[libvirt] [PATCH] qemu: Avoid sending STOPPED event twice

[Daniel P. Berrange]

On Wed, Jan 19, 2011 at 08:19:36PM +0100, Jiri Denemark wrote:
> In some circumstances, libvirtd would issue two STOPPED events after it
> stopped a domain. This was because an EOF event can arrive after a qemu
> process is killed but before qemuMonitorClose() is called.
> 
> qemuHandleMonitorEOF() should ignore EOF when the domain is not running.
> 
> I wasn't able to reproduce this bug directly, only after adding an
> artificial sleep() into qemudShutdownVMDaemon().

That sounds reasonable - it would definitely be a race condition
if it occurred, so sleep() would be expected to trigger it more
often.

> ---
>  src/qemu/qemu_driver.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 22dc272..cff7a43 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -356,6 +356,12 @@ qemuHandleMonitorEOF(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
>  
>      virDomainObjLock(vm);
>  
> +    if (!virDomainObjIsActive(vm)) {
> +        VIR_DEBUG("Domain %p is not active, ignoring EOF", vm);
> +        virDomainObjUnlock(vm);
> +        return;
> +    }
> +
>      priv = vm->privateData;
>      if (!hasError && priv->monJSON && !priv->gotShutdown) {
>          VIR_DEBUG("Monitor connection to '%s' closed without SHUTDOWN event; "

ACK

Daniel