On Thu, 19 Jan 2006 14:32:13 +0100, Eric Faurot wrote:

On 1/19/06, Matt Goodall wrote:

...

Hi,

...

In other words, what is the recommended way of starting services in the correct order, including waiting for them to get initialised fully, these days?

I'd say if service B relies on servcie A, then B.startService must explicitely call A.startService().

Why?

Of course, it requires that A.startService must be a noop if called more than once.

Not a very common property of startService(). Few, if any, of the services Twisted provides offer this property.

Now for deferred, I'm not 100% sure, but I don't think there is something very wrong returning a deferred in startService.

Well, you won't get a spanking for it. Nothing pays any attention to the return value of startService, though. privilegedStartService is run before the reactor has started, so there's no way it could support Deferreds. startService could probably be modified to support Deferreds. MultiService is pretty lax about.... everything. I think this is just one of many possible improvements that could be made. Jean-Paul

Hi. I am coming back to resolve a service starting issue and wanted to bounce this around to see it this is feasible. First I want all services contained in a multiservice however my main service must be fully initialized before starting the other services. It is a pb client and I want to ensure I have a server connection first before the other services from the first once it starts. To do this I am thinking i can attempt start the main service first but run as a separate service (not a child of multiservice) If this main first service starts successfully, I will add it to a multiservice with the other services, then start the multiservice. First issue is that starting a service does not provide a deferred and I need to know I have made a connection to the pb server. Second is whether I can add a running service to a multiservice instance. Can someone advise on the feasibility of this approach. Many thanks. Regards, David