/* Copyright (C) 2008 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by David Bartley , 2008. The GNU C 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 2.1 of the License, or (at your option) any later version. The GNU C 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 the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include #include #include int rw_trywrlock (rwlock) rwlock_t *rwlock; { int errval = mutex_trylock (&rwlock->mutex); if (errval != 0) return errval; if (rwlock->readers) { (void)mutex_unlock (&rwlock->mutex); return EBUSY; } /* Set write lock. */ rwlock->readers = _RWLOCK_WR_LOCK; rwlock->owner = (uintptr_t)THREAD_SELF; if (rwlock->type & LOCK_SHARED) rwlock->ownerpid = THREAD_GETMEM (THREAD_SELF, pid); (void)mutex_unlock (&rwlock->mutex); return 0; }