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.RejectedExecutionException;
47 import java.util.stream.Stream;
48
49 import jdk.internal.loader.NativeLibraries;
50 import jdk.internal.misc.CarrierThreadLocal;
51 import jdk.internal.module.ServicesCatalog;
52 import jdk.internal.reflect.ConstantPool;
53 import jdk.internal.vm.Continuation;
54 import jdk.internal.vm.ContinuationScope;
55 import jdk.internal.vm.StackableScope;
56 import jdk.internal.vm.ThreadContainer;
57 import sun.reflect.annotation.AnnotationType;
58 import sun.nio.ch.Interruptible;
59
60 public interface JavaLangAccess {
61
62 /**
63 * Returns the list of {@code Method} objects for the declared public
64 * methods of this class or interface that have the specified method name
65 * and parameter types.
66 */
67 List<Method> getDeclaredPublicMethods(Class<?> klass, String name, Class<?>... parameterTypes);
68
69 /**
70 * Return most specific method that matches name and parameterTypes.
71 */
72 Method findMethod(Class<?> klass, boolean publicOnly, String name, Class<?>... parameterTypes);
73
74 /**
75 * Return the constant pool for a class.
76 */
77 ConstantPool getConstantPool(Class<?> klass);
78
79 /**
80 * Compare-And-Set the AnnotationType instance corresponding to this class.
81 * (This method only applies to annotation types.)
82 */
83 boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType);
84
85 /**
86 * Get the AnnotationType instance corresponding to this class.
87 * (This method only applies to annotation types.)
88 */
89 AnnotationType getAnnotationType(Class<?> klass);
90
91 /**
92 * Get the declared annotations for a given class, indexed by their types.
93 */
94 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass);
95
96 /**
97 * Get the array of bytes that is the class-file representation
98 * of this Class' annotations.
99 */
100 byte[] getRawClassAnnotations(Class<?> klass);
101
102 /**
103 * Get the array of bytes that is the class-file representation
104 * of this Class' type annotations.
105 */
106 byte[] getRawClassTypeAnnotations(Class<?> klass);
107
108 /**
109 * Get the array of bytes that is the class-file representation
110 * of this Executable's type annotations.
111 */
112 byte[] getRawExecutableTypeAnnotations(Executable executable);
113
114 /**
115 * Get the int value of the Class's class-file access flags.
116 */
117 int getClassFileAccessFlags(Class<?> klass);
118
119 /**
120 * Returns the elements of an enum class or null if the
121 * Class object does not represent an enum type;
122 * the result is uncloned, cached, and shared by all callers.
123 */
124 <E extends Enum<E>> E[] getEnumConstantsShared(Class<E> klass);
125
126 /**
127 * Set current thread's blocker field.
128 */
129 void blockedOn(Interruptible b);
130
131 /**
132 * Registers a shutdown hook.
133 *
134 * It is expected that this method with registerShutdownInProgress=true
135 * is only used to register DeleteOnExitHook since the first file
136 * may be added to the delete on exit list by the application shutdown
137 * hooks.
138 *
139 * @param slot the slot in the shutdown hook array, whose element
140 * will be invoked in order during shutdown
141 * @param registerShutdownInProgress true to allow the hook
142 * to be registered even if the shutdown is in progress.
143 * @param hook the hook to be registered
144 *
145 * @throws IllegalStateException if shutdown is in progress and
146 * the slot is not valid to register.
147 */
148 void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook);
149
150 /**
151 * Invokes the finalize method of the given object.
152 */
153 void invokeFinalize(Object o) throws Throwable;
154
155 /**
156 * Returns the ConcurrentHashMap used as a storage for ClassLoaderValue(s)
157 * associated with the given class loader, creating it if it doesn't already exist.
158 */
159 ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl);
160
161 /**
162 * Defines a class with the given name to a class loader.
163 */
164 Class<?> defineClass(ClassLoader cl, String name, byte[] b, ProtectionDomain pd, String source);
165
166 /**
167 * Defines a class with the given name to a class loader with
168 * the given flags and class data.
