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.
199 if (mainModule == null || addAllDefaultModules) {
200 boolean hasJava = false;
201 if (systemModules.find(JAVA_SE).isPresent()) {
202 // java.se is a system module
203 if (finder == systemModules || finder.find(JAVA_SE).isPresent()) {
204 // java.se is observable
205 hasJava = true;
206 roots.add(JAVA_SE);
207 }
208 }
209
210 for (ModuleReference mref : systemModules.findAll()) {
211 String mn = mref.descriptor().name();
212 if (hasJava && mn.startsWith("java."))
213 continue;
214
215 // add as root if observable and exports at least one package
216 if ((finder == systemModules || finder.find(mn).isPresent())) {
217 ModuleDescriptor descriptor = mref.descriptor();
218 for (ModuleDescriptor.Exports e : descriptor.exports()) {
219 if (!e.isQualified()) {
220 roots.add(mn);
221 break;
222 }
223 }
224 }
225 }
226 }
227
228 // If `--add-modules ALL-SYSTEM` is specified then all observable system
229 // modules will be resolved.
230 if (addAllSystemModules) {
231 ModuleFinder f = finder; // observable modules
232 systemModules.findAll()
233 .stream()
234 .map(ModuleReference::descriptor)
235 .map(ModuleDescriptor::name)
236 .filter(mn -> f.find(mn).isPresent()) // observable
237 .forEach(mn -> roots.add(mn));
238 }
239
240 // If `--add-modules ALL-MODULE-PATH` is specified then all observable
241 // modules on the application module path will be resolved.
242 if (appModulePath != null && addAllApplicationModules) {
243 ModuleFinder f = finder; // observable modules
244 appModulePath.findAll()
245 .stream()
246 .map(ModuleReference::descriptor)
247 .map(ModuleDescriptor::name)
248 .filter(mn -> f.find(mn).isPresent()) // observable
249 .forEach(mn -> roots.add(mn));
250 }
251
252 PerfCounters.optionsAndRootsTime.addElapsedTimeFrom(t2);
253
254
255 long t3 = System.nanoTime();
256
257 // determine if post resolution checks are needed
258 boolean needPostResolutionChecks = true;
259 if (baseUri.getScheme().equals("jrt") // toLowerCase not needed here
260 && (upgradeModulePath == null)
261 && (appModulePath == null)
262 && (patcher.isEmpty())) {
263 needPostResolutionChecks = false;
264 }
265
266 PrintStream traceOutput = null;
267 if (Boolean.getBoolean("jdk.launcher.traceResolver"))
268 traceOutput = System.out;
269
270 // run the resolver to create the configuration
271 Configuration cf = SharedSecrets.getJavaLangModuleAccess()
272 .resolveRequiresAndUses(finder,
273 roots,
274 needPostResolutionChecks,
275 traceOutput);
276
277 // time to create configuration
278 PerfCounters.resolveTime.addElapsedTimeFrom(t3);
279
280
281 // mapping of modules to class loaders
282 Function<String, ClassLoader> clf = ModuleLoaderMap.mappingFunction(cf);
283
284 // check that all modules to be mapped to the boot loader will be
285 // loaded from the runtime image
286 if (needPostResolutionChecks) {
287 for (ResolvedModule resolvedModule : cf.modules()) {
288 ModuleReference mref = resolvedModule.reference();
289 String name = mref.descriptor().name();
290 ClassLoader cl = clf.apply(name);
291 if (cl == null) {
292
293 if (upgradeModulePath != null
294 && upgradeModulePath.find(name).isPresent())
295 fail(name + ": cannot be loaded from upgrade module path");
296
297 if (!systemModules.find(name).isPresent())
298 fail(name + ": cannot be loaded from application module path");
299 }
300 }
301 }
302
303
304 long t4 = System.nanoTime();
305
306 // define modules to VM/runtime
307 Layer bootLayer = Layer.empty().defineModules(cf, clf);
308
309 PerfCounters.layerCreateTime.addElapsedTimeFrom(t4);
310
311
312 long t5 = System.nanoTime();
313
314 // define the module to its class loader, except java.base
315 for (ResolvedModule resolvedModule : cf.modules()) {
316 ModuleReference mref = resolvedModule.reference();
317 String name = mref.descriptor().name();
318 ClassLoader cl = clf.apply(name);
319 if (cl == null) {
320 if (!name.equals(JAVA_BASE)) BootLoader.loadModule(mref);
321 } else {
322 ((BuiltinClassLoader)cl).loadModule(mref);
323 }
324 }
325
326 PerfCounters.loadModulesTime.addElapsedTimeFrom(t5);
327
328
329 // --add-reads, -add-exports/-add-opens
330 addExtraReads(bootLayer);
331 addExtraExportsAndOpens(bootLayer);
332
333 // total time to initialize
334 PerfCounters.bootstrapTime.addElapsedTimeFrom(t0);
335
336 // remember the ModuleFinder
337 initialFinder = finder;
338
339 return bootLayer;
340 }
341
342 /**
343 * Returns a ModuleFinder that limits observability to the given root
344 * modules, their transitive dependences, plus a set of other modules.
