Marcel Offermans | faaed47 | 2010-09-08 10:07:32 +0000 | [diff] [blame] | 1 | package org.apache.felix.dm.tracker; |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) OSGi Alliance (2000, 2009). All Rights Reserved. |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | import java.security.AccessController; |
| 19 | import java.security.PrivilegedAction; |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 20 | import java.util.ArrayList; |
| 21 | import java.util.List; |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 22 | |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 23 | import org.apache.felix.dm.DependencyManager; |
Marcel Offermans | 8b93efa | 2010-07-02 18:27:21 +0000 | [diff] [blame] | 24 | import org.apache.felix.dm.ServiceUtil; |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 25 | import org.osgi.framework.AllServiceListener; |
| 26 | import org.osgi.framework.BundleContext; |
| 27 | import org.osgi.framework.Constants; |
| 28 | import org.osgi.framework.Filter; |
| 29 | import org.osgi.framework.InvalidSyntaxException; |
| 30 | import org.osgi.framework.ServiceEvent; |
| 31 | import org.osgi.framework.ServiceListener; |
| 32 | import org.osgi.framework.ServiceReference; |
| 33 | import org.osgi.framework.Version; |
| 34 | |
| 35 | /** |
| 36 | * The <code>ServiceTracker</code> class simplifies using services from the |
| 37 | * Framework's service registry. |
| 38 | * <p> |
| 39 | * A <code>ServiceTracker</code> object is constructed with search criteria and |
| 40 | * a <code>ServiceTrackerCustomizer</code> object. A <code>ServiceTracker</code> |
| 41 | * can use a <code>ServiceTrackerCustomizer</code> to customize the service |
| 42 | * objects to be tracked. The <code>ServiceTracker</code> can then be opened to |
| 43 | * begin tracking all services in the Framework's service registry that match |
| 44 | * the specified search criteria. The <code>ServiceTracker</code> correctly |
| 45 | * handles all of the details of listening to <code>ServiceEvent</code>s and |
| 46 | * getting and ungetting services. |
| 47 | * <p> |
| 48 | * The <code>getServiceReferences</code> method can be called to get references |
| 49 | * to the services being tracked. The <code>getService</code> and |
| 50 | * <code>getServices</code> methods can be called to get the service objects for |
| 51 | * the tracked service. |
| 52 | * <p> |
| 53 | * The <code>ServiceTracker</code> class is thread-safe. It does not call a |
| 54 | * <code>ServiceTrackerCustomizer</code> while holding any locks. |
| 55 | * <code>ServiceTrackerCustomizer</code> implementations must also be |
| 56 | * thread-safe. |
| 57 | * |
| 58 | * @ThreadSafe |
| 59 | * @version $Revision: 6386 $ |
| 60 | */ |
| 61 | public class ServiceTracker implements ServiceTrackerCustomizer { |
| 62 | /* set this to true to compile in debug messages */ |
| 63 | static final boolean DEBUG = false; |
| 64 | /** |
| 65 | * The Bundle Context used by this <code>ServiceTracker</code>. |
| 66 | */ |
| 67 | protected final BundleContext context; |
| 68 | /** |
| 69 | * The Filter used by this <code>ServiceTracker</code> which specifies the |
| 70 | * search criteria for the services to track. |
| 71 | * |
| 72 | * @since 1.1 |
| 73 | */ |
| 74 | protected final Filter filter; |
| 75 | /** |
| 76 | * The <code>ServiceTrackerCustomizer</code> for this tracker. |
| 77 | */ |
| 78 | final ServiceTrackerCustomizer customizer; |
| 79 | /** |
| 80 | * Filter string for use when adding the ServiceListener. If this field is |
| 81 | * set, then certain optimizations can be taken since we don't have a user |
| 82 | * supplied filter. |
| 83 | */ |
| 84 | final String listenerFilter; |
| 85 | /** |
| 86 | * Class name to be tracked. If this field is set, then we are tracking by |
| 87 | * class name. |
| 88 | */ |
| 89 | private final String trackClass; |
| 90 | /** |
| 91 | * Reference to be tracked. If this field is set, then we are tracking a |
| 92 | * single ServiceReference. |
| 93 | */ |
| 94 | private final ServiceReference trackReference; |
| 95 | /** |
| 96 | * Tracked services: <code>ServiceReference</code> -> customized Object and |
| 97 | * <code>ServiceListener</code> object |
| 98 | */ |
| 99 | private volatile Tracked tracked; |
| 100 | |
| 101 | /** |
| 102 | * Accessor method for the current Tracked object. This method is only |
| 103 | * intended to be used by the unsynchronized methods which do not modify the |
| 104 | * tracked field. |
| 105 | * |
| 106 | * @return The current Tracked object. |
| 107 | */ |
| 108 | private Tracked tracked() { |
| 109 | return tracked; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Cached ServiceReference for getServiceReference. |
| 114 | * |
| 115 | * This field is volatile since it is accessed by multiple threads. |
| 116 | */ |
| 117 | private volatile ServiceReference cachedReference; |
| 118 | /** |
| 119 | * Cached service object for getService. |
| 120 | * |
| 121 | * This field is volatile since it is accessed by multiple threads. |
| 122 | */ |
| 123 | private volatile Object cachedService; |
| 124 | |
| 125 | /** |
| 126 | * org.osgi.framework package version which introduced |
| 127 | * {@link ServiceEvent#MODIFIED_ENDMATCH} |
| 128 | */ |
| 129 | private static final Version endMatchVersion = new Version(1, 5, 0); |
| 130 | |
| 131 | /** |
| 132 | * Create a <code>ServiceTracker</code> on the specified |
| 133 | * <code>ServiceReference</code>. |
| 134 | * |
| 135 | * <p> |
| 136 | * The service referenced by the specified <code>ServiceReference</code> |
| 137 | * will be tracked by this <code>ServiceTracker</code>. |
| 138 | * |
| 139 | * @param context The <code>BundleContext</code> against which the tracking |
| 140 | * is done. |
| 141 | * @param reference The <code>ServiceReference</code> for the service to be |
| 142 | * tracked. |
