am d2f41fe2: Merge "Fix ConcurrentCloseTest flakiness."

* commit 'd2f41fe210bf0fe958345f84e95e8f037c325005':
  Fix ConcurrentCloseTest flakiness.

1 files changed, 35 insertions, 25 deletions

diff --git a/support/src/test/java/tests/net/StuckServer.java b/support/src/test/java/tests/net/StuckServer.java
index eababce..f7a3118 100644
--- a/support/src/test/java/tests/net/StuckServer.java
+++ b/support/src/test/java/tests/net/StuckServer.java
@@ -17,6 +17,7 @@
 package tests.net;
 
 import java.io.IOException;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
@@ -26,48 +27,57 @@ import java.util.ArrayList;
  * A test ServerSocket that you can't connect to --- connects will time out.
  */
 public final class StuckServer {
+    private static final boolean DEBUG = false;
+
     private ServerSocket serverSocket;
+    private InetSocketAddress address;
     private ArrayList<Socket> clients = new ArrayList<Socket>();
 
-    public StuckServer() throws IOException {
+    public StuckServer(boolean useBacklog) throws IOException {
         // Set a backlog and use it up so that we can expect the
-        // connection to time out. According to Steven's
+        // connection to time out. According to Stevens
         // 4.5 "listen function", Linux adds 3 to the specified
         // backlog, so we need to connect 4 times before it will hang.
-        serverSocket = new ServerSocket(0, 1);
-        for (int i = 0; i < 4; i++) {
-            clients.add(new Socket(serverSocket.getInetAddress(), serverSocket.getLocalPort()));
-        }
-    }
-
-    public void unblockAfterMs(final int ms) {
-        Thread t = new Thread(new Runnable() {
-            @Override public void run() {
-                try {
-                    Thread.sleep(ms);
-                    for (Socket client : clients) {
-                        client.close();
-                    }
-                    clients.clear();
-                    clients.add(serverSocket.accept());
-                } catch (Exception ex) {
-                    ex.printStackTrace();
+        // The trouble with this is that it won't hang forever.
+        // After 10s or so, the kernel allows a couple more connections.
+        // This mode is ony useful if you actually want to continue eventually; we use it to
+        // test non-blocking connects, for example, where you want to test every part of the code.
+        if (useBacklog) {
+            this.serverSocket = new ServerSocket(0, 1);
+            this.address = (InetSocketAddress) serverSocket.getLocalSocketAddress();
+            if (DEBUG) {
+                System.err.println("StuckServer: " + serverSocket);
+            }
+            for (int i = 0; i < 4; ++i) {
+                Socket client = new Socket(serverSocket.getInetAddress(), serverSocket.getLocalPort());
+                clients.add(client);
+                if (DEBUG) {
+                    System.err.println("StuckServer client " + i + " - " + client);
                 }
             }
-        });
-        t.start();
+        } else {
+            // In general, though, you don't want to rely on listen(2) backlog. http://b/6971145.
+            // RFC 5737 implies this network will be unreachable. (There are two other networks
+            // to try if we have trouble with this one.)
+            // We've had trouble with 10.* in the past (because test labs running CTS often use
+            // net 10!) but hopefully this network will be better.
+            InetAddress testNet1 = InetAddress.getByAddress(new byte[] { (byte) 192, 0, 2, 0 });
+            this.address = new InetSocketAddress(testNet1, 80);
+        }
     }
 
     public InetSocketAddress getLocalSocketAddress() {
-        return (InetSocketAddress) serverSocket.getLocalSocketAddress();
+        return address;
     }
 
     public int getLocalPort() {
-        return serverSocket.getLocalPort();
+        return address.getPort();
     }
 
     public void close() throws IOException {
-        serverSocket.close();
+        if (serverSocket != null) {
+            serverSocket.close();
+        }
         for (Socket client : clients) {
             client.close();
         }