Ensure CSS modules are closed before blueprint containers on shutdown
[controller.git] / opendaylight / blueprint / src / main / java / org / opendaylight / controller / blueprint / BlueprintBundleTracker.java
index 5727c13..6781b65 100644 (file)
@@ -7,21 +7,29 @@
  */
 package org.opendaylight.controller.blueprint;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.Dictionary;
 import java.util.Enumeration;
+import java.util.HashSet;
 import java.util.Hashtable;
 import java.util.List;
 import org.apache.aries.blueprint.NamespaceHandler;
 import org.apache.aries.blueprint.services.BlueprintExtenderService;
 import org.apache.aries.util.AriesFrameworkUtil;
 import org.opendaylight.controller.blueprint.ext.OpendaylightNamespaceHandler;
+import org.opendaylight.controller.config.api.ConfigSystemService;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.BundleActivator;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.BundleEvent;
 import org.osgi.framework.ServiceReference;
 import org.osgi.framework.ServiceRegistration;
+import org.osgi.framework.SynchronousBundleListener;
+import org.osgi.service.blueprint.container.BlueprintContainer;
 import org.osgi.service.blueprint.container.EventConstants;
 import org.osgi.service.event.Event;
 import org.osgi.service.event.EventHandler;
@@ -40,15 +48,20 @@ import org.slf4j.LoggerFactory;
  *
  * @author Thomas Pantelis
  */
-public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCustomizer<Bundle>, EventHandler {
+public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCustomizer<Bundle>, EventHandler,
+        SynchronousBundleListener {
     private static final Logger LOG = LoggerFactory.getLogger(BlueprintBundleTracker.class);
     private static final String BLUEPRINT_FILE_PATH = "org/opendaylight/blueprint/";
     private static final String BLUEPRINT_FLE_PATTERN = "*.xml";
+    private static final long SYSTEM_BUNDLE_ID = 0;
 
     private ServiceTracker<BlueprintExtenderService, BlueprintExtenderService> serviceTracker;
     private BundleTracker<Bundle> bundleTracker;
+    private BundleContext bundleContext;
     private volatile BlueprintExtenderService blueprintExtenderService;
     private volatile ServiceRegistration<?> blueprintContainerRestartReg;
+    private volatile BlueprintContainerRestartServiceImpl restartService;
+    private volatile boolean shuttingDown;
     private ServiceRegistration<?> eventHandlerReg;
     private ServiceRegistration<?> namespaceReg;
 
@@ -59,6 +72,8 @@ public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCus
     public void start(BundleContext context) {
         LOG.info("Starting {}", getClass().getSimpleName());
 
+        bundleContext = context;
+
         registerBlueprintEventHandler(context);
 
         registerNamespaceHandler(context);
@@ -73,11 +88,13 @@ public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCus
                         blueprintExtenderService = reference.getBundle().getBundleContext().getService(reference);
                         bundleTracker.open();
 
+                        context.addBundleListener(BlueprintBundleTracker.this);
+
                         LOG.debug("Got BlueprintExtenderService");
 
+                        restartService = new BlueprintContainerRestartServiceImpl(blueprintExtenderService);
                         blueprintContainerRestartReg = context.registerService(
-                                BlueprintContainerRestartService.class.getName(),
-                                new BlueprintContainerRestartServiceImpl(blueprintExtenderService), new Hashtable<>());
+                                BlueprintContainerRestartService.class.getName(), restartService, new Hashtable<>());
 
                         return blueprintExtenderService;
                     }
@@ -121,6 +138,18 @@ public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCus
         AriesFrameworkUtil.safeUnregisterService(blueprintContainerRestartReg);
     }
 
+    /**
+     * Implemented from SynchronousBundleListener.
+     */
+    @Override
+    public void bundleChanged(BundleEvent event) {
+        // If the system bundle (id 0) is stopping, do an orderly shutdown of all blueprint containers. On
+        // shutdown the system bundle is stopped first.
+        if(event.getBundle().getBundleId() == SYSTEM_BUNDLE_ID && event.getType() == BundleEvent.STOPPING) {
+            shutdownAllContainers();
+        }
+    }
+
     /**
      * Implemented from BundleActivator.
      */
@@ -135,6 +164,10 @@ public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCus
      */
     @Override
     public void modifiedBundle(Bundle bundle, BundleEvent event, Bundle object) {
+        if(shuttingDown) {
+            return;
+        }
+
         if(bundle.getState() == Bundle.ACTIVE) {
             List<Object> paths = findBlueprintPaths(bundle);
 
