Allow use custom server class

[abersheeran]

Related links:

• https://stackoverflow.com/questions/58133694/graceful-shutdown-of-uvicorn-starlette-app-with-websockets

This PR will allow passing Server to uvicorn.run via parameters. This will make it easier to handle the problem of long connections that cannot be closed normally.

class Server(uvicorn.Server):
    def handle_exit(self, sig, frame):
        application = self.config.loaded_app
        while not isinstance(application, Starlette):
            application = application.app
        application.should_exit = True
        return super().handle_exit(sig, frame)


uvicorn.run(app, server_class=Server)

[euri10]

This PR will allow passing Server to uvicorn.run via parameters. This will make it easier to handle the problem of long connections that cannot be closed normally.

do you have a reproducible application that demonstrate the issue @abersheeran please ?

[euri10]

It brings memory, I think #451 is the very same.

I'd prefer to solve the shutdown hanging on tasks not cancelled once ctrl+c has been sent, instead of this patch

but I need to look at it more before making hasty conclusions

[abersheeran]

For the time being, I don’t have a minimal application that can be reproduced, only a large program. But through related link on StackOverflow, this problem should be able to reproduce.

[Kludex]

There's also #1012 to consider.

[Kludex]

Closing this in favor of #1248.