in reply to Re^3: IPC via named pipes, losing some messages
in thread IPC via named pipes, losing some messages

Thanks for that. I'm going to test it next week. I would do it sooner but I'm off tomorrow and I don't like sending software live before I'm away. It tends to generate tedious wtf have you done now telephone calls... Could you explain what you mean in your bullet points, 1 and 3 please? John
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Re^5: IPC via named pipes, losing some messages
by ikegami (Patriarch) on May 01, 2008 at 09:21 UTC
    • Re: I fixed a bug where a single message could be considered two.

      If "C,DIR,1ROSE" is sent over the pipe, the reader might only read "C,DI" which you were treating as an entire message. Then you would proceed to treat "R,1ROSE" as a second message. I fixed this keeping message fragments in the buffer and appending to the unprocessed data in the buffer instead of using a fresh buffer every pass.

      The bug in question might not actually exist due to the select, but it's hard to be sure and would be OS-dependent.

    • Re: I replaced split since you have a record terminator rather than a record separator.

      split is useful when your data looks like "ITEM SEP ITEM SEP ITEM". It doesn't make much sense when your data looks like "ITEM TERM ITEM TERM ITEM TERM", as is the case for you.

      Ah, I see. Thanks for you time ikegami. The new code works like a charm. Not only does it improve on mine in readability, it appears to be a whole lot more efficient. The load on the machine has gone down! John
        Interesting. Your version only processed data when there's a lull in reading. If the data comes in fast enough, it could be the selects become expensive no-ops and $data .= $buf; builds up to something huge. In my version, I process data as soon as it comes in.