openvidu-server: fix close session and init session race condition

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

@@ -538,33 +538,33 @@ public abstract class SessionManager {
 		if (session == null) {
 			throw new OpenViduException(Code.ROOM_NOT_FOUND_ERROR_CODE, "Session '" + sessionId + "' not found");
 		}
-		if (session.isClosed()) {
-			this.cleanCollections(sessionId);
-			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 {
-				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 only be executed when there were no participants connected
-			// to the session. That is: if the session was in the automatic recording stop
-			// timeout with INDIVIDUAL recording (no docker participant connected)
 		try {
 			if (session.closingLock.writeLock().tryLock(15, TimeUnit.SECONDS)) {
 				try {
 					if (session.isClosed()) {
-							return;
+						this.cleanCollections(sessionId);
+						throw new OpenViduException(Code.ROOM_CLOSED_ERROR_CODE,
+								"Session '" + sessionId + "' already closed");
 					}
+
+					boolean sessionClosedByLastParticipant = false;
+					Set<Participant> participants = getParticipants(sessionId);
+					for (Participant p : participants) {
+						try {
+							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 only be executed when there were no participants connected
+						// to the session. That is: if the session was in the automatic recording stop
+						// timeout with INDIVIDUAL recording (no docker participant connected)
 						this.closeSessionAndEmptyCollections(session, reason, true);
+					}
+
 				} finally {
 					session.closingLock.writeLock().unlock();
 				}
@@ -575,7 +575,6 @@ public abstract class SessionManager {
 			log.error("InterruptedException while waiting for Session {} closing lock to be available", sessionId);
 		}
 	}
-	}
 
 	public void closeNonActiveSessions(Function<Session, Boolean> conditionToRemove) {
 		// Loop through all non active sessions. Safely remove and clean all of
@@ -669,15 +668,15 @@ public abstract class SessionManager {
 	}
 
 	public void closeAllSessionsAndRecordingsOfKms(Kms kms, EndReason reason) {
-		// Close all active sessions
-		kms.getKurentoSessions().forEach(kSession -> {
-			this.closeSession(kSession.getSessionId(), reason);
-		});
 		// Close all non active sessions configured with this Media Node
 		this.closeNonActiveSessions(sessionNotActive -> {
 			return (sessionNotActive.getSessionProperties().mediaNode() != null
 					&& kms.getId().equals(sessionNotActive.getSessionProperties().mediaNode()));
 		});
+		// Close all active sessions
+		kms.getKurentoSessions().forEach(kSession -> {
+			this.closeSession(kSession.getSessionId(), reason);
+		});
 		// Stop all external recordings
 		kms.getActiveRecordings().forEach(recordingIdSessionId -> {
 

openvidu-server/src/main/java/io/openvidu/server/kurento/kms/KmsManager.java

@@ -186,6 +186,13 @@ public abstract class KmsManager {
 			public void disconnected() {
 				final Kms kms = kmss.get(kmsId);
 
+				// TODO: take a look at this
+//				if (kms.getTimeOfKurentoClientDisconnection() > 0) {
+//					log.warn("Event disconnected of KurentoClient {} is already being processed by other thread",
+//							kms.getKurentoClient().toString());
+//					return;
+//				}
+
 				kms.setKurentoClientConnected(false);
 				kms.setTimeOfKurentoClientDisconnection(System.currentTimeMillis());
 
@@ -225,7 +232,11 @@ public abstract class KmsManager {
 						log.warn("Removing Media Node {} after crash", kms.getId());
 						String environmentId = removeMediaNodeUponCrash(kms.getId());
 
-						// 2. Close all sessions and recordings with reason "nodeCrashed"
+						// 2. Send nodeCrashed webhook event
+						sessionEventsHandler.onMediaNodeCrashed(kms, environmentId, timeOfKurentoDisconnection,
+								affectedSessionIds, affectedRecordingIds);
+
+						// 3. Close all sessions and recordings with reason "nodeCrashed"
 						log.warn("Closing {} sessions hosted by KMS with uri {}: {}", kms.getKurentoSessions().size(),
 								kms.getUri(), kms.getKurentoSessions().stream().map(s -> s.getSessionId())
 										.collect(Collectors.joining(",", "[", "]")));
@@ -237,10 +248,6 @@ public abstract class KmsManager {
 							RemoteOperationUtils.revertToRunRemoteOperations();
 						}
 
