1 /*
2 * Copyright (c) 2003, 2026, 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.access;
27
28 import java.io.InputStream;
29 import java.io.PrintStream;
30 import java.lang.annotation.Annotation;
31 import java.lang.foreign.MemorySegment;
32 import java.lang.foreign.SymbolLookup;
33 import java.lang.invoke.MethodHandle;
34 import java.lang.invoke.MethodType;
35 import java.lang.module.ModuleDescriptor;
36 import java.lang.reflect.Executable;
37 import java.lang.reflect.Method;
38 import java.net.URI;
39 import java.nio.charset.CharacterCodingException;
40 import java.nio.charset.Charset;
41 import java.security.ProtectionDomain;
42 import java.util.List;
43 import java.util.Map;
44 import java.util.Set;
45 import java.util.concurrent.ConcurrentHashMap;
46 import java.util.concurrent.Executor;
47 import java.util.concurrent.RejectedExecutionException;
48 import java.util.stream.Stream;
49
50 import jdk.internal.loader.NativeLibraries;
51 import jdk.internal.misc.CarrierThreadLocal;
52 import jdk.internal.module.ServicesCatalog;
53 import jdk.internal.reflect.ConstantPool;
54 import jdk.internal.vm.Continuation;
55 import jdk.internal.vm.ContinuationScope;
56 import jdk.internal.vm.StackableScope;
57 import jdk.internal.vm.ThreadContainer;
58 import sun.reflect.annotation.AnnotationType;
59 import sun.nio.ch.Interruptible;
60
61 public interface JavaLangAccess {
62
63 /**
64 * Returns the list of {@code Method} objects for the declared public
65 * methods of this class or interface that have the specified method name
66 * and parameter types.
67 */
68 List<Method> getDeclaredPublicMethods(Class<?> klass, String name, Class<?>... parameterTypes);
69
70 /**
71 * Return most specific method that matches name and parameterTypes.
72 */
73 Method findMethod(Class<?> klass, boolean publicOnly, String name, Class<?>... parameterTypes);
74
75 /**
76 * Return the constant pool for a class.
77 */
78 ConstantPool getConstantPool(Class<?> klass);
79
80 /**
81 * Compare-And-Set the AnnotationType instance corresponding to this class.
82 * (This method only applies to annotation types.)
83 */
84 boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType);
85
86 /**
87 * Get the AnnotationType instance corresponding to this class.
88 * (This method only applies to annotation types.)
89 */
90 AnnotationType getAnnotationType(Class<?> klass);
91
92 /**
93 * Get the declared annotations for a given class, indexed by their types.
94 */
95 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass);
96
97 /**
98 * Get the array of bytes that is the class-file representation
99 * of this Class' annotations.
100 */
101 byte[] getRawClassAnnotations(Class<?> klass);
102
103 /**
104 * Get the array of bytes that is the class-file representation
105 * of this Class' type annotations.
106 */
107 byte[] getRawClassTypeAnnotations(Class<?> klass);
108
109 /**
110 * Get the array of bytes that is the class-file representation
111 * of this Executable's type annotations.
112 */
113 byte[] getRawExecutableTypeAnnotations(Executable executable);
114
115 /**
116 * Get the int value of the Class's class-file access flags.
117 */
118 int getClassFileAccessFlags(Class<?> klass);
119
120 /**
121 * Returns the elements of an enum class or null if the
122 * Class object does not represent an enum type;
123 * the result is uncloned, cached, and shared by all callers.
124 */
125 <E extends Enum<E>> E[] getEnumConstantsShared(Class<E> klass);
126
127 /**
128 * Set current thread's blocker field.
129 */
130 void blockedOn(Interruptible b);
131
132 /**
133 * Registers a shutdown hook.
134 *
135 * It is expected that this method with registerShutdownInProgress=true
136 * is only used to register DeleteOnExitHook since the first file
137 * may be added to the delete on exit list by the application shutdown
138 * hooks.
139 *
140 * @param slot the slot in the shutdown hook array, whose element
141 * will be invoked in order during shutdown
142 * @param registerShutdownInProgress true to allow the hook
143 * to be registered even if the shutdown is in progress.
