Skip to main content
aboutsummaryrefslogtreecommitdiffstats
blob: 0666185abb12bba70bd1ad2ffe160094933e0b1a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
/*******************************************************************************
 * Copyright (c) 2004, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.osgi.internal.loader;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.osgi.container.Module;
import org.eclipse.osgi.container.ModuleCapability;
import org.eclipse.osgi.container.ModuleLoader;
import org.eclipse.osgi.container.ModuleRequirement;
import org.eclipse.osgi.container.ModuleRevision;
import org.eclipse.osgi.container.ModuleRevisionBuilder;
import org.eclipse.osgi.container.ModuleWire;
import org.eclipse.osgi.container.ModuleWiring;
import org.eclipse.osgi.container.builders.OSGiManifestBuilderFactory;
import org.eclipse.osgi.container.namespaces.EquinoxModuleDataNamespace;
import org.eclipse.osgi.framework.util.KeyedElement;
import org.eclipse.osgi.framework.util.KeyedHashSet;
import org.eclipse.osgi.internal.debug.Debug;
import org.eclipse.osgi.internal.framework.EquinoxConfiguration;
import org.eclipse.osgi.internal.framework.EquinoxContainer;
import org.eclipse.osgi.internal.hookregistry.ClassLoaderHook;
import org.eclipse.osgi.internal.loader.buddy.PolicyHandler;
import org.eclipse.osgi.internal.loader.sources.MultiSourcePackage;
import org.eclipse.osgi.internal.loader.sources.NullPackageSource;
import org.eclipse.osgi.internal.loader.sources.PackageSource;
import org.eclipse.osgi.internal.loader.sources.SingleSourcePackage;
import org.eclipse.osgi.storage.BundleInfo.Generation;
import org.eclipse.osgi.util.ManifestElement;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.framework.namespace.BundleNamespace;
import org.osgi.framework.namespace.HostNamespace;
import org.osgi.framework.namespace.PackageNamespace;
import org.osgi.framework.wiring.BundleWiring;

/**
 * This object is responsible for all classloader delegation for a bundle.
 * It represents the loaded state of the bundle.  BundleLoader objects
 * are created lazily; care should be taken not to force the creation
 * of a BundleLoader unless it is necessary.
 * @see org.eclipse.osgi.internal.loader.BundleLoaderSources
 */
public class BundleLoader extends ModuleLoader {
	public final static String DEFAULT_PACKAGE = "."; //$NON-NLS-1$
	public final static String JAVA_PACKAGE = "java."; //$NON-NLS-1$

	public final static ClassContext CLASS_CONTEXT = AccessController.doPrivileged(new PrivilegedAction<ClassContext>() {
		public ClassContext run() {
			return new ClassContext();
		}
	});
	public final static ClassLoader FW_CLASSLOADER = getClassLoader(EquinoxContainer.class);

	private static final int PRE_CLASS = 1;
	private static final int POST_CLASS = 2;
	private static final int PRE_RESOURCE = 3;
	private static final int POST_RESOURCE = 4;
	private static final int PRE_RESOURCES = 5;
	private static final int POST_RESOURCES = 6;

	private static final Pattern PACKAGENAME_FILTER = Pattern.compile("\\(osgi.wiring.package\\s*=\\s*([^)]+)\\)"); //$NON-NLS-1$

	// TODO needed instead of using Collections.emptyEnumertion until we no longer support Java 6
	@SuppressWarnings("rawtypes")
	private final static Enumeration EMPTY_ENUMERATION = Collections.enumeration(Collections.emptyList());

	private final ModuleWiring wiring;
	private final EquinoxContainer container;
	private final Debug debug;
	private final PolicyHandler policy;

	/* List of package names that are exported by this BundleLoader */
	private final Collection<String> exportedPackages;
	private final BundleLoaderSources exportSources;

	/* cache of required package sources. Key is packagename, value is PackageSource */
	private final KeyedHashSet requiredSources = new KeyedHashSet(false);
	/* cache of imported packages. Key is packagename, Value is PackageSource */
	private final KeyedHashSet importedSources = new KeyedHashSet(false);
	private final List<ModuleWire> requiredBundleWires;

	/* @GuardedBy("importedSources") */
	private boolean importsInitialized = false;
	/* @GuardedBy("importedSources") */
	private boolean dynamicAllPackages;
	/* If not null, list of package stems to import dynamically. */
	/* @GuardedBy("importedSources") */
	private String[] dynamicImportPackageStems;
	/* @GuardedBy("importedSources") */
	/* If not null, list of package names to import dynamically. */
	private String[] dynamicImportPackages;

	private final Object classLoaderCreatedMonitor = new Object();
	/* @GuardedBy("classLoaderCreatedMonitor") */
	private ModuleClassLoader classLoaderCreated;
	private volatile ModuleClassLoader classloader;
	private final ClassLoader parent;
	private final AtomicBoolean triggerClassLoaded = new AtomicBoolean(false);

	/**
	 * Returns the package name from the specified class name.
	 * The returned package is dot seperated.
	 *
	 * @param name   Name of a class.
	 * @return Dot separated package name or null if the class
	 *         has no package name.
	 */
	public final static String getPackageName(String name) {
		if (name != null) {
			int index = name.lastIndexOf('.'); /* find last period in class name */
			if (index > 0)
				return name.substring(0, index);
		}
		return DEFAULT_PACKAGE;
	}

