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.SharedSecrets;
53 import jdk.internal.perf.PerfCounter;
54
55 /**
56 * Initializes/boots the module system.
57 *
58 * The {@link #boot() boot} method is called early in the startup to initialize
59 * the module system. In summary, the boot method creates a Configuration by
60 * resolving a set of module names specified via the launcher (or equivalent)
61 * -m and --add-modules options. The modules are located on a module path that
62 * is constructed from the upgrade module path, system modules, and application
63 * module path. The Configuration is instantiated as the boot Layer with each
64 * module in the the configuration defined to one of the built-in class loaders.
65 */
66
67 public final class ModuleBootstrap {
68 private ModuleBootstrap() { }
69
70 private static final String JAVA_BASE = "java.base";
71
72 private static final String JAVA_SE = "java.se";
73
74 // the token for "all default modules"
75 private static final String ALL_DEFAULT = "ALL-DEFAULT";
76
77 // the token for "all unnamed modules"
78 private static final String ALL_UNNAMED = "ALL-UNNAMED";
79
80 // the token for "all system modules"
81 private static final String ALL_SYSTEM = "ALL-SYSTEM";
82
83 // the token for "all modules on the module path"
84 private static final String ALL_MODULE_PATH = "ALL-MODULE-PATH";
85
86 // The ModulePatcher for the initial configuration
87 private static final ModulePatcher patcher = initModulePatcher();
88
89 // ModuleFinder for the initial configuration
90 private static ModuleFinder initialFinder;
91
92 /**
93 * Returns the ModulePatcher for the initial configuration.
94 */
95 public static ModulePatcher patcher() {
96 return patcher;
97 }
98
99 /**
100 * Returns the ModuleFinder for the initial configuration
101 */
102 public static ModuleFinder finder() {
103 assert initialFinder != null;
104 return initialFinder;
105 }
106
107 /**
108 * Initialize the module system, returning the boot Layer.
109 *
110 * @see java.lang.System#initPhase2()
111 */
112 public static Layer boot() {
113
114 long t0 = System.nanoTime();
115
116 // system modules (may be patched)
117 ModuleFinder systemModules = ModuleFinder.ofSystem();
118
119 PerfCounters.systemModulesTime.addElapsedTimeFrom(t0);
120
121
122 long t1 = System.nanoTime();
123
124 // Once we have the system modules then we define the base module to
125 // the VM. We do this here so that java.base is defined as early as
126 // possible and also that resources in the base module can be located
127 // for error messages that may happen from here on.
128 ModuleReference base = systemModules.find(JAVA_BASE).orElse(null);
129 if (base == null)
130 throw new InternalError(JAVA_BASE + " not found");
131 URI baseUri = base.location().orElse(null);
132 if (baseUri == null)
133 throw new InternalError(JAVA_BASE + " does not have a location");
134 BootLoader.loadModule(base);
135 Modules.defineModule(null, base.descriptor(), baseUri);
136
137 PerfCounters.defineBaseTime.addElapsedTimeFrom(t1);
138
139
140 long t2 = System.nanoTime();
141
142 // --upgrade-module-path option specified to launcher
143 ModuleFinder upgradeModulePath
144 = createModulePathFinder("jdk.module.upgrade.path");
145 if (upgradeModulePath != null)
146 systemModules = ModuleFinder.compose(upgradeModulePath, systemModules);
147
148 // --module-path option specified to the launcher
149 ModuleFinder appModulePath = createModulePathFinder("jdk.module.path");
150
151 // The module finder: [--upgrade-module-path] system [--module-path]
152 ModuleFinder finder = systemModules;
153 if (appModulePath != null)
154 finder = ModuleFinder.compose(finder, appModulePath);
155
156 // The root modules to resolve
157 Set<String> roots = new HashSet<>();
158
159 // launcher -m option to specify the main/initial module
160 String mainModule = System.getProperty("jdk.module.main");
161 if (mainModule != null)
162 roots.add(mainModule);
163
164 // additional module(s) specified by --add-modules
165 boolean addAllDefaultModules = false;
166 boolean addAllSystemModules = false;
167 boolean addAllApplicationModules = false;
168 for (String mod: getExtraAddModules()) {
169 switch (mod) {
170 case ALL_DEFAULT:
171 addAllDefaultModules = true;
172 break;
173 case ALL_SYSTEM:
174 addAllSystemModules = true;
175 break;
176 case ALL_MODULE_PATH:
177 addAllApplicationModules = true;
178 break;
179 default :
180 roots.add(mod);
181 }
182 }
183
184 // --limit-modules
185 String propValue = getAndRemoveProperty("jdk.module.limitmods");
186 if (propValue != null) {
187 Set<String> mods = new HashSet<>();
188 for (String mod: propValue.split(",")) {
189 mods.add(mod);
190 }
191 finder = limitFinder(finder, mods, roots);
192 }
193
194 // If there is no initial module specified then assume that the initial
195 // module is the unnamed module of the application class loader. This
196 // is implemented by resolving "java.se" and all (non-java.*) modules
197 // that export an API. If "java.se" is not observable then all java.*
198 // modules are resolved. Modules that have the DO_NOT_RESOLVE_BY_DEFAULT
199 // bit set in their ModuleResolution attribute flags are excluded from
200 // the default set of roots.
