1 /*
2 * Copyright (c) 2008, 2018, 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.getReferenceKind() == REF_invokeInterface &&
62 member.isMethod() && !member.isAbstract()) {
63 // Check for corner case: invokeinterface of Object method
64 MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind());
65 m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null);
66 if (m != null && m.isPublic()) {
67 assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong
68 member = m;
69 }
70 }
71
72 this.member = member;
73 }
74
75 // Factory methods:
76 static DirectMethodHandle make(byte refKind, Class<?> refc, MemberName member, Class<?> callerClass) {
77 MethodType mtype = member.getMethodOrFieldType();
78 if (!member.isStatic()) {
79 if (!member.getDeclaringClass().isAssignableFrom(refc) || member.isConstructor())
80 throw new InternalError(member.toString());
81 mtype = mtype.insertParameterTypes(0, refc);
82 }
83 if (!member.isField()) {
84 switch (refKind) {
85 case REF_invokeSpecial: {
86 member = member.asSpecial();
87 LambdaForm lform = preparedLambdaForm(member, callerClass);
88 Class<?> checkClass = refc; // Class to use for receiver type check
89 if (callerClass != null) {
90 checkClass = callerClass; // potentially strengthen to caller class
91 }
92 return new Special(mtype, lform, member, checkClass);
93 }
94 case REF_invokeInterface: {
95 LambdaForm lform = preparedLambdaForm(member, callerClass);
96 return new Interface(mtype, lform, member, refc);
97 }
98 default: {
99 LambdaForm lform = preparedLambdaForm(member, callerClass);
100 return new DirectMethodHandle(mtype, lform, member);
101 }
102 }
103 } else {
104 LambdaForm lform = preparedFieldLambdaForm(member);
105 if (member.isStatic()) {
106 long offset = MethodHandleNatives.staticFieldOffset(member);
107 Object base = MethodHandleNatives.staticFieldBase(member);
108 return new StaticAccessor(mtype, lform, member, base, offset);
109 } else {
110 long offset = MethodHandleNatives.objectFieldOffset(member);
111 assert(offset == (int)offset);
112 return new Accessor(mtype, lform, member, (int)offset);
113 }
114 }
115 }
116 static DirectMethodHandle make(Class<?> refc, MemberName member) {
117 byte refKind = member.getReferenceKind();
118 if (refKind == REF_invokeSpecial)
119 refKind = REF_invokeVirtual;
120 return make(refKind, refc, member, null /* no callerClass context */);
121 }
122 static DirectMethodHandle make(MemberName member) {
123 if (member.isConstructor())
124 return makeAllocator(member);
125 return make(member.getDeclaringClass(), member);
126 }
127 private static DirectMethodHandle makeAllocator(MemberName ctor) {
128 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
129 Class<?> instanceClass = ctor.getDeclaringClass();
130 ctor = ctor.asConstructor();
131 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
132 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
133 LambdaForm lform = preparedLambdaForm(ctor);
134 MemberName init = ctor.asSpecial();
135 assert(init.getMethodType().returnType() == void.class);
136 return new Constructor(mtype, lform, ctor, init, instanceClass);
137 }
138
139 @Override
140 BoundMethodHandle rebind() {
141 return BoundMethodHandle.makeReinvoker(this);
142 }
143
144 @Override
145 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
146 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
147 return new DirectMethodHandle(mt, lf, member);
148 }
149
150 @Override
151 String internalProperties() {
152 return "\n& DMH.MN="+internalMemberName();
153 }
154
155 //// Implementation methods.
156 @Override
157 @ForceInline
158 MemberName internalMemberName() {
159 return member;
160 }
161
162 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
163
164 /**
165 * Create a LF which can invoke the given method.
166 * Cache and share this structure among all methods with
167 * the same basicType and refKind.
