1 /*
2 * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.module;
27
28 import java.io.File;
29 import java.io.PrintStream;
30 import java.lang.module.Configuration;
31 import java.lang.module.ModuleDescriptor;
32 import java.lang.module.ModuleFinder;
33 import java.lang.module.ModuleReference;
34 import java.lang.module.ResolvedModule;
35 import java.lang.reflect.Layer;
36 import java.lang.reflect.Module;
37 import java.net.URI;
38 import java.nio.file.Path;
39 import java.nio.file.Paths;
40 import java.util.ArrayList;
41 import java.util.Collections;
42 import java.util.HashMap;
43 import java.util.HashSet;
44 import java.util.List;
45 import java.util.Map;
46 import java.util.Optional;
47 import java.util.Set;
48 import java.util.function.Function;
49
50 import jdk.internal.loader.BootLoader;
51 import jdk.internal.loader.BuiltinClassLoader;
52 import jdk.internal.misc.JavaLangModuleAccess;
53 import jdk.internal.misc.SharedSecrets;
54 import jdk.internal.perf.PerfCounter;
55 import static jdk.internal.module.WarnIfResolvedReason.*;
56
57 /**
58 * Initializes/boots the module system.
59 *
60 * The {@link #boot() boot} method is called early in the startup to initialize
61 * the module system. In summary, the boot method creates a Configuration by
62 * resolving a set of module names specified via the launcher (or equivalent)
63 * -m and --add-modules options. The modules are located on a module path that
64 * is constructed from the upgrade module path, system modules, and application
65 * module path. The Configuration is instantiated as the boot Layer with each
66 * module in the the configuration defined to one of the built-in class loaders.
67 */
68
69 public final class ModuleBootstrap {
70 private ModuleBootstrap() { }
71
72 private static final JavaLangModuleAccess JLMA
73 = SharedSecrets.getJavaLangModuleAccess();
74
75 private static final String JAVA_BASE = "java.base";
76
77 private static final String JAVA_SE = "java.se";
78
79 // the token for "all default modules"
80 private static final String ALL_DEFAULT = "ALL-DEFAULT";
81
82 // the token for "all unnamed modules"
83 private static final String ALL_UNNAMED = "ALL-UNNAMED";
84
85 // the token for "all system modules"
86 private static final String ALL_SYSTEM = "ALL-SYSTEM";
87
88 // the token for "all modules on the module path"
89 private static final String ALL_MODULE_PATH = "ALL-MODULE-PATH";
90
91 // The ModulePatcher for the initial configuration
92 private static final ModulePatcher patcher = initModulePatcher();
93
94 // ModuleFinder for the initial configuration
95 private static ModuleFinder initialFinder;
96
97 /**
98 * Returns the ModulePatcher for the initial configuration.
99 */
100 public static ModulePatcher patcher() {
101 return patcher;
102 }
103
104 /**
105 * Returns the ModuleFinder for the initial configuration
106 */
107 public static ModuleFinder finder() {
108 assert initialFinder != null;
109 return initialFinder;
110 }
111
112 /**
113 * Initialize the module system, returning the boot Layer.
114 *
115 * @see java.lang.System#initPhase2()
116 */
117 public static Layer boot() {
118
119 long t0 = System.nanoTime();
120
121 // system modules (may be patched)
122 ModuleFinder systemModules = ModuleFinder.ofSystem();
123
124 PerfCounters.systemModulesTime.addElapsedTimeFrom(t0);
125
126
127 long t1 = System.nanoTime();
128
129 // Once we have the system modules then we define the base module to
130 // the VM. We do this here so that java.base is defined as early as
131 // possible and also that resources in the base module can be located
132 // for error messages that may happen from here on.
