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 jdk.internal.misc.Unsafe;
29 import jdk.internal.vm.annotation.ForceInline;
30 import jdk.internal.vm.annotation.Stable;
31 import sun.invoke.util.ValueConversions;
32 import sun.invoke.util.VerifyAccess;
33 import sun.invoke.util.VerifyType;
34 import sun.invoke.util.Wrapper;
35
36 import java.lang.ref.WeakReference;
37 import java.util.Arrays;
38 import java.util.Objects;
39
40 import static java.lang.invoke.LambdaForm.*;
41 import static java.lang.invoke.MethodHandleNatives.Constants.*;
42 import static java.lang.invoke.MethodHandleStatics.UNSAFE;
43 import static java.lang.invoke.MethodHandleStatics.newInternalError;
44 import static java.lang.invoke.MethodTypeForm.*;
45
46 /**
47 * The flavor of method handle which implements a constant reference
48 * to a class member.
49 * @author jrose
50 */
51 class DirectMethodHandle extends MethodHandle {
52 final MemberName member;
53
54 // Constructors and factory methods in this class *must* be package scoped or private.
55 private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) {
56 super(mtype, form);
57 if (!member.isResolved()) throw new InternalError();
58
59 if (member.getDeclaringClass().isInterface() &&
60 member.isMethod() && !member.isAbstract()) {
61 // Check for corner case: invokeinterface of Object method
62 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
63 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
64 if (m != null && m.isPublic()) {
65 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
66 member = m;
67 }
68 }
69
70 this.member = member;
71 }
72
73 // Factory methods:
74 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
75 MethodType mtype = member.getMethodOrFieldType();
76 if (!member.isStatic()) {
77 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
78 throw new InternalError(member.toString());
79 mtype = mtype.insertParameterTypes(0, receiver);
80 }
81 if (!member.isField()) {
82 if (refKind == REF_invokeSpecial) {
83 member = member.asSpecial();
84 LambdaForm lform = preparedLambdaForm(member);
85 return new Special(mtype, lform, member);
86 } else {
87 LambdaForm lform = preparedLambdaForm(member);
88 return new DirectMethodHandle(mtype, lform, member);
89 }
90 } else {
91 LambdaForm lform = preparedFieldLambdaForm(member);
92 if (member.isStatic()) {
93 long offset = MethodHandleNatives.staticFieldOffset(member);
94 Object base = MethodHandleNatives.staticFieldBase(member);
95 return new StaticAccessor(mtype, lform, member, base, offset);
96 } else {
97 long offset = MethodHandleNatives.objectFieldOffset(member);
98 assert(offset == (int)offset);
99 return new Accessor(mtype, lform, member, (int)offset);
100 }
101 }
102 }
103 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
104 byte refKind = member.getReferenceKind();
105 if (refKind == REF_invokeSpecial)
106 refKind = REF_invokeVirtual;
107 return make(refKind, receiver, member);
108 }
109 static DirectMethodHandle make(MemberName member) {
110 if (member.isConstructor())
111 return makeAllocator(member);
112 return make(member.getDeclaringClass(), member);
113 }
114 private static DirectMethodHandle makeAllocator(MemberName ctor) {
115 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
116 Class<?> instanceClass = ctor.getDeclaringClass();
117 ctor = ctor.asConstructor();
118 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
119 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
120 LambdaForm lform = preparedLambdaForm(ctor);
121 MemberName init = ctor.asSpecial();
122 assert(init.getMethodType().returnType() == void.class);
123 return new Constructor(mtype, lform, ctor, init, instanceClass);
124 }
125
126 @Override
127 BoundMethodHandle rebind() {
128 return BoundMethodHandle.makeReinvoker(this);
129 }
130
131 @Override
132 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
133 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
134 return new DirectMethodHandle(mt, lf, member);
135 }
136
137 @Override
138 String internalProperties() {
139 return "\n& DMH.MN="+internalMemberName();
140 }
141
142 //// Implementation methods.
143 @Override
144 @ForceInline
145 MemberName internalMemberName() {
146 return member;
147 }
148
149 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
150
151 /**
152 * Create a LF which can invoke the given method.
