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 sun.misc.Unsafe;
29 import java.lang.reflect.Method;
30 import java.util.Arrays;
31 import sun.invoke.util.VerifyAccess;
32 import static java.lang.invoke.MethodHandleNatives.Constants.*;
33 import static java.lang.invoke.LambdaForm.*;
34 import static java.lang.invoke.MethodTypeForm.*;
35 import static java.lang.invoke.MethodHandleStatics.*;
36 import java.lang.ref.WeakReference;
37 import java.lang.reflect.Field;
38 import sun.invoke.util.ValueConversions;
39 import sun.invoke.util.VerifyType;
40 import sun.invoke.util.Wrapper;
41
42 /**
43 * The flavor of method handle which implements a constant reference
44 * to a class member.
45 * @author jrose
46 */
47 class DirectMethodHandle extends MethodHandle {
48 final MemberName member;
49
50 // Constructors and factory methods in this class *must* be package scoped or private.
51 private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) {
52 super(mtype, form);
53 if (!member.isResolved()) throw new InternalError();
54
55 if (member.getDeclaringClass().isInterface() &&
56 member.isMethod() && !member.isAbstract()) {
57 // Check for corner case: invokeinterface of Object method
58 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
59 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
60 if (m != null && m.isPublic()) {
61 member = m;
62 }
63 }
64
65 this.member = member;
66 }
67
68 // Factory methods:
69 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
70 MethodType mtype = member.getMethodOrFieldType();
71 if (!member.isStatic()) {
72 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
73 throw new InternalError(member.toString());
74 mtype = mtype.insertParameterTypes(0, receiver);
75 }
76 if (!member.isField()) {
77 if (refKind == REF_invokeSpecial) {
78 member = member.asSpecial();
79 LambdaForm lform = preparedLambdaForm(member);
80 return new Special(mtype, lform, member);
81 } else {
82 LambdaForm lform = preparedLambdaForm(member);
83 return new DirectMethodHandle(mtype, lform, member);
84 }
85 } else {
86 LambdaForm lform = preparedFieldLambdaForm(member);
87 if (member.isStatic()) {
88 long offset = MethodHandleNatives.staticFieldOffset(member);
89 Object base = MethodHandleNatives.staticFieldBase(member);
90 return new StaticAccessor(mtype, lform, member, base, offset);
91 } else {
92 long offset = MethodHandleNatives.objectFieldOffset(member);
93 assert(offset == (int)offset);
94 return new Accessor(mtype, lform, member, (int)offset);
95 }
96 }
97 }
98 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
99 byte refKind = member.getReferenceKind();
100 if (refKind == REF_invokeSpecial)
101 refKind = REF_invokeVirtual;
102 return make(refKind, receiver, member);
103 }
104 static DirectMethodHandle make(MemberName member) {
105 if (member.isConstructor())
106 return makeAllocator(member);
107 return make(member.getDeclaringClass(), member);
108 }
109 static DirectMethodHandle make(Method method) {
110 return make(method.getDeclaringClass(), new MemberName(method));
111 }
112 static DirectMethodHandle make(Field field) {
113 return make(field.getDeclaringClass(), new MemberName(field));
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 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
129 return new DirectMethodHandle(mt, lf, member);
130 }
131
132 @Override
133 String internalProperties() {
134 return "/DMH="+member.toString();
135 }
136
137 //// Implementation methods.
138 @Override
139 MethodHandle viewAsType(MethodType newType) {
140 return new DirectMethodHandle(newType, form, member);
141 }
142 @Override
143 @ForceInline
144 MemberName internalMemberName() {
145 return member;
146 }
147
148 @Override
149 MethodHandle bindArgument(int pos, byte basicType, Object value) {
150 // If the member needs dispatching, do so.
151 if (pos == 0 && basicType == 'L') {
152 DirectMethodHandle concrete = maybeRebind(value);
153 if (concrete != null)
154 return concrete.bindReceiver(value);
155 }
156 return super.bindArgument(pos, basicType, value);
157 }
158
159 @Override
160 MethodHandle bindReceiver(Object receiver) {
161 // If the member needs dispatching, do so.
