FairMQ: Parameterize the command interface initializing with sub socket

! THIS PATCH BREAKS NANOMSG TRANSPORT !

The subscriber command socket was created using the transport factory of
the channel which might not implement sub sockets. This patch creates
the subscriber command sockets in the device initialization and passes
them down (move) to the command interface initialization.

This patch puts more focus on the GetSocket interface of FairMQSocket,
because all command sockets are now implemented with the default
transport - the channels use an internal poller which polls over sockets
of potentially different transports now (e.g. zeromq command socket and
nanomsg data socket). Basically, all transports need to return file
descriptors compatible to be used in a single poll set. THIS IS NOT THE CASE!

! THIS PATCH BREAKS NANOMSG TRANSPORT !

fairmq/FairMQChannel.cxx

@@ -660,9 +660,9 @@ void FairMQChannel::InitTransport(shared_ptr<FairMQTransportFactory> factory)
     fTransportType = factory->GetType();
 }
 
-bool FairMQChannel::InitCommandInterface()
+bool FairMQChannel::InitCommandInterface(FairMQSocketPtr channelCmdSocket)
 {
-    fChannelCmdSocket = fTransportFactory->CreateSocket("sub", "device-commands");
+    fChannelCmdSocket = std::move(channelCmdSocket);
     if (fChannelCmdSocket)
     {
         fChannelCmdSocket->Connect("inproc://commands");

fairmq/FairMQChannel.h

@@ -322,7 +322,7 @@ class FairMQChannel
     bool CheckCompatibility(std::vector<std::unique_ptr<FairMQMessage>>& msgVec) const;
 
     void InitTransport(std::shared_ptr<FairMQTransportFactory> factory);
-    bool InitCommandInterface();
+    bool InitCommandInterface(FairMQSocketPtr channelCmdSocket);
 
     bool HandleUnblock() const;
 

fairmq/FairMQDevice.cxx

@@ -48,7 +48,7 @@ FairMQDevice::FairMQDevice()
     , fDefaultTransport()
     , fInitializationTimeoutInS(120)
     , fDataCallbacks(false)
-    , fDeviceCmdSockets()
+    , fDeviceCmdSocket(nullptr)
     , fMsgInputs()
     , fMultipartInputs()
     , fMultitransportInputs()
@@ -79,7 +79,7 @@ FairMQDevice::FairMQDevice(const fair::mq::tools::Version version)
     , fDefaultTransport()
     , fInitializationTimeoutInS(120)
     , fDataCallbacks(false)
-    , fDeviceCmdSockets()
+    , fDeviceCmdSocket(nullptr)
     , fMsgInputs()
     , fMultipartInputs()
     , fMultitransportInputs()
@@ -102,21 +102,6 @@ void FairMQDevice::InitWrapper()
         exit(EXIT_FAILURE);
     }
 
-    if (fDeviceCmdSockets.empty())
-    {
-        auto p = fDeviceCmdSockets.emplace(fTransportFactory->GetType(), fTransportFactory->CreateSocket("pub", "device-commands"));
-        if (p.second)
-        {
-            p.first->second->Bind("inproc://commands");
-        }
-        else
-        {
-            exit(EXIT_FAILURE);
-        }
-
-        FairMQMessagePtr msg(fTransportFactory->CreateMessage());
-    }
-
     // Containers to store the uninitialized channels.
     vector<FairMQChannel*> uninitializedBindingChannels;
     vector<FairMQChannel*> uninitializedConnectingChannels;
@@ -248,7 +233,7 @@ void FairMQDevice::AttachChannels(vector<FairMQChannel*>& chans)
         {
             if (AttachChannel(**itr))
             {
-                (*itr)->InitCommandInterface();
+                (*itr)->InitCommandInterface(Transport()->CreateSocket("sub", "device-commands"));
                 (*itr)->SetModified(false);
                 itr = chans.erase(itr);
             }
@@ -476,10 +461,7 @@ void FairMQDevice::RunWrapper()
 
     // notify channels to resume transfers
     FairMQChannel::fInterrupted = false;
-    for (auto& kv : fDeviceCmdSockets)
+    fDeviceCmdSocket->Resume();
-    {
-        kv.second->Resume();
-    }
 
     try
     {
@@ -780,18 +762,12 @@ shared_ptr<FairMQTransportFactory> FairMQDevice::AddTransport(const string& tran
         pair<FairMQ::Transport, shared_ptr<FairMQTransportFactory>> trPair(FairMQ::TransportTypes.at(transport), tr);
         fTransports.insert(trPair);
 
-        auto p = fDeviceCmdSockets.emplace(tr->GetType(), tr->CreateSocket("pub", "device-commands"));
+        if (!fDeviceCmdSocket) {
-        if (p.second)
+            fDeviceCmdSocket = Transport()->CreateSocket("pub", "device-commands");
-        {
+            if(!fDeviceCmdSocket->Bind("inproc://commands")) {
-            p.first->second->Bind("inproc://commands");
+                exit(EXIT_FAILURE);
+            }
         }
-        else
-        {
-            exit(EXIT_FAILURE);
-        }
-
-        FairMQMessagePtr msg(tr->CreateMessage());
-
         return tr;
     }
     else
@@ -974,12 +950,9 @@ void FairMQDevice::LogSocketRates()
 void FairMQDevice::Unblock()
 {
     FairMQChannel::fInterrupted = true;
-    for (auto& kv : fDeviceCmdSockets)
+    fDeviceCmdSocket->Interrupt();
-    {
+    FairMQMessagePtr cmd(Transport()->CreateMessage());
-        kv.second->Interrupt();
+    fDeviceCmdSocket->Send(cmd);
-        FairMQMessagePtr cmd(fTransports.at(kv.first)->CreateMessage());
-        kv.second->Send(cmd);
-    }
 }
 
 void FairMQDevice::ResetTaskWrapper()

fairmq/FairMQDevice.h

@@ -194,7 +194,7 @@ class FairMQDevice : public FairMQStateMachine
     /// @brief Getter for default transport factory
     auto Transport() const -> const FairMQTransportFactory*
     {
-        return fTransports.cbegin()->second.get();
+        return fTransports.at(fair::mq::TransportTypes[GetDefaultTransport()]).get();
     }
 
     template<typename... Args>
@@ -517,7 +517,7 @@ class FairMQDevice : public FairMQStateMachine
     void CreateOwnConfig();
 
     bool fDataCallbacks;
-    std::unordered_map<FairMQ::Transport, FairMQSocketPtr> fDeviceCmdSockets; ///< Sockets used for the internal unblocking mechanism
+    FairMQSocketPtr fDeviceCmdSocket; ///< Socket used for the internal unblocking mechanism
     std::unordered_map<std::string, InputMsgCallback> fMsgInputs;
     std::unordered_map<std::string, InputMultipartCallback> fMultipartInputs;
     std::unordered_map<FairMQ::Transport, std::vector<std::string>> fMultitransportInputs;