153 * Cache and share this structure among all methods with
154 * the same basicType and refKind.
155 */
156 private static LambdaForm preparedLambdaForm(MemberName m) {
157 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
158 MethodType mtype = m.getInvocationType().basicType();
159 assert(!m.isMethodHandleInvoke()) : m;
160 int which;
161 switch (m.getReferenceKind()) {
162 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
163 case REF_invokeStatic: which = LF_INVSTATIC; break;
164 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
165 case REF_invokeInterface: which = LF_INVINTERFACE; break;
166 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
167 default: throw new InternalError(m.toString());
168 }
169 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
170 // precompute the barrier-free version:
171 preparedLambdaForm(mtype, which);
172 which = LF_INVSTATIC_INIT;
173 }
174 LambdaForm lform = preparedLambdaForm(mtype, which);
175 maybeCompile(lform, m);
176 assert(lform.methodType().dropParameterTypes(0, 1)
177 .equals(m.getInvocationType().basicType()))
178 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
179 return lform;
180 }
181
182 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
183 LambdaForm lform = mtype.form().cachedLambdaForm(which);
184 if (lform != null) return lform;
185 lform = makePreparedLambdaForm(mtype, which);
186 return mtype.form().setCachedLambdaForm(which, lform);
187 }
188
189 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
190 boolean needsInit = (which == LF_INVSTATIC_INIT);
191 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
192 String linkerName, lambdaName;
193 switch (which) {
194 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; lambdaName = "DMH.invokeVirtual"; break;
195 case LF_INVSTATIC: linkerName = "linkToStatic"; lambdaName = "DMH.invokeStatic"; break;
196 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; lambdaName = "DMH.invokeStaticInit"; break;
197 case LF_INVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.invokeSpecial"; break;
198 case LF_INVINTERFACE: linkerName = "linkToInterface"; lambdaName = "DMH.invokeInterface"; break;
199 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; lambdaName = "DMH.newInvokeSpecial"; break;
200 default: throw new InternalError("which="+which);
201 }
202
203 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
204 if (doesAlloc)
205 mtypeWithArg = mtypeWithArg
206 .insertParameterTypes(0, Object.class) // insert newly allocated obj
207 .changeReturnType(void.class); // <init> returns void
208 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
209 try {
210 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
211 } catch (ReflectiveOperationException ex) {
212 throw newInternalError(ex);
213 }
214 final int DMH_THIS = 0;
215 final int ARG_BASE = 1;
216 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
217 int nameCursor = ARG_LIMIT;
218 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
219 final int GET_MEMBER = nameCursor++;
220 final int LINKER_CALL = nameCursor++;
221 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
222 assert(names.length == nameCursor);
223 if (doesAlloc) {
224 // names = { argx,y,z,... new C, init method }
225 names[NEW_OBJ] = new Name(NF_allocateInstance, names[DMH_THIS]);
226 names[GET_MEMBER] = new Name(NF_constructorMethod, names[DMH_THIS]);
227 } else if (needsInit) {
228 names[GET_MEMBER] = new Name(NF_internalMemberNameEnsureInit, names[DMH_THIS]);
229 } else {
230 names[GET_MEMBER] = new Name(NF_internalMemberName, names[DMH_THIS]);
231 }
232 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
233 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
234 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
235 int result = LAST_RESULT;
236 if (doesAlloc) {
237 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
238 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
239 outArgs[0] = names[NEW_OBJ];
240 result = NEW_OBJ;
241 }
242 names[LINKER_CALL] = new Name(linker, outArgs);
243 lambdaName += "_" + shortenSignature(basicTypeSignature(mtype));
244 LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result);
245
246 // This is a tricky bit of code. Don't send it through the LF interpreter.
247 lform.compileToBytecode(Holder.class);
248 return lform;
249 }
250
251 static Object findDirectMethodHandle(Name name) {
252 if (name.function == NF_internalMemberName ||
253 name.function == NF_internalMemberNameEnsureInit ||
254 name.function == NF_constructorMethod) {
255 assert(name.arguments.length == 1);
256 return name.arguments[0];
257 }
258 return null;
259 }
260
261 private static void maybeCompile(LambdaForm lform, MemberName m) {
262 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
263 // Help along bootstrapping...
