This patch adds a sockopt ZMQ_DELAY_ATTACH_ON_CONNECT, which if set to 1 will attempt to preempt this behavior. It does this by extending the use of the session_base to include in the outbound as well as the inbound pipe, and only associates the pipe with the socket once it receives the connected callback via a process_attach message. This works, and a test has been added to show so, but may introduce unexpected complications. The shutdown logic in this class has become marginally more awkward because of this, requiring the session to serve as the sink for both pipes if shutdown occurs with a still-connecting pipe in place. It is also possible there could be issues around flushing the messages, but as I could not directly think how to create such an issue I have not written any code with regards to that.
The documentation has been updated to reflect the change, but please do check over the code and test and review.
The patch extends the internal session's API with the reset method.
This method is used to reset a session's state so that it can
handle a new connection.
The PGM transport supports the omission of the network interface to
select the default one like:
announce.connect("epgm://eth0;239.255.128.46:64646"); // Use eth0
announce.connect("epgm://239.255.128.46:64646"); // Use the default
Also, mention C++ in the additional community bindings of 0MQ in
zmq.txt.
The current ZMQ_MONITOR code does not compile in gcc 4.7, as -pedantic
and -Werror are enabled, and ISO C++ doesn't allow casting between
normal pointers (void*) and function pointers, as pedantically their
size could be different. This caused the library not compilable. This
commit workaround the problem by introducing one more indirection, i.e.
instead of calling
(void *)listener
which is an error, we have to use
*(void **)&listener
which is an undefined behavior :) but works on most platforms
Also, `optval_ = monitor` will not set the parameter in getsockopt(),
and the extra casting caused the LHS to be an rvalue which again makes
the code not compilable. The proper way is to pass a pointer of function
pointer and assign with indirection, i.e. `*optval_ = monitor`.
Also, fixed an asciidoc error in zmq_getsockopt.txt because the `~~~~`
is too long.
Expose a ZMQ_MONITOR socket option to register a callback for notification of state changes in socket state ( stream engine, tcp and ipc transport only )
