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.LambdaForm.BasicType.*;
35 import static java.lang.invoke.MethodTypeForm.*;
36 import static java.lang.invoke.MethodHandleStatics.*;
37 import java.lang.ref.WeakReference;
38 import java.lang.reflect.Field;
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.VerifyType;
41 import sun.invoke.util.Wrapper;
42
43 /**
44 * The flavor of method handle which implements a constant reference
45 * to a class member.
46 * @author jrose
47 */
48 class DirectMethodHandle extends MethodHandle {
49 final MemberName member;
50
51 // Constructors and factory methods in this class *must* be package scoped or private.
52 private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) {
53 super(mtype, form);
54 if (!member.isResolved()) throw new InternalError();
55
56 if (member.getDeclaringClass().isInterface() &&
57 member.isMethod() && !member.isAbstract()) {
58 // Check for corner case: invokeinterface of Object method
59 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
60 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
61 if (m != null && m.isPublic()) {
62 member = m;
63 }
64 }
65
66 this.member = member;
67 }
68
69 // Factory methods:
70 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
71 MethodType mtype = member.getMethodOrFieldType();
72 if (!member.isStatic()) {
73 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
74 throw new InternalError(member.toString());
75 mtype = mtype.insertParameterTypes(0, receiver);
76 }
77 if (!member.isField()) {
78 if (refKind == REF_invokeSpecial) {
79 member = member.asSpecial();
80 LambdaForm lform = preparedLambdaForm(member);
81 return new Special(mtype, lform, member);
82 } else {
83 LambdaForm lform = preparedLambdaForm(member);
84 return new DirectMethodHandle(mtype, lform, member);
85 }
86 } else {
87 LambdaForm lform = preparedFieldLambdaForm(member);
88 if (member.isStatic()) {
89 long offset = MethodHandleNatives.staticFieldOffset(member);
90 Object base = MethodHandleNatives.staticFieldBase(member);
91 return new StaticAccessor(mtype, lform, member, base, offset);
92 } else {
93 long offset = MethodHandleNatives.objectFieldOffset(member);
94 assert(offset == (int)offset);
95 return new Accessor(mtype, lform, member, (int)offset);
96 }
97 }
98 }
99 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
100 byte refKind = member.getReferenceKind();
101 if (refKind == REF_invokeSpecial)
102 refKind = REF_invokeVirtual;
103 return make(refKind, receiver, member);
104 }
105 static DirectMethodHandle make(MemberName member) {
106 if (member.isConstructor())
107 return makeAllocator(member);
108 return make(member.getDeclaringClass(), member);
109 }
110 static DirectMethodHandle make(Method method) {
111 return make(method.getDeclaringClass(), new MemberName(method));
112 }
113 static DirectMethodHandle make(Field field) {
114 return make(field.getDeclaringClass(), new MemberName(field));
115 }
116 private static DirectMethodHandle makeAllocator(MemberName ctor) {
117 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
118 Class<?> instanceClass = ctor.getDeclaringClass();
119 ctor = ctor.asConstructor();
120 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
121 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
122 LambdaForm lform = preparedLambdaForm(ctor);
123 MemberName init = ctor.asSpecial();
124 assert(init.getMethodType().returnType() == void.class);
125 return new Constructor(mtype, lform, ctor, init, instanceClass);
126 }
127
128 @Override
129 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
130 return new DirectMethodHandle(mt, lf, member);
131 }
132
133 @Override
134 String internalProperties() {
135 return "/DMH="+member.toString();
136 }
137
138 //// Implementation methods.
139 @Override
140 MethodHandle viewAsType(MethodType newType) {
141 return new DirectMethodHandle(newType, form, member);
142 }
143 @Override
144 @ForceInline
145 MemberName internalMemberName() {
146 return member;
147 }
148
149 @Override
150 MethodHandle bindArgument(int pos, BasicType basicType, Object value) {
151 // If the member needs dispatching, do so.
