lkml.org 
[lkml]   [2009]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: PROPOSAL: extend pipe() to support NULL argument.
    On Fri, Jul 03, 2009 at 12:08:58PM +0800, Changli Gao wrote:
    >On Fri, Jul 3, 2009 at 11:00 AM, Amerigo Wang<xiyou.wangcong@gmail.com> wrote:
    >>
    >> When I said 'pipe', I meant *anonymous* pipe, definitely!
    >> There is nothing related with *named* pipe here.
    >>
    >Pipe means *anonymous* pipe? Who defined that? What the difference
    >between an anonymou pipe and a named pipe? Two ends or one ends? I
    >don't think so. Having explicit name is the right difference between
    >them.

    I have no interests to teach you its definition.

    if you re-read my email, you should conclude what 'pipe' there means,
    according to the contexts.

    >
    >And when I said 'kernel buffer handler', I means it is not a
    >traditional pipe, and I just extend and reuse the pipe API to create a
    >kernel buffer handler for splicing use.


    What pipe(2) creates is exactly an *anonymous* pipe.

    >
    >> You are going to a *wrong* direction.
    >>
    >What is the right direction you think? Keep the pipe() API unchanged
    >and keep two fds refering to the same kernel buffer? If you want to
    >keep the API unchanged just for compatiblity with POSIX, I agree with
    >you, and maybe a new system call is needed.


    Yes, exactly.
    Inventing a new API is better than modifying pipe(2), IMO.

    BUT I still don't agree that you really need this... I think you
    can add a flag or something like that to an fd to do this, e.g.

    fcntl(fd, F_SETFD, FD_PIPERW);

    Isn't this better?

    >
    >>
    >> If you repeat your (pipe,splice,splice,close,close) sequence for
    >> thousands times, it is still the same, nothing saves...
    >>
    >You means that?
    >
    >while (<condition>) {
    > pipe/splice/splice/close/close?
    >}

    At least this is what I understand from your words.

    >
    >You don't know my meaning. As a proxy server, there maybe lots of
    >connections to maintain, and these connections will keep open for a
    >long time. If the data received can be sent in a relay cycle, the
    >kernel buffer can be reused. If not, the kernel buffer must be
    >reserved. When there are lots of these kinds of connections, lots of
    >kernel buffers must be reserved. At this time, whether two fds per
    >kernel buffer or one fds per kernel buffer matters.

    SHow us the code, please.


    \
     
     \ /
      Last update: 2009-07-03 07:19    [W:0.033 / U:1.504 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site