Re: [libvirt] PATCH: 13/25: Remove global state from XM driver

[Daniel Veillard <veillard redhat com>]

On Thu, Jan 15, 2009 at 05:23:33PM +0000, Richard W.M. Jones wrote:
> On Tue, Jan 13, 2009 at 05:44:00PM +0000, Daniel P. Berrange wrote:
> > The 'xm' driver currently keeps all its state in a global static
> > variables. Not cool, since we access this from all sorts of places
> > and its hard to guarentee thread safety. So we move the state into
> > the virConnect object. This will increase memory usage if a single
> > process has multiple Xen connections open though.
> > 
> > Undecided whether this is a big problem or not. If so, I'll can
> > try and redo the next thread locking patch to use a lock over the
> > existing global state.
> > 
> >  xen_inotify.c |    4 
> >  xen_unified.c |    1 
> >  xen_unified.h |   14 ++-
> >  xm_internal.c |  262 +++++++++++++++++++++++++++++-----------------------------
> >  xm_internal.h |    3 
> >  5 files changed, 149 insertions(+), 135 deletions(-)
> 
> The patch appears straightforward enough, and for the XM driver
> (ie. ancient history Xen) I'm sure we don't care much about a tiny bit
> of extra memory.

  I don't care about the memory usage at this point, I'm more concerned
about inserting bugs in that code. Looks a relatively mechanical change
and it's probably safer than something based on locking.

  +1

Daniel

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