@@ -176,4 +209,135 @@ public class BlueprintBundleTracker implements BundleActivator, BundleTrackerCus
             return Collections.list((Enumeration)e);
         }
     }
+
+    private void shutdownAllContainers() {
+        shuttingDown = true;
+
+        restartService.close();
+
+        // Close all CSS modules first.
+        ConfigSystemService configSystem = getOSGiService(ConfigSystemService.class);
+        if(configSystem != null) {
+            configSystem.closeAllConfigModules();
+        }
+
+        LOG.info("Shutting down all blueprint containers...");
+
+        Collection<Bundle> containerBundles = new HashSet<>(Arrays.asList(bundleContext.getBundles()));
+        while(!containerBundles.isEmpty()) {
+            // For each iteration of getBundlesToDestroy, as containers are destroyed, other containers become
+            // eligible to be destroyed. We loop until we've destroyed them all.
+            for(Bundle bundle : getBundlesToDestroy(containerBundles)) {
+                containerBundles.remove(bundle);
+                BlueprintContainer container = blueprintExtenderService.getContainer(bundle);
+                if(container != null) {
+                    blueprintExtenderService.destroyContainer(bundle, container);
+                }
+            }
+        }
+
+        LOG.info("Shutdown of blueprint containers complete");
+    }
+
+    private List<Bundle> getBundlesToDestroy(Collection<Bundle> containerBundles) {
+        List<Bundle> bundlesToDestroy = new ArrayList<Bundle>();
+
+        // Find all container bundles that either have no registered services or whose services are no
+        // longer in use.
+        for(Bundle bundle : containerBundles) {
+            ServiceReference<?>[] references = bundle.getRegisteredServices();
+            int usage = 0;
+            if(references != null) {
+                for(ServiceReference<?> reference : references) {
+                    usage += getServiceUsage(reference);
+                }
+            }
+
+            LOG.debug("Usage for bundle {} is {}", bundle, usage);
+            if(usage == 0) {
+                bundlesToDestroy.add(bundle);
+            }
+        }
+
+        if(!bundlesToDestroy.isEmpty()) {
+            Collections.sort(bundlesToDestroy, new Comparator<Bundle>() {
+                @Override
+                public int compare(Bundle b1, Bundle b2) {
+                    return (int) (b2.getLastModified() - b1.getLastModified());
+                }
+            });
+
+            LOG.debug("Selected bundles {} for destroy (no services in use)", bundlesToDestroy);
+        } else {
+            // There's either no more container bundles or they all have services being used. For
+            // the latter it means there's either circular service usage or a service is being used
+            // by a non-container bundle. But we need to make progress so we pick the bundle with a
+            // used service with the highest service ID. Each service is assigned a monotonically
+            // increasing ID as they are registered. By picking the bundle with the highest service
+            // ID, we're picking the bundle that was (likely) started after all the others and thus
+            // is likely the safest to destroy at this point.
+
+            ServiceReference<?> ref = null;
+            for(Bundle bundle : containerBundles) {
+                ServiceReference<?>[] references = bundle.getRegisteredServices();
+                if(references == null) {
+                    continue;
+                }
+
+                for(ServiceReference<?> reference : references) {
+                    // We did check the service usage above but it's possible the usage has changed since
+                    // then,
+                    if(getServiceUsage(reference) == 0) {
+                        continue;
+                    }
+
+                    // Choose 'reference' if it has a lower service ranking or, if the rankings are equal
+                    // which is usually the case, if it has a higher service ID. For the latter the < 0
+                    // check looks backwards but that's how ServiceReference#compareTo is documented to work.
+                    if(ref == null || reference.compareTo(ref) < 0) {
+                        LOG.debug("Currently selecting bundle {} for destroy (with reference {})", bundle, reference);
+                        ref = reference;
+                    }
+                }
+            }
+
+            if(ref != null) {
+                bundlesToDestroy.add(ref.getBundle());
+            }
+
+            LOG.debug("Selected bundle {} for destroy (lowest ranking service or highest service ID)",
+                    bundlesToDestroy);
+        }
+
+        return bundlesToDestroy;
+    }
+
+    private static int getServiceUsage(ServiceReference<?> ref) {
+        Bundle[] usingBundles = ref.getUsingBundles();
+        return usingBundles != null ? usingBundles.length : 0;
+    }
+
+    private <T> T getOSGiService(Class<T> serviceInterface) {
+        try {
+            ServiceReference<T> serviceReference = bundleContext.getServiceReference(serviceInterface);
+            if(serviceReference == null) {
+                LOG.warn("{} service reference not found", serviceInterface.getSimpleName());
+                return null;
+            }
+
+            T service = bundleContext.getService(serviceReference);
+            if(service == null) {
+                // This could happen on shutdown if the service was already unregistered so we log as debug.
+                LOG.debug("{} service instance was not found", serviceInterface.getSimpleName());
+            }
+
+            return service;
+        } catch(IllegalStateException e) {
+            // This is thrown if the BundleContext is no longer valid which is possible on shutdown so we
+            // log as debug.
+            LOG.debug("Error obtaining OSGi service {}", serviceInterface.getSimpleName(), e);
+        }
+
+        return null;
+    }
 }