1 /*
2 * Copyright (c) 2008, 2018, 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 java.lang.invoke;
27
28 import jdk.internal.misc.Unsafe;
29 import jdk.internal.vm.annotation.ForceInline;
30 import jdk.internal.vm.annotation.Stable;
31 import sun.invoke.util.ValueConversions;
32 import sun.invoke.util.VerifyAccess;
33 import sun.invoke.util.VerifyType;
34 import sun.invoke.util.Wrapper;
35
36 import java.lang.ref.WeakReference;
37 import java.util.Arrays;
38 import java.util.Objects;
39
40 import static java.lang.invoke.LambdaForm.*;
41 import static java.lang.invoke.LambdaForm.Kind.*;
42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
43 import static java.lang.invoke.MethodHandleStatics.UNSAFE;
44 import static java.lang.invoke.MethodHandleStatics.newInternalError;
45 import static java.lang.invoke.MethodTypeForm.*;
46
47 /**
48 * The flavor of method handle which implements a constant reference
49 * to a class member.
50 * @author jrose
51 */
52 class DirectMethodHandle extends MethodHandle {
53 final MemberName member;
54
55 // Constructors and factory methods in this class *must* be package scoped or private.
56 private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) {
57 super(mtype, form);
58 if (!member.isResolved()) throw new InternalError();
59
60 if (member.getDeclaringClass().isInterface() &&
61 member.getReferenceKind() == REF_invokeInterface &&
62 member.isMethod() && !member.isAbstract()) {
63 // Check for corner case: invokeinterface of Object method
64 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
65 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
66 if (m != null && m.isPublic()) {
67 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
68 member = m;
69 }
70 }
71
72 this.member = member;
73 }
74
75 // Factory methods:
76 static DirectMethodHandle make(byte refKind, Class<?> refc, MemberName member, Class<?> callerClass) {
77 MethodType mtype = member.getMethodOrFieldType();
78 if (!member.isStatic()) {
79 if (!member.getDeclaringClass().isAssignableFrom(refc) || member.isConstructor())
80 throw new InternalError(member.toString());
81 mtype = mtype.insertParameterTypes(0, refc);
82 }
83 if (!member.isField()) {
84 // refKind reflects the original type of lookup via findSpecial or
85 // findVirtual etc.
86 switch (refKind) {
87 case REF_invokeSpecial: {
88 member = member.asSpecial();
89 // if caller is an interface we need to adapt to get the
90 // receiver check inserted
91 if (callerClass == null) {
92 throw new InternalError("callerClass must not be null for REF_invokeSpecial");
93 }
94 LambdaForm lform = preparedLambdaForm(member, callerClass.isInterface());
95 return new Special(mtype, lform, member, callerClass);
96 }
97 case REF_invokeInterface: {
98 // for interfaces we always need the receiver typecheck,
99 // so we always pass 'true' to ensure we adapt if needed
100 // to include the REF_invokeSpecial case
101 LambdaForm lform = preparedLambdaForm(member, true);
102 return new Interface(mtype, lform, member, refc);
103 }
104 default: {
105 LambdaForm lform = preparedLambdaForm(member);
106 return new DirectMethodHandle(mtype, lform, member);
107 }
108 }
109 } else {
110 LambdaForm lform = preparedFieldLambdaForm(member);
111 if (member.isStatic()) {
112 long offset = MethodHandleNatives.staticFieldOffset(member);
113 Object base = MethodHandleNatives.staticFieldBase(member);
114 return member.canBeNull() ? new StaticAccessor(mtype, lform, member, base, offset)
115 : new StaticValueAccessor(mtype, lform, member, base, offset);
116 } else {
117 long offset = MethodHandleNatives.objectFieldOffset(member);
118 assert(offset == (int)offset);
119 return member.canBeNull() ? new Accessor(mtype, lform, member, (int)offset)
120 : new ValueAccessor(mtype, lform, member, (int)offset);
121
122 }
123 }
124 }
125 static DirectMethodHandle make(Class<?> refc, MemberName member) {
126 byte refKind = member.getReferenceKind();
127 if (refKind == REF_invokeSpecial)
128 refKind = REF_invokeVirtual;
129 return make(refKind, refc, member, null /* no callerClass context */);
130 }
131 static DirectMethodHandle make(MemberName member) {
132 if (member.isConstructor())
133 return makeAllocator(member);
134 return make(member.getDeclaringClass(), member);
135 }
136 private static DirectMethodHandle makeAllocator(MemberName ctor) {
137 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
138 Class<?> instanceClass = ctor.getDeclaringClass();
139 ctor = ctor.asConstructor();
140 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
141 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
142 LambdaForm lform = preparedLambdaForm(ctor);
143 MemberName init = ctor.asSpecial();
144 assert(init.getMethodType().returnType() == void.class);
145 return new Constructor(mtype, lform, ctor, init, instanceClass);
146 }
147
148 @Override
149 BoundMethodHandle rebind() {
150 return BoundMethodHandle.makeReinvoker(this);
151 }
152
153 @Override
154 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
155 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
156 return new DirectMethodHandle(mt, lf, member);
157 }
158
159 @Override
160 String internalProperties() {
161 return "\n& DMH.MN="+internalMemberName();
162 }
163
164 //// Implementation methods.
