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 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
63 member = m;
64 }
65 }
66
67 this.member = member;
68 }
69
70 // Factory methods:
71 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
72 MethodType mtype = member.getMethodOrFieldType();
73 if (!member.isStatic()) {
74 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
75 throw new InternalError(member.toString());
76 mtype = mtype.insertParameterTypes(0, receiver);
77 }
78 if (!member.isField()) {
79 if (refKind == REF_invokeSpecial) {
80 member = member.asSpecial();
81 LambdaForm lform = preparedLambdaForm(member);
82 return new Special(mtype, lform, member);
83 } else {
84 LambdaForm lform = preparedLambdaForm(member);
85 return new DirectMethodHandle(mtype, lform, member);
86 }
87 } else {
88 LambdaForm lform = preparedFieldLambdaForm(member);
89 if (member.isStatic()) {
90 long offset = MethodHandleNatives.staticFieldOffset(member);
91 Object base = MethodHandleNatives.staticFieldBase(member);
92 return new StaticAccessor(mtype, lform, member, base, offset);
93 } else {
94 long offset = MethodHandleNatives.objectFieldOffset(member);
95 assert(offset == (int)offset);
96 return new Accessor(mtype, lform, member, (int)offset);
97 }
98 }
99 }
100 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
101 byte refKind = member.getReferenceKind();
102 if (refKind == REF_invokeSpecial)
103 refKind = REF_invokeVirtual;
104 return make(refKind, receiver, member);
105 }
106 static DirectMethodHandle make(MemberName member) {
107 if (member.isConstructor())
108 return makeAllocator(member);
109 return make(member.getDeclaringClass(), member);
110 }
111 static DirectMethodHandle make(Method method) {
112 return make(method.getDeclaringClass(), new MemberName(method));
113 }
114 static DirectMethodHandle make(Field field) {
115 return make(field.getDeclaringClass(), new MemberName(field));
116 }
117 private static DirectMethodHandle makeAllocator(MemberName ctor) {
118 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
119 Class<?> instanceClass = ctor.getDeclaringClass();
120 ctor = ctor.asConstructor();
121 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
122 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
123 LambdaForm lform = preparedLambdaForm(ctor);
124 MemberName init = ctor.asSpecial();
125 assert(init.getMethodType().returnType() == void.class);
126 return new Constructor(mtype, lform, ctor, init, instanceClass);
127 }
128
129 @Override
130 String internalProperties() {
131 return "\n& DMH.MN="+internalMemberName();
132 }
133
134 //// Implementation methods.
135 @Override
136 MethodHandle viewAsType(MethodType newType) {
137 return new DirectMethodHandle(newType, form, member);
138 }
139 @Override
140 @ForceInline
141 MemberName internalMemberName() {
142 return member;
143 }
144
145 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
146
147 /**
148 * Create a LF which can invoke the given method.
149 * Cache and share this structure among all methods with
150 * the same basicType and refKind.
151 */
152 private static LambdaForm preparedLambdaForm(MemberName m) {
153 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
154 MethodType mtype = m.getInvocationType().basicType();
155 assert(!m.isMethodHandleInvoke() || "invokeBasic".equals(m.getName())) : m;
156 int which;
157 switch (m.getReferenceKind()) {
158 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
159 case REF_invokeStatic: which = LF_INVSTATIC; break;
160 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
161 case REF_invokeInterface: which = LF_INVINTERFACE; break;
162 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
163 default: throw new InternalError(m.toString());
164 }
165 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
166 // precompute the barrier-free version:
167 preparedLambdaForm(mtype, which);
168 which = LF_INVSTATIC_INIT;
169 }
170 LambdaForm lform = preparedLambdaForm(mtype, which);
171 maybeCompile(lform, m);
172 assert(lform.methodType().dropParameterTypes(0, 1)
173 .equals(m.getInvocationType().basicType()))
174 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
175 return lform;
176 }
177
178 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
179 LambdaForm lform = mtype.form().cachedLambdaForm(which);
180 if (lform != null) return lform;
181 lform = makePreparedLambdaForm(mtype, which);
182 return mtype.form().setCachedLambdaForm(which, lform);
183 }
184
185 private static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
186 boolean needsInit = (which == LF_INVSTATIC_INIT);
187 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
188 String linkerName, lambdaName;
189 switch (which) {
190 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; lambdaName = "DMH.invokeVirtual"; break;
191 case LF_INVSTATIC: linkerName = "linkToStatic"; lambdaName = "DMH.invokeStatic"; break;
192 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; lambdaName = "DMH.invokeStaticInit"; break;
