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