_spin_destroy (pthread_spinlock_t * lock)
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{
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  register pthread_spinlock_t s;
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  int result = 0;
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  if (lock == NULL || *lock == NULL)
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    {
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      return EINVAL;
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    }
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  if ((s = *lock) != PTHREAD_SPINLOCK_INITIALIZER)
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    {
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      if (s->interlock == PTW32_SPIN_USE_MUTEX)
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        {
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          result = pthread_mutex_destroy (&(s->u.mutex));
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        }
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      else if ((PTW32_INTERLOCKED_LONG) PTW32_SPIN_UNLOCKED !=
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               PTW32_INTERLOCKED_COMPARE_EXCHANGE ((PTW32_INTERLOCKED_LPLONG)
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                                                   & (s->interlock),
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                                                   (PTW32_INTERLOCKED_LONG)
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                                                   PTW32_OBJECT_INVALID,
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                                                   (PTW32_INTERLOCKED_LONG)
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                                                   PTW32_SPIN_UNLOCKED))
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        {
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          result = EINVAL;
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        }
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      if (0 == result)
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        {
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          /*
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           * We are relying on the application to ensure that all other threads
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           * have finished with the spinlock before destroying it.
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           */
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          *lock = NULL;
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          (void) free (s);
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        }
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    }
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  else
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    {
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      /*
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       * See notes in ptw32_spinlock_check_need_init() above also.
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       */
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      EnterCriticalSection (&ptw32_spinlock_test_init_lock);
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      /*
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       * Check again.
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       */
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      if (*lock == PTHREAD_SPINLOCK_INITIALIZER)
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        {
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          /*
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           * This is all we need to do to destroy a statically
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           * initialised spinlock that has not yet been used (initialised).
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           * If we get to here, another thread
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           * waiting to initialise this mutex will get an EINVAL.
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           */
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          *lock = NULL;
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        }
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      else
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        {
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          /*
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           * The spinlock has been initialised while we were waiting
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           * so assume it's in use.
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           */
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          result = EBUSY;
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        }
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      LeaveCriticalSection (&ptw32_spinlock_test_init_lock);
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    }
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  return (result);
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}