b4ed3f5506
The example is applications passing invalid arguments to a socket option and then failing to check the return code. The results can be very hard to diagnose. Here are some threads that show the pain this causes: * https://github.com/zeromq/zyre/issues/179 * http://lists.zeromq.org/pipermail/zeromq-dev/2014-June/026388.html One common argument is that a library should never assert, and should pass errors back to the calling application. The counter argument is that when an application is broken enough to pass garbage to libzmq, it cannot be trusted to handle the resulting errors properly. Empirical evidence from CZMQ, where we systematically assert on bad arguments, is that this militant approach makes applications more, not less, robust. I don't see any valid use cases for returning errors on bad arguments, with one exception: zmq_setsockopt can be used to probe whether libzmq was e.g. built with CURVE security. I'd argue that it's nasty to use a side effect like this. If apps need to probe how libzmq was built, this should be done explicitly, and for ALL build options, not just CURVE. There are/were no libzmq test cases that check the return code for an invalid option. For now I've enabled militant assertions using --with-militant at configure time. However I'd like to make this the default setting.
ZeroMQ
Welcome
The 0MQ lightweight messaging kernel is a library which extends the standard socket interfaces with features traditionally provided by specialised messaging middleware products. 0MQ sockets provide an abstraction of asynchronous message queues, multiple messaging patterns, message filtering (subscriptions), seamless access to multiple transport protocols and more.
Building and installation
See the INSTALL file included with the distribution.
Resources
Extensive documentation is provided with the distribution. Refer to doc/zmq.html, or "man zmq" after you have installed 0MQ on your system.
Website: http://www.zeromq.org/
Development mailing list: zeromq-dev@lists.zeromq.org Announcements mailing list: zeromq-announce@lists.zeromq.org
Git repository: http://github.com/zeromq/libzmq
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Copying
Free use of this software is granted under the terms of the GNU Lesser General
Public License (LGPL). For details see the files COPYING and COPYING.LESSER
included with the 0MQ distribution.