Fix for dropped logout message issue

[traggatt]

Fix for issue described in forum post: Acceptor dropping logout messages.

The issue exists in 1.6.x so would be good to merge there too.

Issue

When a FIX acceptor is shutdown, a call is made to SessionConnector.logoutAllSessions(). This calls Session.logout() on all sessions in turn, regardless of prior status. The logout() method is asynchronous and merely sets a private flag in Session. The actual logout message is sent later when the flag is picked up by a background thread (see Session.next()).

After the SessionConnector.logout() call completes, the SessionConnector should wait for all sessions to be logged out. However, due to incorrect use of SessionConnector.isLoggedOn(), waitForLogout() is never called.

isLoggedOn() performs an AND-style operation on the results of all session.isLoggedOn() methods. This means that if one or more sessions are not logged on, we do not wait for those that are.

Fix

The simple fix is to add a new method anyLoggedOn() to check if any of the FIX sessions are logged on. If so, then waitForLogout() is called and the required logout messages are sent before termination of the connection.

[traggatt]

Thanks for the review. Will this be merged soon?

Incidentally, I'd be happy to raise another PR to merge this to the 1.6.x branch if you'd be open to the idea of a 1.6.5 version... :-D

[chrjohn]

Please feel free to open a PR for 1.6.x. However, I cannot say when 1.6.5 will be released, if at all. At the moment the 1.7.0 release has priority.

[traggatt]

Thanks for the merge. I've raised #131 which ports the fix to the 1.6.x branch.