124 lines
2.8 KiB
C
124 lines
2.8 KiB
C
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/*
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* pthread_spin_init.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_init (pthread_spinlock_t * lock, int pshared)
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{
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pthread_spinlock_t s;
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int cpus = 0;
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int result = 0;
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if (lock == NULL)
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{
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return EINVAL;
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}
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if (0 != ptw32_getprocessors (&cpus))
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{
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cpus = 1;
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}
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if (cpus > 1)
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{
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if (pshared == PTHREAD_PROCESS_SHARED)
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{
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/*
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* Creating spinlock that can be shared between
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* processes.
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*/
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#if _POSIX_THREAD_PROCESS_SHARED >= 0
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/*
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* Not implemented yet.
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*/
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#error ERROR [__FILE__, line __LINE__]: Process shared spin locks are not supported yet.
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#else
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return ENOSYS;
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#endif /* _POSIX_THREAD_PROCESS_SHARED */
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}
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}
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s = (pthread_spinlock_t) calloc (1, sizeof (*s));
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if (s == NULL)
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{
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return ENOMEM;
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}
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if (cpus > 1)
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{
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s->u.cpus = cpus;
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s->interlock = PTW32_SPIN_UNLOCKED;
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}
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else
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{
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pthread_mutexattr_t ma;
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result = pthread_mutexattr_init (&ma);
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if (0 == result)
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{
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ma->pshared = pshared;
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result = pthread_mutex_init (&(s->u.mutex), &ma);
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if (0 == result)
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{
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s->interlock = PTW32_SPIN_USE_MUTEX;
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}
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}
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(void) pthread_mutexattr_destroy (&ma);
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}
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if (0 == result)
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{
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*lock = s;
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}
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else
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{
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(void) free (s);
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*lock = NULL;
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}
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return (result);
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}
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