8022584: Memory leak in some NetworkInterface methods

Reviewed-by: alanb, dholmes, chegar, michaelm

src/solaris/native/java/net/NetworkInterface.c

@@ -563,11 +563,9 @@ static int getFlags0(JNIEnv *env, jstring name) {
 
     if ((sock = openSocketWithFallback(env, name_utf)) < 0) {
         (*env)->ReleaseStringUTFChars(env, name, name_utf);
-         return -1;
+        return -1;
     }
 
-    name_utf = (*env)->GetStringUTFChars(env, name, &isCopy);
-
     ret = getFlags(sock, name_utf, &flags);
 
     close(sock);

test/java/net/NetworkInterface/MemLeakTest.java

+/*
+ * Copyright (c) 2013, 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 8022584
+ * @summary Some NetworkInterface methods can leak native memory
+ * @run main/othervm/timeout=700 MemLeakTest
+ */
+
+/* Note: the test can cause a memory leak that's why othervm option is required
+ */
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Collection;
+import java.util.Collections;
+
+public class MemLeakTest {
+
+    /**
+     * Memory leak is assumed, if application consumes more than specified amount of memory during its execution.
+     * The number is given in Kb.
+     */
+    private static final long MEM_LEAK_THRESHOLD = 32 * 1024; // 32Mb
+
+    public static void main(String[] args)
+            throws Exception {
+
+        if (!System.getProperty("os.name").equals("Linux")) {
+            System.out.println("Test only runs on Linux");
+            return;
+        }
+
+        // warm up
+        accessNetInterfaces(3);
+
+        long vMemBefore = getVMemSize();
+        accessNetInterfaces(500_000);
+        long vMemAfter = getVMemSize();
+
+        long vMemDelta = vMemAfter - vMemBefore;
+        if (vMemDelta > MEM_LEAK_THRESHOLD) {
+            throw new Exception("FAIL: Virtual memory usage increased by " + vMemDelta + "Kb " +
+                    "(greater than " + MEM_LEAK_THRESHOLD + "Kb)");
+        }
+
+        System.out.println("PASS: Virtual memory usage increased by " + vMemDelta + "Kb " +
+                "(not greater than " + MEM_LEAK_THRESHOLD + "Kb)");
+    }
+
+    private static void accessNetInterfaces(int times) {
+        try {
+            Collection<NetworkInterface> interfaces =
+                    Collections.list(NetworkInterface.getNetworkInterfaces());
+            for (int i = 0; i != times; ++i) {
+                for (NetworkInterface netInterface : interfaces) {
+                    netInterface.getMTU();
+                    netInterface.isLoopback();
+                    netInterface.isUp();
+                    netInterface.isPointToPoint();
+                    netInterface.supportsMulticast();
+                }
+            }
+        } catch (SocketException ignore) {}
+    }
+
+    /**
+     * Returns size of virtual memory allocated to the process in Kb.
+     * Linux specific. On other platforms and in case of any errors returns 0.
+     */
+    private static long getVMemSize() {
+
+        // Refer to the Linux proc(5) man page for details about /proc/self/stat file
+        //
+        // In short, this file contains status information about the current process
+        // written in one line. The fields are separated with spaces.
+        // The 23rd field is defined as 'vsize %lu   Virtual memory size in bytes'
+
+        try (FileReader fileReader = new FileReader("/proc/self/stat");
+             BufferedReader bufferedReader = new BufferedReader(fileReader)) {
+            String line = bufferedReader.readLine();
+            return Long.parseLong(line.split(" ")[22]) / 1024;
+        } catch (Exception ignore) {}
+        return 0;
+    }
+}