openvidu-server: NullPointer fix when closing not active session

openvidu-server/src/main/java/io/openvidu/server/core/SessionManager.java

@@ -82,7 +82,7 @@ public abstract class SessionManager {
 
 	public abstract void joinRoom(Participant participant, String sessionId, Integer transactionId);
 
-	public abstract void leaveRoom(Participant participant, Integer transactionId, EndReason reason,
+	public abstract boolean leaveRoom(Participant participant, Integer transactionId, EndReason reason,
 			boolean closeWebSocket);
 
 	public abstract void publishVideo(Participant participant, MediaOptions mediaOptions, Integer transactionId);
@@ -105,8 +105,8 @@ public abstract class SessionManager {
 	public abstract boolean unpublishStream(Session session, String streamId, Participant moderator,
 			Integer transactionId, EndReason reason);
 
-	public abstract void evictParticipant(Participant evictedParticipant, Participant moderator, Integer transactionId,
+	public abstract boolean evictParticipant(Participant evictedParticipant, Participant moderator,
-			EndReason reason);
+			Integer transactionId, EndReason reason);
 
 	public abstract void applyFilter(Session session, String streamId, String filterType, JsonObject filterOptions,
 			Participant moderator, Integer transactionId, String reason);
@@ -247,6 +247,18 @@ public abstract class SessionManager {
 		return sessionNotActive;
 	}
 
+	public Session storeSessionNotActive(Session sessionNotActive) {
+		final String sessionId = sessionNotActive.getSessionId();
+		this.sessionsNotActive.put(sessionId, sessionNotActive);
+		this.sessionidParticipantpublicidParticipant.putIfAbsent(sessionId, new ConcurrentHashMap<>());
+		this.sessionidFinalUsers.putIfAbsent(sessionId, new ConcurrentHashMap<>());
+		if (this.openviduConfig.isRecordingModuleEnabled()) {
+			this.sessionidAccumulatedRecordings.putIfAbsent(sessionId, new ConcurrentLinkedQueue<>());
+		}
+		showTokens();
+		return sessionNotActive;
+	}
+
 	public String newToken(String sessionId, OpenViduRole role, String serverMetadata,
 			KurentoTokenOptions kurentoTokenOptions) throws OpenViduException {
 
@@ -440,15 +452,22 @@ public abstract class SessionManager {
 			throw new OpenViduException(Code.ROOM_CLOSED_ERROR_CODE, "Session '" + sessionId + "' already closed");
 		}
 		Set<Participant> participants = getParticipants(sessionId);
+
+		boolean sessionClosedByLastParticipant = false;
+
 		for (Participant p : participants) {
 			try {
-				this.evictParticipant(p, null, null, reason);
+				sessionClosedByLastParticipant = this.evictParticipant(p, null, null, reason);
 			} catch (OpenViduException e) {
 				log.warn("Error evicting participant '{}' from session '{}'", p.getParticipantPublicId(), sessionId, e);
 			}
 		}
 
+		if (!sessionClosedByLastParticipant) {
+			// This code should never be executed, as last evicted participant must trigger
+			// session close
 			this.closeSessionAndEmptyCollections(session, reason);
+		}
 
 		return participants;
 	}
@@ -464,14 +483,18 @@ public abstract class SessionManager {
 			sessionEventsHandler.onSessionClosed(session.getSessionId(), reason);
 		}
 
-		sessions.remove(session.getSessionId());
+		this.cleanCollections(session.getSessionId());
-		sessionsNotActive.remove(session.getSessionId());
-		sessionidParticipantpublicidParticipant.remove(session.getSessionId());
-		sessionidFinalUsers.remove(session.getSessionId());
-		sessionidAccumulatedRecordings.remove(session.getSessionId());
-		sessionidTokenTokenobj.remove(session.getSessionId());
 
 		log.info("Session '{}' removed and closed", session.getSessionId());
 	}
 
+	protected void cleanCollections(String sessionId) {
+		sessions.remove(sessionId);
+		sessionsNotActive.remove(sessionId);
+		sessionidParticipantpublicidParticipant.remove(sessionId);
+		sessionidFinalUsers.remove(sessionId);
+		sessionidAccumulatedRecordings.remove(sessionId);
+		sessionidTokenTokenobj.remove(sessionId);
+	}
+
 }

openvidu-server/src/main/java/io/openvidu/server/kurento/core/KurentoSessionManager.java

@@ -95,6 +95,9 @@ public class KurentoSessionManager extends SessionManager {
 				try {
 					lessLoadedKms = this.kmsManager.getLessLoadedKms();
 				} catch (NoSuchElementException e) {
+					// Restore session not active
+					this.cleanCollections(sessionId);
+					this.storeSessionNotActive(sessionNotActive);
 					throw new OpenViduException(Code.ROOM_CANNOT_BE_CREATED_ERROR_CODE,
 							"There is no available media server where to initialize session '" + sessionId + "'");
 				}
@@ -122,10 +125,12 @@ public class KurentoSessionManager extends SessionManager {
 	}
 
 	@Override
-	public synchronized void leaveRoom(Participant participant, Integer transactionId, EndReason reason,
+	public synchronized boolean leaveRoom(Participant participant, Integer transactionId, EndReason reason,
 			boolean closeWebSocket) {
 		log.debug("Request [LEAVE_ROOM] ({})", participant.getParticipantPublicId());
 
+		boolean sessionClosedByLastParticipant = false;
+
 		KurentoParticipant kParticipant = (KurentoParticipant) participant;
 		KurentoSession session = kParticipant.getSession();
 		String sessionId = session.getSessionId();
@@ -194,6 +199,7 @@ public class KurentoSessionManager extends SessionManager {
 				} else {
 					log.info("No more participants in session '{}', removing it and closing it", sessionId);
 					this.closeSessionAndEmptyCollections(session, reason);
+					sessionClosedByLastParticipant = true;
 					showTokens();
 				}
 			} else if (remainingParticipants.size() == 1 && openviduConfig.isRecordingModuleEnabled()
@@ -212,6 +218,8 @@ public class KurentoSessionManager extends SessionManager {
 		if (closeWebSocket) {
 			sessionEventsHandler.closeRpcSession(participant.getParticipantPrivateId());
 		}
+
+		return sessionClosedByLastParticipant;
 	}
 
 	/**
@@ -522,12 +530,15 @@ public class KurentoSessionManager extends SessionManager {
 	}
 
 	@Override
-	public void evictParticipant(Participant evictedParticipant, Participant moderator, Integer transactionId,
+	public boolean evictParticipant(Participant evictedParticipant, Participant moderator, Integer transactionId,
 			EndReason reason) throws OpenViduException {
+
+		boolean sessionClosedByLastParticipant = false;
+
 		if (evictedParticipant != null) {
 			KurentoParticipant kParticipant = (KurentoParticipant) evictedParticipant;
 			Set<Participant> participants = kParticipant.getSession().getParticipants();
-			this.leaveRoom(kParticipant, null, reason, false);
+			sessionClosedByLastParticipant = this.leaveRoom(kParticipant, null, reason, false);
 			this.sessionEventsHandler.onForceDisconnect(moderator, evictedParticipant, participants, transactionId,
 					null, reason);
 			sessionEventsHandler.closeRpcSession(evictedParticipant.getParticipantPrivateId());
@@ -540,6 +551,8 @@ public class KurentoSessionManager extends SessionManager {
 						null);
 			}
 		}
+
+		return sessionClosedByLastParticipant;
 	}
 
 	@Override