Re: [libvirt] [PATCH V11 2/7] Support for atomic operations on integers

For threading support, add atomic add and sub operations working on integers. Base this on locking support provided by virMutex. --- src/util/viratomic.h | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) Index: libvirt-acl/src/util/viratomic.h =================================================================== --- /dev/null +++ libvirt-acl/src/util/viratomic.h @@ -0,0 +1,91 @@ +/* + * viratomic.h: atomic integer operations + * + * Copyright (C) 2012 IBM Corporation + * + * Authors: + * Stefan Berger <stefanb(a)linux.vnet.ibm.com&gt; + * + * 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 2.1 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; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#ifndef __VIR_ATOMIC_H__ +# define __VIR_ATOMIC_H__ + +# include "threads.h" + +typedef struct _virAtomicInt virAtomicInt; +typedef virAtomicInt *virAtomicIntPtr; + +struct _virAtomicInt { + virMutex lock; + int value; +}; + +static inline int +virAtomicIntInit(virAtomicIntPtr vaip) +{ + vaip->value = 0; + return virMutexInit(&vaip->lock); +} + +static inline void +virAtomicIntSet(virAtomicIntPtr vaip, int value) +{ + virMutexLock(&vaip->lock); + + vaip->value = value; + + virMutexUnlock(&vaip->lock); +} + +static inline int +virAtomicIntRead(virAtomicIntPtr vaip) +{ + return vaip->value; +} + +static inline int +virAtomicIntAdd(virAtomicIntPtr vaip, int add) +{ + int ret; + + virMutexLock(&vaip->lock); + + vaip->value += add; + ret = vaip->value; + + virMutexUnlock(&vaip->lock); + + return ret; +} + +static inline int +virAtomicIntSub(virAtomicIntPtr vaip, int sub) +{ + int ret; + + virMutexLock(&vaip->lock); + + vaip->value -= sub; + ret = vaip->value; + + virMutexUnlock(&vaip->lock); + + return ret; +} + +#endif /* __VIR_ATOMIC_H */