test/java/lang/instrument/RedefineBigClassApp.java

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@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 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.

@@ -19,24 +19,66 @@
  * 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.
  */
 
+import java.io.*;
+
 public class RedefineBigClassApp {
+    /**
+     * 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 {
         System.out.println("Creating instance of " +
             RedefineBigClassAgent.clz);
         RedefineBigClassAgent.clz.newInstance();
 
+        long vMemBefore = getVMemSize();
         int count = 0;
         while (!RedefineBigClassAgent.doneRedefining) {
             System.out.println("App loop count: " + ++count);
             try {
                 Thread.sleep(10 * 1000);
             } catch (InterruptedException ie) {
             }
         }
         System.out.println("App looped  " + count + " times.");
 
+        long vMemAfter = getVMemSize();
+        if (vMemBefore == 0 || vMemAfter == 0) {
+            System.err.println("WARNING: Cannot perform memory leak detection on this OS");
+        } else {
+            long vMemDelta = vMemAfter - vMemBefore;
+            if (vMemDelta > MEM_LEAK_THRESHOLD) {
+                System.err.println("FAIL: Virtual memory usage increased by " + vMemDelta + "Kb " +
+                        "(greater than " + MEM_LEAK_THRESHOLD + "Kb)");
+                System.exit(1);
+            }
+            System.err.println("PASS: Virtual memory usage increased by " + vMemDelta + "Kb " +
+                    "(not greater than " + MEM_LEAK_THRESHOLD + "Kb)");
+        }
         System.exit(0);
     }
+
+    /**
+     * Return size of virtual memory allocated to the process in Kb.
+     * Linux specific. On other platforms and in case of any errors return 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 ex) {}
+        return 0;
+    }
 }