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.IOException;
30 import java.io.PrintStream;
31 import java.io.UncheckedIOException;
32 import java.lang.module.Configuration;
33 import java.lang.module.ModuleDescriptor;
34 import java.lang.module.ModuleFinder;
35 import java.lang.module.ModuleReference;
36 import java.lang.module.ResolvedModule;
37 import java.lang.reflect.Layer;
38 import java.lang.reflect.Module;
39 import java.net.URI;
40 import java.nio.file.Files;
41 import java.nio.file.Path;
42 import java.nio.file.Paths;
43 import java.util.ArrayList;
44 import java.util.Collections;
45 import java.util.HashMap;
46 import java.util.HashSet;
47 import java.util.List;
48 import java.util.Map;
49 import java.util.Optional;
50 import java.util.Set;
51 import java.util.function.Function;
52 import java.util.stream.Stream;
53
54 import jdk.internal.loader.BootLoader;
55 import jdk.internal.loader.BuiltinClassLoader;
56 import jdk.internal.misc.SharedSecrets;
57 import jdk.internal.perf.PerfCounter;
58 import jdk.internal.reflect.Reflection;
59
60 /**
61 * Initializes/boots the module system.
62 *
63 * The {@link #boot() boot} method is called early in the startup to initialize
64 * the module system. In summary, the boot method creates a Configuration by
65 * resolving a set of module names specified via the launcher (or equivalent)
66 * -m and --add-modules options. The modules are located on a module path that
67 * is constructed from the upgrade module path, system modules, and application
68 * module path. The Configuration is instantiated as the boot Layer with each
69 * module in the the configuration defined to one of the built-in class loaders.
70 */
71
72 public final class ModuleBootstrap {
73 private ModuleBootstrap() { }
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 default 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 String mn = mref.descriptor().name();
219 if (hasJava && mn.startsWith("java."))
220 continue;
221
222 if (ModuleResolution.doNotResolveByDefault(mref))
223 continue;
224
225 // add as root if observable and exports at least one package
226 if ((finder == systemModules || finder.find(mn).isPresent())) {
227 ModuleDescriptor descriptor = mref.descriptor();
228 for (ModuleDescriptor.Exports e : descriptor.exports()) {
229 if (!e.isQualified()) {
230 roots.add(mn);
231 break;
232 }
233 }
234 }
235 }
236 }
237
238 // If `--add-modules ALL-SYSTEM` is specified then all observable system
239 // modules will be resolved.
240 if (addAllSystemModules) {
241 ModuleFinder f = finder; // observable modules
242 systemModules.findAll()
243 .stream()
244 .filter(mref -> !ModuleResolution.doNotResolveByDefault(mref))
245 .map(ModuleReference::descriptor)
246 .map(ModuleDescriptor::name)
247 .filter(mn -> f.find(mn).isPresent()) // observable
248 .forEach(mn -> roots.add(mn));
249 }
250
251 // If `--add-modules ALL-MODULE-PATH` is specified then all observable
252 // modules on the application module path will be resolved.
253 if (appModulePath != null && addAllApplicationModules) {
254 ModuleFinder f = finder; // observable modules
255 appModulePath.findAll()
256 .stream()
257 .map(ModuleReference::descriptor)
258 .map(ModuleDescriptor::name)
259 .filter(mn -> f.find(mn).isPresent()) // observable
260 .forEach(mn -> roots.add(mn));
261 }
262
263 PerfCounters.optionsAndRootsTime.addElapsedTimeFrom(t2);
264
265
266 long t3 = System.nanoTime();
267
268 // determine if post resolution checks are needed
269 boolean needPostResolutionChecks = true;
270 if (baseUri.getScheme().equals("jrt") // toLowerCase not needed here
271 && (upgradeModulePath == null)
272 && (appModulePath == null)
273 && (patcher.isEmpty())) {
274 needPostResolutionChecks = false;
275 }
276
277 PrintStream traceOutput = null;
278 if (Boolean.getBoolean("jdk.launcher.traceResolver"))
279 traceOutput = System.out;
280
281 // run the resolver to create the configuration
282 Configuration cf = SharedSecrets.getJavaLangModuleAccess()
283 .resolveRequiresAndUses(finder,
284 roots,
285 needPostResolutionChecks,
286 traceOutput);
287
288 // time to create configuration
289 PerfCounters.resolveTime.addElapsedTimeFrom(t3);
290
291 // check module names and incubating status
292 checkModuleNamesAndStatus(cf);
293
294 // mapping of modules to class loaders
295 Function<String, ClassLoader> clf = ModuleLoaderMap.mappingFunction(cf);
296
297 // check that all modules to be mapped to the boot loader will be