133 ModuleReference base = systemModules.find(JAVA_BASE).orElse(null);
134 if (base == null)
135 throw new InternalError(JAVA_BASE + " not found");
136 URI baseUri = base.location().orElse(null);
137 if (baseUri == null)
138 throw new InternalError(JAVA_BASE + " does not have a location");
139 BootLoader.loadModule(base);
140 Modules.defineModule(null, base.descriptor(), baseUri);
141
142 PerfCounters.defineBaseTime.addElapsedTimeFrom(t1);
143
144
145 long t2 = System.nanoTime();
146
147 // --upgrade-module-path option specified to launcher
148 ModuleFinder upgradeModulePath
149 = createModulePathFinder("jdk.module.upgrade.path");
150 if (upgradeModulePath != null)
151 systemModules = ModuleFinder.compose(upgradeModulePath, systemModules);
152
153 // --module-path option specified to the launcher
154 ModuleFinder appModulePath = createModulePathFinder("jdk.module.path");
155
156 // The module finder: [--upgrade-module-path] system [--module-path]
157 ModuleFinder finder = systemModules;
158 if (appModulePath != null)
159 finder = ModuleFinder.compose(finder, appModulePath);
160
161 // The root modules to resolve
162 Set<String> roots = new HashSet<>();
163
164 // launcher -m option to specify the main/initial module
165 String mainModule = System.getProperty("jdk.module.main");
166 if (mainModule != null)
167 roots.add(mainModule);
168
169 // additional module(s) specified by --add-modules
170 boolean addAllDefaultModules = false;
171 boolean addAllSystemModules = false;
172 boolean addAllApplicationModules = false;
173 for (String mod: getExtraAddModules()) {
174 switch (mod) {
175 case ALL_DEFAULT:
176 addAllDefaultModules = true;
177 break;
178 case ALL_SYSTEM:
179 addAllSystemModules = true;
180 break;
181 case ALL_MODULE_PATH:
182 addAllApplicationModules = true;
183 break;
184 default :
185 roots.add(mod);
186 }
187 }
188
189 // --limit-modules
190 String propValue = getAndRemoveProperty("jdk.module.limitmods");
191 if (propValue != null) {
192 Set<String> mods = new HashSet<>();
193 for (String mod: propValue.split(",")) {
194 mods.add(mod);
195 }
196 finder = limitFinder(finder, mods, roots);
197 }
198
199 // If there is no initial module specified then assume that the initial
200 // module is the unnamed module of the application class loader. This
201 // is implemented by resolving "java.se" and all (non-java.*) modules
202 // that export an API. If "java.se" is not observable then all java.*
203 // modules are resolved. Modules that have the DO_NOT_RESOLVE_BY_DEFAULT
204 // bit set in their ModuleResolution attribute flags are excluded from
205 // the detault set of roots.
206 if (mainModule == null || addAllDefaultModules) {
207 boolean hasJava = false;
208 if (systemModules.find(JAVA_SE).isPresent()) {
209 // java.se is a system module
210 if (finder == systemModules || finder.find(JAVA_SE).isPresent()) {
211 // java.se is observable
212 hasJava = true;
213 roots.add(JAVA_SE);
214 }
215 }
216
217 for (ModuleReference mref : systemModules.findAll()) {
218 ModuleDescriptor descriptor = mref.descriptor();
219 String mn = descriptor.name();
220 if (hasJava && mn.startsWith("java."))
221 continue;
222
223 if (JLMA.doNotResolveByDefault(descriptor)) {
224 continue;
225 }
226
227 // add as root if observable and exports at least one package
228 if ((finder == systemModules || finder.find(mn).isPresent())) {
229 for (ModuleDescriptor.Exports e : descriptor.exports()) {
230 if (!e.isQualified()) {
231 roots.add(mn);
232 break;
233 }
234 }
235 }
236 }
237 }
238
239 // If `--add-modules ALL-SYSTEM` is specified then all observable system
240 // modules will be resolved.
241 if (addAllSystemModules) {
242 ModuleFinder f = finder; // observable modules
243 systemModules.findAll()
244 .stream()
245 .map(ModuleReference::descriptor)
246 .filter(md -> !JLMA.doNotResolveByDefault(md))
247 .map(ModuleDescriptor::name)
248 .filter(mn -> f.find(mn).isPresent()) // observable
249 .forEach(mn -> roots.add(mn));
250 }
251
252 // If `--add-modules ALL-MODULE-PATH` is specified then all observable
253 // modules on the application module path will be resolved.
