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.LambdaForm.Kind.*;
42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
43 import static java.lang.invoke.MethodHandleStatics.UNSAFE;
44 import static java.lang.invoke.MethodHandleStatics.newInternalError;
45 import static java.lang.invoke.MethodTypeForm.*;
46
47 /**
48 * The flavor of method handle which implements a constant reference
49 * to a class member.
50 * @author jrose
51 */
52 class DirectMethodHandle extends MethodHandle {
53 final MemberName member;
54
55 // Constructors and factory methods in this class *must* be package scoped or private.
56 private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) {
57 super(mtype, form);
58 if (!member.isResolved()) throw new InternalError();
59
60 if (member.getDeclaringClass().isInterface() &&
61 member.isMethod() && !member.isAbstract()) {
62 // Check for corner case: invokeinterface of Object method
63 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
64 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
65 if (m != null && m.isPublic()) {
66 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
67 member = m;
68 }
69 }
70
71 this.member = member;
72 }
73
74 // Factory methods:
75 static DirectMethodHandle make(byte refKind, Class<?> receiver, MemberName member) {
76 MethodType mtype = member.getMethodOrFieldType();
77 if (!member.isStatic()) {
78 if (!member.getDeclaringClass().isAssignableFrom(receiver) || member.isConstructor())
79 throw new InternalError(member.toString());
80 mtype = mtype.insertParameterTypes(0, receiver);
81 }
82 if (!member.isField()) {
83 if (refKind == REF_invokeSpecial) {
84 member = member.asSpecial();
85 LambdaForm lform = preparedLambdaForm(member);
86 return new Special(mtype, lform, member);
87 } else {
88 LambdaForm lform = preparedLambdaForm(member);
89 return new DirectMethodHandle(mtype, lform, member);
90 }
91 } else {
92 LambdaForm lform = preparedFieldLambdaForm(member);
93 if (member.isStatic()) {
94 long offset = MethodHandleNatives.staticFieldOffset(member);
95 Object base = MethodHandleNatives.staticFieldBase(member);
96 return new StaticAccessor(mtype, lform, member, base, offset);
97 } else {
98 long offset = MethodHandleNatives.objectFieldOffset(member);
99 assert(offset == (int)offset);
100 return new Accessor(mtype, lform, member, (int)offset);
101 }
102 }
103 }
104 static DirectMethodHandle make(Class<?> receiver, MemberName member) {
105 byte refKind = member.getReferenceKind();
106 if (refKind == REF_invokeSpecial)
107 refKind = REF_invokeVirtual;
108 return make(refKind, receiver, member);
109 }
110 static DirectMethodHandle make(MemberName member) {
111 if (member.isConstructor())
112 return makeAllocator(member);
113 return make(member.getDeclaringClass(), member);
114 }
115 private static DirectMethodHandle makeAllocator(MemberName ctor) {
116 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
117 Class<?> instanceClass = ctor.getDeclaringClass();
118 ctor = ctor.asConstructor();
119 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
120 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
121 LambdaForm lform = preparedLambdaForm(ctor);
122 MemberName init = ctor.asSpecial();
123 assert(init.getMethodType().returnType() == void.class);
124 return new Constructor(mtype, lform, ctor, init, instanceClass);
125 }
126
127 @Override
128 BoundMethodHandle rebind() {
129 return BoundMethodHandle.makeReinvoker(this);
130 }
131
132 @Override
133 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
134 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
135 return new DirectMethodHandle(mt, lf, member);
136 }
137
138 @Override
139 String internalProperties() {
140 return "\n& DMH.MN="+internalMemberName();
141 }
142
143 //// Implementation methods.
144 @Override
145 @ForceInline
146 MemberName internalMemberName() {
147 return member;
148 }
149
150 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
151
152 /**
153 * Create a LF which can invoke the given method.
154 * Cache and share this structure among all methods with
155 * the same basicType and refKind.