152 if (pos == 0 && basicType == L_TYPE) {
153 DirectMethodHandle concrete = maybeRebind(value);
154 if (concrete != null)
155 return concrete.bindReceiver(value);
156 }
157 return super.bindArgument(pos, basicType, value);
158 }
159
160 @Override
161 MethodHandle bindReceiver(Object receiver) {
162 // If the member needs dispatching, do so.
163 DirectMethodHandle concrete = maybeRebind(receiver);
164 if (concrete != null)
165 return concrete.bindReceiver(receiver);
166 return super.bindReceiver(receiver);
167 }
168
169 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
170
171 private DirectMethodHandle maybeRebind(Object receiver) {
172 if (receiver != null) {
173 switch (member.getReferenceKind()) {
174 case REF_invokeInterface:
175 case REF_invokeVirtual:
176 // Pre-dispatch the member.
177 Class<?> concreteClass = receiver.getClass();
178 MemberName concrete = new MemberName(concreteClass, member.getName(), member.getMethodType(), REF_invokeSpecial);
179 concrete = IMPL_NAMES.resolveOrNull(REF_invokeSpecial, concrete, concreteClass);
180 if (concrete != null)
181 return new DirectMethodHandle(type(), preparedLambdaForm(concrete), concrete);
182 break;
183 }
184 }
185 return null;
186 }
187
188 /**
189 * Create a LF which can invoke the given method.
190 * Cache and share this structure among all methods with
191 * the same basicType and refKind.
192 */
193 private static LambdaForm preparedLambdaForm(MemberName m) {
194 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
195 MethodType mtype = m.getInvocationType().basicType();
196 assert(!m.isMethodHandleInvoke() || "invokeBasic".equals(m.getName())) : m;
197 int which;
198 switch (m.getReferenceKind()) {
199 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
200 case REF_invokeStatic: which = LF_INVSTATIC; break;
201 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
202 case REF_invokeInterface: which = LF_INVINTERFACE; break;
203 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
204 default: throw new InternalError(m.toString());
205 }
206 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
207 // precompute the barrier-free version:
208 preparedLambdaForm(mtype, which);
209 which = LF_INVSTATIC_INIT;
210 }
211 LambdaForm lform = preparedLambdaForm(mtype, which);
212 maybeCompile(lform, m);
213 assert(lform.methodType().dropParameterTypes(0, 1)
214 .equals(m.getInvocationType().basicType()))
215 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
216 return lform;
217 }
218
219 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
220 LambdaForm lform = mtype.form().cachedLambdaForm(which);
221 if (lform != null) return lform;
222 lform = makePreparedLambdaForm(mtype, which);
223 return mtype.form().setCachedLambdaForm(which, lform);
224 }
225
226 private static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
227 boolean needsInit = (which == LF_INVSTATIC_INIT);
228 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
229 String linkerName, lambdaName;
230 switch (which) {
231 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; lambdaName = "DMH.invokeVirtual"; break;
232 case LF_INVSTATIC: linkerName = "linkToStatic"; lambdaName = "DMH.invokeStatic"; break;
233 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; lambdaName = "DMH.invokeStaticInit"; break;
234 case LF_INVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.invokeSpecial"; break;
235 case LF_INVINTERFACE: linkerName = "linkToInterface"; lambdaName = "DMH.invokeInterface"; break;
236 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.newInvokeSpecial"; break;
237 default: throw new InternalError("which="+which);
238 }
239 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
240 if (doesAlloc)
241 mtypeWithArg = mtypeWithArg
242 .insertParameterTypes(0, Object.class) // insert newly allocated obj
243 .changeReturnType(void.class); // <init> returns void
244 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
245 try {
246 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
247 } catch (ReflectiveOperationException ex) {
248 throw newInternalError(ex);
249 }
250 final int DMH_THIS = 0;
251 final int ARG_BASE = 1;
252 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
253 int nameCursor = ARG_LIMIT;
254 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
255 final int GET_MEMBER = nameCursor++;
256 final int LINKER_CALL = nameCursor++;
257 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
258 assert(names.length == nameCursor);
259 if (doesAlloc) {
260 // names = { argx,y,z,... new C, init method }
261 names[NEW_OBJ] = new Name(Lazy.NF_allocateInstance, names[DMH_THIS]);
262 names[GET_MEMBER] = new Name(Lazy.NF_constructorMethod, names[DMH_THIS]);
263 } else if (needsInit) {
264 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberNameEnsureInit, names[DMH_THIS]);
265 } else {
266 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberName, names[DMH_THIS]);
267 }
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 = LambdaForm.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 private static void maybeCompile(LambdaForm lform, MemberName m) {
286 if (VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
287 // Help along bootstrapping...
