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 // if caller is an interface we need to adapt to get the
88 // receiver check inserted
89 LambdaForm lform = preparedLambdaForm(member, callerClass.isInterface());
90 Class<?> checkClass = refc; // Class to use for receiver type check
91 if (callerClass != null) {
92 checkClass = callerClass; // potentially strengthen to caller class
93 }
94 return new Special(mtype, lform, member, checkClass);
95 }
96 case REF_invokeInterface: {
97 // we always adapt 'special' when dealing with interfaces
98 LambdaForm lform = preparedLambdaForm(member, true);
99 return new Interface(mtype, lform, member, refc);
100 }
101 default: {
102 LambdaForm lform = preparedLambdaForm(member);
103 return new DirectMethodHandle(mtype, lform, member);
104 }
105 }
106 } else {
107 LambdaForm lform = preparedFieldLambdaForm(member);
108 if (member.isStatic()) {
109 long offset = MethodHandleNatives.staticFieldOffset(member);
110 Object base = MethodHandleNatives.staticFieldBase(member);
111 return new StaticAccessor(mtype, lform, member, base, offset);
112 } else {
113 long offset = MethodHandleNatives.objectFieldOffset(member);
114 assert(offset == (int)offset);
115 return new Accessor(mtype, lform, member, (int)offset);
116 }
117 }
118 }
119 static DirectMethodHandle make(Class<?> refc, MemberName member) {
120 byte refKind = member.getReferenceKind();
121 if (refKind == REF_invokeSpecial)
122 refKind = REF_invokeVirtual;
123 return make(refKind, refc, member, null /* no callerClass context */);
124 }
125 static DirectMethodHandle make(MemberName member) {
126 if (member.isConstructor())
127 return makeAllocator(member);
128 return make(member.getDeclaringClass(), member);
129 }
130 private static DirectMethodHandle makeAllocator(MemberName ctor) {
131 assert(ctor.isConstructor() && ctor.getName().equals("<init>"));
132 Class<?> instanceClass = ctor.getDeclaringClass();
133 ctor = ctor.asConstructor();
134 assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor;
135 MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass);
136 LambdaForm lform = preparedLambdaForm(ctor);
137 MemberName init = ctor.asSpecial();
138 assert(init.getMethodType().returnType() == void.class);
139 return new Constructor(mtype, lform, ctor, init, instanceClass);
140 }
141
142 @Override
143 BoundMethodHandle rebind() {
144 return BoundMethodHandle.makeReinvoker(this);
145 }
146
147 @Override
148 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
149 assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses
150 return new DirectMethodHandle(mt, lf, member);
151 }
152
153 @Override
154 String internalProperties() {
155 return "\n& DMH.MN="+internalMemberName();
156 }
157
158 //// Implementation methods.
159 @Override
160 @ForceInline
161 MemberName internalMemberName() {
162 return member;
163 }
164
165 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
166
167 /**
168 * Create a LF which can invoke the given method.
169 * Cache and share this structure among all methods with
170 * the same basicType and refKind.
171 */
172 private static LambdaForm preparedLambdaForm(MemberName m, boolean adaptToSpecialIfc) {
173 assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead
174 MethodType mtype = m.getInvocationType().basicType();
175 assert(!m.isMethodHandleInvoke()) : m;
176 int which;
177 // MemberName.getReferenceKind may be different from the 'kind' passed to
178 // DMH.make. Specifically private/final methods that use a direct call
179 // have been adapted to REF_invokeSpecial, even though the actual
180 // invocation mode may be invokevirtual or invokeinterface.
