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 26package java.lang.invoke; 27 28import jdk.internal.misc.Unsafe; 29import jdk.internal.vm.annotation.ForceInline; 30import jdk.internal.vm.annotation.Stable; 31import sun.invoke.util.ValueConversions; 32import sun.invoke.util.VerifyAccess; 33import sun.invoke.util.VerifyType; 34import sun.invoke.util.Wrapper; 35 36import java.lang.ref.WeakReference; 37import java.util.Arrays; 38import java.util.Objects; 39 40import static java.lang.invoke.LambdaForm.*; 41import static java.lang.invoke.LambdaForm.Kind.*; 42import static java.lang.invoke.MethodHandleNatives.Constants.*; 43import static java.lang.invoke.MethodHandleStatics.UNSAFE; 44import static java.lang.invoke.MethodHandleStatics.newInternalError; 45import 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 */ 52class 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(getFunction(NF_allocateInstance), names[DMH_THIS]); 228 names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]); 229 } else if (needsInit) { 230 names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]); 231 } else { 232 names[GET_MEMBER] = new Name(getFunction(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 LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind); 246 247 // This is a tricky bit of code. Don't send it through the LF interpreter. 248 lform.compileToBytecode(); 249 return lform; 250 } 251 252 /* assert */ static Object findDirectMethodHandle(Name name) { 253 if (name.function.equals(getFunction(NF_internalMemberName)) || 254 name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) || 255 name.function.equals(getFunction(NF_constructorMethod))) { 256 assert(name.arguments.length == 1); 257 return name.arguments[0]; 258 } 259 return null; 260 } 261 262 private static void maybeCompile(LambdaForm lform, MemberName m) { 263 if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class)) 264 // Help along bootstrapping... 265 lform.compileToBytecode(); 266 } 267 268 /** Static wrapper for DirectMethodHandle.internalMemberName. */ 269 @ForceInline 270 /*non-public*/ static Object internalMemberName(Object mh) { 271 return ((DirectMethodHandle)mh).member; 272 } 273 274 /** Static wrapper for DirectMethodHandle.internalMemberName. 275 * This one also forces initialization. 276 */ 277 /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) { 278 DirectMethodHandle dmh = (DirectMethodHandle)mh; 279 dmh.ensureInitialized(); 280 return dmh.member; 281 } 282 283 /*non-public*/ static 284 boolean shouldBeInitialized(MemberName member) { 285 switch (member.getReferenceKind()) { 286 case REF_invokeStatic: 287 case REF_getStatic: 288 case REF_putStatic: 289 case REF_newInvokeSpecial: 290 break; 291 default: 292 // No need to initialize the class on this kind of member. 293 return false; 294 } 295 Class<?> cls = member.getDeclaringClass(); 296 if (cls == ValueConversions.class || 297 cls == MethodHandleImpl.class || 298 cls == Invokers.class) { 299 // These guys have lots of <clinit> DMH creation but we know 300 // the MHs will not be used until the system is booted. 301 return false; 302 } 303 if (VerifyAccess.isSamePackage(MethodHandle.class, cls) || 304 VerifyAccess.isSamePackage(ValueConversions.class, cls)) { 305 // It is a system class. It is probably in the process of 306 // being initialized, but we will help it along just to be safe. 307 if (UNSAFE.shouldBeInitialized(cls)) { 308 UNSAFE.ensureClassInitialized(cls); 309 } 310 return false; 311 } 312 return UNSAFE.shouldBeInitialized(cls); 313 } 314 315 private static class EnsureInitialized extends ClassValue<WeakReference<Thread>> { 316 @Override 317 protected WeakReference<Thread> computeValue(Class<?> type) { 318 UNSAFE.ensureClassInitialized(type); 319 if (UNSAFE.shouldBeInitialized(type)) 320 // If the previous call didn't block, this can happen. 321 // We are executing inside <clinit>. 322 return new WeakReference<>(Thread.currentThread()); 323 return null; 324 } 325 static final EnsureInitialized INSTANCE = new EnsureInitialized(); 326 } 327 328 private void ensureInitialized() { 329 if (checkInitialized(member)) { 330 // The coast is clear. Delete the <clinit> barrier. 