Fixed race condition when closing redundant sockets.

When more than one invitation socket is opened, Alice should pick which one to use and Bob should use whichever one Alice picks. This fixes a race condition where each party picked a different socket and closed the other.

briar-core/src/org/briarproject/invitation/AliceConnector.java

@@ -51,7 +51,7 @@ class AliceConnector extends Connector {
 	@Override
 	public void run() {
 		// Create an incoming or outgoing connection
-		DuplexTransportConnection conn = createInvitationConnection();
+		DuplexTransportConnection conn = createInvitationConnection(true);
 		if (conn == null) return;
 		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " connected");
 		// Don't proceed with more than one connection

briar-core/src/org/briarproject/invitation/BobConnector.java

@@ -51,7 +51,7 @@ class BobConnector extends Connector {
 	@Override
 	public void run() {
 		// Create an incoming or outgoing connection
-		DuplexTransportConnection conn = createInvitationConnection();
+		DuplexTransportConnection conn = createInvitationConnection(false);
 		if (conn == null) return;
 		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " connected");
 		// Carry out the key agreement protocol

briar-core/src/org/briarproject/invitation/Connector.java

@@ -93,10 +93,12 @@ abstract class Connector extends Thread {
 		messageDigest = crypto.getMessageDigest();
 	}
 
-	protected DuplexTransportConnection createInvitationConnection() {
+	protected DuplexTransportConnection createInvitationConnection(
+			boolean alice) {
 		if (LOG.isLoggable(INFO))
 			LOG.info(pluginName + " creating invitation connection");
-		return plugin.createInvitationConnection(random, CONNECTION_TIMEOUT);
+		return plugin.createInvitationConnection(random, CONNECTION_TIMEOUT,
+				alice);
 	}
 
 	protected void sendPublicKeyHash(BdfWriter w) throws IOException {

briar-core/src/org/briarproject/plugins/tcp/TcpPlugin.java

@@ -246,7 +246,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	}
 
 	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
-			long timeout) {
+			long timeout, boolean alice) {
 		throw new UnsupportedOperationException();
 	}
 

briar-core/src/org/briarproject/util/LatchedReference.java

@@ -1,30 +0,0 @@
-package org.briarproject.util;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.atomic.AtomicReference;
-
-public class LatchedReference<T> {
-
-	private final CountDownLatch latch = new CountDownLatch(1);
-	private final AtomicReference<T> reference = new AtomicReference<T>();
-
-	public boolean isSet() {
-		return reference.get() != null;
-	}
-
-	public boolean set(T t) {
-		if (t == null) throw new IllegalArgumentException();
-		if (reference.compareAndSet(null, t)) {
-			latch.countDown();
-			return true;
-		}
-		return false;
-	}
-
-	public T waitForReference(long timeout) throws InterruptedException {
-		latch.await(timeout, MILLISECONDS);
-		return reference.get();
-	}
-}