162 DirectMethodHandle concrete = maybeRebind(receiver);
163 if (concrete != null)
164 return concrete.bindReceiver(receiver);
165 return super.bindReceiver(receiver);
166 }
167
168 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
169
170 private DirectMethodHandle maybeRebind(Object receiver) {
171 if (receiver != null) {
172 switch (member.getReferenceKind()) {
173 case REF_invokeInterface:
174 case REF_invokeVirtual:
175 // Pre-dispatch the member.
176 Class<?> concreteClass = receiver.getClass();
177 MemberName concrete = new MemberName(concreteClass, member.getName(), member.getMethodType(), REF_invokeSpecial);
178 concrete = IMPL_NAMES.resolveOrNull(REF_invokeSpecial, concrete, concreteClass);
179 if (concrete != null)
180 return new DirectMethodHandle(type(), preparedLambdaForm(concrete), concrete);
181 break;
182 }
183 }
184 return null;
185 }
186
187 /**
188 * Create a LF which can invoke the given method.
189 * Cache and share this structure among all methods with
190 * the same basicType and refKind.
191 */
192 private static LambdaForm preparedLambdaForm(MemberName m) {
193 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
194 MethodType mtype = m.getInvocationType().basicType();
195 assert(!m.isMethodHandleInvoke() || "invokeBasic".equals(m.getName())) : m;
196 int which;
197 switch (m.getReferenceKind()) {
198 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
199 case REF_invokeStatic: which = LF_INVSTATIC; break;
200 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
201 case REF_invokeInterface: which = LF_INVINTERFACE; break;
202 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
203 default: throw new InternalError(m.toString());
204 }
205 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
206 // precompute the barrier-free version:
207 preparedLambdaForm(mtype, which);
208 which = LF_INVSTATIC_INIT;
209 }
210 LambdaForm lform = preparedLambdaForm(mtype, which);
211 maybeCompile(lform, m);
212 assert(lform.methodType().dropParameterTypes(0, 1)
213 .equals(m.getInvocationType().basicType()))
214 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
215 return lform;
216 }
217
218 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
219 LambdaForm lform = mtype.form().cachedLambdaForm(which);
220 if (lform != null) return lform;
221 lform = makePreparedLambdaForm(mtype, which);
222 return mtype.form().setCachedLambdaForm(which, lform);
223 }
224
225 private static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
226 boolean needsInit = (which == LF_INVSTATIC_INIT);
227 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
228 String linkerName, lambdaName;
229 switch (which) {
230 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; lambdaName = "DMH.invokeVirtual"; break;
231 case LF_INVSTATIC: linkerName = "linkToStatic"; lambdaName = "DMH.invokeStatic"; break;
232 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; lambdaName = "DMH.invokeStaticInit"; break;
233 case LF_INVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.invokeSpecial"; break;
234 case LF_INVINTERFACE: linkerName = "linkToInterface"; lambdaName = "DMH.invokeInterface"; break;
235 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.newInvokeSpecial"; break;
236 default: throw new InternalError("which="+which);
237 }
238 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
239 if (doesAlloc)
240 mtypeWithArg = mtypeWithArg
241 .insertParameterTypes(0, Object.class) // insert newly allocated obj
242 .changeReturnType(void.class); // <init> returns void
243 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
244 try {
245 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
246 } catch (ReflectiveOperationException ex) {
247 throw newInternalError(ex);
248 }
249 final int DMH_THIS = 0;
250 final int ARG_BASE = 1;
251 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
252 int nameCursor = ARG_LIMIT;
253 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
254 final int GET_MEMBER = nameCursor++;
255 final int LINKER_CALL = nameCursor++;
256 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
257 assert(names.length == nameCursor);
258 if (doesAlloc) {
259 // names = { argx,y,z,... new C, init method }
260 names[NEW_OBJ] = new Name(Lazy.NF_allocateInstance, names[DMH_THIS]);
261 names[GET_MEMBER] = new Name(Lazy.NF_constructorMethod, names[DMH_THIS]);
262 } else if (needsInit) {
263 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberNameEnsureInit, names[DMH_THIS]);
264 } else {
265 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberName, names[DMH_THIS]);
266 }
267 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
268 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
269 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
270 int result = LAST_RESULT;
271 if (doesAlloc) {
272 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
273 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
274 outArgs[0] = names[NEW_OBJ];
275 result = NEW_OBJ;
276 }
277 names[LINKER_CALL] = new Name(linker, outArgs);
278 lambdaName += "_" + shortenSignature(basicTypeSignature(mtype));
279 LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result);
280 // This is a tricky bit of code. Don't send it through the LF interpreter.