165 @Override
166 @ForceInline
167 MemberName internalMemberName() {
168 return member;
169 }
170
171 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
172
173 /**
174 * Create a LF which can invoke the given method.
175 * Cache and share this structure among all methods with
176 * the same basicType and refKind.
177 */
178 private static LambdaForm preparedLambdaForm(MemberName m, boolean adaptToSpecialIfc) {
179 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
180 MethodType mtype = m.getInvocationType().basicType();
181 assert(!m.isMethodHandleInvoke()) : m;
182 int which;
183 // MemberName.getReferenceKind represents the JVM optimized form of the call
184 // as distinct from the "kind" passed to DMH.make which represents the original
185 // bytecode-equivalent request. Specifically private/final methods that use a direct
186 // call have getReferenceKind adapted to REF_invokeSpecial, even though the actual
187 // invocation mode may be invokevirtual or invokeinterface.
188 switch (m.getReferenceKind()) {
189 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
190 case REF_invokeStatic: which = LF_INVSTATIC; break;
191 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
192 case REF_invokeInterface: which = LF_INVINTERFACE; break;
193 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
194 default: throw new InternalError(m.toString());
195 }
196 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
197 // precompute the barrier-free version:
198 preparedLambdaForm(mtype, which);
199 which = LF_INVSTATIC_INIT;
200 }
201 if (which == LF_INVSPECIAL && adaptToSpecialIfc) {
202 which = LF_INVSPECIAL_IFC;
203 }
204 LambdaForm lform = preparedLambdaForm(mtype, which);
205 maybeCompile(lform, m);
206 assert(lform.methodType().dropParameterTypes(0, 1)
207 .equals(m.getInvocationType().basicType()))
208 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
209 return lform;
210 }
211
212 private static LambdaForm preparedLambdaForm(MemberName m) {
213 return preparedLambdaForm(m, false);
214 }
215
216 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
217 LambdaForm lform = mtype.form().cachedLambdaForm(which);
218 if (lform != null) return lform;
219 lform = makePreparedLambdaForm(mtype, which);
220 return mtype.form().setCachedLambdaForm(which, lform);
221 }
222
223 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
224 boolean needsInit = (which == LF_INVSTATIC_INIT);
225 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
226 boolean needsReceiverCheck = (which == LF_INVINTERFACE ||
227 which == LF_INVSPECIAL_IFC);
228
229 String linkerName;
230 LambdaForm.Kind kind;
231 switch (which) {
232 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break;
233 case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break;
234 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break;
235 case LF_INVSPECIAL_IFC:linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL_IFC; break;
236 case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break;
237 case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break;
238 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break;
239 default: throw new InternalError("which="+which);
240 }
241
242 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
243 if (doesAlloc)
244 mtypeWithArg = mtypeWithArg
245 .insertParameterTypes(0, Object.class) // insert newly allocated obj
246 .changeReturnType(void.class); // <init> returns void
247 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
248 try {
249 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
250 } catch (ReflectiveOperationException ex) {
251 throw newInternalError(ex);
252 }
253 final int DMH_THIS = 0;
254 final int ARG_BASE = 1;
255 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
256 int nameCursor = ARG_LIMIT;
257 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
258 final int GET_MEMBER = nameCursor++;
259 final int CHECK_RECEIVER = (needsReceiverCheck ? nameCursor++ : -1);
260 final int LINKER_CALL = nameCursor++;
261 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
262 assert(names.length == nameCursor);
263 if (doesAlloc) {
264 // names = { argx,y,z,... new C, init method }
265 names[NEW_OBJ] = new Name(getFunction(NF_allocateInstance), names[DMH_THIS]);
266 names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]);
267 } else if (needsInit) {
268 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]);
269 } else {
270 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberName), names[DMH_THIS]);
271 }
272 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
273 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
274 if (needsReceiverCheck) {
275 names[CHECK_RECEIVER] = new Name(getFunction(NF_checkReceiver), names[DMH_THIS], names[ARG_BASE]);
276 outArgs[0] = names[CHECK_RECEIVER];
277 }
278 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
279 int result = LAST_RESULT;
280 if (doesAlloc) {
281 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
282 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
283 outArgs[0] = names[NEW_OBJ];
284 result = NEW_OBJ;
285 }
286 names[LINKER_CALL] = new Name(linker, outArgs);
287 LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind);
288
289 // This is a tricky bit of code. Don't send it through the LF interpreter.