193 case LF_INVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.invokeSpecial"; break;
194 case LF_INVINTERFACE: linkerName = "linkToInterface"; lambdaName = "DMH.invokeInterface"; break;
195 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.newInvokeSpecial"; break;
196 default: throw new InternalError("which="+which);
197 }
198 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
199 if (doesAlloc)
200 mtypeWithArg = mtypeWithArg
201 .insertParameterTypes(0, Object.class) // insert newly allocated obj
202 .changeReturnType(void.class); // <init> returns void
203 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
204 try {
205 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
206 } catch (ReflectiveOperationException ex) {
207 throw newInternalError(ex);
208 }
209 final int DMH_THIS = 0;
210 final int ARG_BASE = 1;
211 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
212 int nameCursor = ARG_LIMIT;
213 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
214 final int GET_MEMBER = nameCursor++;
215 final int LINKER_CALL = nameCursor++;
216 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
217 assert(names.length == nameCursor);
218 if (doesAlloc) {
219 // names = { argx,y,z,... new C, init method }
220 names[NEW_OBJ] = new Name(Lazy.NF_allocateInstance, names[DMH_THIS]);
221 names[GET_MEMBER] = new Name(Lazy.NF_constructorMethod, names[DMH_THIS]);
222 } else if (needsInit) {
223 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberNameEnsureInit, names[DMH_THIS]);
224 } else {
225 names[GET_MEMBER] = new Name(Lazy.NF_internalMemberName, names[DMH_THIS]);
226 }
227 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
228 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
229 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
230 int result = LAST_RESULT;
231 if (doesAlloc) {
232 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
233 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
234 outArgs[0] = names[NEW_OBJ];
235 result = NEW_OBJ;
236 }
237 names[LINKER_CALL] = new Name(linker, outArgs);
238 lambdaName += "_" + shortenSignature(basicTypeSignature(mtype));
239 LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result);
240 // This is a tricky bit of code. Don't send it through the LF interpreter.
241 lform.compileToBytecode();
242 return lform;
243 }
244
245 static Object findDirectMethodHandle(Name name) {
246 if (name.function == Lazy.NF_internalMemberName ||
247 name.function == Lazy.NF_internalMemberNameEnsureInit ||
248 name.function == Lazy.NF_constructorMethod) {
249 assert(name.arguments.length == 1);
250 return name.arguments[0];
251 }
252 return null;
253 }
254
255 private static void maybeCompile(LambdaForm lform, MemberName m) {
256 if (VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
257 // Help along bootstrapping...
258 lform.compileToBytecode();
259 }
260
261 /** Static wrapper for DirectMethodHandle.internalMemberName. */
262 @ForceInline
263 /*non-public*/ static Object internalMemberName(Object mh) {
264 return ((DirectMethodHandle)mh).member;
265 }
266
267 /** Static wrapper for DirectMethodHandle.internalMemberName.
268 * This one also forces initialization.
269 */
270 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
271 DirectMethodHandle dmh = (DirectMethodHandle)mh;
272 dmh.ensureInitialized();
273 return dmh.member;
274 }
275
276 /*non-public*/ static
277 boolean shouldBeInitialized(MemberName member) {
278 switch (member.getReferenceKind()) {
279 case REF_invokeStatic:
280 case REF_getStatic:
281 case REF_putStatic:
282 case REF_newInvokeSpecial:
283 break;
284 default:
285 // No need to initialize the class on this kind of member.
286 return false;
287 }
288 Class<?> cls = member.getDeclaringClass();
289 if (cls == ValueConversions.class ||
290 cls == MethodHandleImpl.class ||
291 cls == Invokers.class) {
292 // These guys have lots of <clinit> DMH creation but we know
293 // the MHs will not be used until the system is booted.
294 return false;
295 }
296 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
297 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
298 // It is a system class. It is probably in the process of
299 // being initialized, but we will help it along just to be safe.
300 if (UNSAFE.shouldBeInitialized(cls)) {
301 UNSAFE.ensureClassInitialized(cls);
302 }
303 return false;
304 }
305 return UNSAFE.shouldBeInitialized(cls);
306 }
307
308 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
309 @Override
310 protected WeakReference<Thread> computeValue(Class<?> type) {
311 UNSAFE.ensureClassInitialized(type);
312 if (UNSAFE.shouldBeInitialized(type))
313 // If the previous call didn't block, this can happen.
314 // We are executing inside <clinit>.
315 return new WeakReference<>(Thread.currentThread());
316 return null;
317 }
318 static final EnsureInitialized INSTANCE = new EnsureInitialized();
319 }
320
321 private void ensureInitialized() {
322 if (checkInitialized(member)) {
323 // The coast is clear. Delete the <clinit> barrier.