254 if (appModulePath != null && addAllApplicationModules) {
255 ModuleFinder f = finder; // observable modules
256 appModulePath.findAll()
257 .stream()
258 .map(ModuleReference::descriptor)
259 .map(ModuleDescriptor::name)
260 .filter(mn -> f.find(mn).isPresent()) // observable
261 .forEach(mn -> roots.add(mn));
262 }
263
264 PerfCounters.optionsAndRootsTime.addElapsedTimeFrom(t2);
265
266
267 long t3 = System.nanoTime();
268
269 // determine if post resolution checks are needed
270 boolean needPostResolutionChecks = true;
271 if (baseUri.getScheme().equals("jrt") // toLowerCase not needed here
272 && (upgradeModulePath == null)
273 && (appModulePath == null)
274 && (patcher.isEmpty())) {
275 needPostResolutionChecks = false;
276 }
277
278 PrintStream traceOutput = null;
279 if (Boolean.getBoolean("jdk.launcher.traceResolver"))
280 traceOutput = System.out;
281
282 // run the resolver to create the configuration
283 Configuration cf = SharedSecrets.getJavaLangModuleAccess()
284 .resolveRequiresAndUses(finder,
285 roots,
286 needPostResolutionChecks,
287 traceOutput);
288
289 // time to create configuration
290 PerfCounters.resolveTime.addElapsedTimeFrom(t3);
291
292 // issue a warning for any incubator modules in the configuration
293 String incubating = null;
294 for (ResolvedModule rm : cf.modules()) {
295 ModuleDescriptor descriptor = rm.reference().descriptor();
296 if (JLMA.warnIfResolvedReason(descriptor) == INCUBATING)
297 if (incubating == null)
298 incubating = descriptor.name();
299 else
300 incubating += ", " + descriptor.name();
301 }
302
303 if (incubating != null)
304 warn("using incubating module(s): " + incubating);
305
306 // mapping of modules to class loaders
307 Function<String, ClassLoader> clf = ModuleLoaderMap.mappingFunction(cf);
308
309 // check that all modules to be mapped to the boot loader will be
310 // loaded from the runtime image
311 if (needPostResolutionChecks) {
312 for (ResolvedModule resolvedModule : cf.modules()) {
313 ModuleReference mref = resolvedModule.reference();
314 String name = mref.descriptor().name();
315 ClassLoader cl = clf.apply(name);
316 if (cl == null) {
317
318 if (upgradeModulePath != null
319 && upgradeModulePath.find(name).isPresent())
320 fail(name + ": cannot be loaded from upgrade module path");
321
322 if (!systemModules.find(name).isPresent())
323 fail(name + ": cannot be loaded from application module path");
324 }
325 }
326 }
327
328
329 long t4 = System.nanoTime();
330
331 // define modules to VM/runtime
332 Layer bootLayer = Layer.empty().defineModules(cf, clf);
333
334 PerfCounters.layerCreateTime.addElapsedTimeFrom(t4);
335
336
337 long t5 = System.nanoTime();
338
339 // define the module to its class loader, except java.base
340 for (ResolvedModule resolvedModule : cf.modules()) {
341 ModuleReference mref = resolvedModule.reference();
342 String name = mref.descriptor().name();
343 ClassLoader cl = clf.apply(name);
344 if (cl == null) {
345 if (!name.equals(JAVA_BASE)) BootLoader.loadModule(mref);
346 } else {
347 ((BuiltinClassLoader)cl).loadModule(mref);
348 }
349 }
350
351 PerfCounters.loadModulesTime.addElapsedTimeFrom(t5);
352
353
354 // --add-reads, -add-exports/-add-opens
355 addExtraReads(bootLayer);
356 addExtraExportsAndOpens(bootLayer);
357
358 // total time to initialize
359 PerfCounters.bootstrapTime.addElapsedTimeFrom(t0);
360
361 // remember the ModuleFinder
362 initialFinder = finder;
363
364 return bootLayer;
365 }
366
367 /**
368 * Returns a ModuleFinder that limits observability to the given root
369 * modules, their transitive dependences, plus a set of other modules.
370 */
371 private static ModuleFinder limitFinder(ModuleFinder finder,
372 Set<String> roots,
373 Set<String> otherMods)
374 {
375 // resolve all root modules
376 Configuration cf = Configuration.empty()
377 .resolveRequires(finder,
378 ModuleFinder.of(),
379 roots);
380
381 // module name -> reference
382 Map<String, ModuleReference> map = new HashMap<>();
383
384 // root modules and their transitive dependences
385 cf.modules().stream()
386 .map(ResolvedModule::reference)
387 .forEach(mref -> map.put(mref.descriptor().name(), mref));
388
389 // additional modules
390 otherMods.stream()
391 .map(finder::find)
392 .flatMap(Optional::stream)
393 .forEach(mref -> map.putIfAbsent(mref.descriptor().name(), mref));
394
395 // set of modules that are observable
396 Set<ModuleReference> mrefs = new HashSet<>(map.values());
397
398 return new ModuleFinder() {
399 @Override
400 public Optional<ModuleReference> find(String name) {
401 return Optional.ofNullable(map.get(name));
402 }
403 @Override
404 public Set<ModuleReference> findAll() {
405 return mrefs;
406 }
407 };
408 }
409
410 /**
411 * Creates a finder from the module path that is the value of the given
412 * system property.