288 lform.compileToBytecode();
289 }
290
291 /** Static wrapper for DirectMethodHandle.internalMemberName. */
292 @ForceInline
293 /*non-public*/ static Object internalMemberName(Object mh) {
294 return ((DirectMethodHandle)mh).member;
295 }
296
297 /** Static wrapper for DirectMethodHandle.internalMemberName.
298 * This one also forces initialization.
299 */
300 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
301 DirectMethodHandle dmh = (DirectMethodHandle)mh;
302 dmh.ensureInitialized();
303 return dmh.member;
304 }
305
306 /*non-public*/ static
307 boolean shouldBeInitialized(MemberName member) {
308 switch (member.getReferenceKind()) {
309 case REF_invokeStatic:
310 case REF_getStatic:
311 case REF_putStatic:
312 case REF_newInvokeSpecial:
313 break;
314 default:
315 // No need to initialize the class on this kind of member.
316 return false;
317 }
318 Class<?> cls = member.getDeclaringClass();
319 if (cls == ValueConversions.class ||
320 cls == MethodHandleImpl.class ||
321 cls == Invokers.class) {
322 // These guys have lots of <clinit> DMH creation but we know
323 // the MHs will not be used until the system is booted.
324 return false;
325 }
326 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
327 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
328 // It is a system class. It is probably in the process of
329 // being initialized, but we will help it along just to be safe.
330 if (UNSAFE.shouldBeInitialized(cls)) {
331 UNSAFE.ensureClassInitialized(cls);
332 }
333 return false;
334 }
335 return UNSAFE.shouldBeInitialized(cls);
336 }
337
338 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
339 @Override
340 protected WeakReference<Thread> computeValue(Class<?> type) {
341 UNSAFE.ensureClassInitialized(type);
342 if (UNSAFE.shouldBeInitialized(type))
343 // If the previous call didn't block, this can happen.
344 // We are executing inside <clinit>.
345 return new WeakReference<>(Thread.currentThread());
346 return null;
347 }
348 static final EnsureInitialized INSTANCE = new EnsureInitialized();
349 }
350
351 private void ensureInitialized() {
352 if (checkInitialized(member)) {
353 // The coast is clear. Delete the <clinit> barrier.
354 if (member.isField())
355 updateForm(preparedFieldLambdaForm(member));
356 else
357 updateForm(preparedLambdaForm(member));
358 }
359 }
360 private static boolean checkInitialized(MemberName member) {
361 Class<?> defc = member.getDeclaringClass();
362 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
363 if (ref == null) {
364 return true; // the final state
365 }
366 Thread clinitThread = ref.get();
367 // Somebody may still be running defc.<clinit>.
368 if (clinitThread == Thread.currentThread()) {
369 // If anybody is running defc.<clinit>, it is this thread.
370 if (UNSAFE.shouldBeInitialized(defc))
371 // Yes, we are running it; keep the barrier for now.
372 return false;
373 } else {
374 // We are in a random thread. Block.
