Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more contributor license |
| 3 | * agreements. See the NOTICE file distributed with this work for additional information |
| 4 | * regarding copyright ownership. The ASF licenses this file to you under the Apache License, |
| 5 | * Version 2.0 (the "License"); you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless |
| 7 | * required by applicable law or agreed to in writing, software distributed under the License is |
| 8 | * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
| 9 | * or implied. See the License for the specific language governing permissions and limitations |
| 10 | * under the License. |
| 11 | */ |
Pierre De Rop | c242986 | 2009-12-04 23:00:03 +0000 | [diff] [blame] | 12 | package org.apache.felix.dm.impl.dependencies; |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 13 | |
| 14 | import java.lang.reflect.InvocationHandler; |
| 15 | import java.lang.reflect.Method; |
| 16 | import java.lang.reflect.Proxy; |
| 17 | |
Pierre De Rop | c242986 | 2009-12-04 23:00:03 +0000 | [diff] [blame] | 18 | import org.apache.felix.dm.DependencyActivatorBase; |
Marcel Offermans | 3d92121 | 2010-08-09 13:37:02 +0000 | [diff] [blame] | 19 | import org.apache.felix.dm.DependencyService; |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 20 | import org.apache.felix.dm.ServiceDependency; |
Marcel Offermans | 8b93efa | 2010-07-02 18:27:21 +0000 | [diff] [blame] | 21 | import org.apache.felix.dm.TemporalServiceDependency; |
Pierre De Rop | c242986 | 2009-12-04 23:00:03 +0000 | [diff] [blame] | 22 | import org.apache.felix.dm.impl.Logger; |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 23 | import org.osgi.framework.Bundle; |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 24 | import org.osgi.framework.BundleContext; |
| 25 | import org.osgi.framework.ServiceReference; |
| 26 | |
| 27 | /** |
Marcel Offermans | 5be5f14 | 2011-04-26 10:47:12 +0000 | [diff] [blame] | 28 | * Temporal Service dependency implementation, used to hide temporary service dependency "outage". |
| 29 | * Only works with a required dependency. |
| 30 | * |
| 31 | * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| 32 | */ |
Pierre De Rop | c242986 | 2009-12-04 23:00:03 +0000 | [diff] [blame] | 33 | public class TemporalServiceDependencyImpl extends ServiceDependencyImpl implements TemporalServiceDependency, InvocationHandler { |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 34 | // Max millis to wait for service availability. |
| 35 | private long m_timeout = 30000; |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 36 | |
| 37 | // Dependency service currently used (with highest rank or highest service id). |
| 38 | private volatile Object m_cachedService; |
| 39 | |
| 40 | // Framework bundle (we use it to detect if the framework is stopping) |
| 41 | private final Bundle m_frameworkBundle; |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 42 | |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 43 | // The service proxy, which blocks when service is not available. |
| 44 | private Object m_serviceInstance; |
| 45 | |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 46 | /** |
| 47 | * Creates a new Temporal Service Dependency. |
| 48 | * |
| 49 | * @param context The bundle context of the bundle which is instantiating this dependency object |
| 50 | * @param logger the logger our Internal logger for logging events. |
| 51 | * @see DependencyActivatorBase#createTemporalServiceDependency() |
| 52 | */ |
Pierre De Rop | c242986 | 2009-12-04 23:00:03 +0000 | [diff] [blame] | 53 | public TemporalServiceDependencyImpl(BundleContext context, Logger logger) { |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 54 | super(context, logger); |
| 55 | super.setRequired(true); |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 56 | m_frameworkBundle = context.getBundle(0); |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 57 | } |
| 58 | |
| 59 | /** |
| 60 | * Sets the timeout for this temporal dependency. Specifying a timeout value of zero means that there is no timeout period, |
| 61 | * and an invocation on a missing service will fail immediately. |
| 62 | * |
| 63 | * @param timeout the dependency timeout value greater or equals to 0 |
| 64 | * @throws IllegalArgumentException if the timeout is negative |
| 65 | * @return this temporal dependency |
| 66 | */ |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 67 | public synchronized TemporalServiceDependency setTimeout(long timeout) { |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 68 | if (timeout < 0) { |
| 69 | throw new IllegalArgumentException("Invalid timeout value: " + timeout); |
| 70 | } |
| 71 | m_timeout = timeout; |
| 72 | return this; |
| 73 | } |
| 74 | |
| 75 | /** |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 76 | * Sets the required flag which determines if this service is required or not. This method |
| 77 | * just override the superclass method in order to check if the required flag is true |
| 78 | * (optional dependency is not supported by this class). |
| 79 | * |
| 80 | * @param required the required flag, which must be set to true |
| 81 | * @return this service dependency |
| 82 | * @throws IllegalArgumentException if the "required" parameter is not true. |
| 83 | */ |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 84 | //@Override |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 85 | public ServiceDependency setRequired(boolean required) { |