144 * @param hook the hook to be registered
145 *
146 * @throws IllegalStateException if shutdown is in progress and
147 * the slot is not valid to register.
148 */
149 void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook);
150
151 /**
152 * Invokes the finalize method of the given object.
153 */
154 void invokeFinalize(Object o) throws Throwable;
155
156 /**
157 * Returns the ConcurrentHashMap used as a storage for ClassLoaderValue(s)
158 * associated with the given class loader, creating it if it doesn't already exist.
159 */
160 ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl);
161
162 /**
163 * Defines a class with the given name to a class loader.
164 */
165 Class<?> defineClass(ClassLoader cl, String name, byte[] b, ProtectionDomain pd, String source);
166
167 /**
168 * Defines a class with the given name to a class loader with
169 * the given flags and class data.
170 *
171 * @see java.lang.invoke.MethodHandles.Lookup#defineClass
172 */
173 Class<?> defineClass(ClassLoader cl, Class<?> lookup, String name, byte[] b, ProtectionDomain pd, boolean initialize, int flags, Object classData);
174
175 /**
176 * Returns a class loaded by the bootstrap class loader.
177 */
178 Class<?> findBootstrapClassOrNull(String name);
179
180 /**
181 * Define a Package of the given name and module by the given class loader.
182 */
183 Package definePackage(ClassLoader cl, String name, Module module);
184
185 /**
186 * Defines a new module to the Java virtual machine. The module
187 * is defined to the given class loader.
188 *
189 * The URI is for information purposes only, it can be {@code null}.
190 */
191 Module defineModule(ClassLoader loader, ModuleDescriptor descriptor, URI uri);
192
193 /**
194 * Defines the unnamed module for the given class loader.
195 */
196 Module defineUnnamedModule(ClassLoader loader);
197
198 /**
199 * Updates the readability so that module m1 reads m2. The new read edge
200 * does not result in a strong reference to m2 (m2 can be GC'ed).
201 *
202 * This method is the same as m1.addReads(m2) but without a caller check.
203 */
204 void addReads(Module m1, Module m2);
205
206 /**
207 * Updates module m to read all unnamed modules.
208 */
209 void addReadsAllUnnamed(Module m);
210
211 /**
212 * Updates module m1 to export a package unconditionally.
213 */
214 void addExports(Module m1, String pkg);
215
216 /**
217 * Updates module m1 to export a package to module m2. The export does
218 * not result in a strong reference to m2 (m2 can be GC'ed).
219 */
220 void addExports(Module m1, String pkg, Module m2);
221
222 /**
223 * Updates a module m to export a package to all unnamed modules.
224 */
225 void addExportsToAllUnnamed(Module m, String pkg);
226
227 /**
228 * Updates module m1 to open a package to module m2. Opening the
229 * package does not result in a strong reference to m2 (m2 can be GC'ed).
230 */
231 void addOpens(Module m1, String pkg, Module m2);
232
233 /**
234 * Updates module m to open a package to all unnamed modules.
235 */
236 void addOpensToAllUnnamed(Module m, String pkg);
237
238 /**
239 * Updates module m to use a service.
240 */
241 void addUses(Module m, Class<?> service);
242
243 /**
244 * Returns true if module m reflectively exports a package to other
245 */
246 boolean isReflectivelyExported(Module module, String pn, Module other);
247
248 /**
249 * Returns true if module m reflectively opens a package to other
250 */
251 boolean isReflectivelyOpened(Module module, String pn, Module other);
252
253 /**
254 * Updates module m to allow access to restricted methods.
255 */
256 void addEnableNativeAccess(Module m);
257
258 /**
259 * Updates module named {@code name} in layer {@code layer} to allow access to
260 * restricted methods. Returns true iff the given module exists in the given layer.
261 */
262 boolean addEnableNativeAccess(ModuleLayer layer, String name);
263
264 /**
265 * Updates all unnamed modules to allow access to restricted methods.
266 */
267 void addEnableNativeAccessToAllUnnamed();
268
269 /**
270 * Ensure that the given module has native access. If not, warn or throw exception
271 * depending on the configuration.