168 */
169 private static LambdaForm preparedLambdaForm(MemberName m, Class<?> callerClass) {
170 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
171 MethodType mtype = m.getInvocationType().basicType();
172 assert(!m.isMethodHandleInvoke()) : m;
173 int which;
174 switch (m.getReferenceKind()) {
175 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
176 case REF_invokeStatic: which = LF_INVSTATIC; break;
177 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
178 case REF_invokeInterface: which = LF_INVINTERFACE; break;
179 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
180 default: throw new InternalError(m.toString());
181 }
182 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
183 // precompute the barrier-free version:
184 preparedLambdaForm(mtype, which);
185 which = LF_INVSTATIC_INIT;
186 }
187 if (which == LF_INVSPECIAL && callerClass != null && callerClass.isInterface()) {
188 which = LF_INVSPECIAL_IFC;
189 }
190 LambdaForm lform = preparedLambdaForm(mtype, which);
191 maybeCompile(lform, m);
192 assert(lform.methodType().dropParameterTypes(0, 1)
193 .equals(m.getInvocationType().basicType()))
194 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
195 return lform;
196 }
197
198 private static LambdaForm preparedLambdaForm(MemberName m) {
199 return preparedLambdaForm(m, null);
200 }
201
202 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
203 LambdaForm lform = mtype.form().cachedLambdaForm(which);
204 if (lform != null) return lform;
205 lform = makePreparedLambdaForm(mtype, which);
206 return mtype.form().setCachedLambdaForm(which, lform);
207 }
208
209 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
210 boolean needsInit = (which == LF_INVSTATIC_INIT);
211 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
212 boolean needsReceiverCheck = (which == LF_INVINTERFACE ||
213 which == LF_INVSPECIAL_IFC);
214
215 String linkerName;
216 LambdaForm.Kind kind;
217 switch (which) {
218 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break;
219 case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break;
220 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break;
221 case LF_INVSPECIAL_IFC:linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL_IFC; break;
222 case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break;
223 case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break;
224 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break;
225 default: throw new InternalError("which="+which);
226 }
227
228 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
229 if (doesAlloc)
230 mtypeWithArg = mtypeWithArg
231 .insertParameterTypes(0, Object.class) // insert newly allocated obj
232 .changeReturnType(void.class); // <init> returns void
233 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
234 try {
235 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
236 } catch (ReflectiveOperationException ex) {
237 throw newInternalError(ex);
238 }
239 final int DMH_THIS = 0;
240 final int ARG_BASE = 1;
241 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
242 int nameCursor = ARG_LIMIT;
243 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
244 final int GET_MEMBER = nameCursor++;
245 final int CHECK_RECEIVER = (needsReceiverCheck ? nameCursor++ : -1);
246 final int LINKER_CALL = nameCursor++;
247 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
248 assert(names.length == nameCursor);
249 if (doesAlloc) {
250 // names = { argx,y,z,... new C, init method }
251 names[NEW_OBJ] = new Name(getFunction(NF_allocateInstance), names[DMH_THIS]);
252 names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]);
253 } else if (needsInit) {
254 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]);
255 } else {
256 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberName), names[DMH_THIS]);
257 }
258 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
259 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
260 if (needsReceiverCheck) {
261 names[CHECK_RECEIVER] = new Name(getFunction(NF_checkReceiver), names[DMH_THIS], names[ARG_BASE]);
262 outArgs[0] = names[CHECK_RECEIVER];
263 }
264 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
265 int result = LAST_RESULT;
266 if (doesAlloc) {
267 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
268 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
269 outArgs[0] = names[NEW_OBJ];
270 result = NEW_OBJ;
271 }
272 names[LINKER_CALL] = new Name(linker, outArgs);
273 LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind);
274
275 // This is a tricky bit of code. Don't send it through the LF interpreter.
276 lform.compileToBytecode();
277 return lform;
278 }
279
280 /* assert */ static Object findDirectMethodHandle(Name name) {
281 if (name.function.equals(getFunction(NF_internalMemberName)) ||
282 name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) ||
283 name.function.equals(getFunction(NF_constructorMethod))) {
284 assert(name.arguments.length == 1);
285 return name.arguments[0];
286 }
287 return null;
288 }
289
290 private static void maybeCompile(LambdaForm lform, MemberName m) {
291 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
292 // Help along bootstrapping...
293 lform.compileToBytecode();
294 }
295
296 /** Static wrapper for DirectMethodHandle.internalMemberName. */
297 @ForceInline
298 /*non-public*/ static Object internalMemberName(Object mh) {
299 return ((DirectMethodHandle)mh).member;
300 }
301
302 /** Static wrapper for DirectMethodHandle.internalMemberName.