324 if (member.isField())
325 updateForm(preparedFieldLambdaForm(member));
326 else
327 updateForm(preparedLambdaForm(member));
328 }
329 }
330 private static boolean checkInitialized(MemberName member) {
331 Class<?> defc = member.getDeclaringClass();
332 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
333 if (ref == null) {
334 return true; // the final state
335 }
336 Thread clinitThread = ref.get();
337 // Somebody may still be running defc.<clinit>.
338 if (clinitThread == Thread.currentThread()) {
339 // If anybody is running defc.<clinit>, it is this thread.
340 if (UNSAFE.shouldBeInitialized(defc))
341 // Yes, we are running it; keep the barrier for now.
342 return false;
343 } else {
344 // We are in a random thread. Block.
345 UNSAFE.ensureClassInitialized(defc);
346 }
347 assert(!UNSAFE.shouldBeInitialized(defc));
348 // put it into the final state
349 EnsureInitialized.INSTANCE.remove(defc);
350 return true;
351 }
352
353 /*non-public*/ static void ensureInitialized(Object mh) {
354 ((DirectMethodHandle)mh).ensureInitialized();
355 }
356
357 /** This subclass represents invokespecial instructions. */
358 static class Special extends DirectMethodHandle {
359 private Special(MethodType mtype, LambdaForm form, MemberName member) {
360 super(mtype, form, member);
361 }
362 @Override
363 boolean isInvokeSpecial() {
364 return true;
365 }
366 @Override
367 MethodHandle viewAsType(MethodType newType) {
368 return new Special(newType, form, member);
369 }
370 }
371
372 /** This subclass handles constructor references. */
373 static class Constructor extends DirectMethodHandle {
374 final MemberName initMethod;
375 final Class<?> instanceClass;
376
377 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
378 MemberName initMethod, Class<?> instanceClass) {
379 super(mtype, form, constructor);
380 this.initMethod = initMethod;
381 this.instanceClass = instanceClass;
382 assert(initMethod.isResolved());
383 }
384 @Override
385 MethodHandle viewAsType(MethodType newType) {
386 return new Constructor(newType, form, member, initMethod, instanceClass);
387 }
388 }
389
390 /*non-public*/ static Object constructorMethod(Object mh) {
391 Constructor dmh = (Constructor)mh;
392 return dmh.initMethod;
393 }
394
395 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
396 Constructor dmh = (Constructor)mh;
397 return UNSAFE.allocateInstance(dmh.instanceClass);
398 }
399
400 /** This subclass handles non-static field references. */
401 static class Accessor extends DirectMethodHandle {
402 final Class<?> fieldType;
403 final int fieldOffset;
404 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
405 int fieldOffset) {
406 super(mtype, form, member);
407 this.fieldType = member.getFieldType();
408 this.fieldOffset = fieldOffset;
409 }
410
411 @Override Object checkCast(Object obj) {
412 return fieldType.cast(obj);
413 }
414 @Override
415 MethodHandle viewAsType(MethodType newType) {
416 return new Accessor(newType, form, member, fieldOffset);
417 }
418 }
419
420 @ForceInline
421 /*non-public*/ static long fieldOffset(Object accessorObj) {
422 // Note: We return a long because that is what Unsafe.getObject likes.
423 // We store a plain int because it is more compact.
424 return ((Accessor)accessorObj).fieldOffset;
425 }
426
427 @ForceInline
428 /*non-public*/ static Object checkBase(Object obj) {
429 // Note that the object's class has already been verified,
430 // since the parameter type of the Accessor method handle
431 // is either member.getDeclaringClass or a subclass.
432 // This was verified in DirectMethodHandle.make.
433 // Therefore, the only remaining check is for null.
434 // Since this check is *not* guaranteed by Unsafe.getInt
435 // and its siblings, we need to make an explicit one here.