290 lform.compileToBytecode();
291 return lform;
292 }
293
294 /* assert */ static Object findDirectMethodHandle(Name name) {
295 if (name.function.equals(getFunction(NF_internalMemberName)) ||
296 name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) ||
297 name.function.equals(getFunction(NF_constructorMethod))) {
298 assert(name.arguments.length == 1);
299 return name.arguments[0];
300 }
301 return null;
302 }
303
304 private static void maybeCompile(LambdaForm lform, MemberName m) {
305 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
306 // Help along bootstrapping...
307 lform.compileToBytecode();
308 }
309
310 /** Static wrapper for DirectMethodHandle.internalMemberName. */
311 @ForceInline
312 /*non-public*/ static Object internalMemberName(Object mh) {
313 return ((DirectMethodHandle)mh).member;
314 }
315
316 /** Static wrapper for DirectMethodHandle.internalMemberName.
317 * This one also forces initialization.
318 */
319 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
320 DirectMethodHandle dmh = (DirectMethodHandle)mh;
321 dmh.ensureInitialized();
322 return dmh.member;
323 }
324
325 /*non-public*/ static
326 boolean shouldBeInitialized(MemberName member) {
327 switch (member.getReferenceKind()) {
328 case REF_invokeStatic:
329 case REF_getStatic:
330 case REF_putStatic:
331 case REF_newInvokeSpecial:
332 break;
333 default:
334 // No need to initialize the class on this kind of member.
335 return false;
336 }
337 Class<?> cls = member.getDeclaringClass();
338 if (cls == ValueConversions.class ||
339 cls == MethodHandleImpl.class ||
340 cls == Invokers.class) {
341 // These guys have lots of <clinit> DMH creation but we know
342 // the MHs will not be used until the system is booted.
343 return false;
344 }
345 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
346 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
347 // It is a system class. It is probably in the process of
348 // being initialized, but we will help it along just to be safe.
349 if (UNSAFE.shouldBeInitialized(cls)) {
350 UNSAFE.ensureClassInitialized(cls);
351 }
352 return false;
353 }
354 return UNSAFE.shouldBeInitialized(cls);
355 }
356
357 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
358 @Override
359 protected WeakReference<Thread> computeValue(Class<?> type) {
360 UNSAFE.ensureClassInitialized(type);
361 if (UNSAFE.shouldBeInitialized(type))
362 // If the previous call didn't block, this can happen.
363 // We are executing inside <clinit>.
364 return new WeakReference<>(Thread.currentThread());
365 return null;
366 }
367 static final EnsureInitialized INSTANCE = new EnsureInitialized();
368 }
369
370 private void ensureInitialized() {
371 if (checkInitialized(member)) {
372 // The coast is clear. Delete the <clinit> barrier.
373 if (member.isField())
374 updateForm(preparedFieldLambdaForm(member));
375 else
376 updateForm(preparedLambdaForm(member));
377 }
378 }
379 private static boolean checkInitialized(MemberName member) {
380 Class<?> defc = member.getDeclaringClass();
381 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
382 if (ref == null) {
383 return true; // the final state
384 }
385 Thread clinitThread = ref.get();
386 // Somebody may still be running defc.<clinit>.
387 if (clinitThread == Thread.currentThread()) {
388 // If anybody is running defc.<clinit>, it is this thread.
389 if (UNSAFE.shouldBeInitialized(defc))
390 // Yes, we are running it; keep the barrier for now.
391 return false;
392 } else {
393 // We are in a random thread. Block.