156 */
157 private static LambdaForm preparedLambdaForm(MemberName m) {
158 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
159 MethodType mtype = m.getInvocationType().basicType();
160 assert(!m.isMethodHandleInvoke()) : m;
161 int which;
162 switch (m.getReferenceKind()) {
163 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
164 case REF_invokeStatic: which = LF_INVSTATIC; break;
165 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
166 case REF_invokeInterface: which = LF_INVINTERFACE; break;
167 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
168 default: throw new InternalError(m.toString());
169 }
170 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
171 // precompute the barrier-free version:
172 preparedLambdaForm(mtype, which);
173 which = LF_INVSTATIC_INIT;
174 }
175 LambdaForm lform = preparedLambdaForm(mtype, which);
176 maybeCompile(lform, m);
177 assert(lform.methodType().dropParameterTypes(0, 1)
178 .equals(m.getInvocationType().basicType()))
179 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
180 return lform;
181 }
182
183 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
184 LambdaForm lform = mtype.form().cachedLambdaForm(which);
185 if (lform != null) return lform;
186 lform = makePreparedLambdaForm(mtype, which);
187 return mtype.form().setCachedLambdaForm(which, lform);
188 }
189
190 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
191 boolean needsInit = (which == LF_INVSTATIC_INIT);
192 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
193 String linkerName;
194 LambdaForm.Kind kind;
195 switch (which) {
196 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break;
197 case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break;
198 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break;
199 case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break;
200 case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break;
201 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break;
202 default: throw new InternalError("which="+which);
203 }
204
205 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
206 if (doesAlloc)
207 mtypeWithArg = mtypeWithArg
208 .insertParameterTypes(0, Object.class) // insert newly allocated obj
209 .changeReturnType(void.class); // <init> returns void
210 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
211 try {
212 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
213 } catch (ReflectiveOperationException ex) {
214 throw newInternalError(ex);
215 }
216 final int DMH_THIS = 0;
217 final int ARG_BASE = 1;
218 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
219 int nameCursor = ARG_LIMIT;
220 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
221 final int GET_MEMBER = nameCursor++;
222 final int LINKER_CALL = nameCursor++;
223 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
224 assert(names.length == nameCursor);
225 if (doesAlloc) {
226 // names = { argx,y,z,... new C, init method }
227 names[NEW_OBJ] = new Name(NF_allocateInstance, names[DMH_THIS]);
228 names[GET_MEMBER] = new Name(NF_constructorMethod, names[DMH_THIS]);
229 } else if (needsInit) {
230 names[GET_MEMBER] = new Name(NF_internalMemberNameEnsureInit, names[DMH_THIS]);
231 } else {
232 names[GET_MEMBER] = new Name(NF_internalMemberName, names[DMH_THIS]);
233 }
234 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
235 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
236 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
237 int result = LAST_RESULT;
238 if (doesAlloc) {
239 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
240 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
241 outArgs[0] = names[NEW_OBJ];
242 result = NEW_OBJ;
243 }
244 names[LINKER_CALL] = new Name(linker, outArgs);
245 String lambdaName = kind.defaultLambdaName + "_" + shortenSignature(basicTypeSignature(mtype));
246 LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result, kind);
247
248 // This is a tricky bit of code. Don't send it through the LF interpreter.
249 lform.compileToBytecode();
250 return lform;
251 }
252
253 static Object findDirectMethodHandle(Name name) {
254 if (name.function == NF_internalMemberName ||
255 name.function == NF_internalMemberNameEnsureInit ||
256 name.function == NF_constructorMethod) {
257 assert(name.arguments.length == 1);
258 return name.arguments[0];
259 }
260 return null;
261 }
262
263 private static void maybeCompile(LambdaForm lform, MemberName m) {
264 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
265 // Help along bootstrapping...
266 lform.compileToBytecode();
267 }
268
269 /** Static wrapper for DirectMethodHandle.internalMemberName. */
270 @ForceInline
271 /*non-public*/ static Object internalMemberName(Object mh) {
272 return ((DirectMethodHandle)mh).member;
273 }
274
275 /** Static wrapper for DirectMethodHandle.internalMemberName.