272 * @param m the module in which native access occurred
273 * @param owner the owner of the restricted method being called (or the JNI method being bound)
274 * @param methodName the name of the restricted method being called (or the JNI method being bound)
275 * @param currentClass the class calling the restricted method (for JNI, this is the same as {@code owner})
276 * @param jni {@code true}, if this event is related to a JNI method being bound
277 */
278 void ensureNativeAccess(Module m, Class<?> owner, String methodName, Class<?> currentClass, boolean jni);
279
280 /**
281 * Enable code in all unnamed modules to mutate final instance fields.
282 */
283 void addEnableFinalMutationToAllUnnamed();
284
285 /**
286 * Enable code in a given module to mutate final instance fields.
287 */
288 boolean tryEnableFinalMutation(Module m);
289
290 /**
291 * Return true if code in a given module is allowed to mutate final instance fields.
292 */
293 boolean isFinalMutationEnabled(Module m);
294
295 /**
296 * Return true if a given module has statically exported the given package to a given other module.
297 */
298 boolean isStaticallyExported(Module module, String pn, Module other);
299
300 /**
301 * Return true if a given module has statically opened the given package to a given other module.
302 */
303 boolean isStaticallyOpened(Module module, String pn, Module other);
304
305 /**
306 * Returns the ServicesCatalog for the given Layer.
307 */
308 ServicesCatalog getServicesCatalog(ModuleLayer layer);
309
310 /**
311 * Record that this layer has at least one module defined to the given
312 * class loader.
313 */
314 void bindToLoader(ModuleLayer layer, ClassLoader loader);
315
316 /**
317 * Returns an ordered stream of layers. The first element is the
318 * given layer, the remaining elements are its parents, in DFS order.
319 */
320 Stream<ModuleLayer> layers(ModuleLayer layer);
321
322 /**
323 * Returns a stream of the layers that have modules defined to the
324 * given class loader.
325 */
326 Stream<ModuleLayer> layers(ClassLoader loader);
327
328 /**
329 * Count the number of leading positive bytes in the range.
330 *
331 * @implSpec Implementations of this method must perform bounds checks.
332 */
333 int countPositives(byte[] ba, int off, int len);
334
335 /**
336 * Count the number of leading non-zero ascii chars in the String.
337 */
338 int countNonZeroAscii(String s);
339
340 /**
341 * Constructs a new {@code String} with the supplied Latin1 bytes.
342 * <p>
343 * <b>WARNING: The caller of this method shall relinquish and transfer the
344 * ownership of the byte array to the callee</b>, since the latter will not
345 * make a copy.
346 *
347 * @param bytes the byte array source
348 * @return the newly created string
349 */
350 String uncheckedNewStringWithLatin1Bytes(byte[] bytes);
351
352 /**
353 * Constructs a new {@code String} by decoding the specified byte array
354 * using the specified {@code Charset}.
355 * <p>
356 * <b>WARNING: The caller of this method shall relinquish and transfer the
357 * ownership of the byte array to the callee</b>, since the latter will not
358 * make a copy.
359 *
360 * @param bytes the byte array source
361 * @param cs the Charset
362 * @return the newly created string
363 * @throws CharacterCodingException for malformed or unmappable bytes
364 * @throws NullPointerException If {@code bytes} or {@code cs} is null
365 */
366 String uncheckedNewStringOrThrow(byte[] bytes, Charset cs) throws CharacterCodingException;
367
368 /**
369 * {@return the sequence of bytes obtained by encoding the given string in
370 * the specified {@code Charset}}
371 * <p>
372 * <b>WARNING: This method returns the {@code byte[]} backing the provided
373 * {@code String}, if the input is ASCII. Hence, the returned byte array
374 * must not be modified.</b>
375 *
376 * @param s the string to encode
377 * @param cs the charset
378 * @throws NullPointerException If {@code s} or {@code cs} is null
379 * @throws CharacterCodingException for malformed input or unmappable characters
380 */
381 byte[] uncheckedGetBytesOrThrow(String s, Charset cs) throws CharacterCodingException;
382
383 /**
384 * Get the {@code char} at {@code index} in a {@code byte[]} in internal
385 * UTF-16 representation.