331 if (member.isField()) 332 updateForm(preparedFieldLambdaForm(member)); 333 else 334 updateForm(preparedLambdaForm(member)); 335 } 336 } 337 private static boolean checkInitialized(MemberName member) { 338 Class<?> defc = member.getDeclaringClass(); 339 WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc); 340 if (ref == null) { 341 return true; // the final state 342 } 343 Thread clinitThread = ref.get(); 344 // Somebody may still be running defc.<clinit>. 345 if (clinitThread == Thread.currentThread()) { 346 // If anybody is running defc.<clinit>, it is this thread. 347 if (UNSAFE.shouldBeInitialized(defc)) 348 // Yes, we are running it; keep the barrier for now. 349 return false; 350 } else { 351 // We are in a random thread. Block. 352 UNSAFE.ensureClassInitialized(defc); 353 } 354 assert(!UNSAFE.shouldBeInitialized(defc)); 355 // put it into the final state 356 EnsureInitialized.INSTANCE.remove(defc); 357 return true; 358 } 359 360 /*non-public*/ static void ensureInitialized(Object mh) { 361 ((DirectMethodHandle)mh).ensureInitialized(); 362 } 363 364 /** This subclass represents invokespecial instructions. */ 365 static class Special extends DirectMethodHandle { 366 private Special(MethodType mtype, LambdaForm form, MemberName member) { 367 super(mtype, form, member); 368 } 369 @Override 370 boolean isInvokeSpecial() { 371 return true; 372 } 373 @Override 374 MethodHandle copyWith(MethodType mt, LambdaForm lf) { 375 return new Special(mt, lf, member); 376 } 377 } 378 379 /** This subclass handles constructor references. */ 380 static class Constructor extends DirectMethodHandle { 381 final MemberName initMethod; 382 final Class<?> instanceClass; 383 384 private Constructor(MethodType mtype, LambdaForm form, MemberName constructor, 385 MemberName initMethod, Class<?> instanceClass) { 386 super(mtype, form, constructor); 387 this.initMethod = initMethod; 388 this.instanceClass = instanceClass; 389 assert(initMethod.isResolved()); 390 } 391 @Override 392 MethodHandle copyWith(MethodType mt, LambdaForm lf) { 393 return new Constructor(mt, lf, member, initMethod, instanceClass); 394 } 395 } 396 397 /*non-public*/ static Object constructorMethod(Object mh) { 398 Constructor dmh = (Constructor)mh; 399 return dmh.initMethod; 400 } 401 402 /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException { 403 Constructor dmh = (Constructor)mh; 404 return UNSAFE.allocateInstance(dmh.instanceClass); 405 } 406 407 /** This subclass handles non-static field references. */ 408 static class Accessor extends DirectMethodHandle { 409 final Class<?> fieldType; 410 final int fieldOffset; 411 private Accessor(MethodType mtype, LambdaForm form, MemberName member, 412 int fieldOffset) { 413 super(mtype, form, member); 414 this.fieldType = member.getFieldType(); 415 this.fieldOffset = fieldOffset; 416 } 417 418 @Override Object checkCast(Object obj) { 419 return fieldType.cast(obj); 420 } 421 @Override 422 MethodHandle copyWith(MethodType mt, LambdaForm lf) { 423 return new Accessor(mt, lf, member, fieldOffset); 424 } 425 } 426 427 @ForceInline 428 /*non-public*/ static long fieldOffset(Object accessorObj) { 429 // Note: We return a long because that is what Unsafe.getObject likes. 430 // We store a plain int because it is more compact. 431 return ((Accessor)accessorObj).fieldOffset; 432 } 433 434 @ForceInline 435 /*non-public*/ static Object checkBase(Object obj) { 436 // Note that the object's class has already been verified, 437 // since the parameter type of the Accessor method handle 438 // is either member.getDeclaringClass or a subclass. 439 // This was verified in DirectMethodHandle.make. 440 // Therefore, the only remaining check is for null. 441 // Since this check is *not* guaranteed by Unsafe.getInt 442 // and its siblings, we need to make an explicit one here. 443 return Objects.requireNonNull(obj); 444 } 445 446 /** This subclass handles static field references. */ 447 static class StaticAccessor extends DirectMethodHandle { 448 private final Class<?