303 * This one also forces initialization.
304 */
305 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
306 DirectMethodHandle dmh = (DirectMethodHandle)mh;
307 dmh.ensureInitialized();
308 return dmh.member;
309 }
310
311 /*non-public*/ static
312 boolean shouldBeInitialized(MemberName member) {
313 switch (member.getReferenceKind()) {
314 case REF_invokeStatic:
315 case REF_getStatic:
316 case REF_putStatic:
317 case REF_newInvokeSpecial:
318 break;
319 default:
320 // No need to initialize the class on this kind of member.
321 return false;
322 }
323 Class<?> cls = member.getDeclaringClass();
324 if (cls == ValueConversions.class ||
325 cls == MethodHandleImpl.class ||
326 cls == Invokers.class) {
327 // These guys have lots of <clinit> DMH creation but we know
328 // the MHs will not be used until the system is booted.
329 return false;
330 }
331 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
332 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
333 // It is a system class. It is probably in the process of
334 // being initialized, but we will help it along just to be safe.
335 if (UNSAFE.shouldBeInitialized(cls)) {
336 UNSAFE.ensureClassInitialized(cls);
337 }
338 return false;
339 }
340 return UNSAFE.shouldBeInitialized(cls);
341 }
342
343 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
344 @Override
345 protected WeakReference<Thread> computeValue(Class<?> type) {
346 UNSAFE.ensureClassInitialized(type);
347 if (UNSAFE.shouldBeInitialized(type))
348 // If the previous call didn't block, this can happen.
349 // We are executing inside <clinit>.
350 return new WeakReference<>(Thread.currentThread());
351 return null;
352 }
353 static final EnsureInitialized INSTANCE = new EnsureInitialized();
354 }
355
356 private void ensureInitialized() {
357 if (checkInitialized(member)) {
358 // The coast is clear. Delete the <clinit> barrier.
359 if (member.isField())
360 updateForm(preparedFieldLambdaForm(member));
361 else
362 updateForm(preparedLambdaForm(member));
363 }
364 }
365 private static boolean checkInitialized(MemberName member) {
366 Class<?> defc = member.getDeclaringClass();
367 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
368 if (ref == null) {
369 return true; // the final state
370 }
371 Thread clinitThread = ref.get();
372 // Somebody may still be running defc.<clinit>.
373 if (clinitThread == Thread.currentThread()) {
374 // If anybody is running defc.<clinit>, it is this thread.
375 if (UNSAFE.shouldBeInitialized(defc))
376 // Yes, we are running it; keep the barrier for now.
377 return false;
378 } else {
379 // We are in a random thread. Block.
380 UNSAFE.ensureClassInitialized(defc);
381 }
382 assert(!UNSAFE.shouldBeInitialized(defc));
383 // put it into the final state
384 EnsureInitialized.INSTANCE.remove(defc);
385 return true;
386 }
387
388 /*non-public*/ static void ensureInitialized(Object mh) {
389 ((DirectMethodHandle)mh).ensureInitialized();
390 }
391
392 /** This subclass represents invokespecial instructions. */
393 static class Special extends DirectMethodHandle {
394 private final Class<?> caller;
395 private Special(MethodType mtype, LambdaForm form, MemberName member, Class<?> caller) {
396 super(mtype, form, member);
397 this.caller = caller;
398 }
399 @Override
400 boolean isInvokeSpecial() {
401 return true;
402 }
403 @Override
404 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
405 return new Special(mt, lf, member, caller);
406 }
407 Object checkReceiver(Object recv) {
408 if (!caller.isInstance(recv)) {
409 String msg = String.format("Receiver class %s is not a subclass of caller class %s",
410 recv.getClass().getName(), caller.getName());
411 throw new IncompatibleClassChangeError(msg);
412 }
413 return recv;
414 }
415 }
416
417 /** This subclass represents invokeinterface instructions. */
418 static class Interface extends DirectMethodHandle {
419 private final Class<?> refc;
420 private Interface(MethodType mtype, LambdaForm form, MemberName member, Class<?> refc) {
421 super(mtype, form, member);
422 assert refc.isInterface() : refc;
423 this.refc = refc;
424 }
425 @Override
426 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
427 return new Interface(mt, lf, member, refc);
428 }
429 @Override
430 Object checkReceiver(Object recv) {
431 if (!refc.isInstance(recv)) {
432 String msg = String.format("Receiver class %s does not implement the requested interface %s",