| 86 | if (! required) { |
| 87 | throw new IllegalArgumentException("A Temporal Service dependency can't be optional"); |
| 88 | } |
| 89 | super.setRequired(required); |
| 90 | return this; |
| 91 | } |
| 92 | |
| 93 | /** |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 94 | * The ServiceTracker calls us here in order to inform about a service arrival. |
| 95 | */ |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 96 | //@Override |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 97 | public synchronized void addedService(ServiceReference ref, Object service) { |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 98 | // Update our service cache, using the tracker. We do this because the |
| 99 | // just added service might not be the service with the highest rank ... |
| 100 | m_cachedService = m_tracker.getService(); |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 101 | boolean makeAvailable = makeAvailable(); |
| 102 | if (makeAvailable) { |
| 103 | m_serviceInstance = Proxy.newProxyInstance(m_trackedServiceName.getClassLoader(), new Class[] { m_trackedServiceName }, this); |
| 104 | } |
| 105 | Object[] services = m_services.toArray(); |
| 106 | for (int i = 0; i < services.length; i++) { |
| 107 | DependencyService ds = (DependencyService) services[i]; |
| 108 | if (makeAvailable) { |
| 109 | ds.dependencyAvailable(this); |
| 110 | } |
| 111 | } |
| 112 | if (!makeAvailable) { |
| 113 | notifyAll(); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * The ServiceTracker calls us here when a tracked service properties are modified. |
| 119 | */ |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 120 | //@Override |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 121 | public void modifiedService(ServiceReference ref, Object service) { |
| 122 | // We don't care. |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * The ServiceTracker calls us here when a tracked service is lost. |
| 127 | */ |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 128 | //@Override |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 129 | public synchronized void removedService(ServiceReference ref, Object service) { |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 130 | // If we detect that the fwk is stopping, we behave as our superclass. That is: |
| 131 | // the lost dependency has to trigger our service deactivation, since the fwk is stopping |
| 132 | // and the lost dependency won't come up anymore. |
| 133 | if (m_frameworkBundle.getState() == Bundle.STOPPING) { |
| 134 | // Important: Notice that calling "super.removedService() might invoke our service "stop" |
| 135 | // callback, which in turn might invoke the just removed service dependency. In this case, |
| 136 | // our "invoke" method won't use the tracker to get the service dependency (because at this point, |
| 137 | // the tracker has withdrawn its reference to the lost service). So, you will see that the "invoke" |
| 138 | // method will use the "m_cachedService" instead ... |
| 139 | super.removedService(ref, service); |
| 140 | } else { |
| 141 | // Unget what we got in addingService (see ServiceTracker 701.4.1) |
| 142 | m_context.ungetService(ref); |
| 143 | // Now, ask the service tracker if there is another available service (with a lower rank). |
| 144 | // If no more service dependencies are available, the tracker will then return null; |
| 145 | // and our invoke method will block the service method invocation, until another service |
| 146 | // becomes available. |
| 147 | m_cachedService = m_tracker.getService(); |
| 148 | } |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 149 | } |
| 150 | |
| 151 | /** |
| 152 | * @returns our dependency instance. Unlike in ServiceDependency, we always returns our proxy. |
| 153 | */ |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 154 | //@Override |
| 155 | protected synchronized Object getService() { |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 156 | return m_serviceInstance; |
| 157 | } |
| 158 | |
Pierre De Rop | 6aaa404 | 2013-10-25 18:40:16 +0000 | [diff] [blame^] | 159 | //@Override |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 160 | public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 161 | Object service = m_cachedService; |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 162 | if (service == null) { |
| 163 | synchronized (this) { |
| 164 | long start = System.currentTimeMillis(); |
| 165 | long waitTime = m_timeout; |
| 166 | while (service == null) { |
| 167 | if (waitTime <= 0) { |
| 168 | throw new IllegalStateException("Service unavailable: " + m_trackedServiceName.getName()); |
| 169 | } |
| 170 | try { |
| 171 | wait(waitTime); |
| 172 | } |
| 173 | catch (InterruptedException e) { |
| 174 | throw new IllegalStateException("Service unavailable: " + m_trackedServiceName.getName()); |
| 175 | } |
| 176 | waitTime = m_timeout - (System.currentTimeMillis() - start); |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 177 | service = m_cachedService; |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 178 | } |
Pierre De Rop | 5fed9ef | 2011-01-26 16:48:33 +0000 | [diff] [blame] | 179 | |
Pierre De Rop | b9dee1a | 2009-12-04 22:59:03 +0000 | [diff] [blame] | 180 | } |
| 181 | } |
| 182 | try { |
| 183 | return method.invoke(service, args); |
| 184 | } |
| 185 | catch (IllegalAccessException iae) { |
| 186 | method.setAccessible(true); |
| 187 | return method.invoke(service, args); |
| 188 | } |
| 189 | } |
| 190 | } |