Re: [libvirt] [PATCH] qemu: Try multiple times to open unix monitor socket

Daniel P. Berrange wrote: > On Wed, Jul 15, 2009 at 11:40:42AM +0200, Daniel Veillard wrote: > > On Tue, Jul 14, 2009 at 06:22:42PM -0400, Cole Robinson wrote: > > > Unlike the pty monitor (which we know exists since we scrape its path from > > > stdout), we have no way of knowing that the unix monitor socket should exist/ > > > be initialized. As a result, some of my KVM guests randomly fail to start on > > > F10 host. > > > > > > Try to open the unix socket in a 3 second timeout loop. Ignore EACCES (path > > > does not exist if a first time run) and ECONNREFUSED (leftover socket from > > > a previous run hasn't been removed yet). Fixes things for me. > > > > It's always a bit annoying to end up with heuristics like this > > but if we don't have any other way, okay, ACK > > I don't like it much either, but this is no worse than what we had todo > to find the /dev/pts/XXX path where we waited ina loop for 3 seconds. > ACK to this patch > > > Long term we'll need to discuss with QEMU developers to find a better > way todo this without needing a timeout. One idea is actually instead > of passing a UNIX domain socket path to QEMU, actually create & bind > the socket in libvirt and then pass the pre-opened FD to QEMU. This > would guarentee that we can instantly connect to the monitor. Of course > then the job of waiting passes to the code that sends monitor commands. What about qemu's -daemonize option: -daemonize Daemonize the QEMU process after initialization. QEMU will not detach from standard IO until it is ready to receive connections on any of its devices. This option is a useful way for external programs to launch QEMU without having to cope with initialization race conditions. It looks like it was introduced in 0.9.0.