in reply to Re^4: Why are people not using POE?
in thread Why are people not using POE?

You're telling me those applications use non-preemptive threading systems? I highly doubt that. They might be select()-based or polling, but that doesn't make them multi-threaded just because they handle multiple tasks simultaneously.

Let's not play semantic games here - threads and tasks are not the same things!

-sam

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Re^6: Why are people not using POE?
by kscaldef (Pilgrim) on Jun 11, 2005 at 05:26 UTC
    You'll notice that I said "multi-(task|thread)ing" originally. Cooperative multi-threading libraries do exist, and I do know of a couple systems build using them, but cooperative multi-tasking, in the form of event-driven state machines are much more common.

    BTW, how many requests per second does your "really high-performance" pre-forked server handle?

[reply]
      You'll notice that I said "multi-(task|thread)ing" originally.

      Yup, I did. I thought it sounded dumb considering that "cooperative multi-threading" is basically extinct and hardly applicable to high-performance servers.

      BTW, how many requests per second does your "really high-performance" pre-forked server handle?

      I don't know off the top of my head. But why ask me? Most of the websites on the internet today use Apache, and thus a pre-forked process model. Ask Amazon or Ticketmaster how they're doing under load, they're both Apache/mod_perl users last I heard.

      -sam

[reply]
        ...considering that "cooperative multi-threading" is basically extinct and hardly applicable to high-performance servers Thought I'd jump here and point out that, while I can't speak for the world of servers, cooperative multithreading is alive and well in the world of simulation. Here, it is really important that the results are determinitic -- the same stimuli should always give the same path through the code. I have become very frustrated over the years as support for cooperative multithreading libraries has slowly dwindled away. I have hopes that good continuation support in parrot (and P6) may stem the trend.

        --Dave
        Opinions my own; statements of fact may be in error.
[reply]
        I don't know off the top of my head. But why ask me? Most of the websites on the internet today use Apache, and thus a pre-forked process model. Ask Amazon or Ticketmaster how they're doing under load, they're both Apache/mod_perl users last I heard.

        Amazon and Ticketmaster are great success stories for mod_perl, no question about it. But, from what I know of the systems, their individual servers are not what I would call "really high performance". Nor, for that matter, are most of the web sites on the internet (sort of by definition).

        To give some context, for me "really high performance" is the world from around 10000 qps and up. Come to my talk at YAPC or OSCON this summer and I'll be happy to talk about some of the techniques we use to build systems like this.

        (To be really fair to Amazon and Ticketmaster, their applications are significantly more challenging to get crazy performance out of. Please don't take this as any criticism of them.)

[reply]

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