413 */
414 private static ModuleFinder createModulePathFinder(String prop) {
415 String s = System.getProperty(prop);
416 if (s == null) {
417 return null;
418 } else {
419 String[] dirs = s.split(File.pathSeparator);
420 Path[] paths = new Path[dirs.length];
421 int i = 0;
422 for (String dir: dirs) {
423 paths[i++] = Paths.get(dir);
424 }
425 return ModuleFinder.of(paths);
426 }
427 }
428
429
430 /**
431 * Initialize the module patcher for the initial configuration passed on the
432 * value of the --patch-module options.
433 */
434 private static ModulePatcher initModulePatcher() {
435 Map<String, List<String>> map = decode("jdk.module.patch.",
436 File.pathSeparator,
437 false);
438 return new ModulePatcher(map);
439 }
440
441 /**
442 * Returns the set of module names specified via --add-modules options
443 * on the command line
444 */
445 private static Set<String> getExtraAddModules() {
446 String prefix = "jdk.module.addmods.";
447 int index = 0;
448
449 // the system property is removed after decoding
450 String value = getAndRemoveProperty(prefix + index);
451 if (value == null) {
452 return Collections.emptySet();
453 }
454
455 Set<String> modules = new HashSet<>();
456 while (value != null) {
457 for (String s : value.split(",")) {
458 if (s.length() > 0) modules.add(s);
459 }
460 index++;
461 value = getAndRemoveProperty(prefix + index);
462 }
463
464 return modules;
465 }
466
467 /**
468 * Process the --add-reads options to add any additional read edges that
469 * are specified on the command-line.
470 */
471 private static void addExtraReads(Layer bootLayer) {
472
473 // decode the command line options
474 Map<String, List<String>> map = decode("jdk.module.addreads.");
475 if (map.isEmpty())
476 return;
477
478 for (Map.Entry<String, List<String>> e : map.entrySet()) {
479
480 // the key is $MODULE
481 String mn = e.getKey();
482 Optional<Module> om = bootLayer.findModule(mn);
483 if (!om.isPresent()) {
484 warn("Unknown module: " + mn);
485 continue;
486 }
487 Module m = om.get();
488
489 // the value is the set of other modules (by name)
490 for (String name : e.getValue()) {
491 if (ALL_UNNAMED.equals(name)) {
492 Modules.addReadsAllUnnamed(m);
493 } else {
494 om = bootLayer.findModule(name);
495 if (om.isPresent()) {
496 Modules.addReads(m, om.get());
497 } else {
498 warn("Unknown module: " + name);
499 }
500 }
501 }
502 }
503 }
504
505 /**
506 * Process the --add-exports and --add-opens options to export/open
507 * additional packages specified on the command-line.
508 */
509 private static void addExtraExportsAndOpens(Layer bootLayer) {
510
511 // --add-exports
512 String prefix = "jdk.module.addexports.";
513 Map<String, List<String>> extraExports = decode(prefix);
514 if (!extraExports.isEmpty()) {
515 addExtraExportsOrOpens(bootLayer, extraExports, false);
516 }
517
518 // --add-opens
519 prefix = "jdk.module.addopens.";
520 Map<String, List<String>> extraOpens = decode(prefix);
521 if (!extraOpens.isEmpty()) {
522 addExtraExportsOrOpens(bootLayer, extraOpens, true);
523 }
524 }
525
526 private static void addExtraExportsOrOpens(Layer bootLayer,
527 Map<String, List<String>> map,
528 boolean opens)
529 {
530 for (Map.Entry<String, List<String>> e : map.entrySet()) {
531
532 // the key is $MODULE/$PACKAGE
533 String key = e.getKey();
534 String[] s = key.split("/");
535 if (s.length != 2)
536 fail("Unable to parse: " + key);
537
538 String mn = s[0];
539 String pn = s[1];
540 if (mn.isEmpty() || pn.isEmpty())
541 fail("Module and package name must be specified:" + key);
542
543 // The exporting module is in the boot layer
544 Module m;
545 Optional<Module> om = bootLayer.findModule(mn);
546 if (!om.isPresent()) {
547 warn("Unknown module: " + mn);
548 continue;
549 }
550
551 m = om.get();
552
553 if (!m.getDescriptor().packages().contains(pn)) {
554 warn("package " + pn + " not in " + mn);
555 continue;
556 }
557
558 // the value is the set of modules to export to (by name)
559 for (String name : e.getValue()) {
560 boolean allUnnamed = false;
561 Module other = null;
562 if (ALL_UNNAMED.equals(name)) {
563 allUnnamed = true;
564 } else {
565 om = bootLayer.findModule(name);
566 if (om.isPresent()) {
567 other = om.get();
568 } else {
569 warn("Unknown module: " + name);
570 continue;
571 }
572 }
573 if (allUnnamed) {
574 if (opens) {
575 Modules.addOpensToAllUnnamed(m, pn);
576 } else {
577 Modules.addExportsToAllUnnamed(m, pn);
578 }
579 } else {
580 if (opens) {
581 Modules.addOpens(m, pn, other);
582 } else {
583 Modules.addExports(m, pn, other);
584 }
585 }
586
587 }
588 }
589 }
590
591 /**
592 * Decodes the values of --add-reads, -add-exports, --add-opens or
593 * --patch-modules options that are encoded in system properties.