264 lform.compileToBytecode();
265 }
266
267 /** Static wrapper for DirectMethodHandle.internalMemberName. */
268 @ForceInline
269 /*non-public*/ static Object internalMemberName(Object mh) {
270 return ((DirectMethodHandle)mh).member;
271 }
272
273 /** Static wrapper for DirectMethodHandle.internalMemberName.
274 * This one also forces initialization.
275 */
276 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
277 DirectMethodHandle dmh = (DirectMethodHandle)mh;
278 dmh.ensureInitialized();
279 return dmh.member;
280 }
281
282 /*non-public*/ static
283 boolean shouldBeInitialized(MemberName member) {
284 switch (member.getReferenceKind()) {
285 case REF_invokeStatic:
286 case REF_getStatic:
287 case REF_putStatic:
288 case REF_newInvokeSpecial:
289 break;
290 default:
291 // No need to initialize the class on this kind of member.
292 return false;
293 }
294 Class<?> cls = member.getDeclaringClass();
295 if (cls == ValueConversions.class ||
296 cls == MethodHandleImpl.class ||
297 cls == Invokers.class) {
298 // These guys have lots of <clinit> DMH creation but we know
299 // the MHs will not be used until the system is booted.
300 return false;
301 }
302 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
303 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
304 // It is a system class. It is probably in the process of
305 // being initialized, but we will help it along just to be safe.
306 if (UNSAFE.shouldBeInitialized(cls)) {
307 UNSAFE.ensureClassInitialized(cls);
308 }
309 return false;
310 }
311 return UNSAFE.shouldBeInitialized(cls);
312 }
313
314 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
315 @Override
316 protected WeakReference<Thread> computeValue(Class<?> type) {
317 UNSAFE.ensureClassInitialized(type);
318 if (UNSAFE.shouldBeInitialized(type))
319 // If the previous call didn't block, this can happen.
320 // We are executing inside <clinit>.
321 return new WeakReference<>(Thread.currentThread());
322 return null;
323 }
324 static final EnsureInitialized INSTANCE = new EnsureInitialized();
325 }
326
327 private void ensureInitialized() {
328 if (checkInitialized(member)) {
329 // The coast is clear. Delete the <clinit> barrier.
330 if (member.isField())
331 updateForm(preparedFieldLambdaForm(member));
332 else
333 updateForm(preparedLambdaForm(member));
334 }
335 }
336 private static boolean checkInitialized(MemberName member) {
337 Class<?> defc = member.getDeclaringClass();
338 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
339 if (ref == null) {
340 return true; // the final state
341 }
342 Thread clinitThread = ref.get();
343 // Somebody may still be running defc.<clinit>.
344 if (clinitThread == Thread.currentThread()) {
345 // If anybody is running defc.<clinit>, it is this thread.
346 if (UNSAFE.shouldBeInitialized(defc))
347 // Yes, we are running it; keep the barrier for now.
348 return false;
349 } else {
350 // We are in a random thread. Block.
