1 /* 2 * Copyright (c) 2014, Google Inc. All rights reserved. 3 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25 /* 26 * @test 27 * @bug 8055949 28 * @summary Check that we can write (almost) Integer.MAX_VALUE bytes 29 * to a ByteArrayOutputStream. 30 * @requires (sun.arch.data.model == "64" & os.maxMemory >= 10g) 31 * @run main/timeout=1800/othervm -Xmx8g MaxCapacity 32 * @author Martin Buchholz 33 */ 34 import java.io.ByteArrayOutputStream; 35 36 public class MaxCapacity { 37 public static void main(String[] args) { 38 long maxHeap = Runtime.getRuntime().maxMemory(); 39 if (maxHeap < 3L * Integer.MAX_VALUE) { 40 System.out.printf("Skipping test; max memory %sM too small%n", 41 maxHeap/(1024*1024)); 42 return; 43 } 44 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 45 for (long n = 0; ; n++) { 46 try { 47 baos.write((byte)'x'); 48 } catch (Throwable t) { 49 // check data integrity while we're here 50 byte[] bytes = baos.toByteArray(); 51 if (bytes.length != n) 52 throw new AssertionError("wrong length"); 53 if (bytes[0] != 'x' || 54 bytes[bytes.length - 1] != 'x') 55 throw new AssertionError("wrong contents"); 56 57 long gap = Integer.MAX_VALUE - n; 58 System.out.printf("gap=%dM %d%n", gap/(1024*1024), gap); 59 if (gap > 1024) 60 throw t; 61 // t.printStackTrace(); 62 break; 63 } 64 } 65 } 66 }