169 *
170 * @see java.lang.invoke.MethodHandles.Lookup#defineClass
171 */
172 Class<?> defineClass(ClassLoader cl, Class<?> lookup, String name, byte[] b, ProtectionDomain pd, boolean initialize, int flags, Object classData);
173
174 /**
175 * Returns a class loaded by the bootstrap class loader.
176 */
177 Class<?> findBootstrapClassOrNull(String name);
178
179 /**
180 * Define a Package of the given name and module by the given class loader.
181 */
182 Package definePackage(ClassLoader cl, String name, Module module);
183
184 /**
185 * Defines a new module to the Java virtual machine. The module
186 * is defined to the given class loader.
187 *
188 * The URI is for information purposes only, it can be {@code null}.
189 */
190 Module defineModule(ClassLoader loader, ModuleDescriptor descriptor, URI uri);
191
192 /**
193 * Defines the unnamed module for the given class loader.
194 */
195 Module defineUnnamedModule(ClassLoader loader);
196
197 /**
198 * Updates the readability so that module m1 reads m2. The new read edge
199 * does not result in a strong reference to m2 (m2 can be GC'ed).
200 *
201 * This method is the same as m1.addReads(m2) but without a caller check.
202 */
203 void addReads(Module m1, Module m2);
204
205 /**
206 * Updates module m to read all unnamed modules.
207 */
208 void addReadsAllUnnamed(Module m);
209
210 /**
211 * Updates module m1 to export a package unconditionally.
212 */
213 void addExports(Module m1, String pkg);
214
215 /**
216 * Updates module m1 to export a package to module m2. The export does
217 * not result in a strong reference to m2 (m2 can be GC'ed).
218 */
219 void addExports(Module m1, String pkg, Module m2);
220
221 /**
222 * Updates a module m to export a package to all unnamed modules.
223 */
224 void addExportsToAllUnnamed(Module m, String pkg);
225
226 /**
227 * Updates module m1 to open a package to module m2. Opening the
228 * package does not result in a strong reference to m2 (m2 can be GC'ed).
229 */
230 void addOpens(Module m1, String pkg, Module m2);
231
232 /**
233 * Updates module m to open a package to all unnamed modules.
234 */
235 void addOpensToAllUnnamed(Module m, String pkg);
236
237 /**
238 * Updates module m to use a service.
239 */
240 void addUses(Module m, Class<?> service);
241
242 /**
243 * Returns true if module m reflectively exports a package to other
244 */
245 boolean isReflectivelyExported(Module module, String pn, Module other);
246
247 /**
248 * Returns true if module m reflectively opens a package to other
249 */
250 boolean isReflectivelyOpened(Module module, String pn, Module other);
251
252 /**
253 * Updates module m to allow access to restricted methods.
254 */
255 void addEnableNativeAccess(Module m);
256
257 /**
258 * Updates module named {@code name} in layer {@code layer} to allow access to
259 * restricted methods. Returns true iff the given module exists in the given layer.
260 */
261 boolean addEnableNativeAccess(ModuleLayer layer, String name);
262
263 /**
264 * Updates all unnamed modules to allow access to restricted methods.
265 */
266 void addEnableNativeAccessToAllUnnamed();
267
268 /**
269 * Ensure that the given module has native access. If not, warn or throw exception
270 * depending on the configuration.
271 * @param m the module in which native access occurred
272 * @param owner the owner of the restricted method being called (or the JNI method being bound)
273 * @param methodName the name of the restricted method being called (or the JNI method being bound)
274 * @param currentClass the class calling the restricted method (for JNI, this is the same as {@code owner})
275 * @param jni {@code true}, if this event is related to a JNI method being bound
276 */
277 void ensureNativeAccess(Module m, Class<?> owner, String methodName, Class<?> currentClass, boolean jni);
278
279 /**
280 * Enable code in all unnamed modules to mutate final instance fields.
281 */
282 void addEnableFinalMutationToAllUnnamed();
283
284 /**
285 * Enable code in a given module to mutate final instance fields.
286 */
287 boolean tryEnableFinalMutation(Module m);
288
289 /**
290 * Return true if code in a given module is allowed to mutate final instance fields.
