| /* |
| * 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); |
| } |