Re: [libvirt] [PATCH 3/4] use monitor fd for domain shutdown

On Tue, Jan 20, 2009 at 08:17:07AM +0100, Guido G?nther wrote: > Hi, > On Mon, Jan 19, 2009 at 01:38:22PM +0000, Daniel P. Berrange wrote: > > > /* Got them all, so now open the monitor console */ > > > - ret = qemudOpenMonitor(conn, vm, monitor); > > > + qemuDriverLock(driver); > > > + ret = qemudOpenMonitor(conn, driver, vm, monitor, 0); > > > + qemuDriverUnlock(driver); > > > > What are the lock/unlock calls here for ? They will cause the whole > > driver to deadlock, because they're violating the rule that a domain > > lock must not be held while acquiring the driver lock. AFAICT in the > > qemudOpenMonitor() method you are just passing the 'driver' object > > straight through to the 'virEventAddHandle' method - since you are > > not using any data fields in it, locking is not required. > I looked at HACKING and couldn't find any explanation of the locking > rules so I added those. They're bogus. Dropped in the new attached > version. Yes, I need to write a doc about threading - its too long to put into the HACKING file directly. ACK, this looks good now.