291 */
292 boolean isFinalMutationEnabled(Module m);
293
294 /**
295 * Return true if a given module has statically exported the given package to a given other module.
296 */
297 boolean isStaticallyExported(Module module, String pn, Module other);
298
299 /**
300 * Return true if a given module has statically opened the given package to a given other module.
301 */
302 boolean isStaticallyOpened(Module module, String pn, Module other);
303
304 /**
305 * Returns the ServicesCatalog for the given Layer.
306 */
307 ServicesCatalog getServicesCatalog(ModuleLayer layer);
308
309 /**
310 * Record that this layer has at least one module defined to the given
311 * class loader.
312 */
313 void bindToLoader(ModuleLayer layer, ClassLoader loader);
314
315 /**
316 * Returns an ordered stream of layers. The first element is the
317 * given layer, the remaining elements are its parents, in DFS order.
318 */
319 Stream<ModuleLayer> layers(ModuleLayer layer);
320
321 /**
322 * Returns a stream of the layers that have modules defined to the
323 * given class loader.
324 */
325 Stream<ModuleLayer> layers(ClassLoader loader);
326
327 /**
328 * Count the number of leading positive bytes in the range.
329 *
330 * @implSpec Implementations of this method must perform bounds checks.
331 */
332 int countPositives(byte[] ba, int off, int len);
333
334 /**
335 * Count the number of leading non-zero ascii chars in the String.
336 */
337 int countNonZeroAscii(String s);
338
339 /**
340 * Constructs a new {@code String} with the supplied Latin1 bytes.
341 * <p>
342 * <b>WARNING: The caller of this method shall relinquish and transfer the
343 * ownership of the byte array to the callee</b>, since the latter will not
344 * make a copy.
345 *
346 * @param bytes the byte array source
347 * @return the newly created string
348 */
349 String uncheckedNewStringWithLatin1Bytes(byte[] bytes);
350
351 /**
352 * Constructs a new {@code String} by decoding the specified byte array
353 * using the specified {@code Charset}.
354 * <p>
355 * <b>WARNING: The caller of this method shall relinquish and transfer the
356 * ownership of the byte array to the callee</b>, since the latter will not
357 * make a copy.
358 *
359 * @param bytes the byte array source
360 * @param cs the Charset
361 * @return the newly created string
362 * @throws CharacterCodingException for malformed or unmappable bytes
363 * @throws NullPointerException If {@code bytes} or {@code cs} is null
364 */
365 String uncheckedNewStringOrThrow(byte[] bytes, Charset cs) throws CharacterCodingException;
366
367 /**
368 * {@return the sequence of bytes obtained by encoding the given string in
369 * the specified {@code Charset}}
370 * <p>
371 * <b>WARNING: This method returns the {@code byte[]} backing the provided
372 * {@code String}, if the input is ASCII. Hence, the returned byte array
373 * must not be modified.</b>
374 *
375 * @param s the string to encode
376 * @param cs the charset
377 * @throws NullPointerException If {@code s} or {@code cs} is null
378 * @throws CharacterCodingException for malformed input or unmappable characters
379 */
380 byte[] uncheckedGetBytesOrThrow(String s, Charset cs) throws CharacterCodingException;
381
382 /**
383 * Get the {@code char} at {@code index} in a {@code byte[]} in internal
384 * UTF-16 representation.
385 * <p>
386 * <b>WARNING: This method does not perform any bound checks.</b>
387 *
388 * @param bytes the UTF-16 encoded bytes
389 * @param index of the char to retrieve, 0 <= index < (bytes.length >> 1)
390 * @return the char value
391 */
392 char uncheckedGetUTF16Char(byte[] bytes, int index);
393
394 /**
395 * Put the {@code ch} at {@code index} in a {@code byte[]} in internal
396 * UTF-16 representation.