394 UNSAFE.ensureClassInitialized(defc);
395 }
396 assert(!UNSAFE.shouldBeInitialized(defc));
397 // put it into the final state
398 EnsureInitialized.INSTANCE.remove(defc);
399 return true;
400 }
401
402 /*non-public*/ static void ensureInitialized(Object mh) {
403 ((DirectMethodHandle)mh).ensureInitialized();
404 }
405
406 /** This subclass represents invokespecial instructions. */
407 static class Special extends DirectMethodHandle {
408 private final Class<?> caller;
409 private Special(MethodType mtype, LambdaForm form, MemberName member, Class<?> caller) {
410 super(mtype, form, member);
411 this.caller = caller;
412 }
413 @Override
414 boolean isInvokeSpecial() {
415 return true;
416 }
417 @Override
418 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
419 return new Special(mt, lf, member, caller);
420 }
421 Object checkReceiver(Object recv) {
422 if (!caller.isInstance(recv)) {
423 String msg = String.format("Receiver class %s is not a subclass of caller class %s",
424 recv.getClass().getName(), caller.getName());
425 throw new IncompatibleClassChangeError(msg);
426 }
427 return recv;
428 }
429 }
430
431 /** This subclass represents invokeinterface instructions. */
432 static class Interface extends DirectMethodHandle {
433 private final Class<?> refc;
434 private Interface(MethodType mtype, LambdaForm form, MemberName member, Class<?> refc) {
435 super(mtype, form, member);
436 assert refc.isInterface() : refc;
437 this.refc = refc;
438 }
439 @Override
440 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
441 return new Interface(mt, lf, member, refc);
442 }
443 @Override
444 Object checkReceiver(Object recv) {
445 if (!refc.isInstance(recv)) {
446 String msg = String.format("Receiver class %s does not implement the requested interface %s",
447 recv.getClass().getName(), refc.getName());
448 throw new IncompatibleClassChangeError(msg);
449 }
450 return recv;
451 }
452 }
453
454 /** Used for interface receiver type checks, by Interface and Special modes. */
455 Object checkReceiver(Object recv) {
456 throw new InternalError("Should only be invoked on a subclass");
457 }
458
459
460 /** This subclass handles constructor references. */
461 static class Constructor extends DirectMethodHandle {
462 final MemberName initMethod;
463 final Class<?> instanceClass;
464
465 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
466 MemberName initMethod, Class<?> instanceClass) {
467 super(mtype, form, constructor);
468 this.initMethod = initMethod;
469 this.instanceClass = instanceClass;
470 assert(initMethod.isResolved());
471 }
472 @Override
473 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
474 return new Constructor(mt, lf, member, initMethod, instanceClass);
475 }
476 }
477
478 /*non-public*/ static Object constructorMethod(Object mh) {
479 Constructor dmh = (Constructor)mh;
480 return dmh.initMethod;
481 }
482
483 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
484 Constructor dmh = (Constructor)mh;
485 return UNSAFE.allocateInstance(dmh.instanceClass);
486 }
487
488 /** This subclass handles non-static field references. */
489 static class Accessor extends DirectMethodHandle {
490 final Class<?> fieldType;
491 final int fieldOffset;
492 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
493 int fieldOffset) {
494 super(mtype, form, member);
495 this.fieldType = member.getFieldType();
496 this.fieldOffset = fieldOffset;
497 }
498
499 @Override Object checkCast(Object obj) {
500 return fieldType.cast(obj);
501 }
502 @Override
503 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
504 return new Accessor(mt, lf, member, fieldOffset);
505 }
506 }
507
508 static class ValueAccessor extends Accessor {
509 private ValueAccessor(MethodType mtype, LambdaForm form, MemberName member,
510 int fieldOffset) {
511 super(mtype, form, member, fieldOffset);
512 }
513
514 @Override Object checkCast(Object obj) {
515 return fieldType.cast(Objects.requireNonNull(obj));
516 }
517 @Override
518 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
519 return new ValueAccessor(mt, lf, member, fieldOffset);
520 }
521 }
522
523 @ForceInline
524 /*non-public*/ static long fieldOffset(Object accessorObj) {
525 // Note: We return a long because that is what Unsafe.getObject likes.
526 // We store a plain int because it is more compact.
527 return ((Accessor)accessorObj).fieldOffset;
528 }
529
530 @ForceInline
531 /*non-public*/ static Object checkBase(Object obj) {
532 // Note that the object's class has already been verified,
533 // since the parameter type of the Accessor method handle
534 // is either member.getDeclaringClass or a subclass.