298 // loaded from the runtime image
299 if (needPostResolutionChecks) {
300 for (ResolvedModule resolvedModule : cf.modules()) {
301 ModuleReference mref = resolvedModule.reference();
302 String name = mref.descriptor().name();
303 ClassLoader cl = clf.apply(name);
304 if (cl == null) {
305
306 if (upgradeModulePath != null
307 && upgradeModulePath.find(name).isPresent())
308 fail(name + ": cannot be loaded from upgrade module path");
309
310 if (!systemModules.find(name).isPresent())
311 fail(name + ": cannot be loaded from application module path");
312 }
313 }
314 }
315
316
317 long t4 = System.nanoTime();
318
319 // define modules to VM/runtime
320 Layer bootLayer = Layer.empty().defineModules(cf, clf);
321
322 PerfCounters.layerCreateTime.addElapsedTimeFrom(t4);
323
324
325 long t5 = System.nanoTime();
326
327 // define the module to its class loader, except java.base
328 for (ResolvedModule resolvedModule : cf.modules()) {
329 ModuleReference mref = resolvedModule.reference();
330 String name = mref.descriptor().name();
331 ClassLoader cl = clf.apply(name);
332 if (cl == null) {
333 if (!name.equals(JAVA_BASE)) BootLoader.loadModule(mref);
334 } else {
335 ((BuiltinClassLoader)cl).loadModule(mref);
336 }
337 }
338
339 PerfCounters.loadModulesTime.addElapsedTimeFrom(t5);
340
341
342 // --add-reads, -add-exports/-add-opens
343 addExtraReads(bootLayer);
344 addExtraExportsAndOpens(bootLayer);
345
346 // total time to initialize
347 PerfCounters.bootstrapTime.addElapsedTimeFrom(t0);
348
349 // remember the ModuleFinder
350 initialFinder = finder;
351
352 return bootLayer;
353 }
354
355 /**
356 * Returns a ModuleFinder that limits observability to the given root
357 * modules, their transitive dependences, plus a set of other modules.
358 */
359 private static ModuleFinder limitFinder(ModuleFinder finder,
360 Set<String> roots,
361 Set<String> otherMods)
362 {
363 // resolve all root modules
364 Configuration cf = Configuration.empty()
365 .resolveRequires(finder,
366 ModuleFinder.of(),
367 roots);
368
369 // module name -> reference
370 Map<String, ModuleReference> map = new HashMap<>();
371
372 // root modules and their transitive dependences
373 cf.modules().stream()
374 .map(ResolvedModule::reference)
375 .forEach(mref -> map.put(mref.descriptor().name(), mref));
376
377 // additional modules
378 otherMods.stream()
379 .map(finder::find)
380 .flatMap(Optional::stream)
381 .forEach(mref -> map.putIfAbsent(mref.descriptor().name(), mref));
382
383 // set of modules that are observable
384 Set<ModuleReference> mrefs = new HashSet<>(map.values());
385
386 return new ModuleFinder() {
387 @Override
388 public Optional<ModuleReference> find(String name) {
389 return Optional.ofNullable(map.get(name));
390 }
391 @Override
392 public Set<ModuleReference> findAll() {
393 return mrefs;
394 }
395 };
396 }
397
398 /**
399 * Creates a finder from the module path that is the value of the given
400 * system property.
401 */
402 private static ModuleFinder createModulePathFinder(String prop) {
403 String s = System.getProperty(prop);
404 if (s == null) {
405 return null;
406 } else {
407 String[] dirs = s.split(File.pathSeparator);
408 Path[] paths = new Path[dirs.length];
409 int i = 0;
410 for (String dir: dirs) {
411 paths[i++] = Paths.get(dir);
412 }
413 return ModuleFinder.of(paths);
414 }
415 }
416
417
418 /**
419 * Initialize the module patcher for the initial configuration passed on the
420 * value of the --patch-module options.
421 */
422 private static ModulePatcher initModulePatcher() {
423 Map<String, List<String>> map = decode("jdk.module.patch.",
424 File.pathSeparator,
425 false);
426 return new ModulePatcher(map);
427 }
428
429 /**
430 * Returns the set of module names specified via --add-modules options
431 * on the command line
432 */
433 private static Set<String> getExtraAddModules() {
434 String prefix = "jdk.module.addmods.";
435 int index = 0;
436
437 // the system property is removed after decoding
438 String value = getAndRemoveProperty(prefix + index);
439 if (value == null) {
440 return Collections.emptySet();
441 }
442
443 Set<String> modules = new HashSet<>();
444 while (value != null) {
445 for (String s : value.split(",")) {
446 if (s.length() > 0) modules.add(s);
447 }
448 index++;
449 value = getAndRemoveProperty(prefix + index);
450 }
451
452 return modules;
453 }
454
455 /**
456 * Process the --add-reads options to add any additional read edges that
457 * are specified on the command-line.