-						// 3. Send nodeCrashed webhook event
-						sessionEventsHandler.onMediaNodeCrashed(kms, environmentId, timeOfKurentoDisconnection,
-								affectedSessionIds, affectedRecordingIds);
-
 						if (infiniteRetry()) {
 							disconnected();
 						}

openvidu-server/src/main/java/io/openvidu/server/rest/SessionRestController.java

@@ -25,9 +25,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Lock;
 import java.util.stream.Collectors;
 
-import io.openvidu.java.client.*;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -53,7 +53,18 @@ import com.google.gson.JsonParser;
 import io.openvidu.client.OpenViduException;
 import io.openvidu.client.OpenViduException.Code;
 import io.openvidu.client.internal.ProtocolElements;
+import io.openvidu.java.client.ConnectionProperties;
+import io.openvidu.java.client.ConnectionType;
+import io.openvidu.java.client.IceServerProperties;
+import io.openvidu.java.client.KurentoOptions;
+import io.openvidu.java.client.MediaMode;
+import io.openvidu.java.client.OpenViduRole;
 import io.openvidu.java.client.Recording.OutputMode;
+import io.openvidu.java.client.RecordingLayout;
+import io.openvidu.java.client.RecordingMode;
+import io.openvidu.java.client.RecordingProperties;
+import io.openvidu.java.client.SessionProperties;
+import io.openvidu.java.client.VideoCodec;
 import io.openvidu.server.config.OpenviduConfig;
 import io.openvidu.server.core.EndReason;
 import io.openvidu.server.core.IdentifierPrefixes;
@@ -101,19 +112,54 @@ public class SessionRestController {
 		}
 
 		String sessionId;
+		Lock sessionLock = null;
+
+		try {
 			if (sessionProperties.customSessionId() != null && !sessionProperties.customSessionId().isEmpty()) {
-			if (sessionManager.getSessionWithNotActive(sessionProperties.customSessionId()) != null) {
+				// Session has custom session id
+				sessionId = sessionProperties.customSessionId();
+				Session session = sessionManager.getSessionWithNotActive(sessionProperties.customSessionId());
+				if (session != null) {
+					// The session appears to already exist
+					if (session.closingLock.readLock().tryLock()) {
+						// The session indeed exists and is not being closed
+						try {
 							log.warn("Session {} is already created", sessionProperties.customSessionId());
 							return new ResponseEntity<>(HttpStatus.CONFLICT);
+						} finally {
+							session.closingLock.readLock().unlock();
+						}
+					} else {
+						// The session exists but is being closed
+						log.warn("Session {} is in the process of closing while calling POST {}/sessions", sessionId,
+								RequestMappings.API);
+						try {
+							if (session.closingLock.writeLock().tryLock(15, TimeUnit.SECONDS)) {
+								if (sessionManager
+										.getSessionWithNotActive(sessionProperties.customSessionId()) != null) {
+									// Other thread took the lock before and rebuilt the closing session
+									session.closingLock.writeLock().unlock();
+									return new ResponseEntity<>(HttpStatus.CONFLICT);
+								} else {
+									// This thread will rebuild the closing session
+									sessionLock = session.closingLock.writeLock();
+								}
+							} else {
+								log.error("Timeout waiting for Session {} closing lock to be available", sessionId);
+							}
+						} catch (InterruptedException e) {
+							log.error("InterruptedException while waiting for Session {} closing lock to be available",
+									sessionId);
+						}
+
+					}
 				}
-			sessionId = sessionProperties.customSessionId();
 			} else {
 				sessionId = IdentifierPrefixes.SESSION_ID + RandomStringUtils.randomAlphabetic(1).toUpperCase()
 						+ RandomStringUtils.randomAlphanumeric(9);
 			}
 
 			Session sessionNotActive = sessionManager.storeSessionNotActive(sessionId, sessionProperties);
-
 			if (sessionNotActive == null) {
 				return new ResponseEntity<>(HttpStatus.CONFLICT);
 			} else {
@@ -122,6 +168,11 @@ public class SessionRestController {
 				return new ResponseEntity<>(sessionNotActive.toJson(false, false).toString(),
 						RestUtils.getResponseHeaders(), HttpStatus.OK);
 			}
+		} finally {
+			if (sessionLock != null) {
+				sessionLock.unlock();
+			}
+		}
 	}
 