535 // This was verified in DirectMethodHandle.make.
536 // Therefore, the only remaining check is for null.
537 // Since this check is *not* guaranteed by Unsafe.getInt
538 // and its siblings, we need to make an explicit one here.
539 return Objects.requireNonNull(obj);
540 }
541
542 /** This subclass handles static field references. */
543 static class StaticAccessor extends DirectMethodHandle {
544 final Class<?> fieldType;
545 final Object staticBase;
546 final long staticOffset;
547
548 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
549 Object staticBase, long staticOffset) {
550 super(mtype, form, member);
551 this.fieldType = member.getFieldType();
552 this.staticBase = staticBase;
553 this.staticOffset = staticOffset;
554 }
555
556 @Override Object checkCast(Object obj) {
557 return fieldType.cast(obj);
558 }
559 @Override
560 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
561 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
562 }
563 }
564
565 static class StaticValueAccessor extends StaticAccessor {
566 private StaticValueAccessor(MethodType mtype, LambdaForm form, MemberName member,
567 Object staticBase, long staticOffset) {
568 super(mtype, form, member, staticBase, staticOffset);
569 }
570
571 @Override Object checkCast(Object obj) {
572 return fieldType.cast(Objects.requireNonNull(obj));
573 }
574 @Override
575 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
576 return new StaticValueAccessor(mt, lf, member, staticBase, staticOffset);
577 }
578 }
579
580
581 @ForceInline
582 /*non-public*/ static Object nullCheck(Object obj) {
583 return Objects.requireNonNull(obj);
584 }
585
586 @ForceInline
587 /*non-public*/ static Object staticBase(Object accessorObj) {
588 return ((StaticAccessor)accessorObj).staticBase;
589 }
590
591 @ForceInline
592 /*non-public*/ static long staticOffset(Object accessorObj) {
593 return ((StaticAccessor)accessorObj).staticOffset;
594 }
595
596 @ForceInline
597 /*non-public*/ static Object checkCast(Object mh, Object obj) {
598 return ((DirectMethodHandle) mh).checkCast(obj);
599 }
600
601 @ForceInline
602 /*non-public*/ static Class<?> fieldValueType(Object accessorObj) {
603 return ((Accessor) accessorObj).fieldType;
604 }
605
606 @ForceInline
607 /*non-public*/ static Class<?> staticFieldValueType(Object accessorObj) {
608 return ((StaticAccessor) accessorObj).fieldType;
609 }
610
611 Object checkCast(Object obj) {
612 return member.getReturnType().cast(obj);
613 }
614
615 // Caching machinery for field accessors:
616 static final byte
617 AF_GETFIELD = 0,
618 AF_PUTFIELD = 1,
619 AF_GETSTATIC = 2,
620 AF_PUTSTATIC = 3,
621 AF_GETSTATIC_INIT = 4,
622 AF_PUTSTATIC_INIT = 5,
623 AF_LIMIT = 6;
624 // Enumerate the different field kinds using Wrapper,
625 // with an extra case added for checked references and value field access
626 static final int
627 FT_LAST_WRAPPER = Wrapper.COUNT-1,
628 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
629 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
630 FT_CHECKED_VALUE = FT_LAST_WRAPPER+2, // flattened and non-flattened
631 FT_LIMIT = FT_LAST_WRAPPER+4;
632 private static int afIndex(byte formOp, boolean isVolatile, boolean isFlatValue, int ftypeKind) {
633 return ((formOp * FT_LIMIT * 2)
634 + (isVolatile ? FT_LIMIT : 0)
635 + (isFlatValue ? 1 : 0)
636 + ftypeKind);
637 }
638 @Stable
639 private static final LambdaForm[] ACCESSOR_FORMS
640 = new LambdaForm[afIndex(AF_LIMIT, false, false, 0)];
641 static int ftypeKind(Class<?> ftype, boolean canBeNull) {
642 if (ftype.isPrimitive())
643 return Wrapper.forPrimitiveType(ftype).ordinal();
644 else if (VerifyType.isNullReferenceConversion(Object.class, ftype)) {
645 return FT_UNCHECKED_REF;
646 } else
647 // null check for value type in addition to check cast
648 return canBeNull ? FT_CHECKED_REF : FT_CHECKED_VALUE;
649 }
650
651 /**
652 * Create a LF which can access the given field.
