[libvirt] [PATCH 10/21] Don't let parent of daemon exit until basic initialization is done

[Daniel Veillard]

On Fri, Oct 23, 2009 at 02:05:39PM +0100, Daniel P. Berrange wrote:
> The daemonizing code lets the parent exit almost immediately. This
> means that it may think it has successfully started even when
> important failures occur like not being able to acquire the PID
> file. It also means network sockets are not yet open.
> 
> To address this when daemonizing the parent passes an open pipe
> file descriptor to the child. The child does its basic initialization
> and then writes a status code to the pipe indicating either success,
> or failure. This ensures that when daemonizing, the parent does not
> exit until the pidfile is acquired & basic network sockets are open.
> 
> Initialization of the libvirt drivers is still done asynchronously
> since this may take a very long time.

  Hum, on the other hand maybe it's still better to wait until having
gone though drivers inits, basically this affects boot time or service
(re) start time, but maybe it's better to give hand when the service is
actually started and ready to get connections. With the parallel boots
only services dependant on libvirt may have to wait a long time, and
maybe it's better that way.

> * daemon/libvirtd.c: Force parent to stay around until basic config
>   file, pidfile & network socket init is completed

  devil is in the details, the code looks okay, but apparently
there is something to iron out.

Daniel

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