Re: Doubts about GPeriodic

[Owen Taylor <otaylor redhat com>]

On Fri, 2010-10-22 at 16:20 -0400, Havoc Pennington wrote:

> Imagine two processes that are both following the rules and have 10
> streams open to each other and they are both processing all 10 at a
> superfast rate just tossing messages back and forth. What's the
> latency between occasions where these processes have 0 sources to
> dispatch? That drives your framerate. While 10 streams between two
> apps sounds contrived, I don't think one big complex app with say a
> sound server and some downloads in the background and some other
> random main loop tasks is all that different.

At some point we do have to realize that preemptive multitasking was
invented for a reason. We can play around the edges, but we can't make a
single thread able to smoothly do 5 things at once.

That may sound weird coming from me - considering that the gnome-shell
approach is to put everything in a single process and write it in
Javascript.

But as I see gnome-shell it is limited in scope - it's the compositor,
it handles selecting and switching tasks. But it isn't playing movies,
it isn't loading web pages. It isn't doing your taxes. If it does start
doing any of those things, we'll have to answer the question of how to
get those activities into a different thread, into a different process.

This is why as web browser become more and more application containers,
you are seeing a move to isolate the pages from each other - separate
threads, separate garbage collection, even separate processes.

- Owen