Re: Multi-Threading

[Gordon Sim <gs...@redhat.com>]

On 11/26/2010 10:43 AM, gcutuli wrote:
>
> Dear all,
> I'm moving toward the implementation of a multithreading application based
> on QPID Messaging 0.7, and I experienced strange behaviors.
>
> This is the background:
>
> - subscription of N subjects with N different receivers (all of them under
> the same session)
> - running N different "diaspatching threads" for each receiver
>
> Basically, each "dispatcher" executes an infinite loop where messages are
> fetched from the related queue:
>
> for (;;)
> {
>      msg = receiver.fetch(Duration::Forever);
> }
>
> After a random number of incoming messages, the library crashes (exactly on
> the "fetch" method) with one of the following exceptions:
> qpid::messaging::NoMessageAvailable or  qpid::messaging::SessionError

Is there any more detail logged for the session errors, either on the 
client or the broker? I suspect that may be the root cause of the issue.

> My suspect is that the native qpid session object is not designed to be used
> in a multi-threading scenario (in other words this object is not
> thread-safe).

It is supposed to be threadsafe (that doesn't of course rule out a bug 
making it unsafe).

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