| 143 | * @param customizer The customizer object to call when services are added, |
| 144 | * modified, or removed in this <code>ServiceTracker</code>. If |
| 145 | * customizer is <code>null</code>, then this |
| 146 | * <code>ServiceTracker</code> will be used as the |
| 147 | * <code>ServiceTrackerCustomizer</code> and this |
| 148 | * <code>ServiceTracker</code> will call the |
| 149 | * <code>ServiceTrackerCustomizer</code> methods on itself. |
| 150 | */ |
| 151 | public ServiceTracker(final BundleContext context, |
| 152 | final ServiceReference reference, |
| 153 | final ServiceTrackerCustomizer customizer) { |
| 154 | this.context = context; |
| 155 | this.trackReference = reference; |
| 156 | this.trackClass = null; |
| 157 | this.customizer = (customizer == null) ? this : customizer; |
| 158 | this.listenerFilter = "(" + Constants.SERVICE_ID + "=" |
| 159 | + reference.getProperty(Constants.SERVICE_ID).toString() + ")"; |
| 160 | try { |
| 161 | this.filter = context.createFilter(listenerFilter); |
| 162 | } |
| 163 | catch (InvalidSyntaxException e) { |
| 164 | /* |
| 165 | * we could only get this exception if the ServiceReference was |
| 166 | * invalid |
| 167 | */ |
| 168 | IllegalArgumentException iae = new IllegalArgumentException( |
| 169 | "unexpected InvalidSyntaxException: " + e.getMessage()); |
| 170 | iae.initCause(e); |
| 171 | throw iae; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Create a <code>ServiceTracker</code> on the specified class name. |
| 177 | * |
| 178 | * <p> |
| 179 | * Services registered under the specified class name will be tracked by |
| 180 | * this <code>ServiceTracker</code>. |
| 181 | * |
| 182 | * @param context The <code>BundleContext</code> against which the tracking |
| 183 | * is done. |
| 184 | * @param clazz The class name of the services to be tracked. |
| 185 | * @param customizer The customizer object to call when services are added, |
| 186 | * modified, or removed in this <code>ServiceTracker</code>. If |
| 187 | * customizer is <code>null</code>, then this |
| 188 | * <code>ServiceTracker</code> will be used as the |
| 189 | * <code>ServiceTrackerCustomizer</code> and this |
| 190 | * <code>ServiceTracker</code> will call the |
| 191 | * <code>ServiceTrackerCustomizer</code> methods on itself. |
| 192 | */ |
| 193 | public ServiceTracker(final BundleContext context, final String clazz, |
| 194 | final ServiceTrackerCustomizer customizer) { |
| 195 | this.context = context; |
| 196 | this.trackReference = null; |
| 197 | this.trackClass = clazz; |
| 198 | this.customizer = (customizer == null) ? this : customizer; |
| 199 | // we call clazz.toString to verify clazz is non-null! |
| 200 | this.listenerFilter = "(" + Constants.OBJECTCLASS + "=" |
| 201 | + clazz.toString() + ")"; |
| 202 | try { |
| 203 | this.filter = context.createFilter(listenerFilter); |
| 204 | } |
| 205 | catch (InvalidSyntaxException e) { |
| 206 | /* |
| 207 | * we could only get this exception if the clazz argument was |
| 208 | * malformed |
| 209 | */ |
| 210 | IllegalArgumentException iae = new IllegalArgumentException( |
| 211 | "unexpected InvalidSyntaxException: " + e.getMessage()); |
| 212 | iae.initCause(e); |
| 213 | throw iae; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Create a <code>ServiceTracker</code> on the specified <code>Filter</code> |
| 219 | * object. |
| 220 | * |
| 221 | * <p> |
| 222 | * Services which match the specified <code>Filter</code> object will be |
| 223 | * tracked by this <code>ServiceTracker</code>. |
| 224 | * |
| 225 | * @param context The <code>BundleContext</code> against which the tracking |
| 226 | * is done. |
| 227 | * @param filter The <code>Filter</code> to select the services to be |
| 228 | * tracked. |
| 229 | * @param customizer The customizer object to call when services are added, |
| 230 | * modified, or removed in this <code>ServiceTracker</code>. If |
| 231 | * customizer is null, then this <code>ServiceTracker</code> will be |
| 232 | * used as the <code>ServiceTrackerCustomizer</code> and this |
| 233 | * <code>ServiceTracker</code> will call the |
| 234 | * <code>ServiceTrackerCustomizer</code> methods on itself. |
| 235 | * @since 1.1 |
| 236 | */ |
| 237 | public ServiceTracker(final BundleContext context, final Filter filter, |
| 238 | final ServiceTrackerCustomizer customizer) { |
| 239 | this.context = context; |
| 240 | this.trackReference = null; |
| 241 | this.trackClass = null; |
| 242 | final Version frameworkVersion = (Version) AccessController |
| 243 | .doPrivileged(new PrivilegedAction() { |
| 244 | public Object run() { |
| 245 | String version = context |
| 246 | .getProperty(Constants.FRAMEWORK_VERSION); |
| 247 | return (version == null) ? Version.emptyVersion |
| 248 | : new Version(version); |
| 249 | } |
| 250 | }); |
| 251 | final boolean endMatchSupported = (frameworkVersion |
| 252 | .compareTo(endMatchVersion) >= 0); |
| 253 | this.listenerFilter = endMatchSupported ? filter.toString() : null; |
| 254 | this.filter = filter; |
| 255 | this.customizer = (customizer == null) ? this : customizer; |
| 256 | if ((context == null) || (filter == null)) { |
| 257 | /* |
| 258 | * we throw a NPE here to be consistent with the other constructors |
| 259 | */ |
| 260 | throw new NullPointerException(); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * Open this <code>ServiceTracker</code> and begin tracking services. |
| 266 | * |
| 267 | * <p> |
| 268 | * This implementation calls <code>open(false)</code>. |
| 269 | * |
| 270 | * @throws java.lang.IllegalStateException If the <code>BundleContext</code> |
| 271 | * with which this <code>ServiceTracker</code> was created is no |
| 272 | * longer valid. |
| 273 | * @see #open(boolean) |
| 274 | */ |
| 275 | public void open() { |
| 276 | open(false); |
| 277 | } |
| 278 | |
| 279 | /** |
| 280 | * Open this <code>ServiceTracker</code> and begin tracking services. |
