Replace LooperExecutor with built-in class in Android AppRTC Demo

webrtc/examples/androidapp/src/org/appspot/apprtc/TCPChannelClient.java

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.appspot.apprtc;
 
 import android.util.Log;
 
-import org.appspot.apprtc.util.LooperExecutor;
+import org.appspot.apprtc.util.AppRTCUtils;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.net.InetAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.net.UnknownHostException;
+import java.util.concurrent.ExecutorService;
 
 /**
  * Replacement for WebSocketChannelClient for direct communication between two IP addresses. Handles
  * the signaling between the two clients using a TCP connection.
  *
  * <p>All public methods should be called from a looper executor thread
  * passed in a constructor, otherwise exception will be thrown.
  * All events are dispatched on the same thread.
  */
 public class TCPChannelClient {
   private static final String TAG = "TCPChannelClient";
 
-  private final LooperExecutor executor;
+  private final ExecutorService executor;
+  private AppRTCUtils.NonThreadSafe executorThreadCheck;

[magjed_webrtc, 2016/05/19 12:07:54]

Can you use ThreadUtils.ThreadChecker in
webrtc/base/java/src/org/webrtc/ThreadUtils.java instead? (And nuke
AppRTCUtils.NonThreadSafe in a separate CL).

Also, make thread checker final and initialize here or in the ctor, and call
detachThread() in the ctor. Then remove checkIfCalledOnValidThread() and inline
all uses with executorThreadCheck.calledOnValidThread().

[sakal, 2016/05/19 12:39:03]

Done.

   private final TCPChannelEvents eventListener;
   private TCPSocket socket;
 
   /**
    * Callback interface for messages delivered on TCP Connection. All callbacks are invoked from the
    * looper executor thread.
    */
   public interface TCPChannelEvents {
     void onTCPConnected(boolean server);
     void onTCPMessage(String message);
     void onTCPError(String description);
     void onTCPClose();
   }
 
   /**
    * Initializes the TCPChannelClient. If IP is a local IP address, starts a listening server on
    * that IP. If not, instead connects to the IP.
    *
    * @param eventListener Listener that will receive events from the client.
    * @param ip IP address to listen on or connect to.
    * @param port Port to listen on or connect to.
    */
   public TCPChannelClient(
-      LooperExecutor executor, TCPChannelEvents eventListener, String ip, int port) {
+      ExecutorService executor, TCPChannelEvents eventListener, String ip, int port) {
     this.executor = executor;
     this.eventListener = eventListener;
 
     InetAddress address;
     try {
       address = InetAddress.getByName(ip);
     } catch (UnknownHostException e) {
       reportError("Invalid IP address.");
       return;
     }
@@ skipping 38 matching lines @@
         eventListener.onTCPError(message);
       }
     });
   }
 
   /**
    * Helper method for debugging purposes.
    * Ensures that TCPChannelClient method is called on a looper thread.
    */
   private void checkIfCalledOnValidThread() {
-    if (!executor.checkOnLooperThread()) {
+    if(executorThreadCheck == null) {
+      executorThreadCheck = new AppRTCUtils.NonThreadSafe();
+    }
+
+    if (!executorThreadCheck.calledOnValidThread()) {
       throw new IllegalStateException(
           "TCPChannelClient method is not called on valid thread");
     }
   }
 
 
   /**
    * Base class for server and client sockets. Contains a listening thread that will call
    * eventListener.onTCPMessage on new messages.
    */
@@ skipping 222 matching lines @@
         return null;
       }
     }
 
     @Override
     public boolean isServer() {
       return false;
     }
   }
 }