From a3406d3dfed952df70b1090b85e8d38a1cbee112 Mon Sep 17 00:00:00 2001
From: pabloFuente <pablofuenteperez@gmail.com>
Date: Fri, 12 Jun 2020 13:21:56 +0200
Subject: [PATCH] openvidu-server: protect concurrent recording start methods

---
 .../java/io/openvidu/server/core/Session.java |  2 +-
 .../recording/service/RecordingManager.java   | 79 ++++++++++++-------
 2 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/openvidu-server/src/main/java/io/openvidu/server/core/Session.java b/openvidu-server/src/main/java/io/openvidu/server/core/Session.java
index 099574ae..9bad28b6 100644
--- a/openvidu-server/src/main/java/io/openvidu/server/core/Session.java
+++ b/openvidu-server/src/main/java/io/openvidu/server/core/Session.java
@@ -80,7 +80,7 @@ public class Session implements SessionInterface {
 
 	/**
 	 * This lock protects initialization of ALWAYS recordings upon first user
-	 * publishing
+	 * publishing, as well as POST /api/recordings/start
 	 */
 	public Lock recordingLock = new ReentrantLock();
 
diff --git a/openvidu-server/src/main/java/io/openvidu/server/recording/service/RecordingManager.java b/openvidu-server/src/main/java/io/openvidu/server/recording/service/RecordingManager.java
index 2f993944..4333f423 100644
--- a/openvidu-server/src/main/java/io/openvidu/server/recording/service/RecordingManager.java
+++ b/openvidu-server/src/main/java/io/openvidu/server/recording/service/RecordingManager.java
@@ -230,38 +230,59 @@ public class RecordingManager {
 	}
 
 	public Recording startRecording(Session session, RecordingProperties properties) throws OpenViduException {
-		Recording recording = null;
 		try {
-			switch (properties.outputMode()) {
-			case COMPOSED:
-				recording = this.composedRecordingService.startRecording(session, properties);
-				break;
-			case INDIVIDUAL:
-				recording = this.singleStreamRecordingService.startRecording(session, properties);
-				break;
+			if (session.recordingLock.tryLock(15, TimeUnit.SECONDS)) {
+				try {
+					if (sessionIsBeingRecorded(session.getSessionId())) {
+						throw new OpenViduException(Code.RECORDING_START_ERROR_CODE,
+								"Concurrent start of recording for session " + session.getSessionId());
+					} else {
+						Recording recording = null;
+						try {
+							switch (properties.outputMode()) {
+							case COMPOSED:
+								recording = this.composedRecordingService.startRecording(session, properties);
+								break;
+							case INDIVIDUAL:
+								recording = this.singleStreamRecordingService.startRecording(session, properties);
+								break;
+							}
+						} catch (Exception e) {
+							throw e;
+						}
+						this.recordingFromStartingToStarted(recording);
+
+						this.cdr.recordRecordingStarted(recording);
+						this.cdr.recordRecordingStatusChanged(recording, null, recording.getCreatedAt(),
+								io.openvidu.java.client.Recording.Status.started);
+
+						if (!(OutputMode.COMPOSED.equals(properties.outputMode()) && properties.hasVideo())) {
+							// Directly send recording started notification for all cases except for
+							// COMPOSED recordings with video (will be sent on first RECORDER subscriber)
+							this.sessionHandler.sendRecordingStartedNotification(session, recording);
+						}
+						if (session.getActivePublishers() == 0) {
+							// Init automatic recording stop if there are now publishers when starting
+							// recording
+							log.info("No publisher in session {}. Starting {} seconds countdown for stopping recording",
+									session.getSessionId(), this.openviduConfig.getOpenviduRecordingAutostopTimeout());
+							this.initAutomaticRecordingStopThread(session);
+						}
+						return recording;
+					}
+				} finally {
+					session.recordingLock.unlock();
+				}
+			} else {
+				throw new OpenViduException(Code.RECORDING_START_ERROR_CODE,
+						"Timeout waiting for recording Session lock to be available for session "
+								+ session.getSessionId());
 			}
-		} catch (Exception e) {
-			throw e;
+		} catch (InterruptedException e) {
+			throw new OpenViduException(Code.RECORDING_START_ERROR_CODE,
+					"InterruptedException waiting for recording Session lock to be available for session "
+							+ session.getSessionId());
 		}
-		this.recordingFromStartingToStarted(recording);
-
-		this.cdr.recordRecordingStarted(recording);
-		this.cdr.recordRecordingStatusChanged(recording, null, recording.getCreatedAt(),
-				io.openvidu.java.client.Recording.Status.started);
-
-		if (!(OutputMode.COMPOSED.equals(properties.outputMode()) && properties.hasVideo())) {
-			// Directly send recording started notification for all cases except for
-			// COMPOSED recordings with video (will be sent on first RECORDER subscriber)
-			this.sessionHandler.sendRecordingStartedNotification(session, recording);
-		}
-		if (session.getActivePublishers() == 0) {
-			// Init automatic recording stop if there are now publishers when starting
-			// recording
-			log.info("No publisher in session {}. Starting {} seconds countdown for stopping recording",
-					session.getSessionId(), this.openviduConfig.getOpenviduRecordingAutostopTimeout());
-			this.initAutomaticRecordingStopThread(session);
-		}
-		return recording;
 	}
 
 	public Recording stopRecording(Session session, String recordingId, EndReason reason) {