458 */
459 private static void addExtraReads(Layer bootLayer) {
460
461 // decode the command line options
462 Map<String, List<String>> map = decode("jdk.module.addreads.");
463 if (map.isEmpty())
464 return;
465
466 for (Map.Entry<String, List<String>> e : map.entrySet()) {
467
468 // the key is $MODULE
469 String mn = e.getKey();
470 Optional<Module> om = bootLayer.findModule(mn);
471 if (!om.isPresent()) {
472 warn("Unknown module: " + mn);
473 continue;
474 }
475 Module m = om.get();
476
477 // the value is the set of other modules (by name)
478 for (String name : e.getValue()) {
479 if (ALL_UNNAMED.equals(name)) {
480 Modules.addReadsAllUnnamed(m);
481 } else {
482 om = bootLayer.findModule(name);
483 if (om.isPresent()) {
484 Modules.addReads(m, om.get());
485 } else {
486 warn("Unknown module: " + name);
487 }
488 }
489 }
490 }
491 }
492
493 /**
494 * Process the --add-exports and --add-opens options to export/open
495 * additional packages specified on the command-line.
496 */
497 private static void addExtraExportsAndOpens(Layer bootLayer) {
498
499 // --add-exports
500 String prefix = "jdk.module.addexports.";
501 Map<String, List<String>> extraExports = decode(prefix);
502 if (!extraExports.isEmpty()) {
503 addExtraExportsOrOpens(bootLayer, extraExports, false);
504 }
505
506 // --add-opens
507 prefix = "jdk.module.addopens.";
508 Map<String, List<String>> extraOpens = decode(prefix);
509 if (!extraOpens.isEmpty()) {
510 addExtraExportsOrOpens(bootLayer, extraOpens, true);
511 }
512
513 // DEBUG_ADD_OPENS is for debugging purposes only
514 String home = System.getProperty("java.home");
515 Path file = Paths.get(home, "conf", "DEBUG_ADD_OPENS");
516 if (Files.exists(file)) {
517 warn(file + " detected; may break encapsulation");
518 try (Stream<String> lines = Files.lines(file)) {
519 lines.map(line -> line.trim())
520 .filter(line -> (!line.isEmpty() && !line.startsWith("#")))
521 .forEach(line -> {
522 String[] s = line.split("/");
523 if (s.length != 2) {
524 fail("Unable to parse as <module>/<package>: " + line);
525 } else {
526 String mn = s[0];
527 String pkg = s[1];
528 openPackage(bootLayer, mn, pkg);
529 }
530 });
531 } catch (IOException ioe) {
532 throw new UncheckedIOException(ioe);
533 }
534 Reflection.enableStackTraces();
535 }
536 }
537
538 private static void openPackage(Layer bootLayer, String mn, String pkg) {
539 if (mn.equals("ALL-RESOLVED") && pkg.equals("ALL-PACKAGES")) {
540 bootLayer.modules().stream().forEach(m ->
541 m.getDescriptor().packages().forEach(pn -> openPackage(m, pn)));
542 } else {
543 bootLayer.findModule(mn)
544 .filter(m -> m.getDescriptor().packages().contains(pkg))
545 .ifPresent(m -> openPackage(m, pkg));
546 }
547 }
548
549 private static void openPackage(Module m, String pn) {
550 Modules.addOpensToAllUnnamed(m, pn);
551 warn("Opened for deep reflection: " + m.getName() + "/" + pn);
552 }
553
554
555 private static void addExtraExportsOrOpens(Layer bootLayer,
556 Map<String, List<String>> map,
557 boolean opens)
558 {
559 for (Map.Entry<String, List<String>> e : map.entrySet()) {
560
561 // the key is $MODULE/$PACKAGE
562 String key = e.getKey();
563 String[] s = key.split("/");
564 if (s.length != 2)
565 fail("Unable to parse as <module>/<package>: " + key);
566
567 String mn = s[0];
568 String pn = s[1];
569 if (mn.isEmpty() || pn.isEmpty())
570 fail("Module and package name must be specified: " + key);
571
572 // The exporting module is in the boot layer
573 Module m;
574 Optional<Module> om = bootLayer.findModule(mn);
575 if (!om.isPresent()) {
576 warn("Unknown module: " + mn);
577 continue;
578 }
579
580 m = om.get();
581
582 if (!m.getDescriptor().packages().contains(pn)) {
583 warn("package " + pn + " not in " + mn);
584 continue;
585 }
586
587 // the value is the set of modules to export to (by name)
588 for (String name : e.getValue()) {
589 boolean allUnnamed = false;
590 Module other = null;
591 if (ALL_UNNAMED.equals(name)) {
592 allUnnamed = true;
593 } else {
594 om = bootLayer.findModule(name);
595 if (om.isPresent()) {
596 other = om.get();
597 } else {
598 warn("Unknown module: " + name);
599 continue;
600 }
601 }
602 if (allUnnamed) {
603 if (opens) {
604 Modules.addOpensToAllUnnamed(m, pn);
605 } else {
606 Modules.addExportsToAllUnnamed(m, pn);
607 }
608 } else {
609 if (opens) {
610 Modules.addOpens(m, pn, other);
611 } else {
612 Modules.addExports(m, pn, other);
613 }
614 }
615
616 }
617 }
618 }
619
620 /**
621 * Decodes the values of --add-reads, -add-exports, --add-opens or
622 * --patch-modules options that are encoded in system properties.