276 * This one also forces initialization.
277 */
278 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
279 DirectMethodHandle dmh = (DirectMethodHandle)mh;
280 dmh.ensureInitialized();
281 return dmh.member;
282 }
283
284 /*non-public*/ static
285 boolean shouldBeInitialized(MemberName member) {
286 switch (member.getReferenceKind()) {
287 case REF_invokeStatic:
288 case REF_getStatic:
289 case REF_putStatic:
290 case REF_newInvokeSpecial:
291 break;
292 default:
293 // No need to initialize the class on this kind of member.
294 return false;
295 }
296 Class<?> cls = member.getDeclaringClass();
297 if (cls == ValueConversions.class ||
298 cls == MethodHandleImpl.class ||
299 cls == Invokers.class) {
300 // These guys have lots of <clinit> DMH creation but we know
301 // the MHs will not be used until the system is booted.
302 return false;
303 }
304 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
305 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
306 // It is a system class. It is probably in the process of
307 // being initialized, but we will help it along just to be safe.
308 if (UNSAFE.shouldBeInitialized(cls)) {
309 UNSAFE.ensureClassInitialized(cls);
310 }
311 return false;
312 }
313 return UNSAFE.shouldBeInitialized(cls);
314 }
315
316 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
317 @Override
318 protected WeakReference<Thread> computeValue(Class<?> type) {
319 UNSAFE.ensureClassInitialized(type);
320 if (UNSAFE.shouldBeInitialized(type))
321 // If the previous call didn't block, this can happen.
322 // We are executing inside <clinit>.
323 return new WeakReference<>(Thread.currentThread());
324 return null;
325 }
326 static final EnsureInitialized INSTANCE = new EnsureInitialized();
327 }
328
329 private void ensureInitialized() {
330 if (checkInitialized(member)) {
331 // The coast is clear. Delete the <clinit> barrier.
332 if (member.isField())
333 updateForm(preparedFieldLambdaForm(member));
334 else
335 updateForm(preparedLambdaForm(member));
336 }
337 }
338 private static boolean checkInitialized(MemberName member) {
339 Class<?> defc = member.getDeclaringClass();
340 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
341 if (ref == null) {
342 return true; // the final state
343 }
344 Thread clinitThread = ref.get();
345 // Somebody may still be running defc.<clinit>.
346 if (clinitThread == Thread.currentThread()) {
347 // If anybody is running defc.<clinit>, it is this thread.
348 if (UNSAFE.shouldBeInitialized(defc))
349 // Yes, we are running it; keep the barrier for now.
350 return false;
351 } else {
352 // We are in a random thread. Block.
353 UNSAFE.ensureClassInitialized(defc);
354 }
355 assert(!UNSAFE.shouldBeInitialized(defc));
356 // put it into the final state
357 EnsureInitialized.INSTANCE.remove(defc);
358 return true;
359 }
360
361 /*non-public*/ static void ensureInitialized(Object mh) {
362 ((DirectMethodHandle)mh).ensureInitialized();
363 }
364
365 /** This subclass represents invokespecial instructions. */
366 static class Special extends DirectMethodHandle {
367 private Special(MethodType mtype, LambdaForm form, MemberName member) {
368 super(mtype, form, member);
369 }
370 @Override
371 boolean isInvokeSpecial() {
372 return true;
373 }
374 @Override
375 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
376 return new Special(mt, lf, member);
377 }
378 }
379
380 /** This subclass handles constructor references. */
381 static class Constructor extends DirectMethodHandle {
382 final MemberName initMethod;
383 final Class<?> instanceClass;
384
385 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
386 MemberName initMethod, Class<?> instanceClass) {
387 super(mtype, form, constructor);
388 this.initMethod = initMethod;
389 this.instanceClass = instanceClass;
390 assert(initMethod.isResolved());
391 }
392 @Override
393 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
394 return new Constructor(mt, lf, member, initMethod, instanceClass);
395 }
396 }
397
398 /*non-public*/ static Object constructorMethod(Object mh) {
399 Constructor dmh = (Constructor)mh;
400 return dmh.initMethod;
401 }
402
403 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
404 Constructor dmh = (Constructor)mh;
405 return UNSAFE.allocateInstance(dmh.instanceClass);
406 }
407
408 /** This subclass handles non-static field references. */
409 static class Accessor extends DirectMethodHandle {
410 final Class<?> fieldType;
411 final int fieldOffset;
412 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
413 int fieldOffset) {
414 super(mtype, form, member);
415 this.fieldType = member.getFieldType();
416 this.fieldOffset = fieldOffset;
417 }
418
419 @Override Object checkCast(Object obj) {
420 return fieldType.cast(obj);
421 }
422 @Override
423 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
424 return new Accessor(mt, lf, member, fieldOffset);
425 }
426 }
427
428 @ForceInline
429 /*non-public*/ static long fieldOffset(Object accessorObj) {
430 // Note: We return a long because that is what Unsafe.getObject likes.