375 UNSAFE.ensureClassInitialized(defc);
376 }
377 assert(!UNSAFE.shouldBeInitialized(defc));
378 // put it into the final state
379 EnsureInitialized.INSTANCE.remove(defc);
380 return true;
381 }
382
383 /*non-public*/ static void ensureInitialized(Object mh) {
384 ((DirectMethodHandle)mh).ensureInitialized();
385 }
386
387 /** This subclass represents invokespecial instructions. */
388 static class Special extends DirectMethodHandle {
389 private Special(MethodType mtype, LambdaForm form, MemberName member) {
390 super(mtype, form, member);
391 }
392 @Override
393 boolean isInvokeSpecial() {
394 return true;
395 }
396 @Override
397 MethodHandle viewAsType(MethodType newType) {
398 return new Special(newType, form, member);
399 }
400 }
401
402 /** This subclass handles constructor references. */
403 static class Constructor extends DirectMethodHandle {
404 final MemberName initMethod;
405 final Class<?> instanceClass;
406
407 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
408 MemberName initMethod, Class<?> instanceClass) {
409 super(mtype, form, constructor);
410 this.initMethod = initMethod;
411 this.instanceClass = instanceClass;
412 assert(initMethod.isResolved());
413 }
414 @Override
415 MethodHandle viewAsType(MethodType newType) {
416 return new Constructor(newType, form, member, initMethod, instanceClass);
417 }
418 }
419
420 /*non-public*/ static Object constructorMethod(Object mh) {
421 Constructor dmh = (Constructor)mh;
422 return dmh.initMethod;
423 }
424
425 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
426 Constructor dmh = (Constructor)mh;
427 return UNSAFE.allocateInstance(dmh.instanceClass);
428 }
429
430 /** This subclass handles non-static field references. */
431 static class Accessor extends DirectMethodHandle {
432 final Class<?> fieldType;
433 final int fieldOffset;
434 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
435 int fieldOffset) {
436 super(mtype, form, member);
437 this.fieldType = member.getFieldType();
438 this.fieldOffset = fieldOffset;
439 }
440
441 @Override Object checkCast(Object obj) {
442 return fieldType.cast(obj);
443 }
444 @Override
445 MethodHandle viewAsType(MethodType newType) {
446 return new Accessor(newType, form, member, fieldOffset);
447 }
448 }
449
450 @ForceInline
451 /*non-public*/ static long fieldOffset(Object accessorObj) {
452 // Note: We return a long because that is what Unsafe.getObject likes.
453 // We store a plain int because it is more compact.
454 return ((Accessor)accessorObj).fieldOffset;
455 }
456
457 @ForceInline
458 /*non-public*/ static Object checkBase(Object obj) {
459 // Note that the object's class has already been verified,
460 // since the parameter type of the Accessor method handle
461 // is either member.getDeclaringClass or a subclass.
462 // This was verified in DirectMethodHandle.make.
463 // Therefore, the only remaining check is for null.
464 // Since this check is *not* guaranteed by Unsafe.getInt
465 // and its siblings, we need to make an explicit one here.
466 obj.getClass(); // maybe throw NPE
467 return obj;
468 }
469
470 /** This subclass handles static field references. */
471 static class StaticAccessor extends DirectMethodHandle {
472 final private Class<?> fieldType;
473 final private Object staticBase;
474 final private long staticOffset;
475
476 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
477 Object staticBase, long staticOffset) {
478 super(mtype, form, member);
479 this.fieldType = member.getFieldType();
480 this.staticBase = staticBase;
481 this.staticOffset = staticOffset;
482 }
483
484 @Override Object checkCast(Object obj) {
485 return fieldType.cast(obj);
486 }
487 @Override
488 MethodHandle viewAsType(MethodType newType) {
489 return new StaticAccessor(newType, form, member, staticBase, staticOffset);
490 }
491 }
492
493 @ForceInline
494 /*non-public*/ static Object nullCheck(Object obj) {
495 obj.getClass();
496 return obj;
497 }
498
499 @ForceInline
500 /*non-public*/ static Object staticBase(Object accessorObj) {
501 return ((StaticAccessor)accessorObj).staticBase;
502 }
503
504 @ForceInline
505 /*non-public*/ static long staticOffset(Object accessorObj) {
506 return ((StaticAccessor)accessorObj).staticOffset;
507 }
508
509 @ForceInline
510 /*non-public*/ static Object checkCast(Object mh, Object obj) {
511 return ((DirectMethodHandle) mh).checkCast(obj);
512 }
513
514 Object checkCast(Object obj) {
515 return member.getReturnType().cast(obj);
516 }
517
518 // Caching machinery for field accessors:
519 private static byte
520 AF_GETFIELD = 0,
521 AF_PUTFIELD = 1,
522 AF_GETSTATIC = 2,
523 AF_PUTSTATIC = 3,
524 AF_GETSTATIC_INIT = 4,
525 AF_PUTSTATIC_INIT = 5,
526 AF_LIMIT = 6;
527 // Enumerate the different field kinds using Wrapper,
528 // with an extra case added for checked references.
