[audio] audio servlet: don't change map while used by interation (ope…

…nhab#801)

We should not remove entries (so keys) from the map while we are using
the key set (a view) of that map (see JavaDoc: otherwise "results of the
iteration undefined").

Signed-off-by: Markus Rathgeb <maggu2810@gmail.com>
GitOrigin-RevId: d19ee33

bundles/org.opensmarthouse.core.audio/src/main/java/org/eclipse/smarthome/core/audio/internal/AudioServlet.java

@@ -15,7 +15,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
@@ -143,16 +146,20 @@ protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws Se
  }
 
  private synchronized void removeTimedOutStreams() {
- for (String streamId : multiTimeStreams.keySet()) {
- if (streamTimeouts.get(streamId) < System.nanoTime()) {
- // the stream has expired, we need to remove it!
- FixedLengthAudioStream stream = multiTimeStreams.remove(streamId);
- streamTimeouts.remove(streamId);
- IOUtils.closeQuietly(stream);
- stream = null;
- logger.debug("Removed timed out stream {}", streamId);
+ // Build list of expired streams.
+ final List<String> toRemove = new LinkedList<>();
+ for (Entry<String, Long> entry : streamTimeouts.entrySet()) {
+ if (entry.getValue() < System.nanoTime()) {
+ toRemove.add(entry.getKey());
  }
  }
+ toRemove.forEach(streamId -> {
+ // the stream has expired, we need to remove it!
+ final FixedLengthAudioStream stream = multiTimeStreams.remove(streamId);
+ streamTimeouts.remove(streamId);
+ IOUtils.closeQuietly(stream);
+ logger.debug("Removed timed out stream {}", streamId);
+ });
  }
 
  @Override