> fieldType; 449 private final Object staticBase; 450 private final long staticOffset; 451 452 private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member, 453 Object staticBase, long staticOffset) { 454 super(mtype, form, member); 455 this.fieldType = member.getFieldType(); 456 this.staticBase = staticBase; 457 this.staticOffset = staticOffset; 458 } 459 460 @Override Object checkCast(Object obj) { 461 return fieldType.cast(obj); 462 } 463 @Override 464 MethodHandle copyWith(MethodType mt, LambdaForm lf) { 465 return new StaticAccessor(mt, lf, member, staticBase, staticOffset); 466 } 467 } 468 469 @ForceInline 470 /*non-public*/ static Object nullCheck(Object obj) { 471 return Objects.requireNonNull(obj); 472 } 473 474 @ForceInline 475 /*non-public*/ static Object staticBase(Object accessorObj) { 476 return ((StaticAccessor)accessorObj).staticBase; 477 } 478 479 @ForceInline 480 /*non-public*/ static long staticOffset(Object accessorObj) { 481 return ((StaticAccessor)accessorObj).staticOffset; 482 } 483 484 @ForceInline 485 /*non-public*/ static Object checkCast(Object mh, Object obj) { 486 return ((DirectMethodHandle) mh).checkCast(obj); 487 } 488 489 Object checkCast(Object obj) { 490 return member.getReturnType().cast(obj); 491 } 492 493 // Caching machinery for field accessors: 494 static final byte 495 AF_GETFIELD = 0, 496 AF_PUTFIELD = 1, 497 AF_GETSTATIC = 2, 498 AF_PUTSTATIC = 3, 499 AF_GETSTATIC_INIT = 4, 500 AF_PUTSTATIC_INIT = 5, 501 AF_LIMIT = 6; 502 // Enumerate the different field kinds using Wrapper, 503 // with an extra case added for checked references. 504 static final int 505 FT_LAST_WRAPPER = Wrapper.COUNT-1, 506 FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(), 507 FT_CHECKED_REF = FT_LAST_WRAPPER+1, 508 FT_LIMIT = FT_LAST_WRAPPER+2; 509 private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) { 510 return ((formOp * FT_LIMIT * 2) 511 + (isVolatile ? FT_LIMIT : 0) 512 + ftypeKind); 513 } 514 @Stable 515 private static final LambdaForm[] ACCESSOR_FORMS 516 = new LambdaForm[afIndex(AF_LIMIT, false, 0)]; 517 static int ftypeKind(Class<?> ftype) { 518 if (ftype.isPrimitive()) 519 return Wrapper.forPrimitiveType(ftype).ordinal(); 520 else if (VerifyType.isNullReferenceConversion(Object.class, ftype)) 521 return FT_UNCHECKED_REF; 522 else 523 return FT_CHECKED_REF; 524 } 525 526 /** 527 * Create a LF which can access the given field. 528 * Cache and share this structure among all fields with 529 * the same basicType and refKind. 530 */ 531 private static LambdaForm preparedFieldLambdaForm(MemberName m) { 532 Class<?> ftype = m.getFieldType(); 533 boolean isVolatile = m.isVolatile(); 534 byte formOp; 535 switch (m.getReferenceKind()) { 536 case REF_getField: formOp = AF_GETFIELD; break; 537 case REF_putField: formOp = AF_PUTFIELD; break; 538 case REF_getStatic: formOp = AF_GETSTATIC; break; 539 case REF_putStatic: formOp = AF_PUTSTATIC; break; 540 default: throw new InternalError(m.toString()); 541 } 542 if (shouldBeInitialized(m)) { 543 // precompute the barrier-free version: 544 preparedFieldLambdaForm(formOp, isVolatile, ftype); 545 assert((AF_GETSTATIC_INIT - AF_GETSTATIC) == 546 (AF_PUTSTATIC_INIT - AF_PUTSTATIC)); 547 formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC); 548 } 549 LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype); 550 maybeCompile(lform, m); 551 assert(lform.methodType().dropParameterTypes(0, 1) 552 .equals(m.getInvocationType().basicType())) 553 : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType()); 554 return lform; 555 } 556 private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class<?> ftype) { 557 int ftypeKind = ftypeKind(ftype); 558 int afIndex = afIndex(formOp, isVolatile, ftypeKind); 559 LambdaForm lform = ACCESSOR_FORMS[afIndex]; 560 if (lform != null) return lform; 561 lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind); 562 ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS 563 return lform; 564 } 565 566 private static final Wrapper[] ALL_WRAPPERS = Wrapper.values(); 567 568 private static Kind getFieldKind(boolean isGetter, boolean isVolatile, Wrapper wrapper) { 569 if (isGetter) { 570 if (isVolatile) { 571 switch (wrapper) { 572 case BOOLEAN: return GET_BOOLEAN_VOLATILE; 573 case BYTE: return GET_BYTE_VOLATILE; 574 case SHORT: return GET_SHORT_VOLATILE; 575 case CHAR: return GET_CHAR_VOLATILE; 576 case INT: return GET_INT_VOLATILE; 577 case LONG: return GET_LONG_VOLATILE; 578 case FLOAT: return GET_FLOAT_VOLATILE; 579 case DOUBLE: return GET_DOUBLE_VOLATILE; 580 case OBJECT: return