433 recv.getClass().getName(), refc.getName());
434 throw new IncompatibleClassChangeError(msg);
435 }
436 return recv;
437 }
438 }
439
440 /** Used for interface receiver type checks, by Interface and Special modes. */
441 Object checkReceiver(Object recv) {
442 throw new InternalError("Should only be invoked on a subclass");
443 }
444
445
446 /** This subclass handles constructor references. */
447 static class Constructor extends DirectMethodHandle {
448 final MemberName initMethod;
449 final Class<?> instanceClass;
450
451 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
452 MemberName initMethod, Class<?> instanceClass) {
453 super(mtype, form, constructor);
454 this.initMethod = initMethod;
455 this.instanceClass = instanceClass;
456 assert(initMethod.isResolved());
457 }
458 @Override
459 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
460 return new Constructor(mt, lf, member, initMethod, instanceClass);
461 }
462 }
463
464 /*non-public*/ static Object constructorMethod(Object mh) {
465 Constructor dmh = (Constructor)mh;
466 return dmh.initMethod;
467 }
468
469 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
470 Constructor dmh = (Constructor)mh;
471 return UNSAFE.allocateInstance(dmh.instanceClass);
472 }
473
474 /** This subclass handles non-static field references. */
475 static class Accessor extends DirectMethodHandle {
476 final Class<?> fieldType;
477 final int fieldOffset;
478 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
479 int fieldOffset) {
480 super(mtype, form, member);
481 this.fieldType = member.getFieldType();
482 this.fieldOffset = fieldOffset;
483 }
484
485 @Override Object checkCast(Object obj) {
486 return fieldType.cast(obj);
487 }
488 @Override
489 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
490 return new Accessor(mt, lf, member, fieldOffset);
491 }
492 }
493
494 @ForceInline
495 /*non-public*/ static long fieldOffset(Object accessorObj) {
496 // Note: We return a long because that is what Unsafe.getObject likes.
497 // We store a plain int because it is more compact.
498 return ((Accessor)accessorObj).fieldOffset;
499 }
500
501 @ForceInline
502 /*non-public*/ static Object checkBase(Object obj) {
503 // Note that the object's class has already been verified,
504 // since the parameter type of the Accessor method handle
505 // is either member.getDeclaringClass or a subclass.
506 // This was verified in DirectMethodHandle.make.
507 // Therefore, the only remaining check is for null.
508 // Since this check is *not* guaranteed by Unsafe.getInt
509 // and its siblings, we need to make an explicit one here.
510 return Objects.requireNonNull(obj);
511 }
512
513 /** This subclass handles static field references. */
514 static class StaticAccessor extends DirectMethodHandle {
515 private final Class<?> fieldType;
516 private final Object staticBase;
517 private final long staticOffset;
518
519 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
520 Object staticBase, long staticOffset) {
521 super(mtype, form, member);
522 this.fieldType = member.getFieldType();
523 this.staticBase = staticBase;
524 this.staticOffset = staticOffset;
525 }
526
527 @Override Object checkCast(Object obj) {
528 return fieldType.cast(obj);
529 }
530 @Override
531 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
532 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
533 }
534 }
535
536 @ForceInline
537 /*non-public*/ static Object nullCheck(Object obj) {
538 return Objects.requireNonNull(obj);
539 }
540
541 @ForceInline
542 /*non-public*/ static Object staticBase(Object accessorObj) {
543 return ((StaticAccessor)accessorObj).staticBase;
544 }
545
546 @ForceInline
547 /*non-public*/ static long staticOffset(Object accessorObj) {
548 return ((StaticAccessor)accessorObj).staticOffset;
549 }
550
551 @ForceInline
552 /*non-public*/ static Object checkCast(Object mh, Object obj) {
553 return ((DirectMethodHandle) mh).checkCast(obj);
554 }
555
556 Object checkCast(Object obj) {
557 return member.getReturnType().cast(obj);
558 }
559
560 // Caching machinery for field accessors:
561 static final byte
562 AF_GETFIELD = 0,
563 AF_PUTFIELD = 1,
564 AF_GETSTATIC = 2,
565 AF_PUTSTATIC = 3,
566 AF_GETSTATIC_INIT = 4,
567 AF_PUTSTATIC_INIT = 5,
568 AF_LIMIT = 6;
569 // Enumerate the different field kinds using Wrapper,
570 // with an extra case added for checked references.