623 *
624 * @param prefix the system property prefix
625 * @praam regex the regex for splitting the RHS of the option value
626 */
627 private static Map<String, List<String>> decode(String prefix,
628 String regex,
629 boolean allowDuplicates) {
630 int index = 0;
631 // the system property is removed after decoding
632 String value = getAndRemoveProperty(prefix + index);
633 if (value == null)
634 return Collections.emptyMap();
635
636 Map<String, List<String>> map = new HashMap<>();
637
638 while (value != null) {
639
640 int pos = value.indexOf('=');
641 if (pos == -1)
642 fail("Unable to parse as <module>=<value>: " + value);
643 if (pos == 0)
644 fail("Missing module name in: " + value);
645
646 // key is <module> or <module>/<package>
647 String key = value.substring(0, pos);
648
649 String rhs = value.substring(pos+1);
650 if (rhs.isEmpty())
651 fail("Unable to parse as <module>=<value>: " + value);
652
653 // value is <module>(,<module>)* or <file>(<pathsep><file>)*
654 if (!allowDuplicates && map.containsKey(key))
655 fail(key + " specified more than once");
656 List<String> values = map.computeIfAbsent(key, k -> new ArrayList<>());
657 for (String s : rhs.split(regex)) {
658 if (s.length() > 0) values.add(s);
659 }
660
661 index++;
662 value = getAndRemoveProperty(prefix + index);
663 }
664
665 return map;
666 }
667
668 /**
669 * Decodes the values of --add-reads, -add-exports or --add-opens
670 * which use the "," to separate the RHS of the option value.
671 */
672 private static Map<String, List<String>> decode(String prefix) {
673 return decode(prefix, ",", true);
674 }
675
676 /**
677 * Gets and remove the named system property
678 */
679 private static String getAndRemoveProperty(String key) {
680 return (String)System.getProperties().remove(key);
681 }
682
683 /**
684 * Checks the names and resolution bit of each module in the configuration,
685 * emitting warnings if needed.
686 */
687 private static void checkModuleNamesAndStatus(Configuration cf) {
688 String incubating = null;
689 for (ResolvedModule rm : cf.modules()) {
690 ModuleReference mref = rm.reference();
691 String mn = mref.descriptor().name();
692
693 // emit warning if module name ends with a non-Java letter
694 //if (!Checks.hasLegalModuleNameLastCharacter(mn))
695 // warn("Module name \"" + mn + "\" may soon be illegal");
696
697 // emit warning if the WARN_INCUBATING module resolution bit set
698 if (ModuleResolution.hasIncubatingWarning(mref)) {
699 if (incubating == null) {
700 incubating = mn;
701 } else {
702 incubating += ", " + mn;
703 }
704 }
705 }
706 if (incubating != null)
707 warn("using incubating module(s): " + incubating);
708 }
709
710 /**
711 * Throws a RuntimeException with the given message
712 */
713 static void fail(String m) {
714 throw new RuntimeException(m);
715 }
716
717 static void warn(String m) {
718 System.err.println("WARNING: " + m);
719 }
720
721 static class PerfCounters {
722
723 static PerfCounter systemModulesTime
724 = PerfCounter.newPerfCounter("jdk.module.bootstrap.systemModulesTime");
725 static PerfCounter defineBaseTime
726 = PerfCounter.newPerfCounter("jdk.module.bootstrap.defineBaseTime");
727 static PerfCounter optionsAndRootsTime
728 = PerfCounter.newPerfCounter("jdk.module.bootstrap.optionsAndRootsTime");
729 static PerfCounter resolveTime
730 = PerfCounter.newPerfCounter("jdk.module.bootstrap.resolveTime");
731 static PerfCounter layerCreateTime
732 = PerfCounter.newPerfCounter("jdk.module.bootstrap.layerCreateTime");
733 static PerfCounter loadModulesTime
734 = PerfCounter.newPerfCounter("jdk.module.bootstrap.loadModulesTime");
735 static PerfCounter bootstrapTime
736 = PerfCounter.newPerfCounter("jdk.module.bootstrap.totalTime");
737 }
738 }