Merge https://github.com/google/ExoPlayer/pull/1397.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=119182077

library/src/main/java/com/google/android/exoplayer/upstream/UdpDataSource.java

@@ -25,6 +25,7 @@ import java.net.DatagramSocket;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.MulticastSocket;
+import java.net.SocketException;
 
 /**
  * A UDP {@link DataSource}.
@@ -51,8 +52,14 @@ public final class UdpDataSource implements DataSource {
    */
   public static final int DEFAULT_MAX_PACKET_SIZE = 2000;
 
+  /**
+   * The default socket timeout, in milliseconds.
+   */
+  public static final int DEAFULT_SOCKET_TIMEOUT_MILLIS = 8 * 1000;
+
   private final TransferListener listener;
   private final DatagramPacket packet;
+  private final int socketTimeoutMillis;
 
   private Uri uri;
   private DatagramSocket socket;
@@ -76,7 +83,18 @@ public final class UdpDataSource implements DataSource {
    * @param maxPacketSize The maximum datagram packet size, in bytes.
    */
   public UdpDataSource(TransferListener listener, int maxPacketSize) {
+    this(listener, maxPacketSize, DEAFULT_SOCKET_TIMEOUT_MILLIS);
+  }
+
+  /**
+   * @param listener An optional listener.
+   * @param maxPacketSize The maximum datagram packet size, in bytes.
+   * @param socketTimeoutMillis The socket timeout in milliseconds. A timeout of zero is interpreted
+   *     as an infinite timeout.
+   */
+  public UdpDataSource(TransferListener listener, int maxPacketSize, int socketTimeoutMillis) {
     this.listener = listener;
+    this.socketTimeoutMillis = socketTimeoutMillis;
     packetBuffer = new byte[maxPacketSize];
     packet = new DatagramPacket(packetBuffer, 0, maxPacketSize);
   }
@@ -101,6 +119,12 @@ public final class UdpDataSource implements DataSource {
       throw new UdpDataSourceException(e);
     }
 
+    try {
+      socket.setSoTimeout(socketTimeoutMillis);
+    } catch (SocketException e) {
+      throw new UdpDataSourceException(e);
+    }
+
     opened = true;
     if (listener != null) {
       listener.onTransferStart();