571 static final int
572 FT_LAST_WRAPPER = Wrapper.COUNT-1,
573 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
574 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
575 FT_LIMIT = FT_LAST_WRAPPER+2;
576 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
577 return ((formOp * FT_LIMIT * 2)
578 + (isVolatile ? FT_LIMIT : 0)
579 + ftypeKind);
580 }
581 @Stable
582 private static final LambdaForm[] ACCESSOR_FORMS
583 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
584 static int ftypeKind(Class<?> ftype) {
585 if (ftype.isPrimitive())
586 return Wrapper.forPrimitiveType(ftype).ordinal();
587 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
588 return FT_UNCHECKED_REF;
589 else
590 return FT_CHECKED_REF;
591 }
592
593 /**
594 * Create a LF which can access the given field.
595 * Cache and share this structure among all fields with
596 * the same basicType and refKind.
597 */
598 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
599 Class<?> ftype = m.getFieldType();
600 boolean isVolatile = m.isVolatile();
601 byte formOp;
602 switch (m.getReferenceKind()) {
603 case REF_getField: formOp = AF_GETFIELD; break;
604 case REF_putField: formOp = AF_PUTFIELD; break;
605 case REF_getStatic: formOp = AF_GETSTATIC; break;
606 case REF_putStatic: formOp = AF_PUTSTATIC; break;
607 default: throw new InternalError(m.toString());
608 }
609 if (shouldBeInitialized(m)) {
610 // precompute the barrier-free version:
611 preparedFieldLambdaForm(formOp, isVolatile, ftype);
612 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
613 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
614 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
615 }
616 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
617 maybeCompile(lform, m);
618 assert(lform.methodType().dropParameterTypes(0, 1)
619 .equals(m.getInvocationType().basicType()))
620 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
621 return lform;
622 }
623 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
624 int ftypeKind = ftypeKind(ftype);
625 int afIndex = afIndex(formOp, isVolatile, ftypeKind);
626 LambdaForm lform = ACCESSOR_FORMS[afIndex];
627 if (lform != null) return lform;
628 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind);
629 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
630 return lform;
631 }
632
633 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
634
635 private static Kind getFieldKind(boolean isGetter, boolean isVolatile, Wrapper wrapper) {
636 if (isGetter) {
637 if (isVolatile) {
638 switch (wrapper) {
639 case BOOLEAN: return GET_BOOLEAN_VOLATILE;
640 case BYTE: return GET_BYTE_VOLATILE;
641 case SHORT: return GET_SHORT_VOLATILE;
642 case CHAR: return GET_CHAR_VOLATILE;
643 case INT: return GET_INT_VOLATILE;
644 case LONG: return GET_LONG_VOLATILE;
645 case FLOAT: return GET_FLOAT_VOLATILE;
646 case DOUBLE: return GET_DOUBLE_VOLATILE;
647 case OBJECT: return GET_OBJECT_VOLATILE;
648 }
649 } else {
650 switch (wrapper) {
651 case BOOLEAN: return GET_BOOLEAN;
652 case BYTE: return GET_BYTE;
653 case SHORT: return GET_SHORT;
654 case CHAR: return GET_CHAR;
655 case INT: return GET_INT;
656 case LONG: return GET_LONG;
657 case FLOAT: return GET_FLOAT;
658 case DOUBLE: return GET_DOUBLE;
659 case OBJECT: return GET_OBJECT;
660 }
661 }
662 } else {
663 if (isVolatile) {
664 switch (wrapper) {
665 case BOOLEAN: return PUT_BOOLEAN_VOLATILE;
666 case BYTE: return PUT_BYTE_VOLATILE;
667 case SHORT: return PUT_SHORT_VOLATILE;
668 case CHAR: return PUT_CHAR_VOLATILE;
669 case INT: return PUT_INT_VOLATILE;
670 case LONG: return PUT_LONG_VOLATILE;
671 case FLOAT: return PUT_FLOAT_VOLATILE;
672 case DOUBLE: return PUT_DOUBLE_VOLATILE;
673 case OBJECT: return PUT_OBJECT_VOLATILE;
674 }
675 } else {
676 switch (wrapper) {
677 case BOOLEAN: return PUT_BOOLEAN;
678 case BYTE: return PUT_BYTE;
679 case SHORT: return PUT_SHORT;
680 case CHAR: return PUT_CHAR;
681 case INT: return PUT_INT;
682 case LONG: return PUT_LONG;
683 case FLOAT: return PUT_FLOAT;
684 case DOUBLE: return PUT_DOUBLE;
685 case OBJECT: return PUT_OBJECT;
686 }
687 }
688 }
689 throw new AssertionError("Invalid arguments");
