1 /*
2 * Copyright (c) 2008, 2013, 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.isMethod() && !member.isAbstract()) {
62 // Check for corner case: invokeinterface of Object method
63 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
64 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
65 if (m != null && m.isPublic()) {
66 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
67 member = m;
68 }
69 }
70
71 this.member = member;
72 }
73
74 // Factory methods:
75 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
76 MethodType mtype = member.getMethodOrFieldType();
77 if (!member.isStatic()) {
78 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
79 throw new InternalError(member.toString());
80 mtype = mtype.insertParameterTypes(0, receiver);
81 }
82 if (!member.isField()) {
83 if (refKind == REF_invokeSpecial) {
84 member = member.asSpecial();
85 LambdaForm lform = preparedLambdaForm(member);
86 return new Special(mtype, lform, member);
87 } else {
88 LambdaForm lform = preparedLambdaForm(member);
89 return new DirectMethodHandle(mtype, lform, member);
90 }
91 } else {
92 LambdaForm lform = preparedFieldLambdaForm(member);
93 if (member.isStatic()) {
94 long offset = MethodHandleNatives.staticFieldOffset(member);
95 Object base = MethodHandleNatives.staticFieldBase(member);
96 return new StaticAccessor(mtype, lform, member, base, offset);
97 } else {
98 long offset = MethodHandleNatives.objectFieldOffset(member);
99 assert(offset == (int)offset);
100 return new Accessor(mtype, lform, member, (int)offset);
101 }
102 }
103 }
104 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
105 byte refKind = member.getReferenceKind();
106 if (refKind == REF_invokeSpecial)
107 refKind = REF_invokeVirtual;
108 return make(refKind, receiver, member);
109 }
110 static DirectMethodHandle make(MemberName member) {
111 if (member.isConstructor())
112 return makeAllocator(member);
113 return make(member.getDeclaringClass(), member);
114 }
115 private static DirectMethodHandle makeAllocator(MemberName ctor) {
116 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
117 Class<?> instanceClass = ctor.getDeclaringClass();
118 ctor = ctor.asConstructor();
119 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
120 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
121 LambdaForm lform = preparedLambdaForm(ctor);
122 MemberName init = ctor.asSpecial();
123 assert(init.getMethodType().returnType() == void.class);
124 return new Constructor(mtype, lform, ctor, init, instanceClass);
125 }
126
127 @Override
128 BoundMethodHandle rebind() {
129 return BoundMethodHandle.makeReinvoker(this);
130 }
131
132 @Override
133 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
134 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
135 return new DirectMethodHandle(mt, lf, member);
136 }
137
138 @Override
139 String internalProperties() {
140 return "\n& DMH.MN="+internalMemberName();
141 }
142
143 //// Implementation methods.
144 @Override
145 @ForceInline
146 MemberName internalMemberName() {
147 return member;
148 }
149
150 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
151
152 /**
153 * Create a LF which can invoke the given method.
154 * Cache and share this structure among all methods with
155 * the same basicType and refKind.
156 */
157 private static LambdaForm preparedLambdaForm(MemberName m) {
158 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
159 MethodType mtype = m.getInvocationType().basicType();
160 assert(!m.isMethodHandleInvoke()) : m;
161 int which;
162 switch (m.getReferenceKind()) {
163 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
164 case REF_invokeStatic: which = LF_INVSTATIC; break;
165 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
166 case REF_invokeInterface: which = LF_INVINTERFACE; break;
167 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
168 default: throw new InternalError(m.toString());
169 }
170 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
171 // precompute the barrier-free version:
172 preparedLambdaForm(mtype, which);
173 which = LF_INVSTATIC_INIT;
174 }
175 LambdaForm lform = preparedLambdaForm(mtype, which);
176 maybeCompile(lform, m);
177 assert(lform.methodType().dropParameterTypes(0, 1)
178 .equals(m.getInvocationType().basicType()))
179 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
180 return lform;
181 }
182
183 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
184 LambdaForm lform = mtype.form().cachedLambdaForm(which);
185 if (lform != null) return lform;
186 lform = makePreparedLambdaForm(mtype, which);
187 return mtype.form().setCachedLambdaForm(which, lform);
188 }
189
190 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
191 boolean needsInit = (which == LF_INVSTATIC_INIT);
192 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
193 String linkerName;
194 LambdaForm.Kind kind;
195 switch (which) {
196 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break;
197 case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break;
