1 /* 2 * Copyright (c) 2010, 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 6907760 6929532 26 * @summary Tests WatchService behavior when lots of events are pending 27 * @library .. 28 * @run main/timeout=180 LotsOfEvents 29 */ 30 31 import java.nio.file.*; 32 import static java.nio.file.StandardWatchEventKind.*; 33 import java.io.IOException; 34 import java.io.OutputStream; 35 import java.util.*; 36 import java.util.concurrent.TimeUnit; 37 38 public class LotsOfEvents { 39 40 static final Random rand = new Random(); 41 42 public static void main(String[] args) throws Exception { 43 Path dir = TestUtil.createTemporaryDirectory(); 44 try { 45 testOverflowEvent(dir); 46 testModifyEventsQueuing(dir); 47 } finally { 48 TestUtil.removeAll(dir); 49 } 50 } 51 52 /** 53 * Tests that OVERFLOW events are not retreived with other events. 54 */ 55 static void testOverflowEvent(Path dir) 56 throws IOException, InterruptedException 57 { 58 try (WatchService watcher = dir.getFileSystem().newWatchService()) { 59 dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE); 60 61 // create a lot of files 62 int n = 1024; 63 Path[] files = new Path[n]; 64 for (int i=0; i<n; i++) { 65 files[i] = Files.createFile(dir.resolve("foo" + i)); 66 } 67 68 // give time for events to accumulate (improve chance of overflow) 69 Thread.sleep(1000); 70 71 // check that we see the create events (or overflow) 72 drainAndCheckOverflowEvents(watcher, ENTRY_CREATE, n); 73 74 // delete the files 75 for (int i=0; i<n; i++) { 76 Files.delete(files[i]); 77 } 78 79 // give time for events to accumulate (improve chance of overflow) 80 Thread.sleep(1000); 81 82 // check that we see the delete events (or overflow) 83 drainAndCheckOverflowEvents(watcher, ENTRY_DELETE, n); 84 } 85 } 86 87 static void drainAndCheckOverflowEvents(WatchService watcher, 88 WatchEvent.Kind<?> expectedKind, 89 int count) 90 throws IOException, InterruptedException 91 { 92 // wait for key to be signalled - the timeout is long to allow for 93 // polling implementations 94 WatchKey key = watcher.poll(15, TimeUnit.SECONDS); 95 if (key != null && count == 0) 96 throw new RuntimeException("Key was signalled (unexpected)"); 97 if (key == null && count > 0) 98 throw new RuntimeException("Key not signalled (unexpected)"); 99 100 int nread = 0; 101 boolean gotOverflow = false; 102 while (key != null) { 103 List<WatchEvent<?>> events = key.pollEvents(); 104 for (WatchEvent<?> event: events) { 105 WatchEvent.Kind<?> kind = event.kind(); 106 if (kind == expectedKind) { 107 // expected event kind 108 if (++nread > count) 109 throw new RuntimeException("More events than expected!!"); 110 } else if (kind == OVERFLOW) { 111 // overflow event should not be retrieved with other events 112 if (events.size() > 1) 113 throw new RuntimeException("Overflow retrieved with other events"); 114 gotOverflow = true; 115 } else { 116 throw new RuntimeException("Unexpected event '" + kind + "'"); 117 } 118 } 119 if (!key.reset()) 120 throw new RuntimeException("Key is no longer valid"); 121 key = watcher.poll(2, TimeUnit.SECONDS); 122 } 123 124 // check that all expected events were received or there was an overflow 125 if (nread < count && !gotOverflow) 126 throw new RuntimeException("Insufficient events"); 127 } 128 129 /** 130 * Tests that check that ENTRY_MODIFY events are queued efficiently 131 */ 132 static void testModifyEventsQueuing(Path dir) 133 throws IOException, InterruptedException 134 { 135 // this test uses a random number of files 136 final int nfiles = 5 + rand.nextInt(10); 137 DirectoryEntry[] entries = new DirectoryEntry[nfiles]; 138 for (int i=0; i<nfiles; i++) { 139 entries[i] = new DirectoryEntry(dir.resolve("foo" + i)); 140 141 // "some" of the files exist, some do not. 142 entries[i].deleteIfExists(); 143 if (rand.nextBoolean()) 144 entries[i].create(); 145 } 146 147 try (WatchService watcher = dir.getFileSystem().newWatchService()) { 148 dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY); 149 150 // do several rounds of noise and test 151 for (int round=0; round<10; round++) { 152 153 // make some noise!!! 154 for (int i=0; i<100; i++) { 155 DirectoryEntry entry = entries[rand.nextInt(nfiles)]; 156 int action = rand.nextInt(10); 157 switch (action) { 158 case 0 : entry.create(); break; 159 case 1 : entry.deleteIfExists(); break; 160 default: entry.modifyIfExists(); 161 } 162 } 163 164 // process events and ensure that we don't get repeated modify 165 // events for the same file. 166 WatchKey key = watcher.poll(15, TimeUnit.SECONDS); 167 while (key != null) { 168 Set<Path> modified = new HashSet<>(); 169 for (WatchEvent<?> event: key.pollEvents()) { 170 WatchEvent.Kind<?> kind = event.kind(); 171 Path file = (kind == OVERFLOW) ? null : (Path)event.context(); 172 if (kind == ENTRY_MODIFY) { 173 boolean added = modified.add(file); 174 if (!added) { 175 throw new RuntimeException( 176 "ENTRY_MODIFY events not queued efficiently"); 177 } 178 } else { 179 if (file != null) modified.remove(file); 180 } 181 } 182 if (!key.reset()) 183 throw new RuntimeException("Key is no longer valid"); 184 key = watcher.poll(2, TimeUnit.SECONDS); 185 } 186 } 187 } 188 } 189 190 static class DirectoryEntry { 191 private final Path file; 192 DirectoryEntry(Path file) { 193 this.file = file; 194 } 195 void create() throws IOException { 196 if (Files.notExists(file)) 197 Files.createFile(file); 198 199 } 200 void deleteIfExists() throws IOException { 201 Files.deleteIfExists(file); 202 } 203 void modifyIfExists() throws IOException { 204 if (Files.exists(file)) { 205 try (OutputStream out = Files.newOutputStream(file, StandardOpenOption.APPEND)) { 206 out.write("message".getBytes()); 207 } 208 } 209 } 210 } 211 212 }