	/**
	 * Returns the package name from the specified resource name.
	 * The returned package is dot seperated.
	 *
	 * @param name   Name of a resource.
	 * @return Dot separated package name or null if the resource
	 *         has no package name.
	 */
	public final static String getResourcePackageName(String name) {
		if (name != null) {
			/* check for leading slash*/
			int begin = ((name.length() > 1) && (name.charAt(0) == '/')) ? 1 : 0;
			int end = name.lastIndexOf('/'); /* index of last slash */
			if (end > begin)
				return name.substring(begin, end).replace('/', '.');
		}
		return DEFAULT_PACKAGE;
	}

	public BundleLoader(ModuleWiring wiring, EquinoxContainer container, ClassLoader parent) {
		this.wiring = wiring;
		this.container = container;
		this.debug = container.getConfiguration().getDebug();
		this.parent = parent;

		// init the provided packages set
		exportSources = new BundleLoaderSources(this);
		List<ModuleCapability> exports = wiring.getModuleCapabilities(PackageNamespace.PACKAGE_NAMESPACE);
		exports = exports == null ? new ArrayList<ModuleCapability>(0) : exports;
		exportedPackages = Collections.synchronizedCollection(exports.size() > 10 ? new HashSet<String>(exports.size()) : new ArrayList<String>(exports.size()));
		initializeExports(exports, exportSources, exportedPackages);

		// init the dynamic imports tables
		addDynamicImportPackage(wiring.getModuleRequirements(PackageNamespace.PACKAGE_NAMESPACE));

		// initialize the required bundle wires
		List<ModuleWire> currentRequireBundleWires = wiring.getRequiredModuleWires(BundleNamespace.BUNDLE_NAMESPACE);
		requiredBundleWires = currentRequireBundleWires == null || currentRequireBundleWires.isEmpty() ? Collections.<ModuleWire> emptyList() : Collections.unmodifiableList(currentRequireBundleWires);

		//Initialize the policy handler
		List<ModuleCapability> moduleDatas = wiring.getRevision().getModuleCapabilities(EquinoxModuleDataNamespace.MODULE_DATA_NAMESPACE);
		@SuppressWarnings("unchecked")
		List<String> buddyList = (List<String>) (moduleDatas.isEmpty() ? null : moduleDatas.get(0).getAttributes().get(EquinoxModuleDataNamespace.CAPABILITY_BUDDY_POLICY));
		policy = buddyList != null ? new PolicyHandler(this, buddyList, container.getPackageAdmin()) : null;
		if (policy != null) {
			Module systemModule = container.getStorage().getModuleContainer().getModule(0);
			Bundle systemBundle = systemModule.getBundle();
			policy.open(systemBundle.getBundleContext());
		}
	}

	public ModuleWiring getWiring() {
		return wiring;
	}

	public void addFragmentExports(List<ModuleCapability> exports) {
		initializeExports(exports, exportSources, exportedPackages);
	}

	private static void initializeExports(List<ModuleCapability> exports, BundleLoaderSources sources, Collection<String> exportNames) {
		if (exports != null) {
			for (ModuleCapability export : exports) {
				String name = (String) export.getAttributes().get(PackageNamespace.PACKAGE_NAMESPACE);
				if (sources.forceSourceCreation(export)) {
					if (!exportNames.contains(name)) {
						// must force filtered and reexport sources to be created early
						// to prevent lazy normal package source creation.
						// We only do this for the first export of a package name. 
						sources.createPackageSource(export, true);
					}
				}
				exportNames.add(name);
			}
		}
	}

	final PackageSource createExportPackageSource(ModuleWire importWire, Collection<BundleLoader> visited) {
		String name = (String) importWire.getCapability().getAttributes().get(PackageNamespace.PACKAGE_NAMESPACE);
		BundleLoader providerLoader = (BundleLoader) importWire.getProviderWiring().getModuleLoader();
		if (providerLoader == null) {
			return createMultiSource(name, new PackageSource[0]);
		}
		PackageSource requiredSource = providerLoader.findRequiredSource(name, visited);
		PackageSource exportSource = providerLoader.exportSources.createPackageSource(importWire.getCapability(), false);
		if (requiredSource == null)
			return exportSource;
		return createMultiSource(name, new PackageSource[] {requiredSource, exportSource});
	}

	private static PackageSource createMultiSource(String packageName, PackageSource[] sources) {
		if (sources.length == 1)
			return sources[0];
		List<SingleSourcePackage> sourceList = new ArrayList<>(sources.length);
		for (int i = 0; i < sources.length; i++) {
			SingleSourcePackage[] innerSources = sources[i].getSuppliers();
			for (int j = 0; j < innerSources.length; j++)
				if (!sourceList.contains(innerSources[j]))
					sourceList.add(innerSources[j]);
		}
		return new MultiSourcePackage(packageName, sourceList.toArray(new SingleSourcePackage[sourceList.size()]));
	}

	public ModuleClassLoader getModuleClassLoader() {
		ModuleClassLoader result = classloader;
		if (result != null) {
			return result;
		}
		// doing optimistic class loader creating here to avoid holding any locks,
		// this may result in multiple classloaders being constructed but only one will be used.
		final List<ClassLoaderHook> hooks = container.getConfiguration().getHookRegistry().getClassLoaderHooks();
		final Generation generation = (Generation) wiring.getRevision().getRevisionInfo();
		if (System.getSecurityManager() == null) {
			result = createClassLoaderPrivledged(parent, generation.getBundleInfo().getStorage().getConfiguration(), this, generation, hooks);
		} else {
			final ClassLoader cl = parent;
			result = AccessController.doPrivileged(new PrivilegedAction<ModuleClassLoader>() {
				@Override
				public ModuleClassLoader run() {
					return createClassLoaderPrivledged(cl, generation.getBundleInfo().getStorage().getConfiguration(), BundleLoader.this, generation, hooks);
				}
			});
		}