| 281 | * |
| 282 | * <p> |
| 283 | * Services which match the search criteria specified when this |
| 284 | * <code>ServiceTracker</code> was created are now tracked by this |
| 285 | * <code>ServiceTracker</code>. |
| 286 | * |
| 287 | * @param trackAllServices If <code>true</code>, then this |
| 288 | * <code>ServiceTracker</code> will track all matching services |
| 289 | * regardless of class loader accessibility. If <code>false</code>, |
| 290 | * then this <code>ServiceTracker</code> will only track matching |
| 291 | * services which are class loader accessible to the bundle whose |
| 292 | * <code>BundleContext</code> is used by this |
| 293 | * <code>ServiceTracker</code>. |
| 294 | * @throws java.lang.IllegalStateException If the <code>BundleContext</code> |
| 295 | * with which this <code>ServiceTracker</code> was created is no |
| 296 | * longer valid. |
| 297 | * @since 1.3 |
| 298 | */ |
| 299 | public void open(boolean trackAllServices) { |
| 300 | final Tracked t; |
| 301 | synchronized (this) { |
| 302 | if (tracked != null) { |
| 303 | return; |
| 304 | } |
| 305 | if (DEBUG) { |
| 306 | System.out.println("ServiceTracker.open: " + filter); |
| 307 | } |
| 308 | t = trackAllServices ? new AllTracked() : new Tracked(); |
| 309 | synchronized (t) { |
| 310 | try { |
| 311 | context.addServiceListener(t, listenerFilter); |
| 312 | ServiceReference[] references = null; |
| 313 | if (trackClass != null) { |
| 314 | references = getInitialReferences(trackAllServices, |
| 315 | trackClass, null); |
| 316 | } |
| 317 | else { |
| 318 | if (trackReference != null) { |
| 319 | if (trackReference.getBundle() != null) { |
| 320 | references = new ServiceReference[] {trackReference}; |
| 321 | } |
| 322 | } |
| 323 | else { /* user supplied filter */ |
| 324 | references = getInitialReferences(trackAllServices, |
| 325 | null, |
| 326 | (listenerFilter != null) ? listenerFilter |
| 327 | : filter.toString()); |
| 328 | } |
| 329 | } |
| 330 | /* set tracked with the initial references */ |
| 331 | t.setInitial(references); |
| 332 | } |
| 333 | catch (InvalidSyntaxException e) { |
| 334 | throw new RuntimeException( |
| 335 | "unexpected InvalidSyntaxException: " |
| 336 | + e.getMessage(), e); |
| 337 | } |
| 338 | } |
| 339 | tracked = t; |
| 340 | } |
| 341 | /* Call tracked outside of synchronized region */ |
| 342 | t.trackInitial(); /* process the initial references */ |
| 343 | } |
| 344 | |
| 345 | /** |
| 346 | * Returns the list of initial <code>ServiceReference</code>s that will be |
| 347 | * tracked by this <code>ServiceTracker</code>. |
| 348 | * |
| 349 | * @param trackAllServices If <code>true</code>, use |
| 350 | * <code>getAllServiceReferences</code>. |
| 351 | * @param className The class name with which the service was registered, or |
| 352 | * <code>null</code> for all services. |
| 353 | * @param filterString The filter criteria or <code>null</code> for all |
| 354 | * services. |
| 355 | * @return The list of initial <code>ServiceReference</code>s. |
| 356 | * @throws InvalidSyntaxException If the specified filterString has an |
| 357 | * invalid syntax. |
| 358 | */ |
| 359 | private ServiceReference[] getInitialReferences(boolean trackAllServices, |
| 360 | String className, String filterString) |
| 361 | throws InvalidSyntaxException { |
| 362 | if (trackAllServices) { |
| 363 | return context.getAllServiceReferences(className, filterString); |
| 364 | } |
| 365 | return context.getServiceReferences(className, filterString); |
| 366 | } |
| 367 | |
| 368 | /** |
| 369 | * Close this <code>ServiceTracker</code>. |
| 370 | * |
| 371 | * <p> |
| 372 | * This method should be called when this <code>ServiceTracker</code> should |
| 373 | * end the tracking of services. |
| 374 | * |
| 375 | * <p> |
| 376 | * This implementation calls {@link #getServiceReferences()} to get the list |
| 377 | * of tracked services to remove. |
| 378 | */ |
| 379 | public void close() { |
| 380 | final Tracked outgoing; |
| 381 | final ServiceReference[] references; |
| 382 | synchronized (this) { |
| 383 | outgoing = tracked; |
| 384 | if (outgoing == null) { |
| 385 | return; |
| 386 | } |
| 387 | if (DEBUG) { |
| 388 | System.out.println("ServiceTracker.close: " + filter); |
| 389 | } |
| 390 | outgoing.close(); |
| 391 | references = getServiceReferences(); |
| 392 | tracked = null; |
| 393 | try { |
| 394 | context.removeServiceListener(outgoing); |
| 395 | } |
| 396 | catch (IllegalStateException e) { |
| 397 | /* In case the context was stopped. */ |
| 398 | } |
| 399 | } |
| 400 | modified(); /* clear the cache */ |
| 401 | synchronized (outgoing) { |
| 402 | outgoing.notifyAll(); /* wake up any waiters */ |
| 403 | } |
| 404 | if (references != null) { |
| 405 | for (int i = 0; i < references.length; i++) { |
| 406 | outgoing.untrack(references[i], null); |
| 407 | } |
| 408 | } |
| 409 | if (DEBUG) { |
| 410 | if ((cachedReference == null) && (cachedService == null)) { |
| 411 | System.out |
| 412 | .println("ServiceTracker.close[cached cleared]: " |
| 413 | + filter); |
| 414 | } |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | /** |
| 419 | * Default implementation of the |
| 420 | * <code>ServiceTrackerCustomizer.addingService</code> method. |
| 421 | * |
| 422 | * <p> |
| 423 | * This method is only called when this <code>ServiceTracker</code> has been |
| 424 | * constructed with a <code>null ServiceTrackerCustomizer</code> argument. |
| 425 | * |
| 426 | * <p> |
| 427 | * This implementation returns the result of calling <code>getService</code> |
| 428 | * on the <code>BundleContext</code> with which this |
| 429 | * <code>ServiceTracker</code> was created passing the specified |
| 430 | * <code>ServiceReference</code>. |
| 431 | * <p> |
| 432 | * This method can be overridden in a subclass to customize the service |
| 433 | * object to be tracked for the service being added. In that case, take care |