GET_OBJECT_VOLATILE; 581 } 582 } else { 583 switch (wrapper) { 584 case BOOLEAN: return GET_BOOLEAN; 585 case BYTE: return GET_BYTE; 586 case SHORT: return GET_SHORT; 587 case CHAR: return GET_CHAR; 588 case INT: return GET_INT; 589 case LONG: return GET_LONG; 590 case FLOAT: return GET_FLOAT; 591 case DOUBLE: return GET_DOUBLE; 592 case OBJECT: return GET_OBJECT; 593 } 594 } 595 } else { 596 if (isVolatile) { 597 switch (wrapper) { 598 case BOOLEAN: return PUT_BOOLEAN_VOLATILE; 599 case BYTE: return PUT_BYTE_VOLATILE; 600 case SHORT: return PUT_SHORT_VOLATILE; 601 case CHAR: return PUT_CHAR_VOLATILE; 602 case INT: return PUT_INT_VOLATILE; 603 case LONG: return PUT_LONG_VOLATILE; 604 case FLOAT: return PUT_FLOAT_VOLATILE; 605 case DOUBLE: return PUT_DOUBLE_VOLATILE; 606 case OBJECT: return PUT_OBJECT_VOLATILE; 607 } 608 } else { 609 switch (wrapper) { 610 case BOOLEAN: return PUT_BOOLEAN; 611 case BYTE: return PUT_BYTE; 612 case SHORT: return PUT_SHORT; 613 case CHAR: return PUT_CHAR; 614 case INT: return PUT_INT; 615 case LONG: return PUT_LONG; 616 case FLOAT: return PUT_FLOAT; 617 case DOUBLE: return PUT_DOUBLE; 618 case OBJECT: return PUT_OBJECT; 619 } 620 } 621 } 622 throw new AssertionError("Invalid arguments"); 623 } 624 625 static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) { 626 boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1); 627 boolean isStatic = (formOp >= AF_GETSTATIC); 628 boolean needsInit = (formOp >= AF_GETSTATIC_INIT); 629 boolean needsCast = (ftypeKind == FT_CHECKED_REF); 630 Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]); 631 Class<?> ft = fw.primitiveType(); 632 assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind); 633 634 // getObject, putIntVolatile, etc. 635 Kind kind = getFieldKind(isGetter, isVolatile, fw); 636 637 MethodType linkerType; 638 if (isGetter) 639 linkerType = MethodType.methodType(ft, Object.class, long.class); 640 else 641 linkerType = MethodType.methodType(void.class, Object.class, long.class, ft); 642 MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual); 643 try { 644 linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class); 645 } catch (ReflectiveOperationException ex) { 646 throw newInternalError(ex); 647 } 648 649 // What is the external type of the lambda form? 650 MethodType mtype; 651 if (isGetter) 652 mtype = MethodType.methodType(ft); 653 else 654 mtype = MethodType.methodType(void.class, ft); 655 mtype = mtype.basicType(); // erase short to int, etc. 656 if (!isStatic) 657 mtype = mtype.insertParameterTypes(0, Object.class); 658 final int DMH_THIS = 0; 659 final int ARG_BASE = 1; 660 final int ARG_LIMIT = ARG_BASE + mtype.parameterCount(); 661 // if this is for non-static access, the base pointer is stored at this index: 662 final int OBJ_BASE = isStatic ? -1 : ARG_BASE; 663 // if this is for write access, the value to be written is stored at this index: 664 final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1; 665 int nameCursor = ARG_LIMIT; 666 final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any 667 final int F_OFFSET = nameCursor++; // Either static offset or field offset. 668 final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1); 669 final int U_HOLDER = nameCursor++; // UNSAFE holder 670 final int INIT_BAR = (needsInit ? nameCursor++ : -1); 671 final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1); 672 final int LINKER_CALL = nameCursor++; 673 final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1); 674 final int RESULT = nameCursor-1; // either the call or the cast 675 Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType()); 676 if (needsInit) 677 names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]); 678 if (needsCast && !isGetter) 679 names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]); 680 Object[] outArgs = new Object[1 + linkerType.parameterCount()]; 681 assert(outArgs.length == (isGetter ? 