529 private static int
530 FT_LAST_WRAPPER = Wrapper.values().length-1,
531 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
532 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
533 FT_LIMIT = FT_LAST_WRAPPER+2;
534 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
535 return ((formOp * FT_LIMIT * 2)
536 + (isVolatile ? FT_LIMIT : 0)
537 + ftypeKind);
538 }
539 private static final LambdaForm[] ACCESSOR_FORMS
540 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
541 private static int ftypeKind(Class<?> ftype) {
542 if (ftype.isPrimitive())
543 return Wrapper.forPrimitiveType(ftype).ordinal();
544 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
545 return FT_UNCHECKED_REF;
546 else
547 return FT_CHECKED_REF;
548 }
549
550 /**
551 * Create a LF which can access the given field.
552 * Cache and share this structure among all fields with
553 * the same basicType and refKind.
554 */
555 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
556 Class<?> ftype = m.getFieldType();
557 boolean isVolatile = m.isVolatile();
558 byte formOp;
559 switch (m.getReferenceKind()) {
560 case REF_getField: formOp = AF_GETFIELD; break;
561 case REF_putField: formOp = AF_PUTFIELD; break;
562 case REF_getStatic: formOp = AF_GETSTATIC; break;
563 case REF_putStatic: formOp = AF_PUTSTATIC; break;
564 default: throw new InternalError(m.toString());
565 }
566 if (shouldBeInitialized(m)) {
567 // precompute the barrier-free version:
568 preparedFieldLambdaForm(formOp, isVolatile, ftype);
569 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
570 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
571 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
572 }
573 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
574 maybeCompile(lform, m);
575 assert(lform.methodType().dropParameterTypes(0, 1)
576 .equals(m.getInvocationType().basicType()))
577 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
578 return lform;
579 }
580 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
581 int afIndex = afIndex(formOp, isVolatile, ftypeKind(ftype));
582 LambdaForm lform = ACCESSOR_FORMS[afIndex];
583 if (lform != null) return lform;
584 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind(ftype));
585 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
586 return lform;
587 }
588
589 private static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
590 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
591 boolean isStatic = (formOp >= AF_GETSTATIC);
592 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
593 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
594 Wrapper fw = (needsCast ? Wrapper.OBJECT : Wrapper.values()[ftypeKind]);
595 Class<?> ft = fw.primitiveType();
596 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
597 String tname = fw.primitiveSimpleName();
598 String ctname = Character.toUpperCase(tname.charAt(0)) + tname.substring(1);
599 if (isVolatile) ctname += "Volatile";
600 String getOrPut = (isGetter ? "get" : "put");
601 String linkerName = (getOrPut + ctname); // getObject, putIntVolatile, etc.
602 MethodType linkerType;
603 if (isGetter)
604 linkerType = MethodType.methodType(ft, Object.class, long.class);
605 else
606 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
607 MemberName linker = new MemberName(Unsafe.class, linkerName, linkerType, REF_invokeVirtual);
608 try {
609 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
610 } catch (ReflectiveOperationException ex) {
611 throw newInternalError(ex);
612 }
613
614 // What is the external type of the lambda form?
615 MethodType mtype;
616 if (isGetter)
617 mtype = MethodType.methodType(ft);
618 else
619 mtype = MethodType.methodType(void.class, ft);
620 mtype = mtype.basicType(); // erase short to int, etc.