653 * Cache and share this structure among all fields with
654 * the same basicType and refKind.
655 */
656 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
657 Class<?> ftype = m.getFieldType();
658 boolean isVolatile = m.isVolatile();
659 boolean isFlatValue = m.isFlatValue();
660 boolean canBeNull = m.canBeNull();
661 byte formOp;
662 switch (m.getReferenceKind()) {
663 case REF_getField: formOp = AF_GETFIELD; break;
664 case REF_putField: formOp = AF_PUTFIELD; break;
665 case REF_getStatic: formOp = AF_GETSTATIC; break;
666 case REF_putStatic: formOp = AF_PUTSTATIC; break;
667 default: throw new InternalError(m.toString());
668 }
669 if (shouldBeInitialized(m)) {
670 // precompute the barrier-free version:
671 preparedFieldLambdaForm(formOp, isVolatile, isFlatValue , canBeNull, ftype);
672 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
673 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
674 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
675 }
676 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, isFlatValue , canBeNull, ftype);
677 maybeCompile(lform, m);
678 assert(lform.methodType().dropParameterTypes(0, 1)
679 .equals(m.getInvocationType().basicType()))
680 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
681 return lform;
682 }
683
684 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, boolean isFlatValue, boolean canBeNull, Class<?> ftype) {
685 int ftypeKind = ftypeKind(ftype, canBeNull);
686 int afIndex = afIndex(formOp, isVolatile, isFlatValue, ftypeKind);
687 LambdaForm lform = ACCESSOR_FORMS[afIndex];
688 if (lform != null) return lform;
689 lform = makePreparedFieldLambdaForm(formOp, isVolatile, isFlatValue, ftypeKind);
690 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
691 return lform;
692 }
693
694 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
695
696 private static Kind getFieldKind(boolean isGetter, boolean isVolatile, boolean isFlatValue, Wrapper wrapper) {
697 if (isGetter) {
698 if (isVolatile) {
699 switch (wrapper) {
700 case BOOLEAN: return GET_BOOLEAN_VOLATILE;
701 case BYTE: return GET_BYTE_VOLATILE;
702 case SHORT: return GET_SHORT_VOLATILE;
703 case CHAR: return GET_CHAR_VOLATILE;
704 case INT: return GET_INT_VOLATILE;
705 case LONG: return GET_LONG_VOLATILE;
706 case FLOAT: return GET_FLOAT_VOLATILE;
707 case DOUBLE: return GET_DOUBLE_VOLATILE;
708 case OBJECT: return isFlatValue ? GET_VALUE_VOLATILE : GET_REFERENCE_VOLATILE;
709 }
710 } else {
711 switch (wrapper) {
712 case BOOLEAN: return GET_BOOLEAN;
713 case BYTE: return GET_BYTE;
714 case SHORT: return GET_SHORT;
715 case CHAR: return GET_CHAR;
716 case INT: return GET_INT;
717 case LONG: return GET_LONG;
718 case FLOAT: return GET_FLOAT;
719 case DOUBLE: return GET_DOUBLE;
720 case OBJECT: return isFlatValue ? GET_VALUE : GET_REFERENCE;
721 }
722 }
723 } else {
724 if (isVolatile) {
725 switch (wrapper) {
726 case BOOLEAN: return PUT_BOOLEAN_VOLATILE;
727 case BYTE: return PUT_BYTE_VOLATILE;
728 case SHORT: return PUT_SHORT_VOLATILE;
729 case CHAR: return PUT_CHAR_VOLATILE;
730 case INT: return PUT_INT_VOLATILE;
731 case LONG: return PUT_LONG_VOLATILE;
732 case FLOAT: return PUT_FLOAT_VOLATILE;
733 case DOUBLE: return PUT_DOUBLE_VOLATILE;
734 case OBJECT: return isFlatValue ? PUT_VALUE_VOLATILE : PUT_REFERENCE_VOLATILE;
735 }
736 } else {
737 switch (wrapper) {
738 case BOOLEAN: return PUT_BOOLEAN;
739 case BYTE: return PUT_BYTE;
740 case SHORT: return PUT_SHORT;
741 case CHAR: return PUT_CHAR;
742 case INT: return PUT_INT;
743 case LONG: return PUT_LONG;
744 case FLOAT: return PUT_FLOAT;
745 case DOUBLE: return PUT_DOUBLE;
746 case OBJECT: return isFlatValue ? PUT_VALUE : PUT_REFERENCE;
747 }
748 }
749 }
750 throw new AssertionError("Invalid arguments");
751 }
752
753 static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, boolean isFlatValue, int ftypeKind) {
754 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
755 boolean isStatic = (formOp >= AF_GETSTATIC);
756 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
757 boolean needsCast = (ftypeKind == FT_CHECKED_REF || ftypeKind == FT_CHECKED_VALUE);
758 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
759 Class<?> ft = fw.primitiveType();
760 assert(needsCast ? true : ftypeKind(ft, ftypeKind != FT_CHECKED_VALUE) == ftypeKind);
761
762 // getObject, putIntVolatile, etc.