181 switch (m.getReferenceKind()) {
182 case REF_invokeVirtual: which = LF_INVVIRTUAL; break;
183 case REF_invokeStatic: which = LF_INVSTATIC; break;
184 case REF_invokeSpecial: which = LF_INVSPECIAL; break;
185 case REF_invokeInterface: which = LF_INVINTERFACE; break;
186 case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break;
187 default: throw new InternalError(m.toString());
188 }
189 if (which == LF_INVSTATIC && shouldBeInitialized(m)) {
190 // precompute the barrier-free version:
191 preparedLambdaForm(mtype, which);
192 which = LF_INVSTATIC_INIT;
193 }
194 if (which == LF_INVSPECIAL && adaptToSpecialIfc) {
195 which = LF_INVSPECIAL_IFC;
196 }
197 LambdaForm lform = preparedLambdaForm(mtype, which);
198 maybeCompile(lform, m);
199 assert(lform.methodType().dropParameterTypes(0, 1)
200 .equals(m.getInvocationType().basicType()))
201 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
202 return lform;
203 }
204
205 private static LambdaForm preparedLambdaForm(MemberName m) {
206 return preparedLambdaForm(m, false);
207 }
208
209 private static LambdaForm preparedLambdaForm(MethodType mtype, int which) {
210 LambdaForm lform = mtype.form().cachedLambdaForm(which);
211 if (lform != null) return lform;
212 lform = makePreparedLambdaForm(mtype, which);
213 return mtype.form().setCachedLambdaForm(which, lform);
214 }
215
216 static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
217 boolean needsInit = (which == LF_INVSTATIC_INIT);
218 boolean doesAlloc = (which == LF_NEWINVSPECIAL);
219 boolean needsReceiverCheck = (which == LF_INVINTERFACE ||
220 which == LF_INVSPECIAL_IFC);
221
222 String linkerName;
223 LambdaForm.Kind kind;
224 switch (which) {
225 case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break;
226 case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break;
227 case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break;
228 case LF_INVSPECIAL_IFC:linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL_IFC; break;
229 case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break;
230 case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break;
231 case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break;
232 default: throw new InternalError("which="+which);
233 }
234
235 MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class);
236 if (doesAlloc)
237 mtypeWithArg = mtypeWithArg
238 .insertParameterTypes(0, Object.class) // insert newly allocated obj
239 .changeReturnType(void.class); // <init> returns void
240 MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic);
241 try {
242 linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class);
243 } catch (ReflectiveOperationException ex) {
244 throw newInternalError(ex);
245 }
246 final int DMH_THIS = 0;
247 final int ARG_BASE = 1;
248 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
249 int nameCursor = ARG_LIMIT;
250 final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1);
251 final int GET_MEMBER = nameCursor++;
252 final int CHECK_RECEIVER = (needsReceiverCheck ? nameCursor++ : -1);
253 final int LINKER_CALL = nameCursor++;
254 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
255 assert(names.length == nameCursor);
256 if (doesAlloc) {
257 // names = { argx,y,z,... new C, init method }
258 names[NEW_OBJ] = new Name(getFunction(NF_allocateInstance), names[DMH_THIS]);
259 names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]);
260 } else if (needsInit) {
261 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]);
262 } else {
263 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberName), names[DMH_THIS]);
264 }
265 assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]);
266 Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
267 if (needsReceiverCheck) {
268 names[CHECK_RECEIVER] = new Name(getFunction(NF_checkReceiver), names[DMH_THIS], names[ARG_BASE]);
269 outArgs[0] = names[CHECK_RECEIVER];
270 }
271 assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args!
272 int result = LAST_RESULT;
273 if (doesAlloc) {
274 assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one
275 System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2);
276 outArgs[0] = names[NEW_OBJ];
277 result = NEW_OBJ;
278 }
279 names[LINKER_CALL] = new Name(linker, outArgs);
280 LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind);
281
282 // This is a tricky bit of code. Don't send it through the LF interpreter.
283 lform.compileToBytecode();
284 return lform;
285 }
286
287 /* assert */ static Object findDirectMethodHandle(Name name) {
288 if (name.function.equals(getFunction(NF_internalMemberName)) ||
289 name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) ||
290 name.function.equals(getFunction(NF_constructorMethod))) {
291 assert(name.arguments.length == 1);
292 return name.arguments[0];
293 }
294 return null;
295 }
296
297 private static void maybeCompile(LambdaForm lform, MemberName m) {
298 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class))
299 // Help along bootstrapping...
300 lform.compileToBytecode();
301 }
302
303 /** Static wrapper for DirectMethodHandle.internalMemberName. */
304 @ForceInline
305 /*non-public*/ static Object internalMemberName(Object mh) {
306 return ((DirectMethodHandle)mh).member;
307 }
308
309 /** Static wrapper for DirectMethodHandle.internalMemberName.
310 * This one also forces initialization.
