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