		// Synchronize on classLoaderCreatedMonitor in order to ensure hooks are called before returning.
		// Note that we do hold a lock here while calling hooks.
		// Not ideal, but hooks really should do little work from classLoaderCreated method.
		synchronized (classLoaderCreatedMonitor) {
			if (classLoaderCreated == null) {
				// must set createdClassloader before calling hooks; otherwise we could enter
				// and endless loop if the hook causes re-entry (that would be a bad hook impl)
				classLoaderCreated = result;
				// only send to hooks if this thread wins in creating the class loader.
				final ModuleClassLoader cl = result;
				// protect with doPriv to avoid bubbling up permission checks that hooks may require
				AccessController.doPrivileged(new PrivilegedAction<Object>() {
					@Override
					public Object run() {
						for (ClassLoaderHook hook : hooks) {
							hook.classLoaderCreated(cl);
						}
						return null;
					}

				});
				// finally set the class loader for use after calling hooks
				classloader = classLoaderCreated;
			} else {
				// return the classLoaderCreated here; not the final classloader
				// this is necessary in case re-entry by a hook.classLoaderCreated method
				result = classLoaderCreated;
				if (debug.DEBUG_LOADER) {
					Debug.println("BundleLoader[" + this + "].getModuleClassLoader() - created duplicate classloader"); //$NON-NLS-1$ //$NON-NLS-2$
				}
			}
		}
		return result;
	}

	@Override
	protected void loadFragments(Collection<ModuleRevision> fragments) {
		addFragmentExports(wiring.getModuleCapabilities(PackageNamespace.PACKAGE_NAMESPACE));
		loadClassLoaderFragments(fragments);
		clearManifestLocalizationCache();
	}

	protected void clearManifestLocalizationCache() {
		Generation hostGen = (Generation) wiring.getRevision().getRevisionInfo();
		hostGen.clearManifestCache();
		List<ModuleWire> hostWires = wiring.getProvidedModuleWires(HostNamespace.HOST_NAMESPACE);
		// doing a null check because there is no lock on the module database here
		if (hostWires != null) {
			for (ModuleWire fragmentWire : hostWires) {
				Generation fragGen = (Generation) fragmentWire.getRequirer().getRevisionInfo();
				fragGen.clearManifestCache();
			}
		}
	}

	void loadClassLoaderFragments(Collection<ModuleRevision> fragments) {
		ModuleClassLoader current = classloader;
		if (current != null) {
			current.loadFragments(fragments);
		}
	}

	static ModuleClassLoader createClassLoaderPrivledged(ClassLoader parent, EquinoxConfiguration configuration, BundleLoader delegate, Generation generation, List<ClassLoaderHook> hooks) {
		// allow hooks to extend the ModuleClassLoader implementation
		for (ClassLoaderHook hook : hooks) {
			ModuleClassLoader hookClassLoader = hook.createClassLoader(parent, configuration, delegate, generation);
			if (hookClassLoader != null) {
				// first one to return non-null wins.
				return hookClassLoader;
			}
		}
		// just use the default one
		return new EquinoxClassLoader(parent, configuration, delegate, generation);
	}

	public void close() {
		if (policy != null) {
			Module systemModule = container.getStorage().getModuleContainer().getModule(0);
			BundleContext context = systemModule.getBundle().getBundleContext();
			if (context != null) {
				policy.close(context);
			}
		}
		ModuleClassLoader current = classloader;
		if (current != null) {
			current.close();
		}
	}

	@Override
	protected ClassLoader getClassLoader() {
		return getModuleClassLoader();
	}

	public ClassLoader getParentClassLoader() {
		return this.parent;
	}

	/**
	 * This method gets a resource from the bundle.  The resource is searched 
	 * for in the same manner as it would if it was being loaded from a bundle 
	 * (i.e. all hosts, fragments, import, required bundles and 
	 * local resources are searched).
	 *
	 * @param name the name of the desired resource.
	 * @return the resulting resource URL or null if it does not exist.
	 */
	final URL getResource(String name) {
		return getModuleClassLoader().getResource(name);
	}

	/**
	 * Finds a class local to this bundle.  Only the classloader for this bundle is searched.
	 * @param name The name of the class to find.
	 * @return The loaded Class or null if the class is not found.
	 * @throws ClassNotFoundException 
	 */
	public Class<?> findLocalClass(String name) throws ClassNotFoundException {
		long start = 0;
		if (debug.DEBUG_LOADER) {
			Debug.println("BundleLoader[" + this + "].findLocalClass(" + name + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
			start = System.currentTimeMillis();
		}
		try {
			Class<?> clazz = getModuleClassLoader().findLocalClass(name);
			if (debug.DEBUG_LOADER && clazz != null) {
				long time = System.currentTimeMillis() - start;
				Debug.println("BundleLoader[" + this + "] found local class " + name + " " + time + "ms"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
			}
			return clazz;
		} catch (ClassNotFoundException e) {
			if (e.getCause() instanceof BundleException) {
				// Here we assume this is because of a lazy activation error
				throw e;
			}
			return null;
		}
	}

	/**
	 * Finds the class for a bundle.  This method is used for delegation by the bundle's classloader.
	 */
	public Class<?> findClass(String name) throws ClassNotFoundException {
		return findClass(name, true);
	}

