Distinguish between started- and connected state for Infiniband nodes
At this moment, the Infiniband node starts and blocks ib_start until a connection request appears and it is fully connected. The node is in the state STARTED. Then, as soon as the remote server disconnects, ib_stop is called and the Infiniband node destroys all IBV and RDMACM components. The state is now STOPPED. Since it is stopped, it doesn't accept new connections.
A solution to this problem is to introduce a new state: CONNECTED. In this proposed implementation, ib_start initializes all structs to accept a connection, starts a separate thread to monitor a global event channel, and sets the state of the node to STARTED. If a connection request appears in the event channel, the thread establishes the connection and sets the state to CONNECTED. Then, if the remote server disconnects, not all components are destroyed and the node is set to the state STARTED (and thus not to STOPPED). If a remote host tries to connect now, it can accept this connection request.