Until now, we only assigned the _handle on
`zmq::socket_t::operator=(socket_t&&)`. This manifests when trying to
monitor a socket initialized by that constructor.
To avoid changing the public interface of the socket_t class, we tested
for the specific monitor usecase, since it's the only class accessing
zmq::socke_t::ctxptr.
NOTE: When running the new unit-test without the fix, it might hang on
`zmq_socket_monitor(socket_, NULL, 0)`. We haven't figured out the cause
for that, but we deemed it unimportant (or at least out of scope).
This commit fixes a regression introduced in a3e5b54c3 (Problem: Socket
options lack type-safety (#393)).
It addresses the following error reported when building the project
on macOS 10.11.6.
Errors like the following:
cppzmq/zmq.hpp:1325:39: error: default initialization of an object of const type 'const affinity_t' (aka 'const integral_option<4, unsigned long long, false>') without a user-provided default constructor
Compiler version:
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Similar issues:
* https://github.com/tensorflow/tensorflow/issues/28839
error: default initialization of an object of const type 'const Subgraph::Identity' without a user-provided default constructor
* https://bugzilla.mozilla.org/show_bug.cgi?id=1451088
Clang 3.8: error: default initialization of an object of const type 'const js::jit::ArithPolicy' without a user-provided default constructor
* https://github.com/googleapis/google-cloud-cpp/issues/1593
[osx] error: default initialization of an object of const type
Co-authored-by: Gudmundur Adalsteinsson <ofpgummi@yahoo.com>
Solution: Implement a type for each socket option.
Each option has an associated type, therefore they
can't be simply defined as an enum class.
Use new sockopt getter in test util
Add socket option get function for strings and tests
* Problem: Macros not defined in older versions
Solution: Guard usage of libzmq macros
* Test older version of libzmq with C++11 or later
* Use a slightly newer libzmq version
Solution: Define an enum class for the context options
Co-Authored-By: Simon Giesecke <simon.giesecke@gmail.com>
Co-authored-by: Simon Giesecke <simon.giesecke@gmail.com>
Solution: Add shutdown(). This function is required
for clean termination of the zmq context in multi-threaded
applications where sockets are used in threads. In particular
if blocking operation are used and if sockets can be created
at any time.
* Improve tests and documentation
For some reason that I didn't get to the root cause, gcc 4.8.1 (that I'm
stuck with) does not like the initializer for `unique_ptr` implemented
as a lambda:
```
third_party/zmqcpp/repo/zmq.hpp: In constructor 'zmq::poller_t<T>::poller_t() [with T = std::function<void(zmq::event_flags)>]':
third_party/zmqcpp/repo/zmq.hpp:1871:5: error: converting to 'std::unique_ptr<void, zmq::poller_t<std::function<void(zmq::event_flags)> >::destroy_poller_t>' from initializer list would use explicit constructor 'std::unique_ptr<_Ty, _Dx>::unique_ptr(std::unique_ptr<_Ty, _Dx>::pointer) [with _Ty = void; _Dx = zmq::poller_t<std::function<void(zmq::event_flags)> >::destroy_poller_t; std::unique_ptr<_Ty, _Dx>::pointer = void*]'
poller_t() = default;
^
In file included from networking/ipc/ipc.cc:6:0:
third_party/zmqcpp/repo/zmq_addon.hpp: At global scope:
third_party/zmqcpp/repo/zmq_addon.hpp:447:40: note: synthesized method 'zmq::poller_t<T>::poller_t() [with T = std::function<void(zmq::event_flags)>]' first required here
poller_t<handler_type> base_poller{};
^
In file included from ./networking/ipc/ipc.h:13:0,
from networking/ipc/ipc.cc:1:
third_party/zmqcpp/repo/zmq.hpp: In constructor 'zmq::poller_t<T>::poller_t() [with T = zmq::socket_t]':
third_party/zmqcpp/repo/zmq.hpp:1871:5: error: converting to 'std::unique_ptr<void, zmq::poller_t<zmq::socket_t>::destroy_poller_t>' from initializer list would use explicit constructor 'std::unique_ptr<_Ty, _Dx>::unique_ptr(std::unique_ptr<_Ty, _Dx>::pointer) [with _Ty = void; _Dx = zmq::poller_t<zmq::socket_t>::destroy_poller_t; std::unique_ptr<_Ty, _Dx>::pointer = void*]'
poller_t() = default;
^
networking/ipc/ipc.cc: In member function 'void networking::ipc::Ipc::ThreadMain()':
networking/ipc/ipc.cc:313:36: note: synthesized method 'zmq::poller_t<T>::poller_t() [with T = zmq::socket_t]' first required here
::zmq::poller_t<::zmq::socket_t> poller;
^
```
This moves the initialization to constructor, and makes gcc happy.