198 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break;
199 case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break;
200 case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break;
201 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break;
202 default: throw new InternalError("which="+which);
203 }
204
205 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
206 if (doesAlloc)
207 mtypeWithArg = mtypeWithArg
208 .insertParameterTypes(0, Object.class) // insert newly allocated obj
209 .changeReturnType(void.class); // <init> returns void
210 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
211 try {
212 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
213 } catch (ReflectiveOperationException ex) {
214 throw newInternalError(ex);
215 }
216 final int DMH_THIS = 0;
217 final int ARG_BASE = 1;
218 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
219 int nameCursor = ARG_LIMIT;
220 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
221 final int GET_MEMBER = nameCursor++;
222 final int LINKER_CALL = nameCursor++;
223 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
224 assert(names.length == nameCursor);
225 if (doesAlloc) {
226 // names = { argx,y,z,... new C, init method }
227 names[NEW_OBJ] = new Name(getFunction(NF_allocateInstance), names[DMH_THIS]);
228 names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]);
229 } else if (needsInit) {
230 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]);
231 } else {
232 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberName), names[DMH_THIS]);
233 }
234 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
235 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
236 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
237 int result = LAST_RESULT;
238 if (doesAlloc) {
239 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
240 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
241 outArgs[0] = names[NEW_OBJ];
242 result = NEW_OBJ;
243 }
244 names[LINKER_CALL] = new Name(linker, outArgs);
245 LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind);
246
247 // This is a tricky bit of code. Don't send it through the LF interpreter.
248 lform.compileToBytecode();
249 return lform;
250 }
251
252 /* assert */ static Object findDirectMethodHandle(Name name) {
253 if (name.function.equals(getFunction(NF_internalMemberName)) ||
254 name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) ||
255 name.function.equals(getFunction(NF_constructorMethod))) {
256 assert(name.arguments.length == 1);
257 return name.arguments[0];
258 }
259 return null;
260 }
261
262 private static void maybeCompile(LambdaForm lform, MemberName m) {
263 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
264 // Help along bootstrapping...
265 lform.compileToBytecode();
266 }
267
268 /** Static wrapper for DirectMethodHandle.internalMemberName. */
269 @ForceInline
270 /*non-public*/ static Object internalMemberName(Object mh) {
271 return ((DirectMethodHandle)mh).member;
272 }
273
274 /** Static wrapper for DirectMethodHandle.internalMemberName.
275 * This one also forces initialization.
276 */
277 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
278 DirectMethodHandle dmh = (DirectMethodHandle)mh;
279 dmh.ensureInitialized();
280 return dmh.member;
281 }
282
283 /*non-public*/ static
284 boolean shouldBeInitialized(MemberName member) {
285 switch (member.getReferenceKind()) {
286 case REF_invokeStatic:
287 case REF_getStatic:
288 case REF_putStatic:
289 case REF_newInvokeSpecial:
290 break;
291 default:
292 // No need to initialize the class on this kind of member.
293 return false;
294 }
295 Class<?> cls = member.getDeclaringClass();
296 if (cls == ValueConversions.class ||
297 cls == MethodHandleImpl.class ||
298 cls == Invokers.class) {
299 // These guys have lots of <clinit> DMH creation but we know
300 // the MHs will not be used until the system is booted.
301 return false;
302 }
303 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
304 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
305 // It is a system class. It is probably in the process of
306 // being initialized, but we will help it along just to be safe.
307 if (UNSAFE.shouldBeInitialized(cls)) {
308 UNSAFE.ensureClassInitialized(cls);
309 }
310 return false;
311 }
312 return UNSAFE.shouldBeInitialized(cls);
313 }
314
315 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
316 @Override
317 protected WeakReference<Thread> computeValue(Class<?> type) {
318 UNSAFE.ensureClassInitialized(type);
319 if (UNSAFE.shouldBeInitialized(type))
320 // If the previous call didn't block, this can happen.
321 // We are executing inside <clinit>.
322 return new WeakReference<>(Thread.currentThread());
323 return null;
324 }
325 static final EnsureInitialized INSTANCE = new EnsureInitialized();
326 }
327
328 private void ensureInitialized() {
329 if (checkInitialized(member)) {
330 // The coast is clear. Delete the <clinit> barrier.