281 lform.compileToBytecode();
282 return lform;
283 }
284
285 static Object findDirectMethodHandle(Name name) {
286 if (name.function == Lazy.NF_internalMemberName ||
287 name.function == Lazy.NF_internalMemberNameEnsureInit ||
288 name.function == Lazy.NF_constructorMethod) {
289 assert(name.arguments.length == 1);
290 return name.arguments[0];
291 }
292 return null;
293 }
294
295 private static void maybeCompile(LambdaForm lform, MemberName m) {
296 if (VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
297 // Help along bootstrapping...
298 lform.compileToBytecode();
299 }
300
301 /** Static wrapper for DirectMethodHandle.internalMemberName. */
302 @ForceInline
303 /*non-public*/ static Object internalMemberName(Object mh) {
304 return ((DirectMethodHandle)mh).member;
305 }
306
307 /** Static wrapper for DirectMethodHandle.internalMemberName.
308 * This one also forces initialization.
309 */
310 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
311 DirectMethodHandle dmh = (DirectMethodHandle)mh;
312 dmh.ensureInitialized();
313 return dmh.member;
314 }
315
316 /*non-public*/ static
317 boolean shouldBeInitialized(MemberName member) {
318 switch (member.getReferenceKind()) {
319 case REF_invokeStatic:
320 case REF_getStatic:
321 case REF_putStatic:
322 case REF_newInvokeSpecial:
323 break;
324 default:
325 // No need to initialize the class on this kind of member.
326 return false;
327 }
328 Class<?> cls = member.getDeclaringClass();
329 if (cls == ValueConversions.class ||
330 cls == MethodHandleImpl.class ||
331 cls == Invokers.class) {
332 // These guys have lots of <clinit> DMH creation but we know
333 // the MHs will not be used until the system is booted.
334 return false;
335 }
336 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
337 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
338 // It is a system class. It is probably in the process of
339 // being initialized, but we will help it along just to be safe.
340 if (UNSAFE.shouldBeInitialized(cls)) {
341 UNSAFE.ensureClassInitialized(cls);
342 }
343 return false;
344 }
345 return UNSAFE.shouldBeInitialized(cls);
346 }
347
348 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
349 @Override
350 protected WeakReference<Thread> computeValue(Class<?> type) {
351 UNSAFE.ensureClassInitialized(type);
352 if (UNSAFE.shouldBeInitialized(type))
353 // If the previous call didn't block, this can happen.
354 // We are executing inside <clinit>.
355 return new WeakReference<>(Thread.currentThread());
356 return null;
357 }
358 static final EnsureInitialized INSTANCE = new EnsureInitialized();
359 }
360
361 private void ensureInitialized() {
362 if (checkInitialized(member)) {
363 // The coast is clear. Delete the <clinit> barrier.
364 if (member.isField())
365 updateForm(preparedFieldLambdaForm(member));
366 else
367 updateForm(preparedLambdaForm(member));
368 }
369 }
370 private static boolean checkInitialized(MemberName member) {
371 Class<?> defc = member.getDeclaringClass();
372 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
373 if (ref == null) {
374 return true; // the final state
375 }
376 Thread clinitThread = ref.get();
377 // Somebody may still be running defc.<clinit>.
378 if (clinitThread == Thread.currentThread()) {
379 // If anybody is running defc.<clinit>, it is this thread.
380 if (UNSAFE.shouldBeInitialized(defc))
381 // Yes, we are running it; keep the barrier for now.
382 return false;
383 } else {
384 // We are in a random thread. Block.
