112 lines
3.1 KiB
C
112 lines
3.1 KiB
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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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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_LONG ((PTW32_INTERLOCKED_LONGPTR) &s->interlock,
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(PTW32_INTERLOCKED_LONG) PTW32_SPIN_INVALID,
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(PTW32_INTERLOCKED_LONG) 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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ptw32_mcs_local_node_t node;
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ptw32_mcs_lock_acquire(&ptw32_spinlock_test_init_lock, &node);
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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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ptw32_mcs_lock_release(&node);
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}
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return (result);
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}
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