763 Kind kind = getFieldKind(isGetter, isVolatile, isFlatValue, fw);
764
765 MethodType linkerType;
766 if (isFlatValue) {
767 linkerType = isGetter ? MethodType.methodType(ft, Object.class, long.class, Class.class)
768 : MethodType.methodType(void.class, Object.class, long.class, Class.class, ft);
769 } else {
770 linkerType = isGetter ? MethodType.methodType(ft, Object.class, long.class)
771 : MethodType.methodType(void.class, Object.class, long.class, ft);
772 }
773 MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual);
774 try {
775 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
776 } catch (ReflectiveOperationException ex) {
777 throw newInternalError(ex);
778 }
779
780 // What is the external type of the lambda form?
781 MethodType mtype;
782 if (isGetter)
783 mtype = MethodType.methodType(ft);
784 else
785 mtype = MethodType.methodType(void.class, ft);
786 mtype = mtype.basicType(); // erase short to int, etc.
787 if (!isStatic)
788 mtype = mtype.insertParameterTypes(0, Object.class);
789 final int DMH_THIS = 0;
790 final int ARG_BASE = 1;
791 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
792 // if this is for non-static access, the base pointer is stored at this index:
793 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
794 // if this is for write access, the value to be written is stored at this index:
795 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
796 int nameCursor = ARG_LIMIT;
797 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
798 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
799 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
800 final int U_HOLDER = nameCursor++; // UNSAFE holder
801 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
802 final int VALUE_TYPE = (isFlatValue ? nameCursor++ : -1);
803 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
804 final int LINKER_CALL = nameCursor++;
805 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
806 final int RESULT = nameCursor-1; // either the call or the cast
807 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
808 if (needsInit)
809 names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]);
810 if (needsCast && !isGetter)
811 names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]);
812 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
813 assert (outArgs.length == (isFlatValue ? (isGetter ? 4 : 5) : (isGetter ? 3 : 4)));
814 outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE));
815 if (isStatic) {
816 outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]);
817 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]);
818 } else {
819 outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]);
820 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]);
821 }
822 int x = 3;
823 if (isFlatValue) {
824 outArgs[x++] = names[VALUE_TYPE] = isStatic ? new Name(getFunction(NF_staticFieldValueType), names[DMH_THIS])
825 : new Name(getFunction(NF_fieldValueType), names[DMH_THIS]);
826 }
827 if (!isGetter) {
828 outArgs[x] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
829 }
830 for (Object a : outArgs) assert(a != null);
831 names[LINKER_CALL] = new Name(linker, outArgs);
832 if (needsCast && isGetter)
833 names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]);
834 for (Name n : names) assert(n != null);
835
836 LambdaForm form;
837 if (needsCast || needsInit) {
838 // can't use the pre-generated form when casting and/or initializing
839 form = new LambdaForm(ARG_LIMIT, names, RESULT);
840 } else {
841 form = new LambdaForm(ARG_LIMIT, names, RESULT, kind);
842 }
843
844 if (LambdaForm.debugNames()) {
845 // add some detail to the lambdaForm debugname,
846 // significant only for debugging
847 StringBuilder nameBuilder = new StringBuilder(kind.methodName);
848 if (isStatic) {
849 nameBuilder.append("Static");
850 } else {
851 nameBuilder.append("Field");
852 }
853 if (needsCast) {
854 nameBuilder.append("Cast");
855 }
856 if (needsInit) {
857 nameBuilder.append("Init");
858 }
859 LambdaForm.associateWithDebugName(form, nameBuilder.toString());
860 }
861 return form;
862 }
863
864 /**
865 * Pre-initialized NamedFunctions for bootstrapping purposes.