201 if (mainModule == null || addAllDefaultModules) {
202 boolean hasJava = false;
203 if (systemModules.find(JAVA_SE).isPresent()) {
204 // java.se is a system module
205 if (finder == systemModules || finder.find(JAVA_SE).isPresent()) {
206 // java.se is observable
207 hasJava = true;
208 roots.add(JAVA_SE);
209 }
210 }
211
212 for (ModuleReference mref : systemModules.findAll()) {
213 String mn = mref.descriptor().name();
214 if (hasJava && mn.startsWith("java."))
215 continue;
216
217 if (ModuleResolution.doNotResolveByDefault(mref))
218 continue;
219
220 // add as root if observable and exports at least one package
221 if ((finder == systemModules || finder.find(mn).isPresent())) {
222 ModuleDescriptor descriptor = mref.descriptor();
223 for (ModuleDescriptor.Exports e : descriptor.exports()) {
224 if (!e.isQualified()) {
225 roots.add(mn);
226 break;
227 }
228 }
229 }
230 }
231 }
232
233 // If `--add-modules ALL-SYSTEM` is specified then all observable system
234 // modules will be resolved.
235 if (addAllSystemModules) {
236 ModuleFinder f = finder; // observable modules
237 systemModules.findAll()
238 .stream()
239 .filter(mref -> !ModuleResolution.doNotResolveByDefault(mref))
240 .map(ModuleReference::descriptor)
241 .map(ModuleDescriptor::name)
242 .filter(mn -> f.find(mn).isPresent()) // observable
243 .forEach(mn -> roots.add(mn));
244 }
245
246 // If `--add-modules ALL-MODULE-PATH` is specified then all observable
247 // modules on the application module path will be resolved.
248 if (appModulePath != null && addAllApplicationModules) {
249 ModuleFinder f = finder; // observable modules
250 appModulePath.findAll()
251 .stream()
252 .map(ModuleReference::descriptor)
253 .map(ModuleDescriptor::name)
254 .filter(mn -> f.find(mn).isPresent()) // observable
255 .forEach(mn -> roots.add(mn));
256 }
257
258 PerfCounters.optionsAndRootsTime.addElapsedTimeFrom(t2);
259
260
261 long t3 = System.nanoTime();
262
263 // determine if post resolution checks are needed
264 boolean needPostResolutionChecks = true;
265 if (baseUri.getScheme().equals("jrt") // toLowerCase not needed here
266 && (upgradeModulePath == null)
267 && (appModulePath == null)
268 && (patcher.isEmpty())) {
269 needPostResolutionChecks = false;
270 }
271
272 PrintStream traceOutput = null;
273 if (Boolean.getBoolean("jdk.launcher.traceResolver"))
274 traceOutput = System.out;
275
276 // run the resolver to create the configuration
277 Configuration cf = SharedSecrets.getJavaLangModuleAccess()
278 .resolveRequiresAndUses(finder,
279 roots,
280 needPostResolutionChecks,
281 traceOutput);
282
283 // time to create configuration
284 PerfCounters.resolveTime.addElapsedTimeFrom(t3);
285
286 // check module names and incubating status
287 checkModuleNamesAndStatus(cf);
288
289 // mapping of modules to class loaders
290 Function<String, ClassLoader> clf = ModuleLoaderMap.mappingFunction(cf);
291
292 // check that all modules to be mapped to the boot loader will be
293 // loaded from the runtime image
294 if (needPostResolutionChecks) {
295 for (ResolvedModule resolvedModule : cf.modules()) {
296 ModuleReference mref = resolvedModule.reference();
297 String name = mref.descriptor().name();
298 ClassLoader cl = clf.apply(name);