331 if (member.isField())
332 updateForm(preparedFieldLambdaForm(member));
333 else
334 updateForm(preparedLambdaForm(member));
335 }
336 }
337 private static boolean checkInitialized(MemberName member) {
338 Class<?> defc = member.getDeclaringClass();
339 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
340 if (ref == null) {
341 return true; // the final state
342 }
343 Thread clinitThread = ref.get();
344 // Somebody may still be running defc.<clinit>.
345 if (clinitThread == Thread.currentThread()) {
346 // If anybody is running defc.<clinit>, it is this thread.
347 if (UNSAFE.shouldBeInitialized(defc))
348 // Yes, we are running it; keep the barrier for now.
349 return false;
350 } else {
351 // We are in a random thread. Block.
352 UNSAFE.ensureClassInitialized(defc);
353 }
354 assert(!UNSAFE.shouldBeInitialized(defc));
355 // put it into the final state
356 EnsureInitialized.INSTANCE.remove(defc);
357 return true;
358 }
359
360 /*non-public*/ static void ensureInitialized(Object mh) {
361 ((DirectMethodHandle)mh).ensureInitialized();
362 }
363
364 /** This subclass represents invokespecial instructions. */
365 static class Special extends DirectMethodHandle {
366 private Special(MethodType mtype, LambdaForm form, MemberName member) {
367 super(mtype, form, member);
368 }
369 @Override
370 boolean isInvokeSpecial() {
371 return true;
372 }
373 @Override
374 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
375 return new Special(mt, lf, member);
376 }
377 }
378
379 /** This subclass handles constructor references. */
380 static class Constructor extends DirectMethodHandle {
381 final MemberName initMethod;
382 final Class<?> instanceClass;
383
384 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
385 MemberName initMethod, Class<?> instanceClass) {
386 super(mtype, form, constructor);
387 this.initMethod = initMethod;
388 this.instanceClass = instanceClass;
389 assert(initMethod.isResolved());
390 }
391 @Override
392 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
393 return new Constructor(mt, lf, member, initMethod, instanceClass);
394 }
395 }
396
397 /*non-public*/ static Object constructorMethod(Object mh) {
398 Constructor dmh = (Constructor)mh;
399 return dmh.initMethod;
400 }
401
402 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
403 Constructor dmh = (Constructor)mh;
404 return UNSAFE.allocateInstance(dmh.instanceClass);
405 }
406
407 /** This subclass handles non-static field references. */
408 static class Accessor extends DirectMethodHandle {
409 final Class<?> fieldType;
410 final int fieldOffset;
411 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
412 int fieldOffset) {
413 super(mtype, form, member);
414 this.fieldType = member.getFieldType();
415 this.fieldOffset = fieldOffset;
416 }
417
418 @Override Object checkCast(Object obj) {
419 return fieldType.cast(obj);
420 }
421 @Override
422 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
423 return new Accessor(mt, lf, member, fieldOffset);
424 }
425 }
426
427 @ForceInline
428 /*non-public*/ static long fieldOffset(Object accessorObj) {
429 // Note: We return a long because that is what Unsafe.getObject likes.
430 // We store a plain int because it is more compact.
431 return ((Accessor)accessorObj).fieldOffset;
432 }
433
434 @ForceInline
435 /*non-public*/ static Object checkBase(Object obj) {
436 // Note that the object's class has already been verified,
437 // since the parameter type of the Accessor method handle
438 // is either member.getDeclaringClass or a subclass.
439 // This was verified in DirectMethodHandle.make.
440 // Therefore, the only remaining check is for null.
441 // Since this check is *not* guaranteed by Unsafe.getInt
442 // and its siblings, we need to make an explicit one here.