	Class<?> findClass(String name, boolean checkParent) throws ClassNotFoundException {
		if (checkParent && parent != null && name.startsWith(JAVA_PACKAGE))
			// 1) if startsWith "java." delegate to parent and terminate search
			// we want to throw ClassNotFoundExceptions if a java.* class cannot be loaded from the parent.
			return parent.loadClass(name);
		return findClassInternal(name, checkParent);
	}

	private Class<?> findClassInternal(String name, boolean checkParent) throws ClassNotFoundException {
		if (debug.DEBUG_LOADER)
			Debug.println("BundleLoader[" + this + "].findClassInternal(" + name + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		String pkgName = getPackageName(name);
		boolean bootDelegation = false;
		// follow the OSGi delegation model
		if (checkParent && parent != null && container.isBootDelegationPackage(pkgName)) {
			// 2) if part of the bootdelegation list then delegate to parent and continue of failure
			try {
				return parent.loadClass(name);
			} catch (ClassNotFoundException cnfe) {
				// we want to continue
				bootDelegation = true;
			}
		}
		Class<?> result = null;
		try {
			result = (Class<?>) searchHooks(name, PRE_CLASS);
		} catch (ClassNotFoundException e) {
			throw e;
		} catch (FileNotFoundException e) {
			// will not happen
		}
		if (result != null)
			return result;
		// 3) search the imported packages
		PackageSource source = findImportedSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from import package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 3) found import source terminate search at the source
			result = source.loadClass(name);
			if (result != null)
				return result;
			throw new ClassNotFoundException(name + " cannot be found by " + this); //$NON-NLS-1$
		}
		// 4) search the required bundles
		source = findRequiredSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from required bundle package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 4) attempt to load from source but continue on failure
			result = source.loadClass(name);
		}
		// 5) search the local bundle
		if (result == null)
			result = findLocalClass(name);
		if (result != null)
			return result;
		// 6) attempt to find a dynamic import source; only do this if a required source was not found
		if (source == null) {
			source = findDynamicSource(pkgName);
			if (source != null) {
				result = source.loadClass(name);
				if (result != null)
					return result;
				// must throw CNFE if dynamic import source does not have the class
				throw new ClassNotFoundException(name + " cannot be found by " + this); //$NON-NLS-1$
			}
		}

		if (result == null)
			try {
				result = (Class<?>) searchHooks(name, POST_CLASS);
			} catch (ClassNotFoundException e) {
				throw e;
			} catch (FileNotFoundException e) {
				// will not happen
			}
		// do buddy policy loading
		if (result == null && policy != null)
			result = policy.doBuddyClassLoading(name);
		if (result != null)
			return result;
		// hack to support backwards compatibility for bootdelegation
		// or last resort; do class context trick to work around VM bugs
		if (parent != null && !bootDelegation && ((checkParent && container.getConfiguration().compatibilityBootDelegation) || isRequestFromVM())) {
			// we don't need to continue if a CNFE is thrown here.
			try {
				return parent.loadClass(name);
			} catch (ClassNotFoundException e) {
				// we want to generate our own exception below
			}
		}
		throw new ClassNotFoundException(name + " cannot be found by " + this); //$NON-NLS-1$
	}

	@SuppressWarnings("unchecked")
	private <E> E searchHooks(String name, int type) throws ClassNotFoundException, FileNotFoundException {

		List<ClassLoaderHook> loaderHooks = container.getConfiguration().getHookRegistry().getClassLoaderHooks();
		if (loaderHooks == null)
			return null;
		E result = null;
		for (ClassLoaderHook hook : loaderHooks) {
			switch (type) {
				case PRE_CLASS :
					result = (E) hook.preFindClass(name, getModuleClassLoader());
					break;
				case POST_CLASS :
					result = (E) hook.postFindClass(name, getModuleClassLoader());
					break;
				case PRE_RESOURCE :
					result = (E) hook.preFindResource(name, getModuleClassLoader());
					break;
				case POST_RESOURCE :
					result = (E) hook.postFindResource(name, getModuleClassLoader());
					break;
				case PRE_RESOURCES :
					result = (E) hook.preFindResources(name, getModuleClassLoader());
					break;
				case POST_RESOURCES :
					result = (E) hook.postFindResources(name, getModuleClassLoader());
					break;
			}
			if (result != null) {
				return result;
			}
		}
		return result;
	}

	private boolean isRequestFromVM() {
		if (!container.getConfiguration().contextBootDelegation)
			return false;
		// works around VM bugs that require all classloaders to have access to parent packages
		Class<?>[] context = CLASS_CONTEXT.getClassContext();
		if (context == null || context.length < 2)
			return false;
		// skip the first class; it is the ClassContext class
		for (int i = 1; i < context.length; i++) {
			Class<?> clazz = context[i];
			// Find the first class in the context which is not BundleLoader or the ModuleClassLoader;
			// We ignore ClassLoader because ModuleClassLoader extends it.
			// We ignore Class because of Class.forName (bug 471551)
			if (clazz != BundleLoader.class && !ModuleClassLoader.class.isAssignableFrom(clazz) && clazz != ClassLoader.class && clazz != Class.class && !clazz.getName().equals("java.lang.J9VMInternals")) { //$NON-NLS-1$
				if (Bundle.class.isAssignableFrom(clazz)) {
					// We ignore any requests from Bundle (e.g. Bundle.loadClass case)
					return false;
				}
				// only find in parent if the class is not loaded with a ModuleClassLoader
				ClassLoader cl = getClassLoader(clazz);
				// extra check incase an adaptor adds another class into the stack besides an instance of ClassLoader
				if (cl != FW_CLASSLOADER) {
					// if the class is loaded from a class loader implemented by a bundle then we do not boot delegate
					ClassLoader last = null;
					while (cl != null && cl != last) {
						last = cl;
						if (cl instanceof ModuleClassLoader) {
							return false;
						}
						cl = getClassLoader(cl.getClass());
					}

					// request is not from a bundle
					return true;
				}
			}
		}
		return false;
	}

	private static ClassLoader getClassLoader(final Class<?> clazz) {
		if (System.getSecurityManager() == null)
			return clazz.getClassLoader();
		return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
			public ClassLoader run() {
				return clazz.getClassLoader();
			}
		});
	}