299 if (cl == null) {
300
301 if (upgradeModulePath != null
302 && upgradeModulePath.find(name).isPresent())
303 fail(name + ": cannot be loaded from upgrade module path");
304
305 if (!systemModules.find(name).isPresent())
306 fail(name + ": cannot be loaded from application module path");
307 }
308 }
309 }
310
311
312 long t4 = System.nanoTime();
313
314 // define modules to VM/runtime
315 Layer bootLayer = Layer.empty().defineModules(cf, clf);
316
317 PerfCounters.layerCreateTime.addElapsedTimeFrom(t4);
318
319
320 long t5 = System.nanoTime();
321
322 // define the module to its class loader, except java.base
323 for (ResolvedModule resolvedModule : cf.modules()) {
324 ModuleReference mref = resolvedModule.reference();
325 String name = mref.descriptor().name();
326 ClassLoader cl = clf.apply(name);
327 if (cl == null) {
328 if (!name.equals(JAVA_BASE)) BootLoader.loadModule(mref);
329 } else {
330 ((BuiltinClassLoader)cl).loadModule(mref);
331 }
332 }
333
334 PerfCounters.loadModulesTime.addElapsedTimeFrom(t5);
335
336
337 // --add-reads, -add-exports/-add-opens
338 addExtraReads(bootLayer);
339 addExtraExportsAndOpens(bootLayer);
340
341 // total time to initialize
342 PerfCounters.bootstrapTime.addElapsedTimeFrom(t0);
343
344 // remember the ModuleFinder
345 initialFinder = finder;
346
347 return bootLayer;
348 }
349
350 /**
351 * Returns a ModuleFinder that limits observability to the given root
352 * modules, their transitive dependences, plus a set of other modules.
353 */
354 private static ModuleFinder limitFinder(ModuleFinder finder,
355 Set<String> roots,
356 Set<String> otherMods)
357 {
358 // resolve all root modules
359 Configuration cf = Configuration.empty()
360 .resolveRequires(finder,
361 ModuleFinder.of(),
362 roots);
363
364 // module name -> reference
365 Map<String, ModuleReference> map = new HashMap<>();
366
367 // root modules and their transitive dependences
368 cf.modules().stream()
369 .map(ResolvedModule::reference)
370 .forEach(mref -> map.put(mref.descriptor().name(), mref));
371
372 // additional modules
373 otherMods.stream()
374 .map(finder::find)
375 .flatMap(Optional::stream)
376 .forEach(mref -> map.putIfAbsent(mref.descriptor().name(), mref));
377
378 // set of modules that are observable
379 Set<ModuleReference> mrefs = new HashSet<>(map.values());
380
381 return new ModuleFinder() {
382 @Override
383 public Optional<ModuleReference> find(String name) {
384 return Optional.ofNullable(map.get(name));
385 }
386 @Override
387 public Set<ModuleReference> findAll() {
388 return mrefs;
389 }
390 };
391 }
392
393 /**
394 * Creates a finder from the module path that is the value of the given
395 * system property.
396 */
397 private static ModuleFinder createModulePathFinder(String prop) {
398 String s = System.getProperty(prop);
399 if (s == null) {
400 return null;
401 } else {
402 String[] dirs = s.split(File.pathSeparator);
403 Path[] paths = new Path[dirs.length];
404 int i = 0;
405 for (String dir: dirs) {
406 paths[i++] = Paths.get(dir);
407 }
408 return ModuleFinder.of(paths);
409 }
410 }
411
412
413 /**
414 * Initialize the module patcher for the initial configuration passed on the
415 * value of the --patch-module options.