443 return Objects.requireNonNull(obj);
444 }
445
446 /** This subclass handles static field references. */
447 static class StaticAccessor extends DirectMethodHandle {
448 private final Class<?> fieldType;
449 private final Object staticBase;
450 private final long staticOffset;
451
452 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
453 Object staticBase, long staticOffset) {
454 super(mtype, form, member);
455 this.fieldType = member.getFieldType();
456 this.staticBase = staticBase;
457 this.staticOffset = staticOffset;
458 }
459
460 @Override Object checkCast(Object obj) {
461 return fieldType.cast(obj);
462 }
463 @Override
464 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
465 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
466 }
467 }
468
469 @ForceInline
470 /*non-public*/ static Object nullCheck(Object obj) {
471 return Objects.requireNonNull(obj);
472 }
473
474 @ForceInline
475 /*non-public*/ static Object staticBase(Object accessorObj) {
476 return ((StaticAccessor)accessorObj).staticBase;
477 }
478
479 @ForceInline
480 /*non-public*/ static long staticOffset(Object accessorObj) {
481 return ((StaticAccessor)accessorObj).staticOffset;
482 }
483
484 @ForceInline
485 /*non-public*/ static Object checkCast(Object mh, Object obj) {
486 return ((DirectMethodHandle) mh).checkCast(obj);
487 }
488
489 Object checkCast(Object obj) {
490 return member.getReturnType().cast(obj);
491 }
492
493 // Caching machinery for field accessors:
494 static final byte
495 AF_GETFIELD = 0,
496 AF_PUTFIELD = 1,
497 AF_GETSTATIC = 2,
498 AF_PUTSTATIC = 3,
499 AF_GETSTATIC_INIT = 4,
500 AF_PUTSTATIC_INIT = 5,
501 AF_LIMIT = 6;
502 // Enumerate the different field kinds using Wrapper,
503 // with an extra case added for checked references.
504 static final int
505 FT_LAST_WRAPPER = Wrapper.COUNT-1,
506 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
507 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
508 FT_LIMIT = FT_LAST_WRAPPER+2;
509 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
510 return ((formOp * FT_LIMIT * 2)
511 + (isVolatile ? FT_LIMIT : 0)
512 + ftypeKind);
513 }
514 @Stable
515 private static final LambdaForm[] ACCESSOR_FORMS
516 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
517 static int ftypeKind(Class<?> ftype) {
518 if (ftype.isPrimitive())
519 return Wrapper.forPrimitiveType(ftype).ordinal();
520 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
521 return FT_UNCHECKED_REF;
522 else
523 return FT_CHECKED_REF;
524 }
525
526 /**
527 * Create a LF which can access the given field.
528 * Cache and share this structure among all fields with
529 * the same basicType and refKind.
530 */
531 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
532 Class<?> ftype = m.getFieldType();
533 boolean isVolatile = m.isVolatile();
534 byte formOp;
535 switch (m.getReferenceKind()) {
536 case REF_getField: formOp = AF_GETFIELD; break;
537 case REF_putField: formOp = AF_PUTFIELD; break;
538 case REF_getStatic: formOp = AF_GETSTATIC; break;
539 case REF_putStatic: formOp = AF_PUTSTATIC; break;
540 default: throw new InternalError(m.toString());
541 }
542 if (shouldBeInitialized(m)) {
543 // precompute the barrier-free version:
544 preparedFieldLambdaForm(formOp, isVolatile, ftype);
545 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
546 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
547 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
548 }
549 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
550 maybeCompile(lform, m);
551 assert(lform.methodType().dropParameterTypes(0, 1)
552 .equals(m.getInvocationType().basicType()))
553 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
554 return lform;
555 }
556 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
557 int ftypeKind = ftypeKind(ftype);
558 int afIndex = afIndex(formOp, isVolatile, ftypeKind);
559 LambdaForm lform = ACCESSOR_FORMS[afIndex];
560 if (lform != null) return lform;
561 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind);
562 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
563 return lform;
564 }
565
566 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
567
568 private static Kind getFieldKind(boolean isGetter, boolean isVolatile, Wrapper wrapper) {
569 if (isGetter) {
570 if (isVolatile) {
571 switch (wrapper) {
572 case BOOLEAN: return GET_BOOLEAN_VOLATILE;
573 case BYTE: return GET_BYTE_VOLATILE;
574 case SHORT: return GET_SHORT_VOLATILE;
575 case CHAR: return GET_CHAR_VOLATILE;
576 case INT: return GET_INT_VOLATILE;
577 case LONG: return GET_LONG_VOLATILE;
578 case FLOAT: return GET_FLOAT_VOLATILE;
579 case DOUBLE: return GET_DOUBLE_VOLATILE;
580 case OBJECT: return GET_OBJECT_VOLATILE;
581 }
582 } else {
583 switch (wrapper) {
584 case BOOLEAN: return GET_BOOLEAN;
585 case BYTE: return GET_BYTE;
586 case SHORT: return GET_SHORT;
587 case CHAR: return GET_CHAR;
588 case INT: return GET_INT;
589 case LONG: return GET_LONG;
590 case FLOAT: return GET_FLOAT;
591 case DOUBLE: return GET_DOUBLE;