3 : 4)); 682 outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE)); 683 if (isStatic) { 684 outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]); 685 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]); 686 } else { 687 outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]); 688 outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]); 689 } 690 if (!isGetter) { 691 outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]); 692 } 693 for (Object a : outArgs) assert(a != null); 694 names[LINKER_CALL] = new Name(linker, outArgs); 695 if (needsCast && isGetter) 696 names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]); 697 for (Name n : names) assert(n != null); 698 699 LambdaForm form; 700 if (needsCast || needsInit) { 701 // can't use the pre-generated form when casting and/or initializing 702 form = new LambdaForm(ARG_LIMIT, names, RESULT); 703 } else { 704 form = new LambdaForm(ARG_LIMIT, names, RESULT, kind); 705 } 706 707 if (LambdaForm.debugNames()) { 708 // add some detail to the lambdaForm debugname, 709 // significant only for debugging 710 StringBuilder nameBuilder = new StringBuilder(kind.methodName); 711 if (isStatic) { 712 nameBuilder.append("Static"); 713 } else { 714 nameBuilder.append("Field"); 715 } 716 if (needsCast) { 717 nameBuilder.append("Cast"); 718 } 719 if (needsInit) { 720 nameBuilder.append("Init"); 721 } 722 LambdaForm.associateWithDebugName(form, nameBuilder.toString()); 723 } 724 return form; 725 } 726 727 /** 728 * Pre-initialized NamedFunctions for bootstrapping purposes. 729 */ 730 static final byte NF_internalMemberName = 0, 731 NF_internalMemberNameEnsureInit = 1, 732 NF_ensureInitialized = 2, 733 NF_fieldOffset = 3, 734 NF_checkBase = 4, 735 NF_staticBase = 5, 736 NF_staticOffset = 6, 737 NF_checkCast = 7, 738 NF_allocateInstance = 8, 739 NF_constructorMethod = 9, 740 NF_UNSAFE = 10, 741 NF_LIMIT = 11; 742 743 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT]; 744 745 private static NamedFunction getFunction(byte func) { 746 NamedFunction nf = NFS[func]; 747 if (nf != null) { 748 return nf; 749 } 750 // Each nf must be statically invocable or we get tied up in our bootstraps. 751 nf = NFS[func] = createFunction(func); 752 assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf)); 753 return nf; 754 } 755 756 private static NamedFunction createFunction(byte func) { 757 try { 758 switch (func) { 759 case NF_internalMemberName: 760 return new NamedFunction(DirectMethodHandle.class 761 .getDeclaredMethod("internalMemberName", Object.class)); 762 case NF_internalMemberNameEnsureInit: 763 return new NamedFunction(DirectMethodHandle.class 764 .getDeclaredMethod("internalMemberNameEnsureInit", Object.class)); 765 case NF_ensureInitialized: 766 return new NamedFunction(DirectMethodHandle.class 767 .getDeclaredMethod("ensureInitialized", Object.class)); 768 case NF_fieldOffset: 769 return new NamedFunction(DirectMethodHandle.class 770 .getDeclaredMethod("fieldOffset", Object.class)); 771 case NF_checkBase: 772 return new NamedFunction(DirectMethodHandle.class 773 .getDeclaredMethod("checkBase", Object.class)); 774 case NF_staticBase: 775 return new NamedFunction(DirectMethodHandle.class 776 .getDeclaredMethod("staticBase", Object.class)); 777 case NF_staticOffset: 778 return new NamedFunction(DirectMethodHandle.class 779 .getDeclaredMethod("staticOffset", Object.class)); 780 case NF_checkCast: 781 return new NamedFunction(DirectMethodHandle.class 782 .getDeclaredMethod("checkCast", Object.class, Object.class)); 783 case NF_allocateInstance: 784 return new NamedFunction(DirectMethodHandle.class 785 .getDeclaredMethod("allocateInstance", Object.class)); 786 case NF_constructorMethod: 787 return new NamedFunction(DirectMethodHandle.class 788 .getDeclaredMethod("constructorMethod", Object.class)); 789 case NF_UNSAFE: 790 return new NamedFunction(new MemberName(MethodHandleStatics.class 791 .getDeclaredField("UNSAFE"))); 792 default: 793 throw newInternalError("Unknown function: " + func); 794 } 795 } catch (ReflectiveOperationException ex) { 796 throw newInternalError(ex); 797 } 798 } 799 800 static { 801 // The Holder class will contain pre-generated DirectMethodHandles resolved 802 // speculatively using MemberName.getFactory().resolveOrNull. However, that 803 // doesn't initialize the class, which subtly breaks inlining etc. By forcing 804 // initialization of the Holder class we avoid these issues. 805 UNSAFE.ensureClassInitialized(Holder.class); 806 } 807 808 /* Placeholder class for DirectMethodHandles generated ahead of time */ 809 final class Holder {} 810} 811