[zeromq-dev] Message corruption

[Conrad Steenberg]

Thanks, Martin! That was it :-)

On Wed, 2009-08-26 at 04:01 +0200, Martin Hurton wrote:
> Hi Conrad,
> 
> On Wed, Aug 26, 2009 at 3:18 AM, Conrad
> Steenberg<conrad.steenberg at gmail.com> wrote:
> > Hi Martin et al,
> >
> > In my application I'm sending a message using
> > void somefunction(){
> >  string data=....;
> >  zmq::message_t out_message ((void *)data.c_str(), data.length(),
> > NULL);
> >  while (!api->send (used_exid, out_message, true));
> > }
> 
> When you construct messages this way, the ZeroMQ takes over the
> ownership of the memory buffer. The problem is you cannot do this with
> memory as returned by c_str () method, as it can be reused later.
> 
> Try to allocate you own buffer and copy the string into it.
> 
> I hope this helps.
> - Martin
> 
> >
> > Sometimes the data in the message (over TCP) that ends up on the wire is
> > different than what is put in the message. Up to and including
> > zmq::pipe_t::write (raw_message_t *msg_) in pipe.cpp, everything seems
> > OK.
> >
> > Is there anything obvious in the above snippet that might lead to memory
> > being trampled upon? Like the "data" string being deallocated when the
> > function returns? My assumption here is that the message gets "sent"
> > before the function returns.
> >
> > What is a reasonable place to check the raw_messages that comes out of
> > the y_pipe once written?
> >
> >
> > Thanks!
> > Conrad
> >
> > _______________________________________________
> > zeromq-dev mailing list
> > zeromq-dev at lists.zeromq.org
> > http://lists.zeromq.org/mailman/listinfo/zeromq-dev
> >
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> http://lists.zeromq.org/mailman/listinfo/zeromq-dev