	/**
	 * Finds the resource for a bundle.  This method is used for delegation by the bundle's classloader.
	 */
	public URL findResource(String name) {
		if (debug.DEBUG_LOADER)
			Debug.println("BundleLoader[" + this + "].findResource(" + name + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		if ((name.length() > 1) && (name.charAt(0) == '/')) /* if name has a leading slash */
			name = name.substring(1); /* remove leading slash before search */
		String pkgName = getResourcePackageName(name);
		boolean bootDelegation = false;
		// follow the OSGi delegation model
		// First check the parent classloader for system resources, if it is a java resource.
		if (parent != null) {
			if (pkgName.startsWith(JAVA_PACKAGE))
				// 1) if startsWith "java." delegate to parent and terminate search
				// we never delegate java resource requests past the parent
				return parent.getResource(name);
			else if (container.isBootDelegationPackage(pkgName)) {
				// 2) if part of the bootdelegation list then delegate to parent and continue of failure
				URL result = parent.getResource(name);
				if (result != null)
					return result;
				bootDelegation = true;
			}
		}

		URL result = null;
		try {
			result = (URL) searchHooks(name, PRE_RESOURCE);
		} catch (FileNotFoundException e) {
			return null;
		} catch (ClassNotFoundException e) {
			// will not happen
		}
		if (result != null)
			return result;
		// 3) search the imported packages
		PackageSource source = findImportedSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from import package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 3) found import source terminate search at the source
			return source.getResource(name);
		}
		// 4) search the required bundles
		source = findRequiredSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from required bundle package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 4) attempt to load from source but continue on failure
			result = source.getResource(name);
		}
		// 5) search the local bundle
		if (result == null)
			result = findLocalResource(name);
		if (result != null)
			return result;
		// 6) attempt to find a dynamic import source; only do this if a required source was not found
		if (source == null) {
			source = findDynamicSource(pkgName);
			if (source != null)
				// must return the result of the dynamic import and do not continue
				return source.getResource(name);
		}

		if (result == null)
			try {
				result = (URL) searchHooks(name, POST_RESOURCE);
			} catch (FileNotFoundException e) {
				return null;
			} catch (ClassNotFoundException e) {
				// will not happen
			}
		// do buddy policy loading
		if (result == null && policy != null)
			result = policy.doBuddyResourceLoading(name);
		if (result != null)
			return result;
		// hack to support backwards compatibility for bootdelegation
		// or last resort; do class context trick to work around VM bugs
		if (parent != null && !bootDelegation && (container.getConfiguration().compatibilityBootDelegation || isRequestFromVM()))
			// we don't need to continue if the resource is not found here
			return parent.getResource(name);
		return result;
	}

	/**
	 * Finds the resources for a bundle.  This  method is used for delegation by the bundle's classloader.
	 */
	public Enumeration<URL> findResources(String name) throws IOException {
		if (debug.DEBUG_LOADER)
			Debug.println("BundleLoader[" + this + "].findResources(" + name + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		// do not delegate to parent because ClassLoader#getResources already did and it is final!!
		if ((name.length() > 1) && (name.charAt(0) == '/')) /* if name has a leading slash */
			name = name.substring(1); /* remove leading slash before search */
		String pkgName = getResourcePackageName(name);
		Enumeration<URL> result = emptyEnumeration();
		boolean bootDelegation = false;
		// follow the OSGi delegation model
		// First check the parent classloader for system resources, if it is a java resource.
		if (parent != null) {
			if (pkgName.startsWith(JAVA_PACKAGE))
				// 1) if startsWith "java." delegate to parent and terminate search
				// we never delegate java resource requests past the parent
				return parent.getResources(name);
			else if (container.isBootDelegationPackage(pkgName)) {
				// 2) if part of the bootdelegation list then delegate to parent and continue
				result = compoundEnumerations(result, parent.getResources(name));
				bootDelegation = true;
			}
		}
		try {
			Enumeration<URL> hookResources = searchHooks(name, PRE_RESOURCES);
			if (hookResources != null) {
				return compoundEnumerations(result, hookResources);
			}
		} catch (ClassNotFoundException e) {
			// will not happen
		} catch (FileNotFoundException e) {
			return result;
		}

		// 3) search the imported packages
		PackageSource source = findImportedSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from import package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 3) found import source terminate search at the source
			return compoundEnumerations(result, source.getResources(name));
		}
		// 4) search the required bundles
		source = findRequiredSource(pkgName, null);
		if (source != null) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] loading from required bundle package: " + source); //$NON-NLS-1$ //$NON-NLS-2$
			}
			// 4) attempt to load from source but continue on failure
			result = compoundEnumerations(result, source.getResources(name));
		}
		// 5) search the local bundle
		// compound the required source results with the local ones
		Enumeration<URL> localResults = findLocalResources(name);
		result = compoundEnumerations(result, localResults);
		// 6) attempt to find a dynamic import source; only do this if a required source was not found
		if (source == null && !result.hasMoreElements()) {
			source = findDynamicSource(pkgName);
			if (source != null)
				return compoundEnumerations(result, source.getResources(name));
		}
		if (!result.hasMoreElements())
			try {
				Enumeration<URL> hookResources = searchHooks(name, POST_RESOURCES);
				result = compoundEnumerations(result, hookResources);
			} catch (ClassNotFoundException e) {
				// will not happen
			} catch (FileNotFoundException e) {
				return null;
			}
		if (policy != null) {
			Enumeration<URL> buddyResult = policy.doBuddyResourcesLoading(name);
			result = compoundEnumerations(result, buddyResult);
		}
		// hack to support backwards compatibility for bootdelegation
		// or last resort; do class context trick to work around VM bugs
		if (!result.hasMoreElements()) {
			if (parent != null && !bootDelegation && (container.getConfiguration().compatibilityBootDelegation || isRequestFromVM()))
				// we don't need to continue if the resource is not found here
				return parent.getResources(name);
		}
		return result;
	}

	private boolean isSubPackage(String parentPackage, String subPackage) {
		String prefix = (parentPackage.length() == 0 || parentPackage.equals(DEFAULT_PACKAGE)) ? "" : parentPackage + '.'; //$NON-NLS-1$
		return subPackage.startsWith(prefix);
	}