385 UNSAFE.ensureClassInitialized(defc);
386 }
387 assert(!UNSAFE.shouldBeInitialized(defc));
388 // put it into the final state
389 EnsureInitialized.INSTANCE.remove(defc);
390 return true;
391 }
392
393 /*non-public*/ static void ensureInitialized(Object mh) {
394 ((DirectMethodHandle)mh).ensureInitialized();
395 }
396
397 /** This subclass represents invokespecial instructions. */
398 static class Special extends DirectMethodHandle {
399 private Special(MethodType mtype, LambdaForm form, MemberName member) {
400 super(mtype, form, member);
401 }
402 @Override
403 boolean isInvokeSpecial() {
404 return true;
405 }
406 @Override
407 MethodHandle viewAsType(MethodType newType) {
408 return new Special(newType, form, member);
409 }
410 }
411
412 /** This subclass handles constructor references. */
413 static class Constructor extends DirectMethodHandle {
414 final MemberName initMethod;
415 final Class<?> instanceClass;
416
417 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
418 MemberName initMethod, Class<?> instanceClass) {
419 super(mtype, form, constructor);
420 this.initMethod = initMethod;
421 this.instanceClass = instanceClass;
422 assert(initMethod.isResolved());
423 }
424 @Override
425 MethodHandle viewAsType(MethodType newType) {
426 return new Constructor(newType, form, member, initMethod, instanceClass);
427 }
428 }
429
430 /*non-public*/ static Object constructorMethod(Object mh) {
431 Constructor dmh = (Constructor)mh;
432 return dmh.initMethod;
433 }
434
435 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
436 Constructor dmh = (Constructor)mh;
437 return UNSAFE.allocateInstance(dmh.instanceClass);
438 }
439
440 /** This subclass handles non-static field references. */
441 static class Accessor extends DirectMethodHandle {
442 final Class<?> fieldType;
443 final int fieldOffset;
444 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
445 int fieldOffset) {
446 super(mtype, form, member);
447 this.fieldType = member.getFieldType();
448 this.fieldOffset = fieldOffset;
449 }
450
451 @Override Object checkCast(Object obj) {
452 return fieldType.cast(obj);
453 }
454 @Override
455 MethodHandle viewAsType(MethodType newType) {
456 return new Accessor(newType, form, member, fieldOffset);
457 }
458 }
459
460 @ForceInline
461 /*non-public*/ static long fieldOffset(Object accessorObj) {
462 // Note: We return a long because that is what Unsafe.getObject likes.
463 // We store a plain int because it is more compact.
464 return ((Accessor)accessorObj).fieldOffset;
465 }
466
467 @ForceInline
468 /*non-public*/ static Object checkBase(Object obj) {
469 // Note that the object's class has already been verified,
470 // since the parameter type of the Accessor method handle
471 // is either member.getDeclaringClass or a subclass.
472 // This was verified in DirectMethodHandle.make.
473 // Therefore, the only remaining check is for null.
474 // Since this check is *not* guaranteed by Unsafe.getInt
475 // and its siblings, we need to make an explicit one here.
476 obj.getClass(); // maybe throw NPE
477 return obj;
478 }
479
480 /** This subclass handles static field references. */
481 static class StaticAccessor extends DirectMethodHandle {
482 final private Class<?> fieldType;
483 final private Object staticBase;
484 final private long staticOffset;
485
486 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
487 Object staticBase, long staticOffset) {
488 super(mtype, form, member);
489 this.fieldType = member.getFieldType();
490 this.staticBase = staticBase;
491 this.staticOffset = staticOffset;
492 }
493
494 @Override Object checkCast(Object obj) {
495 return fieldType.cast(obj);
496 }
497 @Override
498 MethodHandle viewAsType(MethodType newType) {
499 return new StaticAccessor(newType, form, member, staticBase, staticOffset);
500 }
501 }
502
503 @ForceInline
504 /*non-public*/ static Object nullCheck(Object obj) {
505 obj.getClass();
506 return obj;
507 }
508
509 @ForceInline
510 /*non-public*/ static Object staticBase(Object accessorObj) {
511 return ((StaticAccessor)accessorObj).staticBase;
512 }
513
514 @ForceInline
515 /*non-public*/ static long staticOffset(Object accessorObj) {
516 return ((StaticAccessor)accessorObj).staticOffset;
517 }
518
519 @ForceInline
520 /*non-public*/ static Object checkCast(Object mh, Object obj) {
521 return ((DirectMethodHandle) mh).checkCast(obj);
522 }
523
524 Object checkCast(Object obj) {
525 return member.getReturnType().cast(obj);
526 }
527
528 // Caching machinery for field accessors:
529 private static byte
530 AF_GETFIELD = 0,
531 AF_PUTFIELD = 1,
532 AF_GETSTATIC = 2,
533 AF_PUTSTATIC = 3,
534 AF_GETSTATIC_INIT = 4,
535 AF_PUTSTATIC_INIT = 5,
536 AF_LIMIT = 6;
537 // Enumerate the different field kinds using Wrapper,
538 // with an extra case added for checked references.
