1 /* 2 * Copyright (c) 2017 Red Hat, Inc. and/or its affiliates. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 public class TestHeapDump { 25 26 private static final int NUM_ITER = 10000; 27 28 private static final int ARRAY_SIZE = 1000; 29 30 private static final int EXPECTED_OBJECTS = 31 ARRAY_SIZE + // array reachable from instance field 32 1 + // static field root 33 1; // local field root 34 35 static { 36 try { 37 System.loadLibrary("TestHeapDump"); 38 } catch (UnsatisfiedLinkError ule) { 39 System.err.println("Could not load TestHeapDump library"); 40 System.err.println("java.library.path: " 41 + System.getProperty("java.library.path")); 42 throw ule; 43 } 44 } 45 46 native static int heapdump(Class<?> filterClass); 47 48 public static void main(String args[]) { 49 new TestHeapDump().run(); 50 } 51 52 // This root needs to be discovered 53 static Object root = new TestObject(); 54 55 // This field needs to be discovered 56 TestObject[] array; 57 58 public void run() { 59 array = new TestObject[ARRAY_SIZE]; 60 for (int i = 0; i < ARRAY_SIZE; i++) { 61 array[i] = new TestObject(); 62 } 63 TestObject localRoot = new TestObject(); 64 for (int i = 0; i < NUM_ITER; i++) { 65 int numObjs = heapdump(TestObject.class); 66 if (numObjs != EXPECTED_OBJECTS) { 67 throw new RuntimeException("Expected " + EXPECTED_OBJECTS + " objects, but got " + numObjs); 68 } 69 } 70 } 71 72 // We look for the instances of this class during the heap scan 73 public static class TestObject {} 74 }