866 */
867 static final byte NF_internalMemberName = 0,
868 NF_internalMemberNameEnsureInit = 1,
869 NF_ensureInitialized = 2,
870 NF_fieldOffset = 3,
871 NF_checkBase = 4,
872 NF_staticBase = 5,
873 NF_staticOffset = 6,
874 NF_checkCast = 7,
875 NF_allocateInstance = 8,
876 NF_constructorMethod = 9,
877 NF_UNSAFE = 10,
878 NF_checkReceiver = 11,
879 NF_fieldValueType = 12,
880 NF_staticFieldValueType = 13,
881 NF_LIMIT = 14;
882
883 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
884
885 private static NamedFunction getFunction(byte func) {
886 NamedFunction nf = NFS[func];
887 if (nf != null) {
888 return nf;
889 }
890 // Each nf must be statically invocable or we get tied up in our bootstraps.
891 nf = NFS[func] = createFunction(func);
892 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf));
893 return nf;
894 }
895
896 private static final MethodType CLS_OBJ_TYPE = MethodType.methodType(Class.class, Object.class);
897
898 private static final MethodType OBJ_OBJ_TYPE = MethodType.methodType(Object.class, Object.class);
899
900 private static final MethodType LONG_OBJ_TYPE = MethodType.methodType(long.class, Object.class);
901
902 private static NamedFunction createFunction(byte func) {
903 try {
904 switch (func) {
905 case NF_internalMemberName:
906 return getNamedFunction("internalMemberName", OBJ_OBJ_TYPE);
907 case NF_internalMemberNameEnsureInit:
908 return getNamedFunction("internalMemberNameEnsureInit", OBJ_OBJ_TYPE);
909 case NF_ensureInitialized:
910 return getNamedFunction("ensureInitialized", MethodType.methodType(void.class, Object.class));
911 case NF_fieldOffset:
912 return getNamedFunction("fieldOffset", LONG_OBJ_TYPE);
913 case NF_checkBase:
914 return getNamedFunction("checkBase", OBJ_OBJ_TYPE);
915 case NF_staticBase:
916 return getNamedFunction("staticBase", OBJ_OBJ_TYPE);
917 case NF_staticOffset:
918 return getNamedFunction("staticOffset", LONG_OBJ_TYPE);
919 case NF_checkCast:
920 return getNamedFunction("checkCast", MethodType.methodType(Object.class, Object.class, Object.class));
921 case NF_allocateInstance:
922 return getNamedFunction("allocateInstance", OBJ_OBJ_TYPE);
923 case NF_constructorMethod:
924 return getNamedFunction("constructorMethod", OBJ_OBJ_TYPE);
925 case NF_UNSAFE:
926 MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getField);
927 return new NamedFunction(
928 MemberName.getFactory()
929 .resolveOrFail(REF_getField, member, DirectMethodHandle.class, NoSuchMethodException.class));
930 case NF_checkReceiver:
931 member = new MemberName(DirectMethodHandle.class, "checkReceiver", OBJ_OBJ_TYPE, REF_invokeVirtual);
932 return new NamedFunction(
933 MemberName.getFactory()
934 .resolveOrFail(REF_invokeVirtual, member, DirectMethodHandle.class, NoSuchMethodException.class));
935 case NF_fieldValueType:
936 return getNamedFunction("fieldValueType", CLS_OBJ_TYPE);
937 case NF_staticFieldValueType:
938 return getNamedFunction("staticFieldValueType", CLS_OBJ_TYPE);
939 default:
940 throw newInternalError("Unknown function: " + func);
941 }
942 } catch (ReflectiveOperationException ex) {
943 throw newInternalError(ex);
944 }
945 }
946
947 private static NamedFunction getNamedFunction(String name, MethodType type)
948 throws ReflectiveOperationException
949 {
950 MemberName member = new MemberName(DirectMethodHandle.class, name, type, REF_invokeStatic);
951 return new NamedFunction(
952 MemberName.getFactory()
953 .resolveOrFail(REF_invokeStatic, member, DirectMethodHandle.class, NoSuchMethodException.class));
954 }
955
956 static {
957 // The Holder class will contain pre-generated DirectMethodHandles resolved
958 // speculatively using MemberName.getFactory().resolveOrNull. However, that
959 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
960 // initialization of the Holder class we avoid these issues.
961 UNSAFE.ensureClassInitialized(Holder.class);
962 }
963
964 /* Placeholder class for DirectMethodHandles generated ahead of time */
965 final class Holder {}
966 }