Fix possible ConcurrentModificationException

Access to the models list is now secured by a Lock

src/main/java/ctbrec/recorder/LocalRecorder.java

@@ -18,6 +18,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.NoSuchElementException;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -49,6 +50,7 @@ public class LocalRecorder implements Recorder {
     private volatile boolean recording = true;
     private List<File> deleteInProgress = Collections.synchronizedList(new ArrayList<>());
     private RecorderHttpClient client = new RecorderHttpClient();
+    private ReentrantLock lock = new ReentrantLock();
 
     public LocalRecorder(Config config) {
         this.config = config;
@@ -76,13 +78,20 @@ public class LocalRecorder implements Recorder {
     public void startRecording(Model model) {
         if (!models.contains(model)) {
             LOG.info("Model {} added", model);
+            lock.lock();
+            try {
                 models.add(model);
                 config.getSettings().models.add(model);
+            } finally {
+                lock.unlock();
+            }
         }
     }
 
     @Override
     public void stopRecording(Model model) throws IOException {
+        lock.lock();
+        try {
             if (models.contains(model)) {
                 models.remove(model);
                 config.getSettings().models.remove(model);
@@ -93,6 +102,9 @@ public class LocalRecorder implements Recorder {
             } else {
                 throw new NoSuchElementException("Model " + model.getName() + " ["+model.getUrl()+"] not found in list of recorded models");
             }
+        } finally {
+            lock.unlock();
+        }
     }
 
     private void startRecordingProcess(Model model) throws IOException {
@@ -102,10 +114,15 @@ public class LocalRecorder implements Recorder {
             return;
         }
 
+        lock.lock();
+        try {
             if (!models.contains(model)) {
                 LOG.info("Model {} has been removed. Restarting of recording cancelled.", model);
                 return;
             }
+        } finally {
+            lock.unlock();
+        }
 
         Download download;
         if (Config.getInstance().isServerMode()) {
@@ -135,12 +152,17 @@ public class LocalRecorder implements Recorder {
 
     @Override
     public boolean isRecording(Model model) {
+        lock.lock();
+        try {
             return models.contains(model);
+        } finally {
+            lock.unlock();
+        }
     }
 
     @Override
     public List<Model> getModelsRecording() {
-        return Collections.unmodifiableList(models);
+        return Collections.unmodifiableList(new ArrayList<>(models));
     }
 
     @Override
@@ -157,6 +179,8 @@ public class LocalRecorder implements Recorder {
     }
 
     private void stopRecordingProcesses() {
+        lock.lock();
+        try {
             for (Model model : models) {
                 Download recordingProcess = recordingProcesses.get(model);
                 if (recordingProcess != null) {
@@ -168,6 +192,9 @@ public class LocalRecorder implements Recorder {
                     }
                 }
             }
+        } finally {
+            lock.unlock();
+        }
     }
 
     private void tryRestartRecording(Model model) {
@@ -275,6 +302,8 @@ public class LocalRecorder implements Recorder {
         public void run() {
             running = true;
             while (running) {
+                lock.lock();
+                try {
                     for (Model model : getModelsRecording()) {
                         try {
                             if (!recordingProcesses.containsKey(model)) {
@@ -289,6 +318,9 @@ public class LocalRecorder implements Recorder {
                             LOG.error("Couldn't check if model {} is online", model.getName(), e);
                         }
                     }
+                } finally {
+                    lock.unlock();
+                }
 
                 try {
                     if (running)