8278339: ServerSocket::isClosed may return false after accept throws

Reviewed-by: dfuchs

Author: Alan Bateman

src/java.base/share/classes/java/net/ServerSocket.java

@@ -711,15 +711,12 @@ private void ensureCompatible(SocketImpl si) throws IOException {
     public void close() throws IOException {
         synchronized (stateLock) {
             if (!closed) {
-                try {
-                    // close underlying socket if created
-                    if (created) {
-                        impl.close();
-                    }
-                } finally {
-                    closed = true;
-                }
+                closed = true;
 
+                // close underlying socket if created
+                if (created) {
+                    impl.close();
+                }
             }
         }
     }

test/jdk/java/net/ServerSocket/IsClosedAfterAsyncClose.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8278339
+ * @summary Test that ServerSocket::isClosed returns true after async close
+ */
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class IsClosedAfterAsyncClose {
+
+    private static final int ITERATIONS = 100;
+
+    public static void main(String[] args) throws Exception {
+        for (int i = 0; i < ITERATIONS; i++) {
+            System.out.printf("Test %d...%n", i);
+
+            // create listener bound to the loopback address
+            ServerSocket listener = new ServerSocket();
+            InetAddress loopback = InetAddress.getLoopbackAddress();
+            listener.bind(new InetSocketAddress(loopback, 0));
+
+            // task to close listener after a delay
+            Runnable closeListener = () -> {
+                try {
+                    Thread.sleep(100);
+                    listener.close();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            };
+
+            // main thread blocks in accept. When listener is closed then accept
+            // should wakeup with an IOException and isClosed should be true.
+            try (listener) {
+                Thread closer = new Thread(closeListener);
+                closer.start();
+                try {
+                    while (true) {
+                        Socket s = listener.accept();
+                        // close spurious connection
+                        s.close();
+                    }
+                } catch (IOException ioe) {
+                    if (!listener.isClosed()) {
+                        throw new RuntimeException("isClosed returned false!!");
+                    }
+                } finally {
+                    closer.join();
+                }
+            }
+        }
+    }
+}
+