Executor improvements / Bus error logging (#164)

* Remove unnecessary check for Applet thread groups in thread factory.

* Catch and log Throwables during Bus message dispatch.

Author: neilcsmith-net

src/org/freedesktop/gstreamer/Bus.java

@@ -35,6 +35,7 @@
 import com.sun.jna.Pointer;
 import com.sun.jna.ptr.PointerByReference;
 import java.util.Locale;
+import java.util.logging.Level;
 import org.freedesktop.gstreamer.glib.Natives;
 
 import org.freedesktop.gstreamer.lowlevel.GstAPI.GErrorStruct;
@@ -834,9 +835,13 @@ public synchronized <T> void disconnect(Class<T> listenerClass, T listener) {
      */
     private void dispatchMessage(Message msg) {
         // Dispatch to listeners
-        for (Object listener : messageProxies) {
-            ((MessageProxy) listener).busMessage(this, msg);
-        }
+        messageProxies.forEach((listener) -> {
+            try {
+                ((MessageProxy) listener).busMessage(this, msg);
+            } catch (Throwable t) {
+                LOG.log(Level.SEVERE, "Exception thrown by bus message handler", t);
+            }
+        });
     }
 
     private static class MessageProxy implements MESSAGE {

src/org/freedesktop/gstreamer/Gst.java

@@ -630,30 +630,10 @@ public static boolean testVersion(int major, int minor) {
     private static final ThreadFactory threadFactory = new ThreadFactory() {
         private final AtomicInteger counter = new AtomicInteger(0);
 
-        /**
-         * Determines if Gst has been started from an applet and returns it's
-         * parent group.
-         *
-         * This is to avoid a problem where the service thread is killed when an
-         * applet is destroyed. If multiple applets are active simultaneously,
-         * this could be a problem.
-         *
-         * @return Applet's parent ("main") thread group or null, if not running
-         * inside an applet
-         */
-        private ThreadGroup getThreadGroup() {
-            ThreadGroup tg = Thread.currentThread().getThreadGroup();
-            try {
-                Class<?> atgClass = Class.forName("sun.applet.AppletThreadGroup");
-                return atgClass.isInstance(tg) ? tg.getParent() : null;
-            } catch (ClassNotFoundException ex) {
-                return null;
-            }
-        }
-        
+        @Override
         public Thread newThread(Runnable task) {
             final String name = "gstreamer service thread " + counter.incrementAndGet();
-            Thread t = new Thread(getThreadGroup(), task, name);
+            Thread t = new Thread(task, name);
             t.setDaemon(true);
             t.setPriority(Thread.NORM_PRIORITY);
             return t;