/**
* Cancels the outstanding I/O operation on the directory associated with the given key and
* releases the associated resources.
*/
private void releaseResources(WindowsWatchKey key) {
try {
CancelIo(key.handle());
GetOverlappedResult(key.handle(), key.overlappedAddress());
} catch (WindowsException expected) {
// expected as I/O operation has been cancelled
}
CloseHandle(key.handle());
closeAttachedEvent(key.overlappedAddress());
key.buffer().cleaner().clean();
}
/** Poller main loop */
@Override
public void run() {
for (; ; ) {
CompletionStatus info;
try {
info = GetQueuedCompletionStatus(port);
} catch (WindowsException x) {
// this should not happen
x.printStackTrace();
return;
}
// wakeup
if (info.completionKey() == WAKEUP_COMPLETION_KEY) {
boolean shutdown = processRequests();
if (shutdown) {
return;
}
continue;
}
// map completionKey to get WatchKey
WindowsWatchKey key = ck2key.get((int) info.completionKey());
if (key == null) {
// We get here when a registration is changed. In that case
// the directory is closed which causes an event with the
// old completion key.
continue;
}
boolean criticalError = false;
int errorCode = info.error();
int messageSize = info.bytesTransferred();
if (errorCode == ERROR_NOTIFY_ENUM_DIR) {
// buffer overflow
key.signalEvent(StandardWatchEventKinds.OVERFLOW, null);
} else if (errorCode != 0 && errorCode != ERROR_MORE_DATA) {
// ReadDirectoryChangesW failed
criticalError = true;
} else {
// ERROR_MORE_DATA is a warning about incomplete
// data transfer over TCP/UDP stack. For the case
// [messageSize] is zero in the most of cases.
if (messageSize > 0) {
// process non-empty events.
processEvents(key, messageSize);
} else if (errorCode == 0) {
// insufficient buffer size
// not described, but can happen.
key.signalEvent(StandardWatchEventKinds.OVERFLOW, null);
}
// start read for next batch of changes
try {
ReadDirectoryChangesW(
key.handle(),
key.buffer().address(),
CHANGES_BUFFER_SIZE,
key.watchSubtree(),
ALL_FILE_NOTIFY_EVENTS,
key.countAddress(),
key.overlappedAddress());
} catch (WindowsException x) {
// no choice but to cancel key
criticalError = true;
}
}
if (criticalError) {
implCancelKey(key);
key.signal();
}
}
}