416 */
417 private static ModulePatcher initModulePatcher() {
418 Map<String, List<String>> map = decode("jdk.module.patch.",
419 File.pathSeparator,
420 false);
421 return new ModulePatcher(map);
422 }
423
424 /**
425 * Returns the set of module names specified via --add-modules options
426 * on the command line
427 */
428 private static Set<String> getExtraAddModules() {
429 String prefix = "jdk.module.addmods.";
430 int index = 0;
431
432 // the system property is removed after decoding
433 String value = getAndRemoveProperty(prefix + index);
434 if (value == null) {
435 return Collections.emptySet();
436 }
437
438 Set<String> modules = new HashSet<>();
439 while (value != null) {
440 for (String s : value.split(",")) {
441 if (s.length() > 0) modules.add(s);
442 }
443 index++;
444 value = getAndRemoveProperty(prefix + index);
445 }
446
447 return modules;
448 }
449
450 /**
451 * Process the --add-reads options to add any additional read edges that
452 * are specified on the command-line.
453 */
454 private static void addExtraReads(Layer bootLayer) {
455
456 // decode the command line options
457 Map<String, List<String>> map = decode("jdk.module.addreads.");
458 if (map.isEmpty())
459 return;
460
461 for (Map.Entry<String, List<String>> e : map.entrySet()) {
462
463 // the key is $MODULE
464 String mn = e.getKey();
465 Optional<Module> om = bootLayer.findModule(mn);
466 if (!om.isPresent()) {
467 warn("Unknown module: " + mn);
468 continue;
469 }
470 Module m = om.get();
471
472 // the value is the set of other modules (by name)
473 for (String name : e.getValue()) {
474 if (ALL_UNNAMED.equals(name)) {
475 Modules.addReadsAllUnnamed(m);
476 } else {
477 om = bootLayer.findModule(name);
478 if (om.isPresent()) {
479 Modules.addReads(m, om.get());
480 } else {
481 warn("Unknown module: " + name);
482 }
483 }
484 }
485 }
486 }
487
488 /**
489 * Process the --add-exports and --add-opens options to export/open
490 * additional packages specified on the command-line.
491 */
492 private static void addExtraExportsAndOpens(Layer bootLayer) {
493
494 // --add-exports
495 String prefix = "jdk.module.addexports.";
496 Map<String, List<String>> extraExports = decode(prefix);
497 if (!extraExports.isEmpty()) {
498 addExtraExportsOrOpens(bootLayer, extraExports, false);
499 }
500
501 // --add-opens
502 prefix = "jdk.module.addopens.";
503 Map<String, List<String>> extraOpens = decode(prefix);
504 if (!extraOpens.isEmpty()) {
505 addExtraExportsOrOpens(bootLayer, extraOpens, true);
506 }
507 }
508
509 private static void addExtraExportsOrOpens(Layer bootLayer,
510 Map<String, List<String>> map,
511 boolean opens)
512 {
513 for (Map.Entry<String, List<String>> e : map.entrySet()) {
514
515 // the key is $MODULE/$PACKAGE
516 String key = e.getKey();
517 String[] s = key.split("/");
518 if (s.length != 2)
519 fail("Unable to parse as <module>/<package>: " + key);
520
521 String mn = s[0];
522 String pn = s[1];
523 if (mn.isEmpty() || pn.isEmpty())
524 fail("Module and package name must be specified: " + key);
525
526 // The exporting module is in the boot layer
527 Module m;
528 Optional<Module> om = bootLayer.findModule(mn);
529 if (!om.isPresent()) {
530 warn("Unknown module: " + mn);
531 continue;
532 }
533
534 m = om.get();
535
536 if (!m.getDescriptor().packages().contains(pn)) {
537 warn("package " + pn + " not in " + mn);
538 continue;
539 }
540
541 // the value is the set of modules to export to (by name)
542 for (String name : e.getValue()) {
543 boolean allUnnamed = false;
544 Module other = null;
545 if (ALL_UNNAMED.equals(name)) {
546 allUnnamed = true;
547 } else {
548 om = bootLayer.findModule(name);
549 if (om.isPresent()) {
550 other = om.get();
551 } else {
552 warn("Unknown module: " + name);
553 continue;
554 }
555 }
556 if (allUnnamed) {
557 if (opens) {
558 Modules.addOpensToAllUnnamed(m, pn);
559 } else {
560 Modules.addExportsToAllUnnamed(m, pn);
561 }
562 } else {
563 if (opens) {
564 Modules.addOpens(m, pn, other);
565 } else {
566 Modules.addExports(m, pn, other);
567 }
568 }
569
570 }
571 }
572 }
573
574 /**
575 * Decodes the values of --add-reads, -add-exports, --add-opens or
576 * --patch-modules options that are encoded in system properties.