431 // We store a plain int because it is more compact.
432 return ((Accessor)accessorObj).fieldOffset;
433 }
434
435 @ForceInline
436 /*non-public*/ static Object checkBase(Object obj) {
437 // Note that the object's class has already been verified,
438 // since the parameter type of the Accessor method handle
439 // is either member.getDeclaringClass or a subclass.
440 // This was verified in DirectMethodHandle.make.
441 // Therefore, the only remaining check is for null.
442 // Since this check is *not* guaranteed by Unsafe.getInt
443 // and its siblings, we need to make an explicit one here.
444 return Objects.requireNonNull(obj);
445 }
446
447 /** This subclass handles static field references. */
448 static class StaticAccessor extends DirectMethodHandle {
449 private final Class<?> fieldType;
450 private final Object staticBase;
451 private final long staticOffset;
452
453 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
454 Object staticBase, long staticOffset) {
455 super(mtype, form, member);
456 this.fieldType = member.getFieldType();
457 this.staticBase = staticBase;
458 this.staticOffset = staticOffset;
459 }
460
461 @Override Object checkCast(Object obj) {
462 return fieldType.cast(obj);
463 }
464 @Override
465 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
466 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
467 }
468 }
469
470 @ForceInline
471 /*non-public*/ static Object nullCheck(Object obj) {
472 return Objects.requireNonNull(obj);
473 }
474
475 @ForceInline
476 /*non-public*/ static Object staticBase(Object accessorObj) {
477 return ((StaticAccessor)accessorObj).staticBase;
478 }
479
480 @ForceInline
481 /*non-public*/ static long staticOffset(Object accessorObj) {
482 return ((StaticAccessor)accessorObj).staticOffset;
483 }
484
485 @ForceInline
486 /*non-public*/ static Object checkCast(Object mh, Object obj) {
487 return ((DirectMethodHandle) mh).checkCast(obj);
488 }
489
490 Object checkCast(Object obj) {
491 return member.getReturnType().cast(obj);
492 }
493
494 // Caching machinery for field accessors:
495 private static final byte
496 AF_GETFIELD = 0,
497 AF_PUTFIELD = 1,
498 AF_GETSTATIC = 2,
499 AF_PUTSTATIC = 3,
500 AF_GETSTATIC_INIT = 4,
501 AF_PUTSTATIC_INIT = 5,
502 AF_LIMIT = 6;
503 // Enumerate the different field kinds using Wrapper,
504 // with an extra case added for checked references.
