/* * 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"intpthread_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);}