577 *
578 * @param prefix the system property prefix
579 * @praam regex the regex for splitting the RHS of the option value
580 */
581 private static Map<String, List<String>> decode(String prefix,
582 String regex,
583 boolean allowDuplicates) {
584 int index = 0;
585 // the system property is removed after decoding
586 String value = getAndRemoveProperty(prefix + index);
587 if (value == null)
588 return Collections.emptyMap();
589
590 Map<String, List<String>> map = new HashMap<>();
591
592 while (value != null) {
593
594 int pos = value.indexOf('=');
595 if (pos == -1)
596 fail("Unable to parse as <module>=<value>: " + value);
597 if (pos == 0)
598 fail("Missing module name in: " + value);
599
600 // key is <module> or <module>/<package>
601 String key = value.substring(0, pos);
602
603 String rhs = value.substring(pos+1);
604 if (rhs.isEmpty())
605 fail("Unable to parse as <module>=<value>: " + value);
606
607 // value is <module>(,<module>)* or <file>(<pathsep><file>)*
608 if (!allowDuplicates && map.containsKey(key))
609 fail(key + " specified more than once");
610 List<String> values = map.computeIfAbsent(key, k -> new ArrayList<>());
611 for (String s : rhs.split(regex)) {
612 if (s.length() > 0) values.add(s);
613 }
614
615 index++;
616 value = getAndRemoveProperty(prefix + index);
617 }
618
619 return map;
620 }
621
622 /**
623 * Decodes the values of --add-reads, -add-exports or --add-opens
624 * which use the "," to separate the RHS of the option value.
625 */
626 private static Map<String, List<String>> decode(String prefix) {
627 return decode(prefix, ",", true);
628 }
629
630 /**
631 * Gets and remove the named system property
632 */
633 private static String getAndRemoveProperty(String key) {
634 return (String)System.getProperties().remove(key);
635 }
636
637 /**
638 * Checks the names and resolution bit of each module in the configuration,
639 * emitting warnings if needed.
640 */
641 private static void checkModuleNamesAndStatus(Configuration cf) {
642 String incubating = null;
643 for (ResolvedModule rm : cf.modules()) {
644 ModuleReference mref = rm.reference();
645 String mn = mref.descriptor().name();
646
647 // emit warning if module name ends with a non-Java letter
648 if (!Checks.hasLegalModuleNameLastCharacter(mn))
649 warn("Module name \"" + mn + "\" may soon be illegal");
650
651 // emit warning if the WARN_INCUBATING module resolution bit set
652 if (ModuleResolution.hasIncubatingWarning(mref)) {
653 if (incubating == null) {
654 incubating = mn;
655 } else {
656 incubating += ", " + mn;
657 }
658 }
659 }
660 if (incubating != null)
661 warn("Using incubator modules: " + incubating);
662 }
663
664 /**
665 * Throws a RuntimeException with the given message
666 */
667 static void fail(String m) {
668 throw new RuntimeException(m);
669 }
670
671 static void warn(String m) {
672 System.err.println("WARNING: " + m);
673 }
674
675 static class PerfCounters {
676
677 static PerfCounter systemModulesTime
678 = PerfCounter.newPerfCounter("jdk.module.bootstrap.systemModulesTime");
679 static PerfCounter defineBaseTime
680 = PerfCounter.newPerfCounter("jdk.module.bootstrap.defineBaseTime");
681 static PerfCounter optionsAndRootsTime
682 = PerfCounter.newPerfCounter("jdk.module.bootstrap.optionsAndRootsTime");
683 static PerfCounter resolveTime
684 = PerfCounter.newPerfCounter("jdk.module.bootstrap.resolveTime");
685 static PerfCounter layerCreateTime
686 = PerfCounter.newPerfCounter("jdk.module.bootstrap.layerCreateTime");
687 static PerfCounter loadModulesTime
688 = PerfCounter.newPerfCounter("jdk.module.bootstrap.loadModulesTime");
689 static PerfCounter bootstrapTime
690 = PerfCounter.newPerfCounter("jdk.module.bootstrap.totalTime");
691 }
692 }