311 */
312 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) {
313 DirectMethodHandle dmh = (DirectMethodHandle)mh;
314 dmh.ensureInitialized();
315 return dmh.member;
316 }
317
318 /*non-public*/ static
319 boolean shouldBeInitialized(MemberName member) {
320 switch (member.getReferenceKind()) {
321 case REF_invokeStatic:
322 case REF_getStatic:
323 case REF_putStatic:
324 case REF_newInvokeSpecial:
325 break;
326 default:
327 // No need to initialize the class on this kind of member.
328 return false;
329 }
330 Class<?> cls = member.getDeclaringClass();
331 if (cls == ValueConversions.class ||
332 cls == MethodHandleImpl.class ||
333 cls == Invokers.class) {
334 // These guys have lots of <clinit> DMH creation but we know
335 // the MHs will not be used until the system is booted.
336 return false;
337 }
338 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) ||
339 VerifyAccess.isSamePackage(ValueConversions.class, cls)) {
340 // It is a system class. It is probably in the process of
341 // being initialized, but we will help it along just to be safe.
342 if (UNSAFE.shouldBeInitialized(cls)) {
343 UNSAFE.ensureClassInitialized(cls);
344 }
345 return false;
346 }
347 return UNSAFE.shouldBeInitialized(cls);
348 }
349
350 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> {
351 @Override
352 protected WeakReference<Thread> computeValue(Class<?> type) {
353 UNSAFE.ensureClassInitialized(type);
354 if (UNSAFE.shouldBeInitialized(type))
355 // If the previous call didn't block, this can happen.
356 // We are executing inside <clinit>.
357 return new WeakReference<>(Thread.currentThread());
358 return null;
359 }
360 static final EnsureInitialized INSTANCE = new EnsureInitialized();
361 }
362
363 private void ensureInitialized() {
364 if (checkInitialized(member)) {
365 // The coast is clear. Delete the <clinit> barrier.
366 if (member.isField())
367 updateForm(preparedFieldLambdaForm(member));
368 else
369 updateForm(preparedLambdaForm(member));
370 }
371 }
372 private static boolean checkInitialized(MemberName member) {
373 Class<?> defc = member.getDeclaringClass();
374 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
375 if (ref == null) {
376 return true; // the final state
377 }
378 Thread clinitThread = ref.get();
379 // Somebody may still be running defc.<clinit>.
380 if (clinitThread == Thread.currentThread()) {
381 // If anybody is running defc.<clinit>, it is this thread.
382 if (UNSAFE.shouldBeInitialized(defc))
383 // Yes, we are running it; keep the barrier for now.
384 return false;
385 } else {
386 // We are in a random thread. Block.
387 UNSAFE.ensureClassInitialized(defc);
388 }
389 assert(!UNSAFE.shouldBeInitialized(defc));
390 // put it into the final state
391 EnsureInitialized.INSTANCE.remove(defc);
392 return true;
393 }
394
395 /*non-public*/ static void ensureInitialized(Object mh) {
396 ((DirectMethodHandle)mh).ensureInitialized();
397 }
398
399 /** This subclass represents invokespecial instructions. */
400 static class Special extends DirectMethodHandle {
401 private final Class<?> caller;
402 private Special(MethodType mtype, LambdaForm form, MemberName member, Class<?> caller) {
403 super(mtype, form, member);
404 this.caller = caller;
405 }
406 @Override
407 boolean isInvokeSpecial() {
408 return true;
409 }
410 @Override
411 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
412 return new Special(mt, lf, member, caller);
413 }
414 Object checkReceiver(Object recv) {
415 if (!caller.isInstance(recv)) {
416 String msg = String.format("Receiver class %s is not a subclass of caller class %s",
417 recv.getClass().getName(), caller.getName());
418 throw new IncompatibleClassChangeError(msg);
419 }
420 return recv;
421 }
422 }
423
424 /** This subclass represents invokeinterface instructions. */
425 static class Interface extends DirectMethodHandle {
426 private final Class<?> refc;
427 private Interface(MethodType mtype, LambdaForm form, MemberName member, Class<?> refc) {
428 super(mtype, form, member);
429 assert refc.isInterface() : refc;
430 this.refc = refc;
431 }
432 @Override
433 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
434 return new Interface(mt, lf, member, refc);
435 }
436 @Override
437 Object checkReceiver(Object recv) {
438 if (!refc.isInstance(recv)) {
439 String msg = String.format("Receiver class %s does not implement the requested interface %s",