592 case OBJECT: return GET_OBJECT;
593 }
594 }
595 } else {
596 if (isVolatile) {
597 switch (wrapper) {
598 case BOOLEAN: return PUT_BOOLEAN_VOLATILE;
599 case BYTE: return PUT_BYTE_VOLATILE;
600 case SHORT: return PUT_SHORT_VOLATILE;
601 case CHAR: return PUT_CHAR_VOLATILE;
602 case INT: return PUT_INT_VOLATILE;
603 case LONG: return PUT_LONG_VOLATILE;
604 case FLOAT: return PUT_FLOAT_VOLATILE;
605 case DOUBLE: return PUT_DOUBLE_VOLATILE;
606 case OBJECT: return PUT_OBJECT_VOLATILE;
607 }
608 } else {
609 switch (wrapper) {
610 case BOOLEAN: return PUT_BOOLEAN;
611 case BYTE: return PUT_BYTE;
612 case SHORT: return PUT_SHORT;
613 case CHAR: return PUT_CHAR;
614 case INT: return PUT_INT;
615 case LONG: return PUT_LONG;
616 case FLOAT: return PUT_FLOAT;
617 case DOUBLE: return PUT_DOUBLE;
618 case OBJECT: return PUT_OBJECT;
619 }
620 }
621 }
622 throw new AssertionError("Invalid arguments");
623 }
624
625 static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
626 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
627 boolean isStatic = (formOp >= AF_GETSTATIC);
628 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
629 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
630 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
631 Class<?> ft = fw.primitiveType();
632 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
633
634 // getObject, putIntVolatile, etc.
635 Kind kind = getFieldKind(isGetter, isVolatile, fw);
636
637 MethodType linkerType;
638 if (isGetter)
639 linkerType = MethodType.methodType(ft, Object.class, long.class);
640 else
641 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
642 MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual);
643 try {
644 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
645 } catch (ReflectiveOperationException ex) {
646 throw newInternalError(ex);
647 }
648
649 // What is the external type of the lambda form?
650 MethodType mtype;
651 if (isGetter)
652 mtype = MethodType.methodType(ft);
653 else
654 mtype = MethodType.methodType(void.class, ft);
655 mtype = mtype.basicType(); // erase short to int, etc.
656 if (!isStatic)
657 mtype = mtype.insertParameterTypes(0, Object.class);
658 final int DMH_THIS = 0;
659 final int ARG_BASE = 1;
660 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
661 // if this is for non-static access, the base pointer is stored at this index:
662 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
663 // if this is for write access, the value to be written is stored at this index:
664 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
665 int nameCursor = ARG_LIMIT;
666 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
667 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
668 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
669 final int U_HOLDER = nameCursor++; // UNSAFE holder
670 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
671 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
672 final int LINKER_CALL = nameCursor++;
673 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
674 final int RESULT = nameCursor-1; // either the call or the cast
675 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
676 if (needsInit)
677 names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]);
678 if (needsCast && !isGetter)
679 names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]);
680 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
681 assert(outArgs.length == (isGetter ? 3 : 4));
682 outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE));
683 if (isStatic) {
684 outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]);
685 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]);
686 } else {
687 outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]);
688 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]);
689 }
690 if (!isGetter) {
691 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
692 }
693 for (Object a : outArgs) assert(a != null);
694 names[LINKER_CALL] = new Name(linker, outArgs);
695 if (needsCast && isGetter)
696 names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]);
697 for (Name n : names) assert(n != null);
698
699 LambdaForm form;
700 if (needsCast || needsInit) {
701 // can't use the pre-generated form when casting and/or initializing
702 form = new LambdaForm(ARG_LIMIT, names, RESULT);
703 } else {
704 form = new LambdaForm(ARG_LIMIT, names, RESULT, kind);
705 }
706
707 if (LambdaForm.debugNames()) {
708 // add some detail to the lambdaForm debugname,
709 // significant only for debugging
710 StringBuilder nameBuilder = new StringBuilder(kind.methodName);
711 if (isStatic) {
712 nameBuilder.append("Static");
713 } else {
714 nameBuilder.append("Field");
715 }
716 if (needsCast) {
717 nameBuilder.append("Cast");
718 }
719 if (needsInit) {
720 nameBuilder.append("Init");
721 }
722 LambdaForm.associateWithDebugName(form, nameBuilder.toString());
723 }
724 return form;
725 }
726
727 /**
728 * Pre-initialized NamedFunctions for bootstrapping purposes.