345 */
346 private static ModuleFinder limitFinder(ModuleFinder finder,
347 Set<String> roots,
348 Set<String> otherMods)
349 {
350 // resolve all root modules
351 Configuration cf = Configuration.empty()
352 .resolveRequires(finder,
353 ModuleFinder.of(),
354 roots);
355
356 // module name -> reference
357 Map<String, ModuleReference> map = new HashMap<>();
358
359 // root modules and their transitive dependences
360 cf.modules().stream()
361 .map(ResolvedModule::reference)
362 .forEach(mref -> map.put(mref.descriptor().name(), mref));
363
364 // additional modules
365 otherMods.stream()
366 .map(finder::find)
367 .flatMap(Optional::stream)
368 .forEach(mref -> map.putIfAbsent(mref.descriptor().name(), mref));
369
370 // set of modules that are observable
371 Set<ModuleReference> mrefs = new HashSet<>(map.values());
372
373 return new ModuleFinder() {
374 @Override
375 public Optional<ModuleReference> find(String name) {
376 return Optional.ofNullable(map.get(name));
377 }
378 @Override
379 public Set<ModuleReference> findAll() {
380 return mrefs;
381 }
382 };
383 }
384
385 /**
386 * Creates a finder from the module path that is the value of the given
387 * system property.
388 */
389 private static ModuleFinder createModulePathFinder(String prop) {
390 String s = System.getProperty(prop);
391 if (s == null) {
392 return null;
393 } else {
394 String[] dirs = s.split(File.pathSeparator);
395 Path[] paths = new Path[dirs.length];
396 int i = 0;
397 for (String dir: dirs) {
398 paths[i++] = Paths.get(dir);
399 }
400 return ModuleFinder.of(paths);
401 }
402 }
403
404
405 /**
406 * Initialize the module patcher for the initial configuration passed on the
407 * value of the --patch-module options.
408 */
409 private static ModulePatcher initModulePatcher() {
410 Map<String, List<String>> map = decode("jdk.module.patch.",
411 File.pathSeparator,
412 false);
413 return new ModulePatcher(map);
414 }
415
416 /**
417 * Returns the set of module names specified via --add-modules options
418 * on the command line
419 */
420 private static Set<String> getExtraAddModules() {
421 String prefix = "jdk.module.addmods.";
422 int index = 0;
423
424 // the system property is removed after decoding
425 String value = getAndRemoveProperty(prefix + index);
426 if (value == null) {
427 return Collections.emptySet();
428 }
429
430 Set<String> modules = new HashSet<>();
431 while (value != null) {
432 for (String s : value.split(",")) {
433 if (s.length() > 0) modules.add(s);
434 }
435 index++;
436 value = getAndRemoveProperty(prefix + index);
437 }
438
439 return modules;
440 }
441
442 /**
443 * Process the --add-reads options to add any additional read edges that
444 * are specified on the command-line.
445 */
446 private static void addExtraReads(Layer bootLayer) {
447
448 // decode the command line options
449 Map<String, List<String>> map = decode("jdk.module.addreads.");
450 if (map.isEmpty())
451 return;
452
453 for (Map.Entry<String, List<String>> e : map.entrySet()) {
454
455 // the key is $MODULE
456 String mn = e.getKey();
457 Optional<Module> om = bootLayer.findModule(mn);
458 if (!om.isPresent()) {
459 warn("Unknown module: " + mn);
460 continue;
461 }
462 Module m = om.get();
463
464 // the value is the set of other modules (by name)
465 for (String name : e.getValue()) {
466 if (ALL_UNNAMED.equals(name)) {
467 Modules.addReadsAllUnnamed(m);
468 } else {
469 om = bootLayer.findModule(name);
470 if (om.isPresent()) {
471 Modules.addReads(m, om.get());
472 } else {
473 warn("Unknown module: " + name);
474 }
475 }
476 }
477 }
478 }
479
480 /**
481 * Process the --add-exports and --add-opens options to export/open
482 * additional packages specified on the command-line.