| 434 | * not to rely on the default implementation of |
| 435 | * {@link #removedService(ServiceReference, Object) removedService} to unget |
| 436 | * the service. |
| 437 | * |
| 438 | * @param reference The reference to the service being added to this |
| 439 | * <code>ServiceTracker</code>. |
| 440 | * @return The service object to be tracked for the service added to this |
| 441 | * <code>ServiceTracker</code>. |
| 442 | * @see ServiceTrackerCustomizer#addingService(ServiceReference) |
| 443 | */ |
| 444 | public Object addingService(ServiceReference reference) { |
| 445 | return context.getService(reference); |
| 446 | } |
| 447 | |
| 448 | public void addedService(ServiceReference reference, Object service) { |
| 449 | /* do nothing */ |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * Default implementation of the |
| 454 | * <code>ServiceTrackerCustomizer.modifiedService</code> method. |
| 455 | * |
| 456 | * <p> |
| 457 | * This method is only called when this <code>ServiceTracker</code> has been |
| 458 | * constructed with a <code>null ServiceTrackerCustomizer</code> argument. |
| 459 | * |
| 460 | * <p> |
| 461 | * This implementation does nothing. |
| 462 | * |
| 463 | * @param reference The reference to modified service. |
| 464 | * @param service The service object for the modified service. |
| 465 | * @see ServiceTrackerCustomizer#modifiedService(ServiceReference, Object) |
| 466 | */ |
| 467 | public void modifiedService(ServiceReference reference, Object service) { |
| 468 | /* do nothing */ |
| 469 | } |
| 470 | |
| 471 | /** |
| 472 | * Default implementation of the |
| 473 | * <code>ServiceTrackerCustomizer.removedService</code> method. |
| 474 | * |
| 475 | * <p> |
| 476 | * This method is only called when this <code>ServiceTracker</code> has been |
| 477 | * constructed with a <code>null ServiceTrackerCustomizer</code> argument. |
| 478 | * |
| 479 | * <p> |
| 480 | * This implementation calls <code>ungetService</code>, on the |
| 481 | * <code>BundleContext</code> with which this <code>ServiceTracker</code> |
| 482 | * was created, passing the specified <code>ServiceReference</code>. |
| 483 | * <p> |
| 484 | * This method can be overridden in a subclass. If the default |
| 485 | * implementation of {@link #addingService(ServiceReference) addingService} |
| 486 | * method was used, this method must unget the service. |
| 487 | * |
| 488 | * @param reference The reference to removed service. |
| 489 | * @param service The service object for the removed service. |
| 490 | * @see ServiceTrackerCustomizer#removedService(ServiceReference, Object) |
| 491 | */ |
| 492 | public void removedService(ServiceReference reference, Object service) { |
| 493 | context.ungetService(reference); |
| 494 | } |
| 495 | |
| 496 | /** |
| 497 | * Wait for at least one service to be tracked by this |
| 498 | * <code>ServiceTracker</code>. This method will also return when this |
| 499 | * <code>ServiceTracker</code> is closed. |
| 500 | * |
| 501 | * <p> |
| 502 | * It is strongly recommended that <code>waitForService</code> is not used |
| 503 | * during the calling of the <code>BundleActivator</code> methods. |
| 504 | * <code>BundleActivator</code> methods are expected to complete in a short |
| 505 | * period of time. |
| 506 | * |
| 507 | * <p> |
| 508 | * This implementation calls {@link #getService()} to determine if a service |
| 509 | * is being tracked. |
| 510 | * |
| 511 | * @param timeout The time interval in milliseconds to wait. If zero, the |
| 512 | * method will wait indefinitely. |
| 513 | * @return Returns the result of {@link #getService()}. |
| 514 | * @throws InterruptedException If another thread has interrupted the |
| 515 | * current thread. |
| 516 | * @throws IllegalArgumentException If the value of timeout is negative. |
| 517 | */ |
| 518 | public Object waitForService(long timeout) throws InterruptedException { |
| 519 | if (timeout < 0) { |
| 520 | throw new IllegalArgumentException("timeout value is negative"); |
| 521 | } |
| 522 | Object object = getService(); |
| 523 | while (object == null) { |
| 524 | final Tracked t = tracked(); |
| 525 | if (t == null) { /* if ServiceTracker is not open */ |
| 526 | return null; |
| 527 | } |
| 528 | synchronized (t) { |
| 529 | if (t.size() == 0) { |
| 530 | t.wait(timeout); |
| 531 | } |
| 532 | } |
| 533 | object = getService(); |
| 534 | if (timeout > 0) { |
| 535 | return object; |
| 536 | } |
| 537 | } |
| 538 | return object; |
| 539 | } |
| 540 | |
| 541 | /** |
| 542 | * Return an array of <code>ServiceReference</code>s for all services being |
| 543 | * tracked by this <code>ServiceTracker</code>. |
| 544 | * |
| 545 | * @return Array of <code>ServiceReference</code>s or <code>null</code> if |
| 546 | * no services are being tracked. |
| 547 | */ |
| 548 | public ServiceReference[] getServiceReferences() { |
| 549 | final Tracked t = tracked(); |
| 550 | if (t == null) { /* if ServiceTracker is not open */ |
| 551 | return null; |
| 552 | } |
| 553 | synchronized (t) { |
| 554 | int length = t.size(); |
| 555 | if (length == 0) { |
| 556 | return null; |
| 557 | } |
| 558 | return (ServiceReference[]) t |
| 559 | .getTracked(new ServiceReference[length]); |
| 560 | } |
| 561 | } |
| 562 | |
| 563 | /** |
| 564 | * Returns a <code>ServiceReference</code> for one of the services being |
| 565 | * tracked by this <code>ServiceTracker</code>. |
| 566 | * |
| 567 | * <p> |
| 568 | * If multiple services are being tracked, the service with the highest |
| 569 | * ranking (as specified in its <code>service.ranking</code> property) is |
| 570 | * returned. If there is a tie in ranking, the service with the lowest |
| 571 | * service ID (as specified in its <code>service.id</code> property); that |
| 572 | * is, the service that was registered first is returned. This is the same |
