import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+import javax.annotation.concurrent.GuardedBy;
import org.opendaylight.mdsal.dom.api.DOMSchemaService;
import org.opendaylight.yangtools.concepts.ListenerRegistration;
import org.opendaylight.yangtools.concepts.Registration;
ServiceTrackerCustomizer<SchemaContextListener, SchemaContextListener>, AutoCloseable {
private static final Logger LOG = LoggerFactory.getLogger(OsgiBundleScanningSchemaService.class);
+ private static AtomicReference<OsgiBundleScanningSchemaService> globalInstance = new AtomicReference<>();
+
+ @GuardedBy(value = "lock")
private final ListenerRegistry<SchemaContextListener> listeners = new ListenerRegistry<>();
private final YangTextSchemaContextResolver contextResolver = YangTextSchemaContextResolver.create("global-bundle");
private final BundleScanner scanner = new BundleScanner();
private BundleTracker<Iterable<Registration>> bundleTracker;
private boolean starting = true;
private volatile boolean stopping;
- private static OsgiBundleScanningSchemaService instance;
+ private final Object lock = new Object();
private OsgiBundleScanningSchemaService(final BundleContext context) {
this.context = Preconditions.checkNotNull(context);
}
- public static synchronized OsgiBundleScanningSchemaService createInstance(final BundleContext ctx) {
- Preconditions.checkState(instance == null);
- instance = new OsgiBundleScanningSchemaService(ctx);
+ public static OsgiBundleScanningSchemaService createInstance(final BundleContext ctx) {
+ OsgiBundleScanningSchemaService instance = new OsgiBundleScanningSchemaService(ctx);
+ Preconditions.checkState(globalInstance.compareAndSet(null, instance));
instance.start();
return instance;
}
- public static synchronized OsgiBundleScanningSchemaService getInstance() {
+ public static OsgiBundleScanningSchemaService getInstance() {
+ OsgiBundleScanningSchemaService instance = globalInstance.get();
Preconditions.checkState(instance != null, "Global Instance was not instantiated");
return instance;
}
@VisibleForTesting
- public static synchronized void destroyInstance() {
- try {
+ public static void destroyInstance() {
+ OsgiBundleScanningSchemaService instance = globalInstance.getAndSet(null);
+ if (instance != null) {
instance.close();
- } finally {
- instance = null;
}
}
listenerTracker = new ServiceTracker<>(context, SchemaContextListener.class,
OsgiBundleScanningSchemaService.this);
bundleTracker = new BundleTracker<>(context, Bundle.RESOLVED | Bundle.STARTING
- |
- Bundle.STOPPING | Bundle.ACTIVE, scanner);
- bundleTracker.open();
+ | Bundle.STOPPING | Bundle.ACTIVE, scanner);
+
+ synchronized (lock) {
+ bundleTracker.open();
- LOG.debug("BundleTracker.open() complete");
+ LOG.debug("BundleTracker.open() complete");
+
+ boolean hasExistingListeners = Iterables.size(listeners.getListeners()) > 0;
+ if (hasExistingListeners) {
+ tryToUpdateSchemaContext();
+ }
+ }
listenerTracker.open();
starting = false;
- tryToUpdateSchemaContext();
LOG.debug("start() complete");
}
}
@Override
- public synchronized ListenerRegistration<SchemaContextListener>
- registerSchemaContextListener(final SchemaContextListener listener) {
- final Optional<SchemaContext> potentialCtx = contextResolver.getSchemaContext();
- if (potentialCtx.isPresent()) {
- listener.onGlobalContextUpdated(potentialCtx.get());
+ public ListenerRegistration<SchemaContextListener> registerSchemaContextListener(
+ final SchemaContextListener listener) {
+ synchronized (lock) {
+ final Optional<SchemaContext> potentialCtx = contextResolver.getSchemaContext();
+ if (potentialCtx.isPresent()) {
+ listener.onGlobalContextUpdated(potentialCtx.get());
+ }
+ return listeners.register(listener);
}
- return listeners.register(listener);
}
@Override
}
@SuppressWarnings("checkstyle:IllegalCatch")
- private synchronized void updateContext(final SchemaContext snapshot) {
+ @VisibleForTesting
+ @GuardedBy(value = "lock")
+ void notifyListeners(final SchemaContext snapshot) {
final Object[] services = listenerTracker.getServices();
for (final ListenerRegistration<SchemaContextListener> listener : listeners) {
try {
*/
@SuppressWarnings("checkstyle:IllegalCatch")
@Override
- public synchronized void removedBundle(final Bundle bundle, final BundleEvent event,
- final Iterable<Registration> urls) {
+ public void removedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> urls) {
for (final Registration url : urls) {
try {
url.close();
}
@Override
- public synchronized SchemaContextListener addingService(final ServiceReference<SchemaContextListener> reference) {
+ public SchemaContextListener addingService(final ServiceReference<SchemaContextListener> reference) {
final SchemaContextListener listener = context.getService(reference);
final SchemaContext ctxContext = getGlobalContext();
return listener;
}
- public synchronized void tryToUpdateSchemaContext() {
+ public void tryToUpdateSchemaContext() {
if (starting || stopping) {
return;
}
- final Optional<SchemaContext> schema = contextResolver.getSchemaContext();
- if (schema.isPresent()) {
- if (LOG.isDebugEnabled()) {
- LOG.debug("Got new SchemaContext: # of modules {}", schema.get().getAllModuleIdentifiers().size());
- }
- updateContext(schema.get());
+ synchronized (lock) {
+ final Optional<SchemaContext> schema = contextResolver.getSchemaContext();
+ if (schema.isPresent()) {
+ if (LOG.isDebugEnabled()) {
+ LOG.debug("Got new SchemaContext: # of modules {}", schema.get().getAllModuleIdentifiers().size());
+ }
+
+ notifyListeners(schema.get());
+ }
}
}