Re: [libvirt] [PATCH 5/5] Turn nwfilter conf update mutex into a read/write lock
On Thu, Jan 23, 2014 at 02:46:42PM -0500, Stefan Berger wrote:
On 01/23/2014 07:37 AM, Daniel P. Berrange wrote:
>
>@@ -3477,7 +3482,7 @@ int virNWFilterConfLayerInit(virDomainObjListIterator
domUpdateCB,
>
> initialized = true;
>
>- if (virMutexInitRecursive(&updateMutex) < 0)
>+ if (virRWLockInit(&updateLock) < 0)
> return -1;
>
Obviously it was a recursive lock before. Now
pthread_rwlock_wrlock() must not be called twice by the same thread.
I am fine with the conversion below per se. The functions below are
quite low-level now (close to virsh) that they are not called
recursively. So from this perspective for this patch:
The write locks aren't ever acquired recursively, since they're only
held in top level functions. The read locks are still allowed to be
recursive so we're safe in that respect.
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|