| 573 | * algorithm used by <code>BundleContext.getServiceReference</code>. |
| 574 | * |
| 575 | * <p> |
| 576 | * This implementation calls {@link #getServiceReferences()} to get the list |
| 577 | * of references for the tracked services. |
| 578 | * |
| 579 | * @return A <code>ServiceReference</code> or <code>null</code> if no |
| 580 | * services are being tracked. |
| 581 | * @since 1.1 |
| 582 | */ |
| 583 | public ServiceReference getServiceReference() { |
| 584 | ServiceReference reference = cachedReference; |
| 585 | if (reference != null) { |
| 586 | if (DEBUG) { |
| 587 | System.out |
| 588 | .println("ServiceTracker.getServiceReference[cached]: " |
| 589 | + filter); |
| 590 | } |
| 591 | return reference; |
| 592 | } |
| 593 | if (DEBUG) { |
| 594 | System.out.println("ServiceTracker.getServiceReference: " + filter); |
| 595 | } |
| 596 | ServiceReference[] references = getServiceReferences(); |
| 597 | int length = (references == null) ? 0 : references.length; |
| 598 | if (length == 0) { /* if no service is being tracked */ |
| 599 | return null; |
| 600 | } |
| 601 | int index = 0; |
| 602 | if (length > 1) { /* if more than one service, select highest ranking */ |
| 603 | int rankings[] = new int[length]; |
| 604 | int count = 0; |
| 605 | int maxRanking = Integer.MIN_VALUE; |
| 606 | for (int i = 0; i < length; i++) { |
| 607 | Object property = references[i] |
| 608 | .getProperty(Constants.SERVICE_RANKING); |
| 609 | int ranking = (property instanceof Integer) ? ((Integer) property) |
| 610 | .intValue() |
| 611 | : 0; |
| 612 | rankings[i] = ranking; |
| 613 | if (ranking > maxRanking) { |
| 614 | index = i; |
| 615 | maxRanking = ranking; |
| 616 | count = 1; |
| 617 | } |
| 618 | else { |
| 619 | if (ranking == maxRanking) { |
| 620 | count++; |
| 621 | } |
| 622 | } |
| 623 | } |
| 624 | if (count > 1) { /* if still more than one service, select lowest id */ |
| 625 | long minId = Long.MAX_VALUE; |
| 626 | for (int i = 0; i < length; i++) { |
| 627 | if (rankings[i] == maxRanking) { |
| 628 | long id = ((Long) (references[i] |
| 629 | .getProperty(Constants.SERVICE_ID))) |
| 630 | .longValue(); |
| 631 | if (id < minId) { |
| 632 | index = i; |
| 633 | minId = id; |
| 634 | } |
| 635 | } |
| 636 | } |
| 637 | } |
| 638 | } |
| 639 | return cachedReference = references[index]; |
| 640 | } |
| 641 | |
| 642 | /** |
| 643 | * Returns the service object for the specified |
| 644 | * <code>ServiceReference</code> if the specified referenced service is |
| 645 | * being tracked by this <code>ServiceTracker</code>. |
| 646 | * |
| 647 | * @param reference The reference to the desired service. |
| 648 | * @return A service object or <code>null</code> if the service referenced |
| 649 | * by the specified <code>ServiceReference</code> is not being |
| 650 | * tracked. |
| 651 | */ |
| 652 | public Object getService(ServiceReference reference) { |
| 653 | final Tracked t = tracked(); |
| 654 | if (t == null) { /* if ServiceTracker is not open */ |
| 655 | return null; |
| 656 | } |
| 657 | synchronized (t) { |
| 658 | return t.getCustomizedObject(reference); |
| 659 | } |
| 660 | } |
| 661 | |
| 662 | /** |
| 663 | * Return an array of service objects for all services being tracked by this |
| 664 | * <code>ServiceTracker</code>. |
| 665 | * |
| 666 | * <p> |
| 667 | * This implementation calls {@link #getServiceReferences()} to get the list |
| 668 | * of references for the tracked services and then calls |
| 669 | * {@link #getService(ServiceReference)} for each reference to get the |
| 670 | * tracked service object. |
| 671 | * |
| 672 | * @return An array of service objects or <code>null</code> if no services |
| 673 | * are being tracked. |
| 674 | */ |
| 675 | public Object[] getServices() { |
| 676 | final Tracked t = tracked(); |
| 677 | if (t == null) { /* if ServiceTracker is not open */ |
| 678 | return null; |
| 679 | } |
| 680 | synchronized (t) { |
| 681 | ServiceReference[] references = getServiceReferences(); |
| 682 | int length = (references == null) ? 0 : references.length; |
| 683 | if (length == 0) { |
| 684 | return null; |
| 685 | } |
| 686 | Object[] objects = new Object[length]; |
| 687 | for (int i = 0; i < length; i++) { |
| 688 | objects[i] = getService(references[i]); |
| 689 | } |
| 690 | return objects; |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | /** |
| 695 | * Returns a service object for one of the services being tracked by this |
| 696 | * <code>ServiceTracker</code>. |
| 697 | * |
| 698 | * <p> |
| 699 | * If any services are being tracked, this implementation returns the result |
| 700 | * of calling <code>getService(getServiceReference())</code>. |
| 701 | * |
| 702 | * @return A service object or <code>null</code> if no services are being |
| 703 | * tracked. |
| 704 | */ |
| 705 | public Object getService() { |
| 706 | Object service = cachedService; |
| 707 | if (service != null) { |
| 708 | if (DEBUG) { |
| 709 | System.out |
| 710 | .println("ServiceTracker.getService[cached]: " |
| 711 | + filter); |
| 712 | } |
| 713 | return service; |
| 714 | } |
| 715 | if (DEBUG) { |
| 716 | System.out.println("ServiceTracker.getService: " + filter); |
| 717 | } |
| 718 | ServiceReference reference = getServiceReference(); |
| 719 | if (reference == null) { |
| 720 | return null; |
| 721 | } |
| 722 | return cachedService = getService(reference); |
| 723 | } |
| 724 | |
| 725 | /** |
| 726 | * Remove a service from this <code>ServiceTracker</code>. |
| 727 | * |
| 728 | * The specified service will be removed from this |
| 729 | * <code>ServiceTracker</code>. If the specified service was being tracked |
| 730 | * then the <code>ServiceTrackerCustomizer.removedService</code> method will |
| 731 | * be called for that service. |
| 732 | * |
| 733 | * @param reference The reference to the service to be removed. |
| 734 | */ |
