1/* 2 * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24/* 25 * @bug 4858522 26 * @summary Basic unit test of UnixOperatingSystemMXBean.getOpenFileDescriptorCount() 27 * @author Steve Bohne 28 */ 29 30/* 31 * This test is just a sanity check and does not check for the correct 32 * value. The correct value should be checked manually: 33 * Solaris/Linux: 34 * 1. Find the pid of the java process. 35 * 2. In a shell, enter the command: "ls -1 /proc/<pid>/fd | wc -l" 36 */ 37 38import com.sun.management.UnixOperatingSystemMXBean; 39import java.lang.management.*; 40 41public class GetOpenFileDescriptorCount { 42 43 private static UnixOperatingSystemMXBean mbean = 44 (UnixOperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean(); 45 46 // Careful with these values. 47 private static final long MIN_COUNT_FOR_PASS = 1; 48 // Max count for pass dynamically determined below 49 private static long max_count_for_pass = Long.MAX_VALUE; 50 51 private static boolean trace = false; 52 53 public static void main(String args[]) throws Exception { 54 if (args.length > 0 && args[0].equals("trace")) { 55 trace = true; 56 } 57 58 long max_count = mbean.getMaxFileDescriptorCount(); 59 if (max_count > 0) { 60 max_count_for_pass = max_count; 61 } 62 63 long count = mbean.getOpenFileDescriptorCount(); 64 65 if (trace) { 66 System.out.println("Open file descriptor count: " + count); 67 } 68 69 if (count < MIN_COUNT_FOR_PASS || count > max_count_for_pass) { 70 throw new RuntimeException("Open file descriptor count " + 71 "illegal value: " + count + " bytes " + 72 "(MIN = " + MIN_COUNT_FOR_PASS + "; " + 73 "MAX = " + max_count_for_pass + ")"); 74 } 75 76 System.out.println("Test passed."); 77 } 78} 79