397 * <p>
398 * <b>WARNING: This method does not perform any bound checks.</b>
399 *
400 * @param bytes the UTF-16 encoded bytes
401 * @param index of the char to retrieve, 0 <= index < (bytes.length >> 1)
402 */
403 void uncheckedPutCharUTF16(byte[] bytes, int index, int ch);
404
405 /**
406 * {@return the sequence of bytes obtained by encoding the given string in UTF-8}
407 *
408 * @param s the string to encode
409 * @throws NullPointerException If {@code s} is null
410 * @throws CharacterCodingException For malformed input or unmappable characters
411 */
412 byte[] getBytesUTF8OrThrow(String s) throws CharacterCodingException;
413
414 /**
415 * Inflated copy from {@code byte[]} to {@code char[]}, as defined by
416 * {@code StringLatin1.inflate}.
417 *
418 * @implSpec Implementations of this method must perform bounds checks.
419 */
420 void inflateBytesToChars(byte[] src, int srcOff, char[] dst, int dstOff, int len);
421
422 /**
423 * Decodes ASCII from the source byte array into the destination
424 * char array.
425 *
426 * @implSpec Implementations of this method must perform bounds checks.
427 *
428 * @return the number of bytes successfully decoded, at most len
429 */
430 int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len);
431
432 /**
433 * Returns the initial `System.in` to determine if it is replaced
434 * with `System.setIn(newIn)` method
435 */
436 InputStream initialSystemIn();
437
438 /**
439 * Returns the initial value of System.err.
440 */
441 PrintStream initialSystemErr();
442
443 /**
444 * Encodes as many ASCII codepoints as possible from the source
445 * character array into the destination byte array, assuming that
446 * the encoding is ASCII compatible.
447 *
448 * @param sa the source character array
449 * @param sp the index of the source array to start reading from
450 * @param da the target byte array
451 * @param dp the index of the target array to start writing to
452 * @param len the total number of characters to be encoded
453 * @return the total number of characters successfully encoded
454 * @throws NullPointerException if any of the provided arrays is null
455 */
456 int encodeASCII(char[] sa, int sp, byte[] da, int dp, int len);
457
458 /**
459 * Set the cause of Throwable
460 * @param cause set t's cause to new value
461 */
462 void setCause(Throwable t, Throwable cause);
463
464 /**
465 * Get protection domain of the given Class
466 */
467 ProtectionDomain protectionDomain(Class<?> c);
468
469 /**
470 * Get a method handle of string concat helper method
471 */
472 MethodHandle stringConcatHelper(String name, MethodType methodType);
473
474 /**
475 * Creates helper for string concatenation.
476 * <p>
477 * <b>WARNING: The caller of this method shall relinquish and transfer the
478 * ownership of the string array to the callee</b>, since the latter will not
479 * make a copy.
480 */
481 Object uncheckedStringConcat1(String[] constants);
482
483 /**
484 * Get the string initial coder, When COMPACT_STRINGS is on, it returns 0, and when it is off, it returns 1.
485 */
486 byte stringInitCoder();
487
488 /**
489 * Get the Coder of String, which is used by StringConcatFactory to calculate the initCoder of constants
490 */
491 byte stringCoder(String str);
492
493 /**
494 * Join strings
495 */
496 String join(String prefix, String suffix, String delimiter, String[] elements, int size);
497
498 /**
499 * Concatenation of prefix and suffix characters to a String for early bootstrap
500 */
501 String concat(String prefix, Object value, String suffix);
502
503 /*
504 * Get the class data associated with the given class.
505 * @param c the class
506 * @see java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
507 */
508 Object classData(Class<?> c);
509
510 /**
511 * Returns the {@link NativeLibraries} object associated with the provided class loader.
512 * This is used by {@link SymbolLookup#loaderLookup()}.
513 */
514 NativeLibraries nativeLibrariesFor(ClassLoader loader);
515
516 /**
517 * Returns an array of all platform threads.
518 */
519 Thread[] getAllThreads();
520
521 /**
522 * Returns the ThreadContainer for a thread, may be null.
523 */
524 ThreadContainer threadContainer(Thread thread);
525
526 /**
527 * Starts a thread in the given ThreadContainer.
528 */
529 void start(Thread thread, ThreadContainer container);
530
531 /**
532 * Returns the top of the given thread's stackable scope stack.
