/*
* pthread_spin_init.c
*
* Description:
* This translation unit implements spin lock primitives.
*
* --------------------------------------------------------------------------
*
* Pthreads-win32 - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999,2005 Pthreads-win32 contributors
*
* Contact Email: rpj@callisto.canberra.edu.au
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
* http://sources.redhat.com/pthreads-win32/contributors.html
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library in the file COPYING.LIB;
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "pthread.h"
#include "implement.h"
int
pthread_spin_init (pthread_spinlock_t * lock, int pshared)
{
pthread_spinlock_t s;
int cpus = 0;
int result = 0;
if (lock == NULL)
{
return EINVAL;
}
if (0 != ptw32_getprocessors (&cpus))
{
cpus = 1;
}
if (cpus > 1)
{
if (pshared == PTHREAD_PROCESS_SHARED)
{
/*
* Creating spinlock that can be shared between
* processes.
*/
#if _POSIX_THREAD_PROCESS_SHARED >= 0
/*
* Not implemented yet.
*/
#error ERROR [__FILE__, line __LINE__]: Process shared spin locks are not supported yet.
#else
return ENOSYS;
#endif /* _POSIX_THREAD_PROCESS_SHARED */
}
}
s = (pthread_spinlock_t) calloc (1, sizeof (*s));
if (s == NULL)
{
return ENOMEM;
}
if (cpus > 1)
{
s->u.cpus = cpus;
s->interlock = PTW32_SPIN_UNLOCKED;
}
else
{
pthread_mutexattr_t ma;
result = pthread_mutexattr_init (&ma);
if (0 == result)
{
ma->pshared = pshared;
result = pthread_mutex_init (&(s->u.mutex), &ma);
if (0 == result)
{
s->interlock = PTW32_SPIN_USE_MUTEX;
}
}
(void) pthread_mutexattr_destroy (&ma);
}
if (0 == result)
{
*lock = s;
}
else
{
(void) free (s);
*lock = NULL;
}
return (result);
}