Null OSS (LAN Sessions)

Useful links:

• Cedric’s notes on Session Management
• Travelling In Multiplayer - Official Docs
• Session lifecycle

Online Subsystem

Warning

Sessions are copied from the server to the client (NOT REPLICATED) This means that you can still have “valid” session data from a search after a server destroyed the session.

Create Session

Creates a session using a Name and a Owner (Player Controller Net Id)

Start Session

Triggers the session to be in InProgress state.

Update Session

Allow to edit session settings.

Destroy Session

Used by client to leave, or by host on server to destroy a session completely. Destroying a Session has to happen on both server and clients when they leave.

Find Sessions

When you call FindSessions on the Online Subsystem, the search results array will be filled by OnValidResponsePacketReceived if the conditions are true. The data set in Session is done in ReadSessionFromPacket

Debugging

• EnableCheats true
• DumpOnlineSessionState

Player Controller

When a Player Controller gets destroyed (Destroyed) its calls Logout on gamemode, which calls NotifyLogout on gamesession, that calls UnregisterPlayer, and if it finds a session, it calls UnregisterPlayer on that session.