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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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*
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* 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.
*
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*/
/* @test
* @bug 6907760 6929532
* @summary Tests WatchService behavior when lots of events are pending
* @library ..
* @run main/timeout=180 LotsOfEvents
*/
import java.nio.file.*;
import static java.nio.file.StandardWatchEventKind.*;
import java.io.IOException;
import java.io.OutputStream;
import java.util.*;
import java.util.concurrent.TimeUnit;
public class LotsOfEvents {
static final Random rand = new Random();
public static void main(String[] args) throws Exception {
Path dir = TestUtil.createTemporaryDirectory();
try {
testOverflowEvent(dir);
testModifyEventsQueuing(dir);
} finally {
TestUtil.removeAll(dir);
}
}
/**
* Tests that OVERFLOW events are not retreived with other events.
*/
static void testOverflowEvent(Path dir)
throws IOException, InterruptedException
{
WatchService watcher = dir.getFileSystem().newWatchService();
try {
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)
drainAndCheckOverflowEvents(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)
drainAndCheckOverflowEvents(watcher, ENTRY_DELETE, n);
} finally {
watcher.close();
}
}
static void drainAndCheckOverflowEvents(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;
while (key != null) {
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);
}
// check that all expected events were received or there was an overflow
if (nread < count && !gotOverflow)
throw new RuntimeException("Insufficient events");
}
/**
* Tests that check that ENTRY_MODIFY events are queued efficiently
*/
static void testModifyEventsQueuing(Path dir)
throws IOException, InterruptedException
{
// this test uses a random number of files
final int nfiles = 5 + rand.nextInt(10);
DirectoryEntry[] entries = new DirectoryEntry[nfiles];
for (int i=0; i<nfiles; i++) {
entries[i] = new DirectoryEntry(dir.resolve("foo" + i));
// "some" of the files exist, some do not.
entries[i].deleteIfExists();
if (rand.nextBoolean())
entries[i].create();
}
WatchService watcher = dir.getFileSystem().newWatchService();
try {
dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
// do several rounds of noise and test
for (int round=0; round<10; round++) {
// make some noise!!!
for (int i=0; i<100; i++) {
DirectoryEntry entry = entries[rand.nextInt(nfiles)];
int action = rand.nextInt(10);
switch (action) {
case 0 : entry.create(); break;
case 1 : entry.deleteIfExists(); break;
default: entry.modifyIfExists();
}
}
// process events and ensure that we don't get repeated modify
// events for the same file.
WatchKey key = watcher.poll(15, TimeUnit.SECONDS);
while (key != null) {
Set<Path> modified = new HashSet<Path>();
for (WatchEvent<?> event: key.pollEvents()) {
WatchEvent.Kind<?> kind = event.kind();
Path file = (kind == OVERFLOW) ? null : (Path)event.context();
if (kind == ENTRY_MODIFY) {
boolean added = modified.add(file);
if (!added) {
throw new RuntimeException(
"ENTRY_MODIFY events not queued efficiently");
}
} else {
if (file != null) modified.remove(file);
}
}
if (!key.reset())
throw new RuntimeException("Key is no longer valid");
key = watcher.poll(2, TimeUnit.SECONDS);
}
}
} finally {
watcher.close();
}
}
static class DirectoryEntry {
private final Path file;
DirectoryEntry(Path file) {
this.file = file;
}
void create() throws IOException {
if (file.notExists())
file.createFile();
}
void deleteIfExists() throws IOException {
file.deleteIfExists();
}
void modifyIfExists() throws IOException {
if (file.exists()) {
OutputStream out = file.newOutputStream(StandardOpenOption.APPEND);
try {
out.write("message".getBytes());
} finally {
out.close();
}
}
}
}
}