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    SubjectRe: [PATCH] rfc: threaded epoll_wait thundering herd
    On Mon, 7 May 2007, Ulrich Drepper wrote:

    > On 5/7/07, Davi Arnaut <> wrote:
    > > See Linus's message on this same thread.
    > No. I'm talking about the userlevel side, not kernel side.
    > If a thread is canceled *after* it returns from the syscall but before
    > it reports the event to the call (i.e., while still in the syscall
    > wrapper, thread cancellation rules require a check there) the event is
    > lost.

    read(2) is a cancellation point too. So if the fine userspace code issues
    a random pthread_cancel() to a thread handling that, data is lost together
    with the session that thread was handling. Hmm, I wonder how the world
    could have functioned so far.
    Bottom line is, if you really want to throw random cancels to your worker
    threads, you better wrap them into pthread_cleanup_push(). Because
    otherwise, no matter where your cancel hits, you end up with a broken

    - Davide

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      Last update: 2007-05-08 00:39    [W:0.022 / U:2.688 seconds]
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