351 UNSAFE.ensureClassInitialized(defc);
352 }
353 assert(!UNSAFE.shouldBeInitialized(defc));
354 // put it into the final state
355 EnsureInitialized.INSTANCE.remove(defc);
356 return true;
357 }
358
359 /*non-public*/ static void ensureInitialized(Object mh) {
360 ((DirectMethodHandle)mh).ensureInitialized();
361 }
362
363 /** This subclass represents invokespecial instructions. */
364 static class Special extends DirectMethodHandle {
365 private Special(MethodType mtype, LambdaForm form, MemberName member) {
366 super(mtype, form, member);
367 }
368 @Override
369 boolean isInvokeSpecial() {
370 return true;
371 }
372 @Override
373 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
374 return new Special(mt, lf, member);
375 }
376 }
377
378 /** This subclass handles constructor references. */
379 static class Constructor extends DirectMethodHandle {
380 final MemberName initMethod;
381 final Class<?> instanceClass;
382
383 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
384 MemberName initMethod, Class<?> instanceClass) {
385 super(mtype, form, constructor);
386 this.initMethod = initMethod;
387 this.instanceClass = instanceClass;
388 assert(initMethod.isResolved());
389 }
390 @Override
391 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
392 return new Constructor(mt, lf, member, initMethod, instanceClass);
393 }
394 }
395
396 /*non-public*/ static Object constructorMethod(Object mh) {
397 Constructor dmh = (Constructor)mh;
398 return dmh.initMethod;
399 }
400
401 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
402 Constructor dmh = (Constructor)mh;
403 return UNSAFE.allocateInstance(dmh.instanceClass);
404 }
405
406 /** This subclass handles non-static field references. */
407 static class Accessor extends DirectMethodHandle {
408 final Class<?> fieldType;
409 final int fieldOffset;
410 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
411 int fieldOffset) {
412 super(mtype, form, member);
413 this.fieldType = member.getFieldType();
414 this.fieldOffset = fieldOffset;
415 }
416
417 @Override Object checkCast(Object obj) {
418 return fieldType.cast(obj);
419 }
420 @Override
421 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
422 return new Accessor(mt, lf, member, fieldOffset);
423 }
424 }
425
426 @ForceInline
427 /*non-public*/ static long fieldOffset(Object accessorObj) {
428 // Note: We return a long because that is what Unsafe.getObject likes.
429 // We store a plain int because it is more compact.
430 return ((Accessor)accessorObj).fieldOffset;
431 }
432
433 @ForceInline
434 /*non-public*/ static Object checkBase(Object obj) {
435 // Note that the object's class has already been verified,
436 // since the parameter type of the Accessor method handle
437 // is either member.getDeclaringClass or a subclass.
438 // This was verified in DirectMethodHandle.make.
439 // Therefore, the only remaining check is for null.
440 // Since this check is *not* guaranteed by Unsafe.getInt
441 // and its siblings, we need to make an explicit one here.
442 return Objects.requireNonNull(obj);
443 }
444
445 /** This subclass handles static field references. */
446 static class StaticAccessor extends DirectMethodHandle {
447 private final Class<?> fieldType;
448 private final Object staticBase;
449 private final long staticOffset;
450
451 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
452 Object staticBase, long staticOffset) {
453 super(mtype, form, member);
454 this.fieldType = member.getFieldType();
455 this.staticBase = staticBase;
456 this.staticOffset = staticOffset;
457 }
458
459 @Override Object checkCast(Object obj) {
460 return fieldType.cast(obj);
461 }
462 @Override
463 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
464 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
465 }
466 }
467
468 @ForceInline
469 /*non-public*/ static Object nullCheck(Object obj) {
470 return Objects.requireNonNull(obj);
471 }
472
473 @ForceInline
474 /*non-public*/ static Object staticBase(Object accessorObj) {
475 return ((StaticAccessor)accessorObj).staticBase;
476 }
477
478 @ForceInline
479 /*non-public*/ static long staticOffset(Object accessorObj) {
480 return ((StaticAccessor)accessorObj).staticOffset;
481 }
482
483 @ForceInline
484 /*non-public*/ static Object checkCast(Object mh, Object obj) {
485 return ((DirectMethodHandle) mh).checkCast(obj);
486 }
487
488 Object checkCast(Object obj) {
489 return member.getReturnType().cast(obj);
490 }
491
492 // Caching machinery for field accessors:
493 private static final byte
494 AF_GETFIELD = 0,
495 AF_PUTFIELD = 1,
496 AF_GETSTATIC = 2,
497 AF_PUTSTATIC = 3,
498 AF_GETSTATIC_INIT = 4,
499 AF_PUTSTATIC_INIT = 5,
500 AF_LIMIT = 6;
501 // Enumerate the different field kinds using Wrapper,
502 // with an extra case added for checked references.
