- Proper process termination:

if interrupted with CTRL+C blocking socket calls will return with -1. Each device should call FairMQDevice::Shutdown() before ending the running state to close open sockets, otherwise the interrupt call itself will block.

- FIX: Update number of received messages for FairMQFileSink.
- Add ability to poll on outputs for FairMQPoller.

fairmq/nanomsg/FairMQPollerNN.cxx

@@ -41,6 +41,14 @@ bool FairMQPollerNN::CheckInput(int index)
     return false;
 }
 
+bool FairMQPollerNN::CheckOutput(int index)
+{
+    if (items[index].revents & NN_POLLOUT)
+        return true;
+
+    return false;
+}
+
 FairMQPollerNN::~FairMQPollerNN()
 {
     if (items != NULL)