436 obj.getClass(); // maybe throw NPE
437 return obj;
438 }
439
440 /** This subclass handles static field references. */
441 static class StaticAccessor extends DirectMethodHandle {
442 final private Class<?> fieldType;
443 final private Object staticBase;
444 final private long staticOffset;
445
446 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
447 Object staticBase, long staticOffset) {
448 super(mtype, form, member);
449 this.fieldType = member.getFieldType();
450 this.staticBase = staticBase;
451 this.staticOffset = staticOffset;
452 }
453
454 @Override Object checkCast(Object obj) {
455 return fieldType.cast(obj);
456 }
457 @Override
458 MethodHandle viewAsType(MethodType newType) {
459 return new StaticAccessor(newType, form, member, staticBase, staticOffset);
460 }
461 }
462
463 @ForceInline
464 /*non-public*/ static Object nullCheck(Object obj) {
465 obj.getClass();
466 return obj;
467 }
468
469 @ForceInline
470 /*non-public*/ static Object staticBase(Object accessorObj) {
471 return ((StaticAccessor)accessorObj).staticBase;
472 }
473
474 @ForceInline
475 /*non-public*/ static long staticOffset(Object accessorObj) {
476 return ((StaticAccessor)accessorObj).staticOffset;
477 }
478
479 @ForceInline
480 /*non-public*/ static Object checkCast(Object mh, Object obj) {
481 return ((DirectMethodHandle) mh).checkCast(obj);
482 }
483
484 Object checkCast(Object obj) {
485 return member.getReturnType().cast(obj);
486 }
487
488 // Caching machinery for field accessors:
489 private static byte
490 AF_GETFIELD = 0,
491 AF_PUTFIELD = 1,
492 AF_GETSTATIC = 2,
493 AF_PUTSTATIC = 3,
494 AF_GETSTATIC_INIT = 4,
495 AF_PUTSTATIC_INIT = 5,
496 AF_LIMIT = 6;
497 // Enumerate the different field kinds using Wrapper,
498 // with an extra case added for checked references.
499 private static int
500 FT_LAST_WRAPPER = Wrapper.values().length-1,
501 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
502 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
503 FT_LIMIT = FT_LAST_WRAPPER+2;
504 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
505 return ((formOp * FT_LIMIT * 2)
506 + (isVolatile ? FT_LIMIT : 0)
507 + ftypeKind);
508 }
509 private static final LambdaForm[] ACCESSOR_FORMS
510 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
511 private static int ftypeKind(Class<?> ftype) {
512 if (ftype.isPrimitive())
513 return Wrapper.forPrimitiveType(ftype).ordinal();
514 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
515 return FT_UNCHECKED_REF;
516 else
517 return FT_CHECKED_REF;
518 }
519
520 /**
521 * Create a LF which can access the given field.
522 * Cache and share this structure among all fields with
523 * the same basicType and refKind.
524 */
525 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
526 Class<?> ftype = m.getFieldType();
527 boolean isVolatile = m.isVolatile();
528 byte formOp;
529 switch (m.getReferenceKind()) {
530 case REF_getField: formOp = AF_GETFIELD; break;
531 case REF_putField: formOp = AF_PUTFIELD; break;
532 case REF_getStatic: formOp = AF_GETSTATIC; break;
533 case REF_putStatic: formOp = AF_PUTSTATIC; break;
534 default: throw new InternalError(m.toString());
535 }
536 if (shouldBeInitialized(m)) {
537 // precompute the barrier-free version:
538 preparedFieldLambdaForm(formOp, isVolatile, ftype);
539 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
540 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
541 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
542 }
543 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
544 maybeCompile(lform, m);
545 assert(lform.methodType().dropParameterTypes(0, 1)
546 .equals(m.getInvocationType().basicType()))
547 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
548 return lform;
549 }
550 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
551 int afIndex = afIndex(formOp, isVolatile, ftypeKind(ftype));
552 LambdaForm lform = ACCESSOR_FORMS[afIndex];
553 if (lform != null) return lform;
554 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind(ftype));
555 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
556 return lform;
557 }
558
559 private static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
560 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
561 boolean isStatic = (formOp >= AF_GETSTATIC);
562 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
563 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
564 Wrapper fw = (needsCast ? Wrapper.OBJECT : Wrapper.values()[ftypeKind]);
565 Class<?> ft = fw.primitiveType();
566 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
567 String tname = fw.primitiveSimpleName();
568 String ctname = Character.toUpperCase(tname.charAt(0)) + tname.substring(1);
569 if (isVolatile) ctname += "Volatile";
570 String getOrPut = (isGetter ? "get" : "put");
571 String linkerName = (getOrPut + ctname); // getObject, putIntVolatile, etc.
572 MethodType linkerType;
573 if (isGetter)
574 linkerType = MethodType.methodType(ft, Object.class, long.class);
575 else
576 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
577 MemberName linker = new MemberName(Unsafe.class, linkerName, linkerType, REF_invokeVirtual);
578 try {
579 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
580 } catch (ReflectiveOperationException ex) {
581 throw newInternalError(ex);
582 }
583
584 // What is the external type of the lambda form?
