7181793: Socket getOutputStream create streams that cannot be GC'ed until Socket is closed

Reviewed-by: alanb, chegar

src/share/classes/java/net/AbstractPlainSocketImpl.java

@@ -52,6 +52,7 @@ abstract class AbstractPlainSocketImpl extends SocketImpl
     private boolean shut_wr = false;
 
     private SocketInputStream socketInputStream = null;
+    private SocketOutputStream socketOutputStream = null;
 
     /* number of threads using the FileDescriptor */
     protected int fdUseCount = 0;
@@ -436,7 +437,10 @@ abstract class AbstractPlainSocketImpl extends SocketImpl
         if (shut_wr) {
             throw new IOException("Socket output is shutdown");
         }
-        return new SocketOutputStream(this);
+        if (socketOutputStream == null) {
+            socketOutputStream = new SocketOutputStream(this);
+        }
+        return socketOutputStream;
     }
 
     void setFileDescriptor(FileDescriptor fd) {

test/java/net/Socket/SocketGrowth.java

+/*
+ * Copyright (c) 2012, 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 7181793
+ * @summary getOutputStream create streams that cannot be GC'ed until Socket is closed
+ * @run main/othervm -Xmx32m SocketGrowth
+ */
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class SocketGrowth {
+
+    public static void main(String[] args) throws IOException {
+
+        try (ServerSocket ss = new ServerSocket(0)) {
+            try (Socket s = new Socket("localhost", ss.getLocalPort());
+                    Socket peer = ss.accept()) {
+                for (int i=0; i<1000000; i++) {
+                    // buggy JDK will run out of memory in this loop
+                    s.getOutputStream();
+                    // test InputStream also while we're here
+                    s.getInputStream();
+                    if (i % 100000 == 0) System.out.println(i);
+                }
+            }
+        }
+    }
+}