Hopefully fixed some deadlocks

common/src/main/java/ctbrec/recorder/NextGenLocalRecorder.java

@@ -411,18 +411,20 @@ public class NextGenLocalRecorder implements Recorder {
             for (Recording rec : toStop) {
                 Optional.ofNullable(rec.getDownload()).ifPresent(Download::stop);
             }
+        } finally {
+            recordingsLock.unlock();
+        }
 
         // wait for post-processing to finish
         LOG.info("Waiting for downloads to finish");
-            while (!recordingProcesses.isEmpty()) {
+        for (int i = 0; i < 60; i++) {
+            if (!recordingProcesses.isEmpty()) {
                 try {
                     Thread.sleep(1000);
                 } catch (InterruptedException e) {
                     LOG.error("Error while waiting for downloads to finish", e);
                 }
             }
-        } finally {
-            recordingsLock.unlock();
         }
 
         // shutdown threadpools

common/src/main/java/ctbrec/recorder/download/HlsDownload.java

@@ -237,7 +237,8 @@ public class HlsDownload extends AbstractHlsDownload {
     }
 
     @Override
-    public void stop() {
+    public synchronized void stop() {
+        if (running) {
             internalStop();
             try {
                 synchronized (downloadFinished) {
@@ -247,6 +248,7 @@ public class HlsDownload extends AbstractHlsDownload {
                 LOG.error("Couldn't wait for download to finish", e);
             }
         }
+    }
 
     @Override
     void internalStop() {

common/src/main/java/ctbrec/recorder/download/MergedHlsDownload.java

@@ -374,7 +374,8 @@ public class MergedHlsDownload extends AbstractHlsDownload {
     }
 
     @Override
-    public void stop() {
+    public synchronized void stop() {
+        if (running) {
             internalStop();
             try {
                 synchronized (downloadFinished) {
@@ -386,6 +387,7 @@ public class MergedHlsDownload extends AbstractHlsDownload {
             }
             LOG.debug("Download stopped");
         }
+    }
 
     @Override
     void internalStop() {