585 MethodType mtype;
586 if (isGetter)
587 mtype = MethodType.methodType(ft);
588 else
589 mtype = MethodType.methodType(void.class, ft);
590 mtype = mtype.basicType(); // erase short to int, etc.
591 if (!isStatic)
592 mtype = mtype.insertParameterTypes(0, Object.class);
593 final int DMH_THIS = 0;
594 final int ARG_BASE = 1;
595 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
596 // if this is for non-static access, the base pointer is stored at this index:
597 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
598 // if this is for write access, the value to be written is stored at this index:
599 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
600 int nameCursor = ARG_LIMIT;
601 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
602 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
603 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
604 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
605 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
606 final int LINKER_CALL = nameCursor++;
607 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
608 final int RESULT = nameCursor-1; // either the call or the cast
609 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
610 if (needsInit)
611 names[INIT_BAR] = new Name(Lazy.NF_ensureInitialized, names[DMH_THIS]);
612 if (needsCast && !isGetter)
613 names[PRE_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
614 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
615 assert(outArgs.length == (isGetter ? 3 : 4));
616 outArgs[0] = UNSAFE;
617 if (isStatic) {
618 outArgs[1] = names[F_HOLDER] = new Name(Lazy.NF_staticBase, names[DMH_THIS]);
619 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_staticOffset, names[DMH_THIS]);
620 } else {
621 outArgs[1] = names[OBJ_CHECK] = new Name(Lazy.NF_checkBase, names[OBJ_BASE]);
622 outArgs[2] = names[F_OFFSET] = new Name(Lazy.NF_fieldOffset, names[DMH_THIS]);
623 }
624 if (!isGetter) {
625 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
626 }
627 for (Object a : outArgs) assert(a != null);
628 names[LINKER_CALL] = new Name(linker, outArgs);
629 if (needsCast && isGetter)
630 names[POST_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
631 for (Name n : names) assert(n != null);
632 String fieldOrStatic = (isStatic ? "Static" : "Field");
633 String lambdaName = (linkerName + fieldOrStatic); // significant only for debugging
634 if (needsCast) lambdaName += "Cast";
635 if (needsInit) lambdaName += "Init";
636 return new LambdaForm(lambdaName, ARG_LIMIT, names, RESULT);
637 }
638
639 /**
640 * Pre-initialized NamedFunctions for bootstrapping purposes.
641 * Factored in an inner class to delay initialization until first usage.
642 */
643 private static class Lazy {
644 static final NamedFunction
645 NF_internalMemberName,
646 NF_internalMemberNameEnsureInit,
647 NF_ensureInitialized,
648 NF_fieldOffset,
649 NF_checkBase,
650 NF_staticBase,
651 NF_staticOffset,
652 NF_checkCast,
653 NF_allocateInstance,
654 NF_constructorMethod;
655 static {
656 try {
657 NamedFunction nfs[] = {
658 NF_internalMemberName = new NamedFunction(DirectMethodHandle.class
659 .getDeclaredMethod("internalMemberName", Object.class)),
660 NF_internalMemberNameEnsureInit = new NamedFunction(DirectMethodHandle.class
661 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)),
662 NF_ensureInitialized = new NamedFunction(DirectMethodHandle.class
663 .getDeclaredMethod("ensureInitialized", Object.class)),
664 NF_fieldOffset = new NamedFunction(DirectMethodHandle.class
665 .getDeclaredMethod("fieldOffset", Object.class)),
666 NF_checkBase = new NamedFunction(DirectMethodHandle.class
667 .getDeclaredMethod("checkBase", Object.class)),
668 NF_staticBase = new NamedFunction(DirectMethodHandle.class
669 .getDeclaredMethod("staticBase", Object.class)),
670 NF_staticOffset = new NamedFunction(DirectMethodHandle.class
671 .getDeclaredMethod("staticOffset", Object.class)),
672 NF_checkCast = new NamedFunction(DirectMethodHandle.class
673 .getDeclaredMethod("checkCast", Object.class, Object.class)),
674 NF_allocateInstance = new NamedFunction(DirectMethodHandle.class
675 .getDeclaredMethod("allocateInstance", Object.class)),
676 NF_constructorMethod = new NamedFunction(DirectMethodHandle.class
677 .getDeclaredMethod("constructorMethod", Object.class))
678 };
679 for (NamedFunction nf : nfs) {
680 // Each nf must be statically invocable or we get tied up in our bootstraps.
681 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf.member)) : nf;
682 nf.resolve();
683 }
684 } catch (ReflectiveOperationException ex) {
685 throw newInternalError(ex);
686 }
687 }
688 }
689 }