	@Override
	protected Collection<String> listResources(String path, String filePattern, int options) {
		String pkgName = getResourcePackageName(path.endsWith("/") ? path : path + '/'); //$NON-NLS-1$
		if ((path.length() > 1) && (path.charAt(0) == '/')) /* if name has a leading slash */
			path = path.substring(1); /* remove leading slash before search */
		boolean subPackages = (options & BundleWiring.LISTRESOURCES_RECURSE) != 0;
		List<String> packages = new ArrayList<>();
		// search imported package names
		KeyedHashSet importSources = getImportedSources(null);
		KeyedElement[] imports;
		synchronized (importSources) {
			imports = importSources.elements();
		}
		for (KeyedElement keyedElement : imports) {
			String id = ((PackageSource) keyedElement).getId();
			if (id.equals(pkgName) || (subPackages && isSubPackage(pkgName, id)))
				packages.add(id);
		}

		// now add package names from required bundles
		Collection<BundleLoader> visited = new ArrayList<>();
		visited.add(this); // always add ourselves so we do not recurse back to ourselves
		for (ModuleWire bundleWire : requiredBundleWires) {
			BundleLoader loader = (BundleLoader) bundleWire.getProviderWiring().getModuleLoader();
			if (loader != null) {
				loader.addProvidedPackageNames(pkgName, packages, subPackages, visited);
			}
		}

		boolean localSearch = (options & BundleWiring.LISTRESOURCES_LOCAL) != 0;
		// Use LinkedHashSet for optimized performance of contains() plus
		// ordering guarantees.
		LinkedHashSet<String> result = new LinkedHashSet<>();
		Set<String> importedPackages = new HashSet<>(0);
		for (String name : packages) {
			// look for import source
			PackageSource externalSource = findImportedSource(name, null);
			if (externalSource != null) {
				// record this package is imported
				importedPackages.add(name);
			} else {
				// look for require bundle source
				externalSource = findRequiredSource(name, null);
			}
			// only add the content of the external source if this is not a localSearch
			if (externalSource != null && !localSearch) {
				String packagePath = name.replace('.', '/');
				Collection<String> externalResources = externalSource.listResources(packagePath, filePattern);
				for (String resource : externalResources) {
					if (!result.contains(resource)) // prevent duplicates; could happen if the package is split or exporter has fragments/multiple jars
						result.add(resource);
				}
			}
		}

		// now search locally
		Collection<String> localResources = getModuleClassLoader().listLocalResources(path, filePattern, options);
		for (String resource : localResources) {
			String resourcePkg = getResourcePackageName(resource);
			if (!importedPackages.contains(resourcePkg) && !result.contains(resource))
				result.add(resource);
		}
		return result;
	}

	@Override
	protected List<URL> findEntries(String path, String filePattern, int options) {
		return getModuleClassLoader().findEntries(path, filePattern, options);
	}

	public static <E> Enumeration<E> compoundEnumerations(Enumeration<E> list1, Enumeration<E> list2) {
		if (list2 == null || !list2.hasMoreElements())
			return list1 == null ? BundleLoader.<E> emptyEnumeration() : list1;
		if (list1 == null || !list1.hasMoreElements())
			return list2 == null ? BundleLoader.<E> emptyEnumeration() : list2;
		List<E> compoundResults = new ArrayList<>();
		while (list1.hasMoreElements())
			compoundResults.add(list1.nextElement());
		while (list2.hasMoreElements()) {
			E item = list2.nextElement();
			if (!compoundResults.contains(item)) //don't add duplicates
				compoundResults.add(item);
		}
		return Collections.enumeration(compoundResults);
	}

	@SuppressWarnings("unchecked")
	private static <E> Enumeration<E> emptyEnumeration() {
		return EMPTY_ENUMERATION;
	}

	/**
	 * Finds a resource local to this bundle.  Only the classloader for this bundle is searched.
	 * @param name The name of the resource to find.
	 * @return The URL to the resource or null if the resource is not found.
	 */
	public URL findLocalResource(final String name) {
		return getModuleClassLoader().findLocalResource(name);
	}

	/**
	 * Returns an Enumeration of URLs representing all the resources with
	 * the given name. Only the classloader for this bundle is searched.
	 *
	 * @param  name the resource name
	 * @return an Enumeration of URLs for the resources
	 */
	public Enumeration<URL> findLocalResources(String name) {
		return getModuleClassLoader().findLocalResources(name);
	}

	/**
	 * Return a string representation of this loader.
	 * @return String
	 */
	public final String toString() {
		ModuleRevision revision = wiring.getRevision();
		String name = revision.getSymbolicName();
		if (name == null)
			name = "unknown"; //$NON-NLS-1$
		return name + '_' + revision.getVersion();
	}

	/**
	 * Return true if the target package name matches
	 * a name in the DynamicImport-Package manifest header.
	 *
	 * @param pkgname The name of the requested class' package.
	 * @return true if the package should be imported.
	 */
	private final boolean isDynamicallyImported(String pkgname) {
		if (this instanceof SystemBundleLoader)
			return false; // system bundle cannot dynamically import
		// must check for startsWith("java.") to satisfy R3 section 4.7.2
		if (pkgname.startsWith("java.")) //$NON-NLS-1$
			return true;

		synchronized (importedSources) {
			/* "*" shortcut */
			if (dynamicAllPackages)
				return true;

			/* match against specific names */
			if (dynamicImportPackages != null)
				for (int i = 0; i < dynamicImportPackages.length; i++)
					if (pkgname.equals(dynamicImportPackages[i]))
						return true;