690 }
691
692 static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
693 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
694 boolean isStatic = (formOp >= AF_GETSTATIC);
695 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
696 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
697 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
698 Class<?> ft = fw.primitiveType();
699 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
700
701 // getObject, putIntVolatile, etc.
702 Kind kind = getFieldKind(isGetter, isVolatile, fw);
703
704 MethodType linkerType;
705 if (isGetter)
706 linkerType = MethodType.methodType(ft, Object.class, long.class);
707 else
708 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
709 MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual);
710 try {
711 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
712 } catch (ReflectiveOperationException ex) {
713 throw newInternalError(ex);
714 }
715
716 // What is the external type of the lambda form?
717 MethodType mtype;
718 if (isGetter)
719 mtype = MethodType.methodType(ft);
720 else
721 mtype = MethodType.methodType(void.class, ft);
722 mtype = mtype.basicType(); // erase short to int, etc.
723 if (!isStatic)
724 mtype = mtype.insertParameterTypes(0, Object.class);
725 final int DMH_THIS = 0;
726 final int ARG_BASE = 1;
727 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
728 // if this is for non-static access, the base pointer is stored at this index:
729 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
730 // if this is for write access, the value to be written is stored at this index:
731 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
732 int nameCursor = ARG_LIMIT;
733 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
734 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
735 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
736 final int U_HOLDER = nameCursor++; // UNSAFE holder
737 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
738 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
739 final int LINKER_CALL = nameCursor++;
740 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
741 final int RESULT = nameCursor-1; // either the call or the cast
742 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
743 if (needsInit)
744 names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]);
745 if (needsCast && !isGetter)
746 names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]);
747 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
748 assert(outArgs.length == (isGetter ? 3 : 4));
749 outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE));
750 if (isStatic) {
751 outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]);
752 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]);
753 } else {
754 outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]);
755 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]);
756 }
757 if (!isGetter) {
758 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
759 }
760 for (Object a : outArgs) assert(a != null);
761 names[LINKER_CALL] = new Name(linker, outArgs);
762 if (needsCast && isGetter)
763 names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]);
764 for (Name n : names) assert(n != null);
765
766 LambdaForm form;
767 if (needsCast || needsInit) {
768 // can't use the pre-generated form when casting and/or initializing
769 form = new LambdaForm(ARG_LIMIT, names, RESULT);
770 } else {
771 form = new LambdaForm(ARG_LIMIT, names, RESULT, kind);
772 }
773
774 if (LambdaForm.debugNames()) {
775 // add some detail to the lambdaForm debugname,
776 // significant only for debugging
777 StringBuilder nameBuilder = new StringBuilder(kind.methodName);
778 if (isStatic) {
779 nameBuilder.append("Static");
780 } else {
781 nameBuilder.append("Field");
782 }
783 if (needsCast) {
784 nameBuilder.append("Cast");
785 }
786 if (needsInit) {
787 nameBuilder.append("Init");
788 }
789 LambdaForm.associateWithDebugName(form, nameBuilder.toString());
790 }
791 return form;
792 }
793
794 /**
795 * Pre-initialized NamedFunctions for bootstrapping purposes.