539 private static int
540 FT_LAST_WRAPPER = Wrapper.values().length-1,
541 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
542 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
543 FT_LIMIT = FT_LAST_WRAPPER+2;
544 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
545 return ((formOp * FT_LIMIT * 2)
546 + (isVolatile ? FT_LIMIT : 0)
547 + ftypeKind);
548 }
549 private static final LambdaForm[] ACCESSOR_FORMS
550 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
551 private static int ftypeKind(Class<?> ftype) {
552 if (ftype.isPrimitive())
553 return Wrapper.forPrimitiveType(ftype).ordinal();
554 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
555 return FT_UNCHECKED_REF;
556 else
557 return FT_CHECKED_REF;
558 }
559
560 /**
561 * Create a LF which can access the given field.
562 * Cache and share this structure among all fields with
563 * the same basicType and refKind.
564 */
565 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
566 Class<?> ftype = m.getFieldType();
567 boolean isVolatile = m.isVolatile();
568 byte formOp;
569 switch (m.getReferenceKind()) {
570 case REF_getField: formOp = AF_GETFIELD; break;
571 case REF_putField: formOp = AF_PUTFIELD; break;
572 case REF_getStatic: formOp = AF_GETSTATIC; break;
573 case REF_putStatic: formOp = AF_PUTSTATIC; break;
574 default: throw new InternalError(m.toString());
575 }
576 if (shouldBeInitialized(m)) {
577 // precompute the barrier-free version:
578 preparedFieldLambdaForm(formOp, isVolatile, ftype);
579 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
580 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
581 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
582 }
583 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
584 maybeCompile(lform, m);
585 assert(lform.methodType().dropParameterTypes(0, 1)
586 .equals(m.getInvocationType().basicType()))
587 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
588 return lform;
589 }
590 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
591 int afIndex = afIndex(formOp, isVolatile, ftypeKind(ftype));
592 LambdaForm lform = ACCESSOR_FORMS[afIndex];
593 if (lform != null) return lform;
594 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind(ftype));
595 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
596 return lform;
597 }
598
599 private static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
600 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
601 boolean isStatic = (formOp >= AF_GETSTATIC);
602 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
603 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
604 Wrapper fw = (needsCast ? Wrapper.OBJECT : Wrapper.values()[ftypeKind]);
605 Class<?> ft = fw.primitiveType();
606 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
607 String tname = fw.primitiveSimpleName();
608 String ctname = Character.toUpperCase(tname.charAt(0)) + tname.substring(1);
609 if (isVolatile) ctname += "Volatile";
610 String getOrPut = (isGetter ? "get" : "put");
611 String linkerName = (getOrPut + ctname); // getObject, putIntVolatile, etc.
612 MethodType linkerType;
613 if (isGetter)
614 linkerType = MethodType.methodType(ft, Object.class, long.class);
615 else
616 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
617 MemberName linker = new MemberName(Unsafe.class, linkerName, linkerType, REF_invokeVirtual);
618 try {
619 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
620 } catch (ReflectiveOperationException ex) {
621 throw newInternalError(ex);
622 }
623
624 // What is the external type of the lambda form?
625 MethodType mtype;
626 if (isGetter)
627 mtype = MethodType.methodType(ft);
628 else
629 mtype = MethodType.methodType(void.class, ft);
630 mtype = mtype.basicType(); // erase short to int, etc.