440 recv.getClass().getName(), refc.getName());
441 throw new IncompatibleClassChangeError(msg);
442 }
443 return recv;
444 }
445 }
446
447 /** Used for interface receiver type checks, by Interface and Special modes. */
448 Object checkReceiver(Object recv) {
449 throw new InternalError("Should only be invoked on a subclass");
450 }
451
452
453 /** This subclass handles constructor references. */
454 static class Constructor extends DirectMethodHandle {
455 final MemberName initMethod;
456 final Class<?> instanceClass;
457
458 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor,
459 MemberName initMethod, Class<?> instanceClass) {
460 super(mtype, form, constructor);
461 this.initMethod = initMethod;
462 this.instanceClass = instanceClass;
463 assert(initMethod.isResolved());
464 }
465 @Override
466 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
467 return new Constructor(mt, lf, member, initMethod, instanceClass);
468 }
469 }
470
471 /*non-public*/ static Object constructorMethod(Object mh) {
472 Constructor dmh = (Constructor)mh;
473 return dmh.initMethod;
474 }
475
476 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException {
477 Constructor dmh = (Constructor)mh;
478 return UNSAFE.allocateInstance(dmh.instanceClass);
479 }
480
481 /** This subclass handles non-static field references. */
482 static class Accessor extends DirectMethodHandle {
483 final Class<?> fieldType;
484 final int fieldOffset;
485 private Accessor(MethodType mtype, LambdaForm form, MemberName member,
486 int fieldOffset) {
487 super(mtype, form, member);
488 this.fieldType = member.getFieldType();
489 this.fieldOffset = fieldOffset;
490 }
491
492 @Override Object checkCast(Object obj) {
493 return fieldType.cast(obj);
494 }
495 @Override
496 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
497 return new Accessor(mt, lf, member, fieldOffset);
498 }
499 }
500
501 @ForceInline
502 /*non-public*/ static long fieldOffset(Object accessorObj) {
503 // Note: We return a long because that is what Unsafe.getObject likes.
504 // We store a plain int because it is more compact.
505 return ((Accessor)accessorObj).fieldOffset;
506 }
507
508 @ForceInline
509 /*non-public*/ static Object checkBase(Object obj) {
510 // Note that the object's class has already been verified,
511 // since the parameter type of the Accessor method handle
512 // is either member.getDeclaringClass or a subclass.
513 // This was verified in DirectMethodHandle.make.
514 // Therefore, the only remaining check is for null.
515 // Since this check is *not* guaranteed by Unsafe.getInt
516 // and its siblings, we need to make an explicit one here.
517 return Objects.requireNonNull(obj);
518 }
519
520 /** This subclass handles static field references. */
521 static class StaticAccessor extends DirectMethodHandle {
522 private final Class<?> fieldType;
523 private final Object staticBase;
524 private final long staticOffset;
525
526 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member,
527 Object staticBase, long staticOffset) {
528 super(mtype, form, member);
529 this.fieldType = member.getFieldType();
530 this.staticBase = staticBase;
531 this.staticOffset = staticOffset;
532 }
533
534 @Override Object checkCast(Object obj) {
535 return fieldType.cast(obj);
536 }
537 @Override
538 MethodHandle copyWith(MethodType mt, LambdaForm lf) {
539 return new StaticAccessor(mt, lf, member, staticBase, staticOffset);
540 }
541 }
542
543 @ForceInline
544 /*non-public*/ static Object nullCheck(Object obj) {
545 return Objects.requireNonNull(obj);
546 }
547
548 @ForceInline
549 /*non-public*/ static Object staticBase(Object accessorObj) {
550 return ((StaticAccessor)accessorObj).staticBase;
551 }
552
553 @ForceInline
554 /*non-public*/ static long staticOffset(Object accessorObj) {
555 return ((StaticAccessor)accessorObj).staticOffset;
556 }
557
558 @ForceInline
559 /*non-public*/ static Object checkCast(Object mh, Object obj) {
560 return ((DirectMethodHandle) mh).checkCast(obj);
561 }
562
563 Object checkCast(Object obj) {
564 return member.getReturnType().cast(obj);
565 }
566
567 // Caching machinery for field accessors:
568 static final byte
569 AF_GETFIELD = 0,
570 AF_PUTFIELD = 1,
571 AF_GETSTATIC = 2,
572 AF_PUTSTATIC = 3,
573 AF_GETSTATIC_INIT = 4,
574 AF_PUTSTATIC_INIT = 5,
575 AF_LIMIT = 6;
576 // Enumerate the different field kinds using Wrapper,
577 // with an extra case added for checked references.