505 private static final int
506 FT_LAST_WRAPPER = Wrapper.COUNT-1,
507 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
508 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
509 FT_LIMIT = FT_LAST_WRAPPER+2;
510 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
511 return ((formOp * FT_LIMIT * 2)
512 + (isVolatile ? FT_LIMIT : 0)
513 + ftypeKind);
514 }
515 @Stable
516 private static final LambdaForm[] ACCESSOR_FORMS
517 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
518 private static int ftypeKind(Class<?> ftype) {
519 if (ftype.isPrimitive())
520 return Wrapper.forPrimitiveType(ftype).ordinal();
521 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
522 return FT_UNCHECKED_REF;
523 else
524 return FT_CHECKED_REF;
525 }
526
527 /**
528 * Create a LF which can access the given field.
529 * Cache and share this structure among all fields with
530 * the same basicType and refKind.
531 */
532 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
533 Class<?> ftype = m.getFieldType();
534 boolean isVolatile = m.isVolatile();
535 byte formOp;
536 switch (m.getReferenceKind()) {
537 case REF_getField: formOp = AF_GETFIELD; break;
538 case REF_putField: formOp = AF_PUTFIELD; break;
539 case REF_getStatic: formOp = AF_GETSTATIC; break;
540 case REF_putStatic: formOp = AF_PUTSTATIC; break;
541 default: throw new InternalError(m.toString());
542 }
543 if (shouldBeInitialized(m)) {
544 // precompute the barrier-free version:
545 preparedFieldLambdaForm(formOp, isVolatile, ftype);
546 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
547 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
548 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
549 }
550 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
551 maybeCompile(lform, m);
552 assert(lform.methodType().dropParameterTypes(0, 1)
553 .equals(m.getInvocationType().basicType()))
554 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
555 return lform;
556 }
557 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
558 int ftypeKind = ftypeKind(ftype);
559 int afIndex = afIndex(formOp, isVolatile, ftypeKind);
560 LambdaForm lform = ACCESSOR_FORMS[afIndex];
561 if (lform != null) return lform;
562 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind);
563 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
564 return lform;
565 }
566
567 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
568
569 private static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
570 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
571 boolean isStatic = (formOp >= AF_GETSTATIC);
572 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
573 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
574 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
575 Class<?> ft = fw.primitiveType();
576 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
577
578 // getObject, putIntVolatile, etc.
579 StringBuilder nameBuilder = new StringBuilder();
580 if (isGetter) {
581 nameBuilder.append("get");
582 } else {
583 nameBuilder.append("put");
584 }
585 nameBuilder.append(fw.primitiveSimpleName());
586 nameBuilder.setCharAt(3, Character.toUpperCase(nameBuilder.charAt(3)));
587 if (isVolatile) {
588 nameBuilder.append("Volatile");
589 }
590
591 MethodType linkerType;
592 if (isGetter)
593 linkerType = MethodType.methodType(ft, Object.class, long.class);
594 else
595 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
596 MemberName linker = new MemberName(Unsafe.class, nameBuilder.toString(), linkerType, REF_invokeVirtual);
597 try {
598 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
599 } catch (ReflectiveOperationException ex) {
600 throw newInternalError(ex);
601 }
602
603 // What is the external type of the lambda form?
604 MethodType mtype;
605 if (isGetter)
606 mtype = MethodType.methodType(ft);
607 else
608 mtype = MethodType.methodType(void.class, ft);
609 mtype = mtype.basicType(); // erase short to int, etc.
