Re: [Civil-devel]removing threads?

[Jan E. <ch...@in...>]

On Mon, 12 Apr 2004, Marcus Alanen wrote:

>Uf. Taking a much-needed look at Civil's network handling, I must
>confess that the whole circus with threads feels odd.
>
>I think the server-side connection handling is actually racy somewhere,
>since my civil server hangs on the futex syscall when the client crashes
>with a traceback:
>
>futex(0x82420e0, FUTEX_WAIT, 0, NULL <unfinished ...>
>
>(futex == fast user-space mutex, Linux 2.6's new way to handle mutexes)

I wasn't aware that Python already utilized futexes, but apparently it
does?

>I actually have code that removes the client-side "poller thread", I was
>thinking of committing it. It would use socket.setblocking(0) to make
>sure that it can't block on receving network data. [1] Opinions?

Would that make it poll, and thus increase load? The original reason for a
thread was to get rid of the load that polling introduced?

>Similarly, I'd like to try to remove the server-side "poller thread",
>opinions?

The serverside should be simple to get rid of, it's basically just
something like this:

while 1:
    sleep 1s
    while socket.hasData():
        socket.readNoBlock()

    calculateStuff()

Yes, I'm all for getting rid of extra complexity if you think it's a good
idea. Please commit.

>[1] I just have to get myself Stevens' networking book(s). Saw one in
>the bookstore on Saturday, mere 90+ euros. Argh.

There are quite a few of them, actually. If you get the networking bible
be sure to get the newest edition. I have the old one and it's also good,
but the newer one has some more goodies. All Stevens books are excellent
toilet and bedtime reading. :)

--
             In the Beginning it was a nice day.
                           -- Terry Pratchett & Neil Gaiman, Good Omens