386 * <p>
387 * <b>WARNING: This method does not perform any bound checks.</b>
388 *
389 * @param bytes the UTF-16 encoded bytes
390 * @param index of the char to retrieve, 0 <= index < (bytes.length >> 1)
391 * @return the char value
392 */
393 char uncheckedGetUTF16Char(byte[] bytes, int index);
394
395 /**
396 * Put the {@code ch} at {@code index} in a {@code byte[]} in internal
397 * UTF-16 representation.
398 * <p>
399 * <b>WARNING: This method does not perform any bound checks.</b>
400 *
401 * @param bytes the UTF-16 encoded bytes
402 * @param index of the char to retrieve, 0 <= index < (bytes.length >> 1)
403 */
404 void uncheckedPutCharUTF16(byte[] bytes, int index, int ch);
405
406 /**
407 * {@return the sequence of bytes obtained by encoding the given string in UTF-8}
408 *
409 * @param s the string to encode
410 * @throws NullPointerException If {@code s} is null
411 * @throws CharacterCodingException For malformed input or unmappable characters
412 */
413 byte[] getBytesUTF8OrThrow(String s) throws CharacterCodingException;
414
415 /**
416 * Inflated copy from {@code byte[]} to {@code char[]}, as defined by
417 * {@code StringLatin1.inflate}.
418 *
419 * @implSpec Implementations of this method must perform bounds checks.
420 */
421 void inflateBytesToChars(byte[] src, int srcOff, char[] dst, int dstOff, int len);
422
423 /**
424 * Decodes ASCII from the source byte array into the destination
425 * char array.
426 *
427 * @implSpec Implementations of this method must perform bounds checks.
428 *
429 * @return the number of bytes successfully decoded, at most len
430 */
431 int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len);
432
433 /**
434 * Returns the initial `System.in` to determine if it is replaced
435 * with `System.setIn(newIn)` method
436 */
437 InputStream initialSystemIn();
438
439 /**
440 * Returns the initial value of System.err.
441 */
442 PrintStream initialSystemErr();
443
444 /**
445 * Encodes as many ASCII codepoints as possible from the source
446 * character array into the destination byte array, assuming that
447 * the encoding is ASCII compatible.
448 *
449 * @param sa the source character array
450 * @param sp the index of the source array to start reading from
451 * @param da the target byte array
452 * @param dp the index of the target array to start writing to
453 * @param len the total number of characters to be encoded
454 * @return the total number of characters successfully encoded
455 * @throws NullPointerException if any of the provided arrays is null
456 */
457 int encodeASCII(char[] sa, int sp, byte[] da, int dp, int len);
458
459 /**
460 * Set the cause of Throwable
461 * @param cause set t's cause to new value
462 */
463 void setCause(Throwable t, Throwable cause);
464
465 /**
466 * Get protection domain of the given Class
467 */
468 ProtectionDomain protectionDomain(Class<?> c);
469
470 /**
471 * Get a method handle of string concat helper method
472 */
473 MethodHandle stringConcatHelper(String name, MethodType methodType);
474
475 /**
476 * Creates helper for string concatenation.
477 * <p>
478 * <b>WARNING: The caller of this method shall relinquish and transfer the
479 * ownership of the string array to the callee</b>, since the latter will not
480 * make a copy.
481 */
482 Object uncheckedStringConcat1(String[] constants);
483
484 /**
485 * Get the string initial coder, When COMPACT_STRINGS is on, it returns 0, and when it is off, it returns 1.
486 */
487 byte stringInitCoder();
488
489 /**
490 * Get the Coder of String, which is used by StringConcatFactory to calculate the initCoder of constants
491 */
492 byte stringCoder(String str);
493
494 /**
495 * Join strings
496 */
497 String join(String prefix, String suffix, String delimiter, String[] elements, int size);
498
499 /**
500 * Concatenation of prefix and suffix characters to a String for early bootstrap
501 */
502 String concat(String prefix, Object value, String suffix);
503
504 /*
505 * Get the class data associated with the given class.
506 * @param c the class
507 * @see java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
508 */
509 Object classData(Class<?> c);
510
511 /**
512 * Returns the {@link NativeLibraries} object associated with the provided class loader.
513 * This is used by {@link SymbolLookup#loaderLookup()}.
514 */
515 NativeLibraries nativeLibrariesFor(ClassLoader loader);
516
517 /**
518 * Returns an array of all platform threads.