			/* match against names with trailing wildcards */
			if (dynamicImportPackageStems != null)
				for (int i = 0; i < dynamicImportPackageStems.length; i++)
					if (pkgname.startsWith(dynamicImportPackageStems[i]))
						return true;
		}
		return false;
	}

	final void addExportedProvidersFor(String packageName, List<PackageSource> result, Collection<BundleLoader> visited) {
		if (visited.contains(this))
			return;
		visited.add(this);
		// See if we locally provide the package.
		PackageSource local = null;
		if (isExportedPackage(packageName))
			local = exportSources.getPackageSource(packageName);
		else if (isSubstitutedExport(packageName)) {
			result.add(findImportedSource(packageName, visited));
			return; // should not continue to required bundles in this case
		}
		// Must search required bundles that are exported first.
		for (ModuleWire bundleWire : requiredBundleWires) {
			if (local != null || BundleNamespace.VISIBILITY_REEXPORT.equals(bundleWire.getRequirement().getDirectives().get(BundleNamespace.REQUIREMENT_VISIBILITY_DIRECTIVE))) {
				// always add required bundles first if we locally provide the package
				// This allows a bundle to provide a package from a required bundle without 
				// re-exporting the whole required bundle.
				BundleLoader loader = (BundleLoader) bundleWire.getProviderWiring().getModuleLoader();
				if (loader != null) {
					loader.addExportedProvidersFor(packageName, result, visited);
				}
			}
		}
		// now add the locally provided package.
		if (local != null)
			result.add(local);
	}

	final void addProvidedPackageNames(String packageName, List<String> result, boolean subPackages, Collection<BundleLoader> visited) {
		if (visited.contains(this))
			return;
		visited.add(this);
		synchronized (exportedPackages) {
			for (String exported : exportedPackages) {
				if (exported.equals(packageName) || (subPackages && isSubPackage(packageName, exported))) {
					if (!result.contains(exported))
						result.add(exported);
				}
			}
		}
		for (String substituted : wiring.getSubstitutedNames()) {
			if (substituted.equals(packageName) || (subPackages && isSubPackage(packageName, substituted))) {
				if (!result.contains(substituted))
					result.add(substituted);
			}
		}
		for (ModuleWire bundleWire : requiredBundleWires) {
			if (BundleNamespace.VISIBILITY_REEXPORT.equals(bundleWire.getRequirement().getDirectives().get(BundleNamespace.REQUIREMENT_VISIBILITY_DIRECTIVE))) {
				BundleLoader loader = (BundleLoader) bundleWire.getProviderWiring().getModuleLoader();
				if (loader != null) {
					loader.addProvidedPackageNames(packageName, result, subPackages, visited);
				}
			}
		}
	}

	public final boolean isExportedPackage(String name) {
		return exportedPackages.contains(name);
	}

	final boolean isSubstitutedExport(String name) {
		return wiring.isSubstitutedPackage(name);
	}

	private void addDynamicImportPackage(List<ModuleRequirement> packageImports) {
		if (packageImports == null || packageImports.isEmpty()) {
			return;
		}
		List<String> dynamicImports = new ArrayList<>(packageImports.size());
		for (ModuleRequirement packageImport : packageImports) {
			if (PackageNamespace.RESOLUTION_DYNAMIC.equals(packageImport.getDirectives().get(PackageNamespace.REQUIREMENT_RESOLUTION_DIRECTIVE))) {
				Matcher matcher = PACKAGENAME_FILTER.matcher(packageImport.getDirectives().get(PackageNamespace.REQUIREMENT_FILTER_DIRECTIVE));
				if (matcher.find()) {
					String dynamicName = matcher.group(1);
					if (dynamicName != null) {
						dynamicImports.add(dynamicName);
					}
				}
			}
		}
		if (dynamicImports.size() > 0)
			addDynamicImportPackage(dynamicImports.toArray(new String[dynamicImports.size()]));
	}

	/**
	 * Adds a list of DynamicImport-Package manifest elements to the dynamic
	 * import tables of this BundleLoader.  Duplicate packages are checked and
	 * not added again.  This method is not thread safe.  Callers should ensure
	 * synchronization when calling this method.
	 * @param packages the DynamicImport-Package elements to add.
	 */
	private void addDynamicImportPackage(String[] packages) {
		if (packages == null)
			return;

		synchronized (importedSources) {
			int size = packages.length;
			List<String> stems;
			if (dynamicImportPackageStems == null) {
				stems = new ArrayList<>(size);
			} else {
				stems = new ArrayList<>(size + dynamicImportPackageStems.length);
				for (int i = 0; i < dynamicImportPackageStems.length; i++) {
					stems.add(dynamicImportPackageStems[i]);
				}
			}

			List<String> names;
			if (dynamicImportPackages == null) {
				names = new ArrayList<>(size);
			} else {
				names = new ArrayList<>(size + dynamicImportPackages.length);
				for (int i = 0; i < dynamicImportPackages.length; i++) {
					names.add(dynamicImportPackages[i]);
				}
			}

			for (int i = 0; i < size; i++) {
				String name = packages[i];
				if (isDynamicallyImported(name))
					continue;
				if (name.equals("*")) { //$NON-NLS-1$
					// shortcut
					dynamicAllPackages = true;
					return;
				}

				if (name.endsWith(".*")) //$NON-NLS-1$
					stems.add(name.substring(0, name.length() - 1));
				else
					names.add(name);
			}

			size = stems.size();
			if (size > 0)
				dynamicImportPackageStems = stems.toArray(new String[size]);

			size = names.size();
			if (size > 0)
				dynamicImportPackages = names.toArray(new String[size]);
		}
	}