578 static final int
579 FT_LAST_WRAPPER = Wrapper.COUNT-1,
580 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(),
581 FT_CHECKED_REF = FT_LAST_WRAPPER+1,
582 FT_LIMIT = FT_LAST_WRAPPER+2;
583 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) {
584 return ((formOp * FT_LIMIT * 2)
585 + (isVolatile ? FT_LIMIT : 0)
586 + ftypeKind);
587 }
588 @Stable
589 private static final LambdaForm[] ACCESSOR_FORMS
590 = new LambdaForm[afIndex(AF_LIMIT, false, 0)];
591 static int ftypeKind(Class<?> ftype) {
592 if (ftype.isPrimitive())
593 return Wrapper.forPrimitiveType(ftype).ordinal();
594 else if (VerifyType.isNullReferenceConversion(Object.class, ftype))
595 return FT_UNCHECKED_REF;
596 else
597 return FT_CHECKED_REF;
598 }
599
600 /**
601 * Create a LF which can access the given field.
602 * Cache and share this structure among all fields with
603 * the same basicType and refKind.
604 */
605 private static LambdaForm preparedFieldLambdaForm(MemberName m) {
606 Class<?> ftype = m.getFieldType();
607 boolean isVolatile = m.isVolatile();
608 byte formOp;
609 switch (m.getReferenceKind()) {
610 case REF_getField: formOp = AF_GETFIELD; break;
611 case REF_putField: formOp = AF_PUTFIELD; break;
612 case REF_getStatic: formOp = AF_GETSTATIC; break;
613 case REF_putStatic: formOp = AF_PUTSTATIC; break;
614 default: throw new InternalError(m.toString());
615 }
616 if (shouldBeInitialized(m)) {
617 // precompute the barrier-free version:
618 preparedFieldLambdaForm(formOp, isVolatile, ftype);
619 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) ==
620 (AF_PUTSTATIC_INIT - AF_PUTSTATIC));
621 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC);
622 }
623 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype);
624 maybeCompile(lform, m);
625 assert(lform.methodType().dropParameterTypes(0, 1)
626 .equals(m.getInvocationType().basicType()))
627 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType());
628 return lform;
629 }
630 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) {
631 int ftypeKind = ftypeKind(ftype);
632 int afIndex = afIndex(formOp, isVolatile, ftypeKind);
633 LambdaForm lform = ACCESSOR_FORMS[afIndex];
634 if (lform != null) return lform;
635 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind);
636 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS
637 return lform;
638 }
639
640 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values();
641
642 private static Kind getFieldKind(boolean isGetter, boolean isVolatile, Wrapper wrapper) {
643 if (isGetter) {
644 if (isVolatile) {
645 switch (wrapper) {
646 case BOOLEAN: return GET_BOOLEAN_VOLATILE;
647 case BYTE: return GET_BYTE_VOLATILE;
648 case SHORT: return GET_SHORT_VOLATILE;
649 case CHAR: return GET_CHAR_VOLATILE;
650 case INT: return GET_INT_VOLATILE;
651 case LONG: return GET_LONG_VOLATILE;
652 case FLOAT: return GET_FLOAT_VOLATILE;
653 case DOUBLE: return GET_DOUBLE_VOLATILE;
654 case OBJECT: return GET_OBJECT_VOLATILE;
655 }
656 } else {
657 switch (wrapper) {
658 case BOOLEAN: return GET_BOOLEAN;
659 case BYTE: return GET_BYTE;
660 case SHORT: return GET_SHORT;
661 case CHAR: return GET_CHAR;
662 case INT: return GET_INT;
663 case LONG: return GET_LONG;
664 case FLOAT: return GET_FLOAT;
665 case DOUBLE: return GET_DOUBLE;
666 case OBJECT: return GET_OBJECT;
667 }
668 }
669 } else {
670 if (isVolatile) {
671 switch (wrapper) {
672 case BOOLEAN: return PUT_BOOLEAN_VOLATILE;
673 case BYTE: return PUT_BYTE_VOLATILE;
674 case SHORT: return PUT_SHORT_VOLATILE;
675 case CHAR: return PUT_CHAR_VOLATILE;
676 case INT: return PUT_INT_VOLATILE;
677 case LONG: return PUT_LONG_VOLATILE;
678 case FLOAT: return PUT_FLOAT_VOLATILE;
679 case DOUBLE: return PUT_DOUBLE_VOLATILE;
680 case OBJECT: return PUT_OBJECT_VOLATILE;
681 }
682 } else {
683 switch (wrapper) {
684 case BOOLEAN: return PUT_BOOLEAN;
685 case BYTE: return PUT_BYTE;
686 case SHORT: return PUT_SHORT;
687 case CHAR: return PUT_CHAR;
688 case INT: return PUT_INT;
689 case LONG: return PUT_LONG;
690 case FLOAT: return PUT_FLOAT;
691 case DOUBLE: return PUT_DOUBLE;
692 case OBJECT: return PUT_OBJECT;
693 }
694 }
695 }
696 throw new AssertionError("Invalid arguments");
