6907760: (file) OVERFLOW event should cause pending events to be purged
Reviewed-by: chegar
--- a/jdk/src/share/classes/sun/nio/fs/AbstractWatchKey.java Thu Jan 07 19:42:43 2010 -0800
+++ b/jdk/src/share/classes/sun/nio/fs/AbstractWatchKey.java Sat Jan 09 19:32:58 2010 +0000
@@ -88,26 +88,24 @@
final void signalEvent(WatchEvent.Kind<?> kind, Object context) {
synchronized (this) {
int size = events.size();
- if (size > 1) {
- // don't let list get too big
- if (size >= MAX_EVENT_LIST_SIZE) {
- kind = StandardWatchEventKind.OVERFLOW;
- context = null;
+ if (size > 0) {
+ // if the previous event is an OVERFLOW event or this is a
+ // repeated event then we simply increment the counter
+ WatchEvent<?> prev = events.get(size-1);
+ if ((prev.kind() == StandardWatchEventKind.OVERFLOW) ||
+ ((kind == prev.kind() &&
+ Objects.equals(context, prev.context()))))
+ {
+ ((Event<?>)prev).increment();
+ return;
}
- // repeated event
- WatchEvent<?> prev = events.get(size-1);
- if (kind == prev.kind()) {
- boolean isRepeat;
- if (context == null) {
- isRepeat = (prev.context() == null);
- } else {
- isRepeat = context.equals(prev.context());
- }
- if (isRepeat) {
- ((Event<?>)prev).increment();
- return;
- }
+ // if the list has reached the limit then drop pending events
+ // and queue an OVERFLOW event
+ if (size >= MAX_EVENT_LIST_SIZE) {
+ events.clear();
+ kind = StandardWatchEventKind.OVERFLOW;
+ context = null;
}
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/nio/file/WatchService/OverflowEventIsLoner.java Sat Jan 09 19:32:58 2010 +0000
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2010 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 6907760
+ * @summary Check that the OVERFLOW event is not retrieved with other events
+ * @library ..
+ */
+
+import java.nio.file.*;
+import static java.nio.file.StandardWatchEventKind.*;
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+public class OverflowEventIsLoner {
+
+ static void drainEvents(WatchService watcher,
+ WatchEvent.Kind<?> expectedKind,
+ int count)
+ throws IOException, InterruptedException
+ {
+ // wait for key to be signalled - the timeout is long to allow for
+ // polling implementations
+ WatchKey key = watcher.poll(15, TimeUnit.SECONDS);
+ if (key != null && count == 0)
+ throw new RuntimeException("Key was signalled (unexpected)");
+ if (key == null && count > 0)
+ throw new RuntimeException("Key not signalled (unexpected)");
+
+ int nread = 0;
+ boolean gotOverflow = false;
+ do {
+ List<WatchEvent<?>> events = key.pollEvents();
+ for (WatchEvent<?> event: events) {
+ WatchEvent.Kind<?> kind = event.kind();
+ if (kind == expectedKind) {
+ // expected event kind
+ if (++nread > count)
+ throw new RuntimeException("More events than expected!!");
+ } else if (kind == OVERFLOW) {
+ // overflow event should not be retrieved with other events
+ if (events.size() > 1)
+ throw new RuntimeException("Overflow retrieved with other events");
+ gotOverflow = true;
+ } else {
+ throw new RuntimeException("Unexpected event '" + kind + "'");
+ }
+ }
+ if (!key.reset())
+ throw new RuntimeException("Key is no longer valid");
+ key = watcher.poll(2, TimeUnit.SECONDS);
+ } while (key != null);
+
+ // check that all expected events were received or there was an overflow
+ if (nread < count && !gotOverflow)
+ throw new RuntimeException("Insufficient events");
+ }
+
+
+ static void test(Path dir) throws IOException, InterruptedException {
+ WatchService watcher = dir.getFileSystem().newWatchService();
+ try {
+ WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
+
+ // create a lot of files
+ int n = 1024;
+ Path[] files = new Path[n];
+ for (int i=0; i<n; i++) {
+ files[i] = dir.resolve("foo" + i).createFile();
+ }
+
+ // give time for events to accumulate (improve chance of overflow)
+ Thread.sleep(1000);
+
+ // check that we see the create events (or overflow)
+ drainEvents(watcher, ENTRY_CREATE, n);
+
+ // delete the files
+ for (int i=0; i<n; i++) {
+ files[i].delete();
+ }
+
+ // give time for events to accumulate (improve chance of overflow)
+ Thread.sleep(1000);
+
+ // check that we see the delete events (or overflow)
+ drainEvents(watcher, ENTRY_DELETE, n);
+ } finally {
+ watcher.close();
+ }
+ }
+
+ public static void main(String[] args) throws Exception {
+ Path dir = TestUtil.createTemporaryDirectory();
+ try {
+ test(dir);
+ } finally {
+ TestUtil.removeAll(dir);
+ }
+ }
+}