TIF: make the tune request handling more efficient

- Clear the pending tune operations to handle consecutive tune requests
  efficiently.
- Add time out for onTune() to make developers not to handle whole tune
  process in the onTune() method.

Bug: 18179595
Change-Id: I571e55b78d7c4d17c7237c5ce70203941bec2130
diff --git a/media/java/android/media/tv/ITvInputSessionWrapper.java b/media/java/android/media/tv/ITvInputSessionWrapper.java
index 1ac80c1..da6f3fc 100644
--- a/media/java/android/media/tv/ITvInputSessionWrapper.java
+++ b/media/java/android/media/tv/ITvInputSessionWrapper.java
@@ -42,6 +42,7 @@
     private static final String TAG = "TvInputSessionWrapper";
 
     private static final int MESSAGE_HANDLING_DURATION_THRESHOLD_MILLIS = 50;
+    private static final int MESSAGE_TUNE_DURATION_THRESHOLD_MILLIS = 1000;
 
     private static final int DO_RELEASE = 1;
     private static final int DO_SET_MAIN = 2;
@@ -161,6 +162,11 @@
         if (duration > MESSAGE_HANDLING_DURATION_THRESHOLD_MILLIS) {
             Log.w(TAG, "Handling message (" + msg.what + ") took too long time (duration="
                     + duration + "ms)");
+            if (msg.what == DO_TUNE && duration > MESSAGE_TUNE_DURATION_THRESHOLD_MILLIS) {
+                throw new RuntimeException("Too much time to handle tune request. (" + duration
+                        + "ms > " + MESSAGE_TUNE_DURATION_THRESHOLD_MILLIS + "ms) "
+                        + "Consider handling the tune request in a separate thread.");
+            }
         }
     }
 
@@ -193,6 +199,8 @@
 
     @Override
     public void tune(Uri channelUri, Bundle params) {
+        // Clear the pending tune requests.
+        mCaller.removeMessages(DO_TUNE);
         mCaller.executeOrSendMessage(mCaller.obtainMessageOO(DO_TUNE, channelUri, params));
     }