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Contains the entire NEBA core implementation, i.e. the framework that interprets the NEBA API annotations and provides implementations for the service and lifecycle callback interfaces provided in the NEBA API. This package must not export anything as its implementation details are entirely private.

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/**
 * Copyright 2013 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 the "License";
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 

 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

package io.neba.core.blueprint;

import io.neba.core.mvc.MvcServlet;
import io.neba.core.resourcemodels.registration.ModelRegistrar;
import io.neba.core.selftests.SelftestRegistrar;
import org.osgi.framework.Bundle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * Base class for services reacting to context shutdowns.
 *
 * @author Olaf Otto
 */
public abstract class ContextShutdownHandler {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    @Autowired
    private SelftestRegistrar selftestRegistrar;
    @Autowired
    private ModelRegistrar modelRegistrar;
    @Autowired
    private MvcServlet dispatcherServlet;

    /**
     * We must guarantee the order in which the event is consumed by the
     * collaborators since subsequent operations may depend on the resulting
     * state.

     * Furthermore, the operations performed by the event handling parties may
     * encounter further locks which may be blocked by threads waiting for the
     * {@link io.neba.core.blueprint.EventhandlingBarrier}, thus resulting in a deadlock. 

     * To prevent this, the handling is performed {@link org.springframework.scheduling.annotation.Async asynchronously}.
     */
    public void handleStop(Bundle bundle) {
        this.logger.info("Removing infrastructure for bundle: " + bundle + "...");
        EventhandlingBarrier.begin();
        try {
            this.selftestRegistrar.unregister(bundle);
            this.modelRegistrar.unregister(bundle);
            this.dispatcherServlet.disableMvc(bundle);
        } finally {
            EventhandlingBarrier.end();
        }
        this.logger.info("Infrastructure for " + bundle + " removed.");
    }
}