594 *
595 * @param prefix the system property prefix
596 * @praam regex the regex for splitting the RHS of the option value
597 */
598 private static Map<String, List<String>> decode(String prefix,
599 String regex,
600 boolean allowDuplicates) {
601 int index = 0;
602 // the system property is removed after decoding
603 String value = getAndRemoveProperty(prefix + index);
604 if (value == null)
605 return Collections.emptyMap();
606
607 Map<String, List<String>> map = new HashMap<>();
608
609 while (value != null) {
610
611 int pos = value.indexOf('=');
612 if (pos == -1)
613 fail("Unable to parse: " + value);
614 if (pos == 0)
615 fail("Missing module name in: " + value);
616
617 // key is <module> or <module>/<package>
618 String key = value.substring(0, pos);
619
620 String rhs = value.substring(pos+1);
621 if (rhs.isEmpty())
622 fail("Unable to parse: " + value);
623
624 // value is <module>(,<module>)* or <file>(<pathsep><file>)*
625 if (!allowDuplicates && map.containsKey(key))
626 fail(key + " specified more than once");
627 List<String> values = map.computeIfAbsent(key, k -> new ArrayList<>());
628 for (String s : rhs.split(regex)) {
629 if (s.length() > 0) values.add(s);
630 }
631
632 index++;
633 value = getAndRemoveProperty(prefix + index);
634 }
635
636 return map;
637 }
638
639 /**
640 * Decodes the values of --add-reads, -add-exports or --add-opens
641 * which use the "," to separate the RHS of the option value.
642 */
643 private static Map<String, List<String>> decode(String prefix) {
644 return decode(prefix, ",", true);
645 }
646
647 /**
648 * Gets and remove the named system property
649 */
650 private static String getAndRemoveProperty(String key) {
651 return (String)System.getProperties().remove(key);
652 }
653
654 /**
655 * Throws a RuntimeException with the given message
656 */
657 static void fail(String m) {
658 throw new RuntimeException(m);
659 }
660
661 static void warn(String m) {
662 System.err.println("WARNING: " + m);
663 }
664
665 static class PerfCounters {
666
667 static PerfCounter systemModulesTime
668 = PerfCounter.newPerfCounter("jdk.module.bootstrap.systemModulesTime");
669 static PerfCounter defineBaseTime
670 = PerfCounter.newPerfCounter("jdk.module.bootstrap.defineBaseTime");
671 static PerfCounter optionsAndRootsTime
672 = PerfCounter.newPerfCounter("jdk.module.bootstrap.optionsAndRootsTime");
673 static PerfCounter resolveTime
674 = PerfCounter.newPerfCounter("jdk.module.bootstrap.resolveTime");
675 static PerfCounter layerCreateTime
676 = PerfCounter.newPerfCounter("jdk.module.bootstrap.layerCreateTime");
677 static PerfCounter loadModulesTime
678 = PerfCounter.newPerfCounter("jdk.module.bootstrap.loadModulesTime");
679 static PerfCounter bootstrapTime
680 = PerfCounter.newPerfCounter("jdk.module.bootstrap.totalTime");
681 }
682 }