483 */
484 private static void addExtraExportsAndOpens(Layer bootLayer) {
485
486 // --add-exports
487 String prefix = "jdk.module.addexports.";
488 Map<String, List<String>> extraExports = decode(prefix);
489 if (!extraExports.isEmpty()) {
490 addExtraExportsOrOpens(bootLayer, extraExports, false);
491 }
492
493 // --add-opens
494 prefix = "jdk.module.addopens.";
495 Map<String, List<String>> extraOpens = decode(prefix);
496 if (!extraOpens.isEmpty()) {
497 addExtraExportsOrOpens(bootLayer, extraOpens, true);
498 }
499 }
500
501 private static void addExtraExportsOrOpens(Layer bootLayer,
502 Map<String, List<String>> map,
503 boolean opens)
504 {
505 for (Map.Entry<String, List<String>> e : map.entrySet()) {
506
507 // the key is $MODULE/$PACKAGE
508 String key = e.getKey();
509 String[] s = key.split("/");
510 if (s.length != 2)
511 fail("Unable to parse: " + key);
512
513 String mn = s[0];
514 String pn = s[1];
515 if (mn.isEmpty() || pn.isEmpty())
516 fail("Module and package name must be specified:" + key);
517
518 // The exporting module is in the boot layer
519 Module m;
520 Optional<Module> om = bootLayer.findModule(mn);
521 if (!om.isPresent()) {
522 warn("Unknown module: " + mn);
523 continue;
524 }
525
526 m = om.get();
527
528 if (!m.getDescriptor().packages().contains(pn)) {
529 warn("package " + pn + " not in " + mn);
530 continue;
531 }
532
533 // the value is the set of modules to export to (by name)
534 for (String name : e.getValue()) {
535 boolean allUnnamed = false;
536 Module other = null;
537 if (ALL_UNNAMED.equals(name)) {
538 allUnnamed = true;
539 } else {
540 om = bootLayer.findModule(name);
541 if (om.isPresent()) {
542 other = om.get();
543 } else {
544 warn("Unknown module: " + name);
545 continue;
546 }
547 }
548 if (allUnnamed) {
549 if (opens) {
550 Modules.addOpensToAllUnnamed(m, pn);
551 } else {
552 Modules.addExportsToAllUnnamed(m, pn);
553 }
554 } else {
555 if (opens) {
556 Modules.addOpens(m, pn, other);
557 } else {
558 Modules.addExports(m, pn, other);
559 }
560 }
561
562 }
563 }
564 }
565
566 /**
567 * Decodes the values of --add-reads, -add-exports, --add-opens or
568 * --patch-modules options that are encoded in system properties.
569 *
570 * @param prefix the system property prefix
571 * @praam regex the regex for splitting the RHS of the option value
572 */
573 private static Map<String, List<String>> decode(String prefix,
574 String regex,
575 boolean allowDuplicates) {
576 int index = 0;
577 // the system property is removed after decoding
578 String value = getAndRemoveProperty(prefix + index);
579 if (value == null)
580 return Collections.emptyMap();
581
582 Map<String, List<String>> map = new HashMap<>();
583
584 while (value != null) {
585
586 int pos = value.indexOf('=');
587 if (pos == -1)
588 fail("Unable to parse: " + value);
589 if (pos == 0)
590 fail("Missing module name in: " + value);
591
592 // key is <module> or <module>/<package>
593 String key = value.substring(0, pos);
594
595 String rhs = value.substring(pos+1);
596 if (rhs.isEmpty())
597 fail("Unable to parse: " + value);
598
599 // value is <module>(,<module>)* or <file>(<pathsep><file>)*
600 if (!allowDuplicates && map.containsKey(key))
601 fail(key + " specified more than once");
602 List<String> values = map.computeIfAbsent(key, k -> new ArrayList<>());
603 for (String s : rhs.split(regex)) {
604 if (s.length() > 0) values.add(s);
605 }
606
607 index++;
608 value = getAndRemoveProperty(prefix + index);
609 }
610
611 return map;
612 }
613
614 /**
615 * Decodes the values of --add-reads, -add-exports or --add-opens
616 * which use the "," to separate the RHS of the option value.
617 */
618 private static Map<String, List<String>> decode(String prefix) {
619 return decode(prefix, ",", true);
620 }
621
622 /**
623 * Gets and remove the named system property
624 */
625 private static String getAndRemoveProperty(String key) {
626 return (String)System.getProperties().remove(key);
627 }
628
629 /**
630 * Throws a RuntimeException with the given message
631 */
632 static void fail(String m) {
633 throw new RuntimeException(m);
634 }
635
636 static void warn(String m) {
637 System.err.println("WARNING: " + m);
638 }
639
640 static class PerfCounters {
641
642 static PerfCounter systemModulesTime
643 = PerfCounter.newPerfCounter("jdk.module.bootstrap.systemModulesTime");
644 static PerfCounter defineBaseTime
645 = PerfCounter.newPerfCounter("jdk.module.bootstrap.defineBaseTime");
646 static PerfCounter optionsAndRootsTime
647 = PerfCounter.newPerfCounter("jdk.module.bootstrap.optionsAndRootsTime");
648 static PerfCounter resolveTime
649 = PerfCounter.newPerfCounter("jdk.module.bootstrap.resolveTime");
650 static PerfCounter layerCreateTime
651 = PerfCounter.newPerfCounter("jdk.module.bootstrap.layerCreateTime");
652 static PerfCounter loadModulesTime
653 = PerfCounter.newPerfCounter("jdk.module.bootstrap.loadModulesTime");
654 static PerfCounter bootstrapTime
655 = PerfCounter.newPerfCounter("jdk.module.bootstrap.totalTime");
656 }
657 }