533 */
534 StackableScope headStackableScope(Thread thread);
535
536 /**
537 * Sets the top of the current thread's stackable scope stack.
538 */
539 void setHeadStackableScope(StackableScope scope);
540
541 /**
542 * Returns the Thread object for the current platform thread. If the
543 * current thread is a virtual thread then this method returns the carrier.
544 */
545 Thread currentCarrierThread();
546
547 /**
548 * Returns the value of the current carrier thread's copy of a thread-local.
549 */
550 <T> T getCarrierThreadLocal(CarrierThreadLocal<T> local);
551
552 /**
553 * Sets the value of the current carrier thread's copy of a thread-local.
554 */
555 <T> void setCarrierThreadLocal(CarrierThreadLocal<T> local, T value);
556
557 /**
558 * Removes the value of the current carrier thread's copy of a thread-local.
559 */
560 void removeCarrierThreadLocal(CarrierThreadLocal<?> local);
561
562 /**
563 * Returns the current thread's scoped values cache
564 */
565 Object[] scopedValueCache();
566
567 /**
568 * Sets the current thread's scoped values cache
569 */
570 void setScopedValueCache(Object[] cache);
571
572 /**
573 * Return the current thread's scoped value bindings.
574 */
575 Object scopedValueBindings();
576
577 /**
578 * Returns the native thread ID for the given platform thread or 0 if not set.
579 */
580 long nativeThreadID(Thread thread);
581
582 /**
583 * Sets the native thread ID for the current platform thread.
584 */
585 void setThreadNativeID(long id);
586
587 /**
588 * Returns the innermost mounted continuation
589 */
590 Continuation getContinuation(Thread thread);
591
592 /**
593 * Sets the innermost mounted continuation
594 */
595 void setContinuation(Thread thread, Continuation continuation);
596
597 /**
598 * The ContinuationScope of virtual thread continuations
599 */
600 ContinuationScope virtualThreadContinuationScope();
601
602 /**
603 * Parks the current virtual thread.
604 * @throws WrongThreadException if the current thread is not a virtual thread
605 */
606 void parkVirtualThread();
607
608 /**
609 * Parks the current virtual thread for up to the given waiting time.
610 * @param nanos the maximum number of nanoseconds to wait
611 * @throws WrongThreadException if the current thread is not a virtual thread
612 */
613 void parkVirtualThread(long nanos);
614
615 /**
616 * Re-enables a virtual thread for scheduling. If the thread is parked then it will
617 * be scheduled to continue, otherwise its next attempt to park will not block.
618 * @param thread the virtual thread to unpark
619 * @throws IllegalArgumentException if the thread is not a virtual thread
620 * @throws RejectedExecutionException if the scheduler cannot accept a task
621 */
622 void unparkVirtualThread(Thread thread);
623
624 /**
625 * Returns the builtin virtual thread scheduler.
626 */
627 Thread.VirtualThreadScheduler builtinVirtualThreadScheduler();
628
629 /**
630 * Returns the default virtual thread scheduler.
631 */
632 Thread.VirtualThreadScheduler defaultVirtualThreadScheduler();
633
634 /**
635 * Creates a new StackWalker
636 */
637 StackWalker newStackWalkerInstance(Set<StackWalker.Option> options,
638 ContinuationScope contScope,
639 Continuation continuation);
640 /**
641 * Returns '<loader-name>' @<id> if classloader has a name
642 * explicitly set otherwise <qualified-class-name> @<id>
643 */
644 String getLoaderNameID(ClassLoader loader);
645
646 /**
647 * Copy the string bytes to an existing segment, avoiding intermediate copies.
648 */
649 void copyToSegmentRaw(String string, MemorySegment segment, long offset, int srcIndex, int srcLength);
650
651 /**
652 * Are the string bytes compatible with the given charset?
653 */
654 boolean bytesCompatible(String string, Charset charset, int srcIndex, int numChars);
655
656 /**
657 * Finish initialization of the StackTraceElement objects in a stack trace.
658 */
659 void finishInit(StackTraceElement[] stackTrace);
660 }