697 }
698
699 static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) {
700 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1);
701 boolean isStatic = (formOp >= AF_GETSTATIC);
702 boolean needsInit = (formOp >= AF_GETSTATIC_INIT);
703 boolean needsCast = (ftypeKind == FT_CHECKED_REF);
704 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]);
705 Class<?> ft = fw.primitiveType();
706 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind);
707
708 // getObject, putIntVolatile, etc.
709 Kind kind = getFieldKind(isGetter, isVolatile, fw);
710
711 MethodType linkerType;
712 if (isGetter)
713 linkerType = MethodType.methodType(ft, Object.class, long.class);
714 else
715 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft);
716 MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual);
717 try {
718 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class);
719 } catch (ReflectiveOperationException ex) {
720 throw newInternalError(ex);
721 }
722
723 // What is the external type of the lambda form?
724 MethodType mtype;
725 if (isGetter)
726 mtype = MethodType.methodType(ft);
727 else
728 mtype = MethodType.methodType(void.class, ft);
729 mtype = mtype.basicType(); // erase short to int, etc.
730 if (!isStatic)
731 mtype = mtype.insertParameterTypes(0, Object.class);
732 final int DMH_THIS = 0;
733 final int ARG_BASE = 1;
734 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount();
735 // if this is for non-static access, the base pointer is stored at this index:
736 final int OBJ_BASE = isStatic ? -1 : ARG_BASE;
737 // if this is for write access, the value to be written is stored at this index:
738 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1;
739 int nameCursor = ARG_LIMIT;
740 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any
741 final int F_OFFSET = nameCursor++; // Either static offset or field offset.
742 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1);
743 final int U_HOLDER = nameCursor++; // UNSAFE holder
744 final int INIT_BAR = (needsInit ? nameCursor++ : -1);
745 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1);
746 final int LINKER_CALL = nameCursor++;
747 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1);
748 final int RESULT = nameCursor-1; // either the call or the cast
749 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
750 if (needsInit)
751 names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]);
752 if (needsCast && !isGetter)
753 names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]);
754 Object[] outArgs = new Object[1 + linkerType.parameterCount()];
755 assert(outArgs.length == (isGetter ? 3 : 4));
756 outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE));
757 if (isStatic) {
758 outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]);
759 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]);
760 } else {
761 outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]);
762 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]);
763 }
764 if (!isGetter) {
765 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
766 }
767 for (Object a : outArgs) assert(a != null);
768 names[LINKER_CALL] = new Name(linker, outArgs);
769 if (needsCast && isGetter)
770 names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]);
771 for (Name n : names) assert(n != null);
772
773 LambdaForm form;
774 if (needsCast || needsInit) {
775 // can't use the pre-generated form when casting and/or initializing
776 form = new LambdaForm(ARG_LIMIT, names, RESULT);
777 } else {
778 form = new LambdaForm(ARG_LIMIT, names, RESULT, kind);
779 }
780
781 if (LambdaForm.debugNames()) {
782 // add some detail to the lambdaForm debugname,
783 // significant only for debugging
784 StringBuilder nameBuilder = new StringBuilder(kind.methodName);
785 if (isStatic) {
786 nameBuilder.append("Static");
787 } else {
788 nameBuilder.append("Field");
789 }
790 if (needsCast) {
791 nameBuilder.append("Cast");
792 }
793 if (needsInit) {
794 nameBuilder.append("Init");
795 }
796 LambdaForm.associateWithDebugName(form, nameBuilder.toString());
797 }
798 return form;
799 }
800
801 /**
802 * Pre-initialized NamedFunctions for bootstrapping purposes.