519 */
520 Thread[] getAllThreads();
521
522 /**
523 * Returns the ThreadContainer for a thread, may be null.
524 */
525 ThreadContainer threadContainer(Thread thread);
526
527 /**
528 * Starts a thread in the given ThreadContainer.
529 */
530 void start(Thread thread, ThreadContainer container);
531
532 /**
533 * Returns the top of the given thread's stackable scope stack.
534 */
535 StackableScope headStackableScope(Thread thread);
536
537 /**
538 * Sets the top of the current thread's stackable scope stack.
539 */
540 void setHeadStackableScope(StackableScope scope);
541
542 /**
543 * Returns the Thread object for the current platform thread. If the
544 * current thread is a virtual thread then this method returns the carrier.
545 */
546 Thread currentCarrierThread();
547
548 /**
549 * Returns the value of the current carrier thread's copy of a thread-local.
550 */
551 <T> T getCarrierThreadLocal(CarrierThreadLocal<T> local);
552
553 /**
554 * Sets the value of the current carrier thread's copy of a thread-local.
555 */
556 <T> void setCarrierThreadLocal(CarrierThreadLocal<T> local, T value);
557
558 /**
559 * Removes the value of the current carrier thread's copy of a thread-local.
560 */
561 void removeCarrierThreadLocal(CarrierThreadLocal<?> local);
562
563 /**
564 * Returns the current thread's scoped values cache
565 */
566 Object[] scopedValueCache();
567
568 /**
569 * Sets the current thread's scoped values cache
570 */
571 void setScopedValueCache(Object[] cache);
572
573 /**
574 * Return the current thread's scoped value bindings.
575 */
576 Object scopedValueBindings();
577
578 /**
579 * Returns the native thread ID for the given platform thread or 0 if not set.
580 */
581 long nativeThreadID(Thread thread);
582
583 /**
584 * Sets the native thread ID for the current platform thread.
585 */
586 void setThreadNativeID(long id);
587
588 /**
589 * Returns the innermost mounted continuation
590 */
591 Continuation getContinuation(Thread thread);
592
593 /**
594 * Sets the innermost mounted continuation
595 */
596 void setContinuation(Thread thread, Continuation continuation);
597
598 /**
599 * The ContinuationScope of virtual thread continuations
600 */
601 ContinuationScope virtualThreadContinuationScope();
602
603 /**
604 * Parks the current virtual thread.
605 * @throws WrongThreadException if the current thread is not a virtual thread
606 */
607 void parkVirtualThread();
608
609 /**
610 * Parks the current virtual thread for up to the given waiting time.
611 * @param nanos the maximum number of nanoseconds to wait
612 * @throws WrongThreadException if the current thread is not a virtual thread
613 */
614 void parkVirtualThread(long nanos);
615
616 /**
617 * Re-enables a virtual thread for scheduling. If the thread was parked then
618 * it will be unblocked, otherwise its next attempt to park will not block
619 * @param thread the virtual thread to unpark
620 * @throws IllegalArgumentException if the thread is not a virtual thread
621 * @throws RejectedExecutionException if the scheduler cannot accept a task
622 */
623 void unparkVirtualThread(Thread thread);
624
625 /**
626 * Returns the virtual thread default scheduler.
627 */
628 Executor virtualThreadDefaultScheduler();
629
630 /**
631 * Creates a new StackWalker
632 */
633 StackWalker newStackWalkerInstance(Set<StackWalker.Option> options,
634 ContinuationScope contScope,
635 Continuation continuation);
636 /**
637 * Returns '<loader-name>' @<id> if classloader has a name
638 * explicitly set otherwise <qualified-class-name> @<id>
639 */
640 String getLoaderNameID(ClassLoader loader);
641
642 /**
643 * Copy the string bytes to an existing segment, avoiding intermediate copies.
644 */
645 void copyToSegmentRaw(String string, MemorySegment segment, long offset, int srcIndex, int srcLength);
646
647 /**
648 * Are the string bytes compatible with the given charset?
649 */
650 boolean bytesCompatible(String string, Charset charset, int srcIndex, int numChars);
651
652 /**
653 * Finish initialization of the StackTraceElement objects in a stack trace.
654 */
655 void finishInit(StackTraceElement[] stackTrace);
656 }