729 */
730 static final byte NF_internalMemberName = 0,
731 NF_internalMemberNameEnsureInit = 1,
732 NF_ensureInitialized = 2,
733 NF_fieldOffset = 3,
734 NF_checkBase = 4,
735 NF_staticBase = 5,
736 NF_staticOffset = 6,
737 NF_checkCast = 7,
738 NF_allocateInstance = 8,
739 NF_constructorMethod = 9,
740 NF_UNSAFE = 10,
741 NF_LIMIT = 11;
742
743 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
744
745 private static NamedFunction getFunction(byte func) {
746 NamedFunction nf = NFS[func];
747 if (nf != null) {
748 return nf;
749 }
750 // Each nf must be statically invocable or we get tied up in our bootstraps.
751 nf = NFS[func] = createFunction(func);
752 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf));
753 return nf;
754 }
755
756 private static final MethodType OBJ_OBJ_TYPE = MethodType.methodType(Object.class, Object.class);
757
758 private static final MethodType LONG_OBJ_TYPE = MethodType.methodType(long.class, Object.class);
759
760 private static NamedFunction createFunction(byte func) {
761 try {
762 switch (func) {
763 case NF_internalMemberName:
764 return getNamedFunction("internalMemberName", OBJ_OBJ_TYPE);
765 case NF_internalMemberNameEnsureInit:
766 return getNamedFunction("internalMemberNameEnsureInit", OBJ_OBJ_TYPE);
767 case NF_ensureInitialized:
768 return getNamedFunction("ensureInitialized", MethodType.methodType(void.class, Object.class));
769 case NF_fieldOffset:
770 return getNamedFunction("fieldOffset", LONG_OBJ_TYPE);
771 case NF_checkBase:
772 return getNamedFunction("checkBase", OBJ_OBJ_TYPE);
773 case NF_staticBase:
774 return getNamedFunction("staticBase", OBJ_OBJ_TYPE);
775 case NF_staticOffset:
776 return getNamedFunction("staticOffset", LONG_OBJ_TYPE);
777 case NF_checkCast:
778 return getNamedFunction("checkCast", MethodType.methodType(Object.class, Object.class, Object.class));
779 case NF_allocateInstance:
780 return getNamedFunction("allocateInstance", OBJ_OBJ_TYPE);
781 case NF_constructorMethod:
782 return getNamedFunction("constructorMethod", OBJ_OBJ_TYPE);
783 case NF_UNSAFE:
784 MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getField);
785 return new NamedFunction(
786 MemberName.getFactory()
787 .resolveOrFail(REF_getField, member, DirectMethodHandle.class, NoSuchMethodException.class));
788 default:
789 throw newInternalError("Unknown function: " + func);
790 }
791 } catch (ReflectiveOperationException ex) {
792 throw newInternalError(ex);
793 }
794 }
795
796 private static NamedFunction getNamedFunction(String name, MethodType type)
797 throws ReflectiveOperationException
798 {
799 MemberName member = new MemberName(DirectMethodHandle.class, name, type, REF_invokeStatic);
800 return new NamedFunction(
801 MemberName.getFactory()
802 .resolveOrFail(REF_invokeStatic, member, DirectMethodHandle.class, NoSuchMethodException.class));
803 }
804
805 static {
806 // The Holder class will contain pre-generated DirectMethodHandles resolved
807 // speculatively using MemberName.getFactory().resolveOrNull. However, that
808 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
809 // initialization of the Holder class we avoid these issues.
810 UNSAFE.ensureClassInitialized(Holder.class);
811 }
812
813 /* Placeholder class for DirectMethodHandles generated ahead of time */
814 final class Holder {}
815 }