796 */
797 static final byte NF_internalMemberName = 0,
798 NF_internalMemberNameEnsureInit = 1,
799 NF_ensureInitialized = 2,
800 NF_fieldOffset = 3,
801 NF_checkBase = 4,
802 NF_staticBase = 5,
803 NF_staticOffset = 6,
804 NF_checkCast = 7,
805 NF_allocateInstance = 8,
806 NF_constructorMethod = 9,
807 NF_UNSAFE = 10,
808 NF_checkReceiver = 11,
809 NF_LIMIT = 12;
810
811 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
812
813 private static NamedFunction getFunction(byte func) {
814 NamedFunction nf = NFS[func];
815 if (nf != null) {
816 return nf;
817 }
818 // Each nf must be statically invocable or we get tied up in our bootstraps.
819 nf = NFS[func] = createFunction(func);
820 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf));
821 return nf;
822 }
823
824 private static final MethodType OBJ_OBJ_TYPE = MethodType.methodType(Object.class, Object.class);
825
826 private static final MethodType LONG_OBJ_TYPE = MethodType.methodType(long.class, Object.class);
827
828 private static NamedFunction createFunction(byte func) {
829 try {
830 switch (func) {
831 case NF_internalMemberName:
832 return getNamedFunction("internalMemberName", OBJ_OBJ_TYPE);
833 case NF_internalMemberNameEnsureInit:
834 return getNamedFunction("internalMemberNameEnsureInit", OBJ_OBJ_TYPE);
835 case NF_ensureInitialized:
836 return getNamedFunction("ensureInitialized", MethodType.methodType(void.class, Object.class));
837 case NF_fieldOffset:
838 return getNamedFunction("fieldOffset", LONG_OBJ_TYPE);
839 case NF_checkBase:
840 return getNamedFunction("checkBase", OBJ_OBJ_TYPE);
841 case NF_staticBase:
842 return getNamedFunction("staticBase", OBJ_OBJ_TYPE);
843 case NF_staticOffset:
844 return getNamedFunction("staticOffset", LONG_OBJ_TYPE);
845 case NF_checkCast:
846 return getNamedFunction("checkCast", MethodType.methodType(Object.class, Object.class, Object.class));
847 case NF_allocateInstance:
848 return getNamedFunction("allocateInstance", OBJ_OBJ_TYPE);
849 case NF_constructorMethod:
850 return getNamedFunction("constructorMethod", OBJ_OBJ_TYPE);
851 case NF_UNSAFE:
852 MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getField);
853 return new NamedFunction(
854 MemberName.getFactory()
855 .resolveOrFail(REF_getField, member, DirectMethodHandle.class, NoSuchMethodException.class));
856 case NF_checkReceiver:
857 member = new MemberName(DirectMethodHandle.class, "checkReceiver", OBJ_OBJ_TYPE, REF_invokeVirtual);
858 return new NamedFunction(
859 MemberName.getFactory()
860 .resolveOrFail(REF_invokeVirtual, member, DirectMethodHandle.class, NoSuchMethodException.class));
861 default:
862 throw newInternalError("Unknown function: " + func);
863 }
864 } catch (ReflectiveOperationException ex) {
865 throw newInternalError(ex);
866 }
867 }
868
869 private static NamedFunction getNamedFunction(String name, MethodType type)
870 throws ReflectiveOperationException
871 {
872 MemberName member = new MemberName(DirectMethodHandle.class, name, type, REF_invokeStatic);
873 return new NamedFunction(
874 MemberName.getFactory()
875 .resolveOrFail(REF_invokeStatic, member, DirectMethodHandle.class, NoSuchMethodException.class));
876 }
877
878 static {
879 // The Holder class will contain pre-generated DirectMethodHandles resolved
880 // speculatively using MemberName.getFactory().resolveOrNull. However, that
881 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
882 // initialization of the Holder class we avoid these issues.
883 UNSAFE.ensureClassInitialized(Holder.class);
884 }
885
886 /* Placeholder class for DirectMethodHandles generated ahead of time */
887 final class Holder {}
888 }