| 735 | public void remove(ServiceReference reference) { |
| 736 | final Tracked t = tracked(); |
| 737 | if (t == null) { /* if ServiceTracker is not open */ |
| 738 | return; |
| 739 | } |
| 740 | t.untrack(reference, null); |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * Return the number of services being tracked by this |
| 745 | * <code>ServiceTracker</code>. |
| 746 | * |
| 747 | * @return The number of services being tracked. |
| 748 | */ |
| 749 | public int size() { |
| 750 | final Tracked t = tracked(); |
| 751 | if (t == null) { /* if ServiceTracker is not open */ |
| 752 | return 0; |
| 753 | } |
| 754 | synchronized (t) { |
| 755 | return t.size(); |
| 756 | } |
| 757 | } |
| 758 | |
| 759 | /** |
| 760 | * Returns the tracking count for this <code>ServiceTracker</code>. |
| 761 | * |
| 762 | * The tracking count is initialized to 0 when this |
| 763 | * <code>ServiceTracker</code> is opened. Every time a service is added, |
| 764 | * modified or removed from this <code>ServiceTracker</code>, the tracking |
| 765 | * count is incremented. |
| 766 | * |
| 767 | * <p> |
| 768 | * The tracking count can be used to determine if this |
| 769 | * <code>ServiceTracker</code> has added, modified or removed a service by |
| 770 | * comparing a tracking count value previously collected with the current |
| 771 | * tracking count value. If the value has not changed, then no service has |
| 772 | * been added, modified or removed from this <code>ServiceTracker</code> |
| 773 | * since the previous tracking count was collected. |
| 774 | * |
| 775 | * @since 1.2 |
| 776 | * @return The tracking count for this <code>ServiceTracker</code> or -1 if |
| 777 | * this <code>ServiceTracker</code> is not open. |
| 778 | */ |
| 779 | public int getTrackingCount() { |
| 780 | final Tracked t = tracked(); |
| 781 | if (t == null) { /* if ServiceTracker is not open */ |
| 782 | return -1; |
| 783 | } |
| 784 | synchronized (t) { |
| 785 | return t.getTrackingCount(); |
| 786 | } |
| 787 | } |
| 788 | |
| 789 | /** |
| 790 | * Called by the Tracked object whenever the set of tracked services is |
| 791 | * modified. Clears the cache. |
| 792 | */ |
| 793 | /* |
| 794 | * This method must not be synchronized since it is called by Tracked while |
| 795 | * Tracked is synchronized. We don't want synchronization interactions |
| 796 | * between the listener thread and the user thread. |
| 797 | */ |
| 798 | void modified() { |
| 799 | cachedReference = null; /* clear cached value */ |
| 800 | cachedService = null; /* clear cached value */ |
| 801 | if (DEBUG) { |
| 802 | System.out.println("ServiceTracker.modified: " + filter); |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | /** |
| 807 | * Inner class which subclasses AbstractTracked. This class is the |
| 808 | * <code>ServiceListener</code> object for the tracker. |
| 809 | * |
| 810 | * @ThreadSafe |
| 811 | */ |
| 812 | class Tracked extends AbstractTracked implements ServiceListener { |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 813 | /** A list of services that are currently hidden because there is an aspect available with a higher ranking. */ |
| 814 | private final List m_hidden = new ArrayList(); |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 815 | |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 816 | /** |
| 817 | * Returns the highest hidden aspect for the specified service ID. |
| 818 | * |
| 819 | * @param serviceId the service ID |
| 820 | * @return a service reference, or <code>null</code> if there was no such service |
| 821 | */ |
| 822 | private ServiceReference highestHidden(long serviceId) { |
| 823 | ServiceReference result = null; |
| 824 | int max = Integer.MIN_VALUE; |
Marcel Offermans | f9a7e34 | 2010-10-07 12:22:46 +0000 | [diff] [blame] | 825 | synchronized (m_hidden) { |
| 826 | for (int i = 0; i < m_hidden.size(); i++) { |
| 827 | ServiceReference ref = (ServiceReference) m_hidden.get(i); |
| 828 | Long sid = (Long) ref.getProperty(Constants.SERVICE_ID); |
| 829 | Long aid = (Long) ref.getProperty(DependencyManager.ASPECT); |
| 830 | if ((aid != null && aid.longValue() == serviceId) |
| 831 | || (aid == null && sid != null && sid.longValue() == serviceId)) { |
| 832 | Integer ranking = (Integer) ref.getProperty(Constants.SERVICE_RANKING); |
| 833 | int r = 0; |
| 834 | if (ranking != null) { |
| 835 | r = ranking.intValue(); |
| 836 | } |
| 837 | if (r > max) { |
| 838 | max = r; |
| 839 | result = ref; |
| 840 | } |
| 841 | } |
| 842 | } |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 843 | } |
| 844 | return result; |
| 845 | } |
| 846 | |
| 847 | /** |
| 848 | * Returns the highest tracked service for the specified service ID. |
| 849 | * |
| 850 | * @param serviceId the service ID |
| 851 | * @return a service reference, or <code>null</code> if there was no such service |
| 852 | */ |
| 853 | private ServiceReference highestTracked(long serviceId) { |
| 854 | ServiceReference result = null; |
| 855 | int max = Integer.MIN_VALUE; |
| 856 | Object[] trackedServices = getTracked(new Object[] {}); |
| 857 | for (int i = 0; i < trackedServices.length; i++) { |
| 858 | ServiceReference ref = (ServiceReference) trackedServices[i]; |
| 859 | Long sid = (Long) ref.getProperty(Constants.SERVICE_ID); |
| 860 | Long aid = (Long) ref.getProperty(DependencyManager.ASPECT); |
| 861 | if ((aid != null && aid.longValue() == serviceId) |
| 862 | || (aid == null && sid != null && sid.longValue() == serviceId)) { |
| 863 | Integer ranking = (Integer) ref.getProperty(Constants.SERVICE_RANKING); |
| 864 | int r = 0; |
| 865 | if (ranking != null) { |
| 866 | r = ranking.intValue(); |
| 867 | } |
| 868 | if (r > max) { |
| 869 | max = r; |
| 870 | result = ref; |
| 871 | } |
| 872 | } |
| 873 | } |
| 874 | return result; |
| 875 | } |
| 876 | |
| 877 | /** |
| 878 | * Hide a service reference, placing it in the list of hidden services. |