	/**
	 * Adds a list of DynamicImport-Package manifest elements to the dynamic
	 * import tables of this BundleLoader.  Duplicate packages are checked and
	 * not added again.
	 * @param packages the DynamicImport-Package elements to add.
	 */
	public final void addDynamicImportPackage(ManifestElement[] packages) {
		if (packages == null)
			return;
		List<String> dynamicImports = new ArrayList<>(packages.length);
		StringBuilder importSpec = new StringBuilder();
		for (ManifestElement dynamicImportElement : packages) {
			String[] names = dynamicImportElement.getValueComponents();
			for (String name : names)
				dynamicImports.add(name);
			if (importSpec.length() > 0) {
				importSpec.append(',');
			}
			importSpec.append(dynamicImportElement.toString());
		}

		if (dynamicImports.size() > 0) {
			addDynamicImportPackage(dynamicImports.toArray(new String[dynamicImports.size()]));

			Map<String, String> dynamicImportMap = new HashMap<>();
			dynamicImportMap.put(Constants.DYNAMICIMPORT_PACKAGE, importSpec.toString());

			try {
				ModuleRevisionBuilder builder = OSGiManifestBuilderFactory.createBuilder(dynamicImportMap);
				wiring.addDynamicImports(builder);
			} catch (BundleException e) {
				throw new RuntimeException(e);
			}

		}
	}

	/*
	 * Finds a packagesource that is either imported or required from another bundle.
	 * This will not include an local package source
	 */
	private PackageSource findSource(String pkgName) {
		if (pkgName == null)
			return null;
		PackageSource result = findImportedSource(pkgName, null);
		if (result != null)
			return result;
		// Note that dynamic imports are not checked to avoid aggressive wiring (bug 105779)  
		return findRequiredSource(pkgName, null);
	}

	private PackageSource findImportedSource(String pkgName, Collection<BundleLoader> visited) {
		KeyedHashSet imports = getImportedSources(visited);
		synchronized (imports) {
			return (PackageSource) imports.getByKey(pkgName);
		}
	}

	private KeyedHashSet getImportedSources(Collection<BundleLoader> visited) {
		synchronized (importedSources) {
			if (importsInitialized) {
				return importedSources;
			}
			List<ModuleWire> importWires = wiring.getRequiredModuleWires(PackageNamespace.PACKAGE_NAMESPACE);
			if (importWires != null) {
				for (ModuleWire importWire : importWires) {
					PackageSource source = createExportPackageSource(importWire, visited);
					if (source != null) {
						importedSources.add(source);
					}
				}
			}
			importsInitialized = true;
			return importedSources;
		}
	}

	private PackageSource findDynamicSource(String pkgName) {
		if (!isExportedPackage(pkgName) && isDynamicallyImported(pkgName)) {
			if (debug.DEBUG_LOADER) {
				Debug.println("BundleLoader[" + this + "] attempting to resolve dynamic package: " + pkgName); //$NON-NLS-1$ //$NON-NLS-2$
			}
			ModuleRevision revision = wiring.getRevision();
			ModuleWire dynamicWire = revision.getRevisions().getModule().getContainer().resolveDynamic(pkgName, revision);
			if (dynamicWire != null) {
				PackageSource source = createExportPackageSource(dynamicWire, null);
				if (debug.DEBUG_LOADER) {
					Debug.println("BundleLoader[" + this + "] using dynamic import source: " + source); //$NON-NLS-1$ //$NON-NLS-2$
				}
				synchronized (importedSources) {
					importedSources.add(source);
				}
				return source;
			}
		}
		return null;
	}

	private PackageSource findRequiredSource(String pkgName, Collection<BundleLoader> visited) {
		synchronized (requiredSources) {
			PackageSource result = (PackageSource) requiredSources.getByKey(pkgName);
			if (result != null)
				return result.isNullSource() ? null : result;
		}
		if (visited == null)
			visited = new ArrayList<>();
		if (!visited.contains(this))
			visited.add(this); // always add ourselves so we do not recurse back to ourselves
		List<PackageSource> result = new ArrayList<>(3);
		for (ModuleWire bundleWire : requiredBundleWires) {
			BundleLoader loader = (BundleLoader) bundleWire.getProviderWiring().getModuleLoader();
			if (loader != null) {
				loader.addExportedProvidersFor(pkgName, result, visited);
			}
		}
		// found some so cache the result for next time and return
		PackageSource source;
		if (result.size() == 0) {
			// did not find it in our required bundles lets record the failure
			// so we do not have to do the search again for this package.
			source = NullPackageSource.getNullPackageSource(pkgName);
		} else if (result.size() == 1) {
			// if there is just one source, remember just the single source 
			source = result.get(0);
		} else {
			// if there was more than one source, build a multisource and cache that.
			PackageSource[] srcs = result.toArray(new PackageSource[result.size()]);
			source = createMultiSource(pkgName, srcs);
		}
		synchronized (requiredSources) {
			requiredSources.add(source);
		}
		return source.isNullSource() ? null : source;
	}

	/*
	 * Gets the package source for the pkgName.  This will include the local package source
	 * if the bundle exports the package.  This is used to compare the PackageSource of a 
	 * package from two different bundles.
	 */
	public final PackageSource getPackageSource(String pkgName) {
		PackageSource result = findSource(pkgName);
		if (!isExportedPackage(pkgName))
			return result;
		// if the package is exported then we need to get the local source
		PackageSource localSource = exportSources.getPackageSource(pkgName);
		if (result == null)
			return localSource;
		if (localSource == null)
			return result;
		return createMultiSource(pkgName, new PackageSource[] {result, localSource});
	}

	static final class ClassContext extends SecurityManager {
		// need to make this method public
		public Class<?>[] getClassContext() {
			return super.getClassContext();
		}
	}

	@Override
	protected boolean getAndSetTrigger() {
		return triggerClassLoaded.getAndSet(true);
	}

	@Override
	public boolean isTriggerSet() {
		return triggerClassLoaded.get();
	}
}

Back to the top