diff options
Diffstat (limited to 'sbin/hastd/refcnt.h')
-rw-r--r-- | sbin/hastd/refcnt.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/sbin/hastd/refcnt.h b/sbin/hastd/refcnt.h new file mode 100644 index 0000000..a989df0 --- /dev/null +++ b/sbin/hastd/refcnt.h @@ -0,0 +1,57 @@ +/*- + * Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef __REFCNT_H__ +#define __REFCNT_H__ + +#include <machine/atomic.h> + +#include "pjdlog.h" + +static __inline void +refcnt_acquire(volatile unsigned int *count) +{ + + atomic_add_acq_int(count, 1); +} + +static __inline unsigned int +refcnt_release(volatile unsigned int *count) +{ + unsigned int old; + + /* XXX: Should this have a rel membar? */ + old = atomic_fetchadd_int(count, -1); + PJDLOG_ASSERT(old > 0); + return (old - 1); +} + +#endif /* ! __REFCNT_H__ */ |