| 879 | * |
| 880 | * @param ref the service reference to add to the hidden list |
| 881 | */ |
| 882 | private void hide(ServiceReference ref) { |
Marcel Offermans | e5187f6 | 2010-08-20 12:12:49 +0000 | [diff] [blame] | 883 | if (DEBUG) { System.out.println("ServiceTracker.Tracked.hide " + ServiceUtil.toString(ref)); } |
Marcel Offermans | f9a7e34 | 2010-10-07 12:22:46 +0000 | [diff] [blame] | 884 | synchronized (m_hidden) { |
| 885 | if (DEBUG) { if (m_hidden.contains(ref)) { System.out.println("ServiceTracker.Tracked.hide ERROR: " + ServiceUtil.toString(ref)); }}; |
| 886 | m_hidden.add(ref); |
| 887 | } |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 888 | } |
| 889 | |
| 890 | /** |
| 891 | * Unhide a service reference, removing it from the list of hidden services. |
| 892 | * |
| 893 | * @param ref the service reference to remove from the hidden list |
| 894 | */ |
| 895 | private void unhide(ServiceReference ref) { |
Marcel Offermans | e5187f6 | 2010-08-20 12:12:49 +0000 | [diff] [blame] | 896 | if (DEBUG) { System.out.println("ServiceTracker.Tracked.unhide " + ServiceUtil.toString(ref)); } |
Marcel Offermans | f9a7e34 | 2010-10-07 12:22:46 +0000 | [diff] [blame] | 897 | synchronized (m_hidden) { |
| 898 | if (DEBUG) { if (!m_hidden.contains(ref)) { System.out.println("ServiceTracker.Tracked.unhide ERROR: " + ServiceUtil.toString(ref)); }}; |
| 899 | m_hidden.remove(ref); |
| 900 | } |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 901 | } |
| 902 | |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 903 | /** |
| 904 | * Tracked constructor. |
| 905 | */ |
| 906 | Tracked() { |
| 907 | super(); |
| 908 | } |
Marcel Offermans | e5187f6 | 2010-08-20 12:12:49 +0000 | [diff] [blame] | 909 | |
| 910 | void setInitial(Object[] list) { |
| 911 | if (list == null) { |
| 912 | return; |
| 913 | } |
| 914 | // we need to split this list into the highest matching service references for each aspect |
| 915 | // and a list of 'hidden' service references |
| 916 | int counter = list.length; |
| 917 | for (int i = 0; i < list.length; i++) { |
| 918 | ServiceReference sr = (ServiceReference) list[i]; |
| 919 | if (sr != null) { |
| 920 | for (int j = 0; j < list.length; j++) { |
| 921 | ServiceReference sr2 = (ServiceReference) list[j]; |
| 922 | if (sr2 != null && j != i) { |
| 923 | long sid = ServiceUtil.getServiceId(sr); |
| 924 | long sid2 = ServiceUtil.getServiceId(sr2); |
| 925 | if (sid == sid2) { |
| 926 | long r = ServiceUtil.getRanking(sr); |
| 927 | long r2 = ServiceUtil.getRanking(sr2); |
| 928 | if (r > r2) { |
| 929 | if (DEBUG) { System.out.println("ServiceTracker.Tracked.setInitial: hiding " + ServiceUtil.toString(sr2)); } |
| 930 | hide(sr2); |
| 931 | list[j] = null; |
| 932 | counter--; |
| 933 | } |
| 934 | else { |
| 935 | if (DEBUG) { System.out.println("ServiceTracker.Tracked.setInitial: hiding " + ServiceUtil.toString(sr)); } |
| 936 | hide(sr); |
| 937 | list[i] = null; |
| 938 | counter--; |
| 939 | break; |
| 940 | } |
| 941 | } |
| 942 | } |
| 943 | } |
| 944 | } |
| 945 | } |
| 946 | if (counter > 0) { |
| 947 | Object[] result = new Object[counter]; |
| 948 | int index = 0; |
| 949 | for (int i = 0; i < list.length; i++) { |
| 950 | if (list[i] != null) { |
| 951 | if (DEBUG) { System.out.println("ServiceTracker.Tracked.setInitial: propagating " + ServiceUtil.toString((ServiceReference) list[i])); } |
| 952 | result[index] = list[i]; |
| 953 | index++; |
| 954 | } |
| 955 | } |
| 956 | // we only invoke super if we actually have |
| 957 | // results in our initial list |
| 958 | super.setInitial(result); |
| 959 | } |
| 960 | } |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 961 | |
| 962 | /** |
| 963 | * <code>ServiceListener</code> method for the |
| 964 | * <code>ServiceTracker</code> class. This method must NOT be |
| 965 | * synchronized to avoid deadlock potential. |
| 966 | * |
| 967 | * @param event <code>ServiceEvent</code> object from the framework. |
| 968 | */ |
| 969 | public void serviceChanged(final ServiceEvent event) { |
| 970 | /* |
| 971 | * Check if we had a delayed call (which could happen when we |
| 972 | * close). |
| 973 | */ |
| 974 | if (closed) { |
| 975 | return; |
| 976 | } |
| 977 | final ServiceReference reference = event.getServiceReference(); |
| 978 | if (DEBUG) { |
| 979 | System.out |
| 980 | .println("ServiceTracker.Tracked.serviceChanged[" |
| 981 | + event.getType() + "]: " + reference); |
| 982 | } |
| 983 | |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 984 | long sid = ServiceUtil.getServiceId(reference); |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 985 | switch (event.getType()) { |
| 986 | case ServiceEvent.REGISTERED : |
| 987 | case ServiceEvent.MODIFIED : |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 988 | ServiceReference higher = null; |
| 989 | ServiceReference lower = null; |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 990 | ServiceReference sr = highestTracked(sid); |
| 991 | if (sr != null) { |
| 992 | int ranking = ServiceUtil.getRanking(reference); |
| 993 | int trackedRanking = ServiceUtil.getRanking(sr); |
| 994 | if (ranking > trackedRanking) { |
| 995 | // found a higher ranked one! |
| 996 | if (DEBUG) { |
| 997 | System.out.println("ServiceTracker.Tracked.serviceChanged[" + event.getType() + "]: Found a higher ranked aspect: " + ServiceUtil.toString(reference) + " vs " + ServiceUtil.toString(sr)); |
| 998 | } |
| 999 | higher = sr; |
| 1000 | } |
| 1001 | else { |
| 1002 | // found lower ranked one! |
| 1003 | if (DEBUG) { |
| 1004 | System.out.println("ServiceTracker.Tracked.serviceChanged[" + event.getType() + "]: Found a lower ranked aspect: " + ServiceUtil.toString(reference) + " vs " + ServiceUtil.toString(sr)); |
| 1005 | } |
| 1006 | lower = sr; |
| 1007 | } |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 1008 | } |
| 1009 | |