 	@RequestMapping(value = "/sessions/{sessionId}", method = RequestMethod.GET)
@@ -133,8 +184,17 @@ public class SessionRestController {
 
 		Session session = this.sessionManager.getSession(sessionId);
 		if (session != null) {
+			try {
 				JsonObject response = session.toJson(pendingConnections, webRtcStats);
 				return new ResponseEntity<>(response.toString(), RestUtils.getResponseHeaders(), HttpStatus.OK);
+			} catch (OpenViduException e) {
+				if (e.getCodeValue() == Code.ROOM_CLOSED_ERROR_CODE.getValue()) {
+					log.warn("Session closed while calling GET {}/sessions/{}", RequestMappings.API, sessionId);
+					return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+				} else {
+					throw e;
+				}
+			}
 		} else {
 			Session sessionNotActive = this.sessionManager.getSessionNotActive(sessionId);
 			if (sessionNotActive != null) {
@@ -157,10 +217,16 @@ public class SessionRestController {
 		JsonObject json = new JsonObject();
 		JsonArray jsonArray = new JsonArray();
 		sessions.forEach(session -> {
+			try {
 				JsonObject sessionJson = session.toJson(pendingConnections, webRtcStats);
 				jsonArray.add(sessionJson);
+			} catch (OpenViduException e) {
+				if (e.getCodeValue() != Code.ROOM_CLOSED_ERROR_CODE.getValue()) {
+					throw e;
+				}
+			}
 		});
-		json.addProperty("numberOfElements", sessions.size());
+		json.addProperty("numberOfElements", jsonArray.size());
 		json.add("content", jsonArray);
 		return new ResponseEntity<>(json.toString(), RestUtils.getResponseHeaders(), HttpStatus.OK);
 	}
@@ -655,6 +721,9 @@ public class SessionRestController {
 				Token token = sessionManager.newToken(session, connectionProperties.getRole(),
 						connectionProperties.getData(), connectionProperties.record(),
 						connectionProperties.getKurentoOptions(), connectionProperties.getCustomIceServers());
+
+				log.info("Generated token {}", token.getToken());
+
 				return new ResponseEntity<>(token.toJsonAsParticipant().toString(), RestUtils.getResponseHeaders(),
 						HttpStatus.OK);
 			} catch (Exception e) {
@@ -923,7 +992,8 @@ public class SessionRestController {
 						IceServerProperties.Builder iceServerPropertiesBuilder = new IceServerProperties.Builder();
 						iceServerPropertiesBuilder.url(customIceServerJson.get("url").getAsString());
 						if (customIceServerJson.has("staticAuthSecret")) {
-							iceServerPropertiesBuilder.staticAuthSecret(customIceServerJson.get("staticAuthSecret").getAsString());
+							iceServerPropertiesBuilder
+									.staticAuthSecret(customIceServerJson.get("staticAuthSecret").getAsString());
 						}
 						if (customIceServerJson.has("username")) {
 							iceServerPropertiesBuilder.username(customIceServerJson.get("username").getAsString());
@@ -939,7 +1009,8 @@ public class SessionRestController {
 				}
 			} else if (!openviduConfig.getWebrtcIceServersBuilders().isEmpty()) {
 				// If not defined in connection, check if defined in openvidu config
-				for (IceServerProperties.Builder iceServerPropertiesBuilder: openviduConfig.getWebrtcIceServersBuilders()) {
+				for (IceServerProperties.Builder iceServerPropertiesBuilder : openviduConfig
+						.getWebrtcIceServersBuilders()) {
 					IceServerProperties.Builder configIceBuilder = iceServerPropertiesBuilder.clone();
 					builder.addCustomIceServer(configIceBuilder.build());
 				}
@@ -970,8 +1041,6 @@ public class SessionRestController {
 					.onlyPlayWithSubscribers(onlyPlayWithSubscribers).networkCache(networkCache).build();
 		}
 
-
-
 		return builder;
 	}