503 private static final int
504 FT_LAST_WRAPPER = Wrapper.COUNT-1,
505 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
506 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
507 FT_LIMIT = FT_LAST_WRAPPER+2;
508 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
509 return ((formOp * FT_LIMIT * 2)
510 + (isVolatile ? FT_LIMIT : 0)
511 + ftypeKind);
512 }
513 @Stable
514 private static final LambdaForm[] ACCESSOR_FORMS
515 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
516 private static int ftypeKind(Class<?> ftype) {
517 if (ftype.isPrimitive())
518 return Wrapper.forPrimitiveType(ftype).ordinal();
519 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
520 return FT_UNCHECKED_REF;
521 else
522 return FT_CHECKED_REF;
523 }
524
525 /**
526 * Create a LF which can access the given field.
527 * Cache and share this structure among all fields with
528 * the same basicType and refKind.
529 */
530 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
531 Class<?> ftype = m.getFieldType();
532 boolean isVolatile = m.isVolatile();
533 byte formOp;
534 switch (m.getReferenceKind()) {
535 case REF_getField: formOp = AF_GETFIELD; break;
536 case REF_putField: formOp = AF_PUTFIELD; break;
537 case REF_getStatic: formOp = AF_GETSTATIC; break;
538 case REF_putStatic: formOp = AF_PUTSTATIC; break;
539 default: throw new InternalError(m.toString());
540 }
541 if (shouldBeInitialized(m)) {
542 // precompute the barrier-free version:
543 preparedFieldLambdaForm(formOp, isVolatile, ftype);
544 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
545 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
546 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
547 }
548 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
549 maybeCompile(lform, m);
550 assert(lform.methodType().dropParameterTypes(0, 1)
551 .equals(m.getInvocationType().basicType()))
552 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
553 return lform;
554 }
555 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
556 int ftypeKind = ftypeKind(ftype);
557 int afIndex = afIndex(formOp, isVolatile, ftypeKind);
558 LambdaForm lform = ACCESSOR_FORMS[afIndex];
559 if (lform != null) return lform;
560 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind);
561 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
562 return lform;
563 }
564
565 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
566
567 private static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
568 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
569 boolean isStatic = (formOp >= AF_GETSTATIC);
570 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
571 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
572 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
573 Class<?> ft = fw.primitiveType();
574 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
575
576 // getObject, putIntVolatile, etc.
577 StringBuilder nameBuilder = new StringBuilder();
578 if (isGetter) {
579 nameBuilder.append("get");
580 } else {
581 nameBuilder.append("put");
582 }
583 nameBuilder.append(fw.primitiveSimpleName());
584 nameBuilder.setCharAt(3, Character.toUpperCase(nameBuilder.charAt(3)));
585 if (isVolatile) {
586 nameBuilder.append("Volatile");
587 }
588
589 MethodType linkerType;
590 if (isGetter)
591 linkerType = MethodType.methodType(ft, Object.class, long.class);
592 else
593 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
594 MemberName linker = new MemberName(Unsafe.class, nameBuilder.toString(), linkerType, REF_invokeVirtual);
595 try {
596 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
597 } catch (ReflectiveOperationException ex) {
598 throw newInternalError(ex);
599 }
600
601 // What is the external type of the lambda form?
602 MethodType mtype;
603 if (isGetter)
604 mtype = MethodType.methodType(ft);
605 else
606 mtype = MethodType.methodType(void.class, ft);
607 mtype = mtype.basicType(); // erase short to int, etc.
