1 /* 2 * Copyright (c) 2007, 2018, 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 import java.io.File; 25 import java.io.FileDescriptor; 26 import java.io.FileNotFoundException; 27 import java.io.IOException; 28 import java.io.RandomAccessFile; 29 import java.lang.management.ManagementFactory; 30 import java.lang.management.OperatingSystemMXBean; 31 import java.lang.ref.Cleaner; 32 import java.lang.ref.Reference; 33 import java.lang.ref.ReferenceQueue; 34 import java.lang.ref.WeakReference; 35 import java.lang.reflect.Field; 36 import java.nio.file.Path; 37 import java.util.ArrayDeque; 38 import java.util.HashSet; 39 40 import com.sun.management.UnixOperatingSystemMXBean; 41 42 import jdk.test.lib.util.FileUtils; 43 44 /** 45 * @test 46 * @bug 8080225 47 * @library /test/lib 48 * @build jdk.test.lib.util.FileUtils UnreferencedRAFClosesFd 49 * @modules java.base/java.io:open 50 * @summary Test to ensure that an unclosed and unreferenced RandomAccessFile closes the fd 51 * @run main/othervm UnreferencedRAFClosesFd 52 */ 53 public class UnreferencedRAFClosesFd { 54 55 static final String FILE_NAME = "empty.txt"; 56 57 /* standalone interface */ 58 public static void main(String argv[]) throws Exception { 59 60 File inFile= new File(System.getProperty("test.dir", "."), FILE_NAME); 61 inFile.createNewFile(); 62 inFile.deleteOnExit(); 63 64 FileUtils.listFileDescriptors(System.out); 65 long fdCount0 = getFdCount(); 66 67 String name = inFile.getPath(); 68 RandomAccessFile raf; 69 try { 70 // raf is explicitly *not* closed to allow cleaner to work 71 raf = new RandomAccessFile(name, "rw"); 72 } catch (FileNotFoundException e) { 73 System.out.println("Unexpected exception " + e); 74 throw(e); 75 } 76 FileDescriptor fd = raf.getFD(); 77 78 Field fdField = FileDescriptor.class.getDeclaredField("cleanup"); 79 fdField.setAccessible(true); 80 Cleaner.Cleanable cleanup = (Cleaner.Cleanable)fdField.get(fd); 81 82 // Prepare to wait for FOS, FD, Cleanup to be reclaimed 83 ReferenceQueue<Object> queue = new ReferenceQueue<>(); 84 HashSet<Reference<?>> pending = new HashSet<>(3); 85 pending.add(new WeakReference<>(cleanup, queue)); 86 pending.add(new WeakReference<>(raf, queue)); 87 pending.add(new WeakReference<>(fd, queue)); 88 89 Reference<?> r; 90 while (((r = queue.remove(10L)) != null) 91 || !pending.isEmpty()) { 92 System.out.printf("r: %s, pending: %d%n", r, pending.size()); 93 if (r != null) { 94 pending.remove(r); 95 } else { 96 cleanup = null; 97 raf = null; 98 fd = null; 99 System.gc(); // attempt to reclaim the RAF, cleanup, and fd 100 } 101 } 102 103 // Keep these variables in scope as gc roots 104 Reference.reachabilityFence(cleanup); 105 Reference.reachabilityFence(fd); 106 Reference.reachabilityFence(raf); 107 Reference.reachabilityFence(pending); 108 109 // Check the final count of open file descriptors 110 long fdCount = getFdCount(); 111 if (fdCount != fdCount0) { 112 System.out.printf("initial count of open file descriptors: %d%n", fdCount0); 113 System.out.printf("final count of open file descriptors: %d%n", fdCount); 114 FileUtils.listFileDescriptors(System.out); 115 } 116 } 117 118 119 // Get the count of open file descriptors, or -1 if not available 120 private static long getFdCount() { 121 OperatingSystemMXBean mxBean = ManagementFactory.getOperatingSystemMXBean(); 122 return (mxBean instanceof UnixOperatingSystemMXBean) 123 ? ((UnixOperatingSystemMXBean) mxBean).getOpenFileDescriptorCount() 124 : -1L; 125 } 126 }