610 if (!isStatic)
611 mtype = mtype.insertParameterTypes(0, Object.class);
612 final int DMH_THIS = 0;
613 final int ARG_BASE = 1;
614 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
615 // if this is for non-static access, the base pointer is stored at this index:
616 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
617 // if this is for write access, the value to be written is stored at this index:
618 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
619 int nameCursor = ARG_LIMIT;
620 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
621 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
622 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
623 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
624 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
625 final int LINKER_CALL = nameCursor++;
626 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
627 final int RESULT = nameCursor-1; // either the call or the cast
628 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
629 if (needsInit)
630 names[INIT_BAR] = new Name(NF_ensureInitialized, names[DMH_THIS]);
631 if (needsCast && !isGetter)
632 names[PRE_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
633 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
634 assert(outArgs.length == (isGetter ? 3 : 4));
635 outArgs[0] = UNSAFE;
636 if (isStatic) {
637 outArgs[1] = names[F_HOLDER] = new Name(NF_staticBase, names[DMH_THIS]);
638 outArgs[2] = names[F_OFFSET] = new Name(NF_staticOffset, names[DMH_THIS]);
639 } else {
640 outArgs[1] = names[OBJ_CHECK] = new Name(NF_checkBase, names[OBJ_BASE]);
641 outArgs[2] = names[F_OFFSET] = new Name(NF_fieldOffset, names[DMH_THIS]);
642 }
643 if (!isGetter) {
644 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
645 }
646 for (Object a : outArgs) assert(a != null);
647 names[LINKER_CALL] = new Name(linker, outArgs);
648 if (needsCast && isGetter)
649 names[POST_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
650 for (Name n : names) assert(n != null);
651 // add some detail to the lambdaForm debugname,
652 // significant only for debugging
653 if (isStatic) {
654 nameBuilder.append("Static");
655 } else {
656 nameBuilder.append("Field");
657 }
658 if (needsCast) nameBuilder.append("Cast");
659 if (needsInit) nameBuilder.append("Init");
660 return new LambdaForm(nameBuilder.toString(), ARG_LIMIT, names, RESULT);
661 }
662
663 /**
664 * Pre-initialized NamedFunctions for bootstrapping purposes.
665 * Factored in an inner class to delay initialization until first usage.
666 */
667 static final NamedFunction
668 NF_internalMemberName,
669 NF_internalMemberNameEnsureInit,
670 NF_ensureInitialized,
671 NF_fieldOffset,
672 NF_checkBase,
673 NF_staticBase,
674 NF_staticOffset,
675 NF_checkCast,
676 NF_allocateInstance,
677 NF_constructorMethod;
678 static {
679 try {
680 NamedFunction nfs[] = {
681 NF_internalMemberName = new NamedFunction(DirectMethodHandle.class
682 .getDeclaredMethod("internalMemberName", Object.class)),
683 NF_internalMemberNameEnsureInit = new NamedFunction(DirectMethodHandle.class
684 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)),
685 NF_ensureInitialized = new NamedFunction(DirectMethodHandle.class
686 .getDeclaredMethod("ensureInitialized", Object.class)),
687 NF_fieldOffset = new NamedFunction(DirectMethodHandle.class
688 .getDeclaredMethod("fieldOffset", Object.class)),
689 NF_checkBase = new NamedFunction(DirectMethodHandle.class
690 .getDeclaredMethod("checkBase", Object.class)),
691 NF_staticBase = new NamedFunction(DirectMethodHandle.class
692 .getDeclaredMethod("staticBase", Object.class)),
693 NF_staticOffset = new NamedFunction(DirectMethodHandle.class
694 .getDeclaredMethod("staticOffset", Object.class)),
695 NF_checkCast = new NamedFunction(DirectMethodHandle.class
696 .getDeclaredMethod("checkCast", Object.class, Object.class)),
697 NF_allocateInstance = new NamedFunction(DirectMethodHandle.class
698 .getDeclaredMethod("allocateInstance", Object.class)),
699 NF_constructorMethod = new NamedFunction(DirectMethodHandle.class
700 .getDeclaredMethod("constructorMethod", Object.class))
701 };
702 // Each nf must be statically invocable or we get tied up in our bootstraps.
703 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nfs));
704 } catch (ReflectiveOperationException ex) {
705 throw newInternalError(ex);
706 }
707 }
708
709 static {
710 // The Holder class will contain pre-generated DirectMethodHandles resolved
711 // speculatively using MemberName.getFactory().resolveOrNull. However, that
712 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
713 // initialization of the Holder class we avoid these issues.
714 UNSAFE.ensureClassInitialized(Holder.class);
715 }
716
717 /* Placeholder class for DirectMethodHandles generated ahead of time */
718 final class Holder {}
719 }