1/* 2 * Copyright (c) 2016, 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/* @test 25 * @bug 8029516 26 * @summary Bash on WatchKey.cancel with a view to causing a crash when 27 * an outstanding I/O operation on directory completes after the 28 * directory has been closed 29 */ 30import java.nio.file.ClosedWatchServiceException; 31import java.nio.file.FileSystems; 32import java.nio.file.Files; 33import java.nio.file.Path; 34import java.nio.file.Paths; 35import java.nio.file.WatchKey; 36import java.nio.file.WatchService; 37import static java.nio.file.StandardWatchEventKinds.*; 38import java.util.concurrent.ExecutorService; 39import java.util.concurrent.Executors; 40import java.util.concurrent.TimeUnit; 41 42public class LotsOfCancels { 43 44 // set to true for any exceptions 45 static volatile boolean failed; 46 47 public static void main(String[] args) throws Exception { 48 49 // create a bunch of directories. Create two tasks for each directory, 50 // one to bash on cancel, the other to poll the events 51 ExecutorService pool = Executors.newCachedThreadPool(); 52 try { 53 Path testDir = Paths.get(System.getProperty("test.dir", ".")); 54 Path top = Files.createTempDirectory(testDir, "LotsOfCancels"); 55 for (int i=1; i<=16; i++) { 56 int id = i; 57 Path dir = Files.createDirectory(top.resolve("dir-" + i)); 58 WatchService watcher = FileSystems.getDefault().newWatchService(); 59 pool.submit(() -> handle(id, dir, watcher)); 60 pool.submit(() -> poll(id, watcher)); 61 } 62 } finally { 63 pool.shutdown(); 64 } 65 66 // give thread pool lots of time to terminate 67 if (!pool.awaitTermination(5L, TimeUnit.MINUTES)) 68 throw new RuntimeException("Thread pool did not terminate"); 69 70 if (failed) 71 throw new RuntimeException("Test failed, see log for details"); 72 } 73 74 /** 75 * Stress the given WatchService, specifically the cancel method, in 76 * the given directory. Closes the WatchService when done. 77 */ 78 static void handle(int id, Path dir, WatchService watcher) { 79 System.out.printf("begin handle %d%n", id); 80 try { 81 try { 82 Path file = dir.resolve("anyfile"); 83 for (int i=0; i<2000; i++) { 84 WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE); 85 Files.createFile(file); 86 Files.delete(file); 87 key.cancel(); 88 } 89 } finally { 90 System.out.printf("WatchService %d closing ...%n", id); 91 watcher.close(); 92 System.out.printf("WatchService %d closed %n", id); 93 } 94 } catch (Exception e) { 95 e.printStackTrace(); 96 failed = true; 97 } 98 System.out.printf("end handle %d%n", id); 99 } 100 101 /** 102 * Polls the given WatchService in a tight loop. This keeps the event 103 * queue drained, it also hogs a CPU core which seems necessary to 104 * tickle the original bug. 105 */ 106 static void poll(int id, WatchService watcher) { 107 System.out.printf("begin poll %d%n", id); 108 try { 109 for (;;) { 110 WatchKey key = watcher.take(); 111 if (key != null) { 112 key.pollEvents(); 113 key.reset(); 114 } 115 } 116 } catch (ClosedWatchServiceException expected) { 117 // nothing to do but print 118 System.out.printf("poll %d expected exception %s%n", id, expected); 119 } catch (Exception e) { 120 e.printStackTrace(); 121 failed = true; 122 } 123 System.out.printf("end poll %d%n", id); 124 } 125} 126