608 if (!isStatic)
609 mtype = mtype.insertParameterTypes(0, Object.class);
610 final int DMH_THIS = 0;
611 final int ARG_BASE = 1;
612 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
613 // if this is for non-static access, the base pointer is stored at this index:
614 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
615 // if this is for write access, the value to be written is stored at this index:
616 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
617 int nameCursor = ARG_LIMIT;
618 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
619 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
620 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
621 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
622 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
623 final int LINKER_CALL = nameCursor++;
624 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
625 final int RESULT = nameCursor-1; // either the call or the cast
626 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
627 if (needsInit)
628 names[INIT_BAR] = new Name(NF_ensureInitialized, names[DMH_THIS]);
629 if (needsCast && !isGetter)
630 names[PRE_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
631 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
632 assert(outArgs.length == (isGetter ? 3 : 4));
633 outArgs[0] = UNSAFE;
634 if (isStatic) {
635 outArgs[1] = names[F_HOLDER] = new Name(NF_staticBase, names[DMH_THIS]);
636 outArgs[2] = names[F_OFFSET] = new Name(NF_staticOffset, names[DMH_THIS]);
637 } else {
638 outArgs[1] = names[OBJ_CHECK] = new Name(NF_checkBase, names[OBJ_BASE]);
639 outArgs[2] = names[F_OFFSET] = new Name(NF_fieldOffset, names[DMH_THIS]);
640 }
641 if (!isGetter) {
642 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
643 }
644 for (Object a : outArgs) assert(a != null);
645 names[LINKER_CALL] = new Name(linker, outArgs);
646 if (needsCast && isGetter)
647 names[POST_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
648 for (Name n : names) assert(n != null);
649 // add some detail to the lambdaForm debugname,
650 // significant only for debugging
651 if (isStatic) {
652 nameBuilder.append("Static");
653 } else {
654 nameBuilder.append("Field");
655 }
656 if (needsCast) nameBuilder.append("Cast");
657 if (needsInit) nameBuilder.append("Init");
658 return new LambdaForm(nameBuilder.toString(), ARG_LIMIT, names, RESULT);
659 }
660
661 /**
662 * Pre-initialized NamedFunctions for bootstrapping purposes.
663 * Factored in an inner class to delay initialization until first usage.
664 */
665 static final NamedFunction
666 NF_internalMemberName,
667 NF_internalMemberNameEnsureInit,
668 NF_ensureInitialized,
669 NF_fieldOffset,
670 NF_checkBase,
671 NF_staticBase,
672 NF_staticOffset,
673 NF_checkCast,
674 NF_allocateInstance,
675 NF_constructorMethod;
676 static {
677 try {
678 NamedFunction nfs[] = {
679 NF_internalMemberName = new NamedFunction(DirectMethodHandle.class
680 .getDeclaredMethod("internalMemberName", Object.class)),
681 NF_internalMemberNameEnsureInit = new NamedFunction(DirectMethodHandle.class
682 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)),
683 NF_ensureInitialized = new NamedFunction(DirectMethodHandle.class
684 .getDeclaredMethod("ensureInitialized", Object.class)),
685 NF_fieldOffset = new NamedFunction(DirectMethodHandle.class
686 .getDeclaredMethod("fieldOffset", Object.class)),
687 NF_checkBase = new NamedFunction(DirectMethodHandle.class
688 .getDeclaredMethod("checkBase", Object.class)),
689 NF_staticBase = new NamedFunction(DirectMethodHandle.class
690 .getDeclaredMethod("staticBase", Object.class)),
691 NF_staticOffset = new NamedFunction(DirectMethodHandle.class
692 .getDeclaredMethod("staticOffset", Object.class)),
693 NF_checkCast = new NamedFunction(DirectMethodHandle.class
694 .getDeclaredMethod("checkCast", Object.class, Object.class)),
695 NF_allocateInstance = new NamedFunction(DirectMethodHandle.class
696 .getDeclaredMethod("allocateInstance", Object.class)),
697 NF_constructorMethod = new NamedFunction(DirectMethodHandle.class
698 .getDeclaredMethod("constructorMethod", Object.class))
699 };
700 // Each nf must be statically invocable or we get tied up in our bootstraps.
701 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nfs));
702 } catch (ReflectiveOperationException ex) {
703 throw newInternalError(ex);
704 }
705 }
706
707 static {
708 // The DMH class will contain pre-generated DirectMethodHandles resolved
709 // speculatively using MemberName.getFactory().resolveOrNull. However, that
710 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
711 // initialization of the Holder class we avoid these issues.
712 UNSAFE.ensureClassInitialized(Holder.class);
713 }
714
715 /* Placeholder class for DirectMethodHandles generated ahead of time */
716 private final class Holder {}
717 }