621 if (!isStatic)
622 mtype = mtype.insertParameterTypes(0, Object.class);
623 final int DMH_THIS = 0;
624 final int ARG_BASE = 1;
625 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
626 // if this is for non-static access, the base pointer is stored at this index:
627 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
628 // if this is for write access, the value to be written is stored at this index:
629 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
630 int nameCursor = ARG_LIMIT;
631 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
632 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
633 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
634 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
635 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
636 final int LINKER_CALL = nameCursor++;
637 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
638 final int RESULT = nameCursor-1; // either the call or the cast
639 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
640 if (needsInit)
641 names[INIT_BAR] = new Name(Lazy.NF_ensureInitialized, names[DMH_THIS]);
642 if (needsCast && !isGetter)
643 names[PRE_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
644 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
645 assert(outArgs.length == (isGetter ? 3 : 4));
646 outArgs[0] = UNSAFE;
647 if (isStatic) {
648 outArgs[1] = names[F_HOLDER] = new Name(Lazy.NF_staticBase, names[DMH_THIS]);
649 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_staticOffset, names[DMH_THIS]);
650 } else {
651 outArgs[1] = names[OBJ_CHECK] = new Name(Lazy.NF_checkBase, names[OBJ_BASE]);
652 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_fieldOffset, names[DMH_THIS]);
653 }
654 if (!isGetter) {
655 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
656 }
657 for (Object a : outArgs) assert(a != null);
658 names[LINKER_CALL] = new Name(linker, outArgs);
659 if (needsCast && isGetter)
660 names[POST_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
661 for (Name n : names) assert(n != null);
662 String fieldOrStatic = (isStatic ? "Static" : "Field");
663 String lambdaName = (linkerName + fieldOrStatic); // significant only for debugging
664 if (needsCast) lambdaName += "Cast";
665 if (needsInit) lambdaName += "Init";
666 return new LambdaForm(lambdaName, ARG_LIMIT, names, RESULT);
667 }
668
669 /**
670 * Pre-initialized NamedFunctions for bootstrapping purposes.
671 * Factored in an inner class to delay initialization until first usage.
672 */
673 private static class Lazy {
674 static final NamedFunction
675 NF_internalMemberName,
676 NF_internalMemberNameEnsureInit,
677 NF_ensureInitialized,
678 NF_fieldOffset,
679 NF_checkBase,
680 NF_staticBase,
681 NF_staticOffset,
682 NF_checkCast,
683 NF_allocateInstance,
684 NF_constructorMethod;
685 static {
686 try {
687 NamedFunction nfs[] = {
688 NF_internalMemberName = new NamedFunction(DirectMethodHandle.class
689 .getDeclaredMethod("internalMemberName", Object.class)),
690 NF_internalMemberNameEnsureInit = new NamedFunction(DirectMethodHandle.class
691 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)),
692 NF_ensureInitialized = new NamedFunction(DirectMethodHandle.class
693 .getDeclaredMethod("ensureInitialized", Object.class)),
694 NF_fieldOffset = new NamedFunction(DirectMethodHandle.class
695 .getDeclaredMethod("fieldOffset", Object.class)),
696 NF_checkBase = new NamedFunction(DirectMethodHandle.class
697 .getDeclaredMethod("checkBase", Object.class)),
698 NF_staticBase = new NamedFunction(DirectMethodHandle.class
699 .getDeclaredMethod("staticBase", Object.class)),
700 NF_staticOffset = new NamedFunction(DirectMethodHandle.class
701 .getDeclaredMethod("staticOffset", Object.class)),
702 NF_checkCast = new NamedFunction(DirectMethodHandle.class
703 .getDeclaredMethod("checkCast", Object.class, Object.class)),
704 NF_allocateInstance = new NamedFunction(DirectMethodHandle.class
705 .getDeclaredMethod("allocateInstance", Object.class)),
706 NF_constructorMethod = new NamedFunction(DirectMethodHandle.class
707 .getDeclaredMethod("constructorMethod", Object.class))
708 };
709 for (NamedFunction nf : nfs) {
710 // Each nf must be statically invocable or we get tied up in our bootstraps.
711 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf.member)) : nf;
712 nf.resolve();
713 }
714 } catch (ReflectiveOperationException ex) {
715 throw newInternalError(ex);
716 }
717 }
718 }
719 }