| 1010 | if (listenerFilter != null) { // service listener added with filter |
| 1011 | if (lower != null) { |
| 1012 | hide(reference); |
| 1013 | } |
| 1014 | else { |
| 1015 | try { |
| 1016 | track(reference, event); |
| 1017 | } |
| 1018 | finally { |
| 1019 | if (higher != null) { |
| 1020 | try { |
| 1021 | untrack(higher, null); |
| 1022 | } |
| 1023 | finally { |
| 1024 | hide(higher); |
| 1025 | } |
| 1026 | } |
| 1027 | } |
| 1028 | } |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 1029 | /* |
| 1030 | * If the customizer throws an unchecked exception, it |
| 1031 | * is safe to let it propagate |
| 1032 | */ |
| 1033 | } |
| 1034 | else { // service listener added without filter |
| 1035 | if (filter.match(reference)) { |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 1036 | if (lower != null) { |
| 1037 | hide(reference); |
| 1038 | } |
| 1039 | else { |
| 1040 | try { |
| 1041 | track(reference, event); |
| 1042 | } |
| 1043 | finally { |
| 1044 | if (higher != null) { |
| 1045 | try { |
| 1046 | untrack(higher, null); |
| 1047 | } |
| 1048 | finally { |
| 1049 | hide(higher); |
| 1050 | } |
| 1051 | } |
| 1052 | } |
| 1053 | } |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 1054 | /* |
| 1055 | * If the customizer throws an unchecked exception, |
| 1056 | * it is safe to let it propagate |
| 1057 | */ |
| 1058 | } |
| 1059 | else { |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 1060 | ServiceReference ht = highestTracked(sid); |
| 1061 | ServiceReference hh = highestHidden(sid); |
| 1062 | if (reference.equals(ht)) { |
| 1063 | try { |
| 1064 | if (hh != null) { |
| 1065 | unhide(hh); |
| 1066 | track(hh, null); |
| 1067 | } |
| 1068 | } |
| 1069 | finally { |
| 1070 | untrack(reference, event); |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 1071 | } |
| 1072 | } |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 1073 | else { |
| 1074 | unhide(reference); |
Marcel Offermans | 7f68748 | 2010-05-11 09:12:34 +0000 | [diff] [blame] | 1075 | } |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 1076 | /* |
| 1077 | * If the customizer throws an unchecked exception, |
| 1078 | * it is safe to let it propagate |
| 1079 | */ |
| 1080 | } |
| 1081 | } |
| 1082 | break; |
Marcel Offermans | 001db05 | 2009-12-08 08:58:40 +0000 | [diff] [blame] | 1083 | case 8 /* ServiceEvent.MODIFIED_ENDMATCH */ : |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 1084 | case ServiceEvent.UNREGISTERING : |
Marcel Offermans | 1c944ec | 2010-10-11 13:55:02 +0000 | [diff] [blame^] | 1085 | ServiceReference ht = highestTracked(sid); |
| 1086 | ServiceReference hh = highestHidden(sid); |
| 1087 | if (reference.equals(ht)) { |
| 1088 | try { |
| 1089 | if (hh != null) { |
| 1090 | unhide(hh); |
| 1091 | track(hh, null); |
| 1092 | } |
| 1093 | } |
| 1094 | finally { |
| 1095 | untrack(reference, event); |
| 1096 | } |
| 1097 | } |
| 1098 | else { |
| 1099 | unhide(reference); |
| 1100 | } |
Marcel Offermans | c854d1a | 2009-11-24 15:41:41 +0000 | [diff] [blame] | 1101 | /* |
| 1102 | * If the customizer throws an unchecked exception, it is |
| 1103 | * safe to let it propagate |
| 1104 | */ |
| 1105 | break; |
| 1106 | } |
| 1107 | } |
| 1108 | |
| 1109 | /** |
| 1110 | * Increment the tracking count and tell the tracker there was a |
| 1111 | * modification. |
| 1112 | * |
| 1113 | * @GuardedBy this |
| 1114 | */ |
| 1115 | void modified() { |
| 1116 | super.modified(); /* increment the modification count */ |
| 1117 | ServiceTracker.this.modified(); |
| 1118 | } |
| 1119 | |
| 1120 | /** |
| 1121 | * Call the specific customizer adding method. This method must not be |
| 1122 | * called while synchronized on this object. |
| 1123 | * |
| 1124 | * @param item Item to be tracked. |
| 1125 | * @param related Action related object. |
| 1126 | * @return Customized object for the tracked item or <code>null</code> |
| 1127 | * if the item is not to be tracked. |
| 1128 | */ |
| 1129 | Object customizerAdding(final Object item, |
| 1130 | final Object related) { |
| 1131 | return customizer.addingService((ServiceReference) item); |
| 1132 | } |
| 1133 | |
| 1134 | void customizerAdded(final Object item, final Object related, final Object object) { |
| 1135 | customizer.addedService((ServiceReference) item, object); |
| 1136 | } |
| 1137 | |
| 1138 | /** |
| 1139 | * Call the specific customizer modified method. This method must not be |
| 1140 | * called while synchronized on this object. |
| 1141 | * |
| 1142 | * @param item Tracked item. |
| 1143 | * @param related Action related object. |
| 1144 | * @param object Customized object for the tracked item. |
| 1145 | */ |
| 1146 | void customizerModified(final Object item, |
| 1147 | final Object related, final Object object) { |
| 1148 | customizer.modifiedService((ServiceReference) item, object); |
| 1149 | } |
| 1150 | |
| 1151 | /** |
| 1152 | * Call the specific customizer removed method. This method must not be |
| 1153 | * called while synchronized on this object. |
| 1154 | * |
| 1155 | * @param item Tracked item. |
| 1156 | * @param related Action related object. |
| 1157 | * @param object Customized object for the tracked item. |
| 1158 | */ |
| 1159 | void customizerRemoved(final Object item, |
| 1160 | final Object related, final Object object) { |
| 1161 | customizer.removedService((ServiceReference) item, object); |
| 1162 | } |
| 1163 | } |
| 1164 | |
| 1165 | /** |
| 1166 | * Subclass of Tracked which implements the AllServiceListener interface. |
| 1167 | * This class is used by the ServiceTracker if open is called with true. |
| 1168 | * |
| 1169 | * @since 1.3 |
| 1170 | * @ThreadSafe |
| 1171 | */ |
| 1172 | class AllTracked extends Tracked implements AllServiceListener { |
| 1173 | /** |
| 1174 | * AllTracked constructor. |
| 1175 | */ |
| 1176 | AllTracked() { |
| 1177 | super(); |
| 1178 | } |
| 1179 | } |
| 1180 | } |