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Re: Non-deterministic behavior of multithreaded software

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itt ium <ittium@gmail.com> writes:
> I have recently modified a software from single threaded to
> multithreaded design. In single threaded version, a connection fd was
> read by single thread, so event were always delivered in order. Now
> since multiple threads handle different events (on the same fd), the
> events are sometimes delivered out of order. Please note, on the
> connection fd, events are received in proper order and this non-
> deterministic behavior is introduced by my software only.
>
> Following are my doubt
>
> 1. How to handle such a situation

If you need such an ordering and it isn't implicitly guaranteed
anymore because it is now possible to work an several requests in
parallel, the intended order needs to be restored after the parts of
the task which are parallelizable have completed. A simple idea how
this could be done would be to include a 'ticket number' in the
request that can later be used to determine the ordering which was
lost in between again.

> 2. Is it a bad idea to have multiple threads for the same fd. If yes
> than how to increase capacity of a software that receives large amount
> of data on a single fd only.

'Multiple threads' can only be of help if at least some parts of the
work some program is supposed to do can be performed indepedently of
each other in parallell. Otherwise, if you cannot used more than one
CPU/ 'execution unit' and need to increase the capacity, you need to
get a faster execution unit or reduce the resource-intensity of
request processing so that the same 'execution unit' can process more
requests during some time interval.

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Thread

Non-deterministic behavior of multithreaded software itt ium <ittium@gmail.com> - 2011-08-05 02:38 -0700
  Re: Non-deterministic behavior of multithreaded software Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-05 15:41 +0100
  Re: Non-deterministic behavior of multithreaded software BGB <cr88192@hotmail.com> - 2011-08-05 14:46 -0700
    Re: Non-deterministic behavior of multithreaded software Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-05 23:04 +0100
      Re: Non-deterministic behavior of multithreaded software BGB <cr88192@hotmail.com> - 2011-08-05 18:54 -0700
        Re: Non-deterministic behavior of multithreaded software Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-06 14:59 +0100
          Re: Non-deterministic behavior of multithreaded software BGB <cr88192@hotmail.com> - 2011-08-06 20:29 -0700
            Re: Non-deterministic behavior of multithreaded software Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-07 20:02 +0100
              Re: Non-deterministic behavior of multithreaded software BGB <cr88192@hotmail.com> - 2011-08-07 18:09 -0700
                Re: Non-deterministic behavior of multithreaded software ittium <ittium@gmail.com> - 2011-08-09 09:48 +0530

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