Understanding Handler States

Handler's States

Please find all the available states of the Handler in the list below.

• HandlerState::Disconnected

  The Handler is disconnected.

• HandlerState::Disconnecting

  The intermediate state when the Handler is not disconnected but not connected.

• HandlerState::Connected

  Handler is connected.

• HandlerState::Connecting

  The intermediate state when the Handler is not connected but not disconnected.

Tracking Handler's State

To track the Handler's state you need to implement HandlerStateListener class interface and register an instance with the Handler using Handler::registerHandlerStateListener member.

Handler's States Transitions

Let's take a closer look what triggers transitions between the Handler's states.

Handler's States Transition Diagram

Disconnected -> Connecting

• When Handler::connect is called.
• When the Handler is restarting.

Connecting -> Connected

• When TCP connection to Eurex is established and Logon Request is accepted.

Connecting -> Disconnected

• When TCP connection to Eurex can't be established.
• When TCP connection to Eurex is established but Logon request is rejected.

Connected -> Disconnecting

• When Handler::disconnect is called.
• When TCP connection is disconnected and no reconnect attempts left.

Disconnecting -> Disconnected

• When TCP connection is closed and the Handler is stopped all the activity.

Connecting the Handler

If the Handler is in the Disconnected state and user code calls Handler::connect, user code will receive a callback with new state set to HandlerState::Connecting.

If the Handler is in any other state except Disconnected and user code calls Handler::connect, the Handler will first disconnects and only after successful disconnect user code will receive a callback with new state set to HandlerState::Connecting.

Disconnecting the Handler

If the Handler is in the Disconnected state and user code calls Handler::disconnect, user code will not receive any callback.

If the Handler is in any other state except Disconnected and user code calls Handler::disconnect, user code will receive a callback with new state set to HandlerState::Disconnecting.