- 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/zeromq/FairMQContextZMQ.cxx

@@ -51,8 +51,11 @@ void FairMQContextZMQ::Close()
     int rc = zmq_ctx_destroy(fContext);
     if (rc != 0)
     {
-        LOG(ERROR) << "failed closing context, reason: " << zmq_strerror(errno);
+        if (errno == EINTR) {
+            LOG(ERROR) << " failed closing context, reason: " << zmq_strerror(errno);
+        } else {
+            fContext = NULL;
+            return;
+        }
     }
-
-    fContext = NULL;
 }