803 */
804 static final byte NF_internalMemberName = 0,
805 NF_internalMemberNameEnsureInit = 1,
806 NF_ensureInitialized = 2,
807 NF_fieldOffset = 3,
808 NF_checkBase = 4,
809 NF_staticBase = 5,
810 NF_staticOffset = 6,
811 NF_checkCast = 7,
812 NF_allocateInstance = 8,
813 NF_constructorMethod = 9,
814 NF_UNSAFE = 10,
815 NF_checkReceiver = 11,
816 NF_LIMIT = 12;
817
818 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
819
820 private static NamedFunction getFunction(byte func) {
821 NamedFunction nf = NFS[func];
822 if (nf != null) {
823 return nf;
824 }
825 // Each nf must be statically invocable or we get tied up in our bootstraps.
826 nf = NFS[func] = createFunction(func);
827 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf));
828 return nf;
829 }
830
831 private static final MethodType OBJ_OBJ_TYPE = MethodType.methodType(Object.class, Object.class);
832
833 private static final MethodType LONG_OBJ_TYPE = MethodType.methodType(long.class, Object.class);
834
835 private static NamedFunction createFunction(byte func) {
836 try {
837 switch (func) {
838 case NF_internalMemberName:
839 return getNamedFunction("internalMemberName", OBJ_OBJ_TYPE);
840 case NF_internalMemberNameEnsureInit:
841 return getNamedFunction("internalMemberNameEnsureInit", OBJ_OBJ_TYPE);
842 case NF_ensureInitialized:
843 return getNamedFunction("ensureInitialized", MethodType.methodType(void.class, Object.class));
844 case NF_fieldOffset:
845 return getNamedFunction("fieldOffset", LONG_OBJ_TYPE);
846 case NF_checkBase:
847 return getNamedFunction("checkBase", OBJ_OBJ_TYPE);
848 case NF_staticBase:
849 return getNamedFunction("staticBase", OBJ_OBJ_TYPE);
850 case NF_staticOffset:
851 return getNamedFunction("staticOffset", LONG_OBJ_TYPE);
852 case NF_checkCast:
853 return getNamedFunction("checkCast", MethodType.methodType(Object.class, Object.class, Object.class));
854 case NF_allocateInstance:
855 return getNamedFunction("allocateInstance", OBJ_OBJ_TYPE);
856 case NF_constructorMethod:
857 return getNamedFunction("constructorMethod", OBJ_OBJ_TYPE);
858 case NF_UNSAFE:
859 MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getField);
860 return new NamedFunction(
861 MemberName.getFactory()
862 .resolveOrFail(REF_getField, member, DirectMethodHandle.class, NoSuchMethodException.class));
863 case NF_checkReceiver:
864 member = new MemberName(DirectMethodHandle.class, "checkReceiver", OBJ_OBJ_TYPE, REF_invokeVirtual);
865 return new NamedFunction(
866 MemberName.getFactory()
867 .resolveOrFail(REF_invokeVirtual, member, DirectMethodHandle.class, NoSuchMethodException.class));
868 default:
869 throw newInternalError("Unknown function: " + func);
870 }
871 } catch (ReflectiveOperationException ex) {
872 throw newInternalError(ex);
873 }
874 }
875
876 private static NamedFunction getNamedFunction(String name, MethodType type)
877 throws ReflectiveOperationException
878 {
879 MemberName member = new MemberName(DirectMethodHandle.class, name, type, REF_invokeStatic);
880 return new NamedFunction(
881 MemberName.getFactory()
882 .resolveOrFail(REF_invokeStatic, member, DirectMethodHandle.class, NoSuchMethodException.class));
883 }
884
885 static {
886 // The Holder class will contain pre-generated DirectMethodHandles resolved
887 // speculatively using MemberName.getFactory().resolveOrNull. However, that
888 // doesn't initialize the class, which subtly breaks inlining etc. By forcing
889 // initialization of the Holder class we avoid these issues.
890 UNSAFE.ensureClassInitialized(Holder.class);
891 }
892
893 /* Placeholder class for DirectMethodHandles generated ahead of time */
894 final class Holder {}
895 }