631 if (!isStatic)
632 mtype = mtype.insertParameterTypes(0, Object.class);
633 final int DMH_THIS = 0;
634 final int ARG_BASE = 1;
635 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
636 // if this is for non-static access, the base pointer is stored at this index:
637 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
638 // if this is for write access, the value to be written is stored at this index:
639 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
640 int nameCursor = ARG_LIMIT;
641 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
642 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
643 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
644 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
645 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
646 final int LINKER_CALL = nameCursor++;
647 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
648 final int RESULT = nameCursor-1; // either the call or the cast
649 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
650 if (needsInit)
651 names[INIT_BAR] = new Name(Lazy.NF_ensureInitialized, names[DMH_THIS]);
652 if (needsCast && !isGetter)
653 names[PRE_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
654 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
655 assert(outArgs.length == (isGetter ? 3 : 4));
656 outArgs[0] = UNSAFE;
657 if (isStatic) {
658 outArgs[1] = names[F_HOLDER] = new Name(Lazy.NF_staticBase, names[DMH_THIS]);
659 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_staticOffset, names[DMH_THIS]);
660 } else {
661 outArgs[1] = names[OBJ_CHECK] = new Name(Lazy.NF_checkBase, names[OBJ_BASE]);
662 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_fieldOffset, names[DMH_THIS]);
663 }
664 if (!isGetter) {
665 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
666 }
667 for (Object a : outArgs) assert(a != null);
668 names[LINKER_CALL] = new Name(linker, outArgs);
669 if (needsCast && isGetter)
670 names[POST_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
671 for (Name n : names) assert(n != null);
672 String fieldOrStatic = (isStatic ? "Static" : "Field");
673 String lambdaName = (linkerName + fieldOrStatic); // significant only for debugging
674 if (needsCast) lambdaName += "Cast";
675 if (needsInit) lambdaName += "Init";
676 return new LambdaForm(lambdaName, ARG_LIMIT, names, RESULT);
677 }
678
679 /**
680 * Pre-initialized NamedFunctions for bootstrapping purposes.
681 * Factored in an inner class to delay initialization until first usage.
682 */
683 private static class Lazy {
684 static final NamedFunction
685 NF_internalMemberName,
686 NF_internalMemberNameEnsureInit,
687 NF_ensureInitialized,
688 NF_fieldOffset,
689 NF_checkBase,
690 NF_staticBase,
691 NF_staticOffset,
692 NF_checkCast,
693 NF_allocateInstance,
694 NF_constructorMethod;
695 static {
696 try {
697 NamedFunction nfs[] = {
698 NF_internalMemberName = new NamedFunction(DirectMethodHandle.class
699 .getDeclaredMethod("internalMemberName", Object.class)),
700 NF_internalMemberNameEnsureInit = new NamedFunction(DirectMethodHandle.class
701 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)),
702 NF_ensureInitialized = new NamedFunction(DirectMethodHandle.class
703 .getDeclaredMethod("ensureInitialized", Object.class)),
704 NF_fieldOffset = new NamedFunction(DirectMethodHandle.class
705 .getDeclaredMethod("fieldOffset", Object.class)),
706 NF_checkBase = new NamedFunction(DirectMethodHandle.class
707 .getDeclaredMethod("checkBase", Object.class)),
708 NF_staticBase = new NamedFunction(DirectMethodHandle.class
709 .getDeclaredMethod("staticBase", Object.class)),
710 NF_staticOffset = new NamedFunction(DirectMethodHandle.class
711 .getDeclaredMethod("staticOffset", Object.class)),
712 NF_checkCast = new NamedFunction(DirectMethodHandle.class
713 .getDeclaredMethod("checkCast", Object.class, Object.class)),
714 NF_allocateInstance = new NamedFunction(DirectMethodHandle.class
715 .getDeclaredMethod("allocateInstance", Object.class)),
716 NF_constructorMethod = new NamedFunction(DirectMethodHandle.class
717 .getDeclaredMethod("constructorMethod", Object.class))
718 };
719 for (NamedFunction nf : nfs) {
720 // Each nf must be statically invocable or we get tied up in our bootstraps.
721 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf.member)) : nf;
722 nf.resolve();
723 }
724 } catch (ReflectiveOperationException ex) {
725 throw newInternalError(ex);
726 }
727 }
728 }
729 }