/* * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.lang.invoke; import jdk.internal.misc.Unsafe; import jdk.internal.vm.annotation.ForceInline; import jdk.internal.vm.annotation.Stable; import sun.invoke.util.ValueConversions; import sun.invoke.util.VerifyAccess; import sun.invoke.util.VerifyType; import sun.invoke.util.Wrapper; import java.lang.ref.WeakReference; import java.util.Arrays; import java.util.Objects; import static java.lang.invoke.LambdaForm.*; import static java.lang.invoke.LambdaForm.Kind.*; import static java.lang.invoke.MethodHandleNatives.Constants.*; import static java.lang.invoke.MethodHandleStatics.UNSAFE; import static java.lang.invoke.MethodHandleStatics.newInternalError; import static java.lang.invoke.MethodTypeForm.*; /** * The flavor of method handle which implements a constant reference * to a class member. * @author jrose */ class DirectMethodHandle extends MethodHandle { final MemberName member; // Constructors and factory methods in this class *must* be package scoped or private. private DirectMethodHandle(MethodType mtype, LambdaForm form, MemberName member) { super(mtype, form); if (!member.isResolved()) throw new InternalError(); if (member.getDeclaringClass().isInterface() && member.getReferenceKind() == REF_invokeInterface && member.isMethod() && !member.isAbstract()) { // Check for corner case: invokeinterface of Object method MemberName m = new MemberName(Object.class, member.getName(), member.getMethodType(), member.getReferenceKind()); m = MemberName.getFactory().resolveOrNull(m.getReferenceKind(), m, null); if (m != null && m.isPublic()) { assert(member.getReferenceKind() == m.getReferenceKind()); // else this.form is wrong member = m; } } this.member = member; } // Factory methods: static DirectMethodHandle make(byte refKind, Class refc, MemberName member, Class callerClass) { MethodType mtype = member.getMethodOrFieldType(); if (!member.isStatic()) { if (!member.getDeclaringClass().isAssignableFrom(refc) || member.isConstructor()) throw new InternalError(member.toString()); mtype = mtype.insertParameterTypes(0, refc); } if (!member.isField()) { // refKind reflects the original type of lookup via findSpecial or // findVirtual etc. switch (refKind) { case REF_invokeSpecial: { member = member.asSpecial(); // if caller is an interface we need to adapt to get the // receiver check inserted if (callerClass == null) { throw new InternalError("callerClass must not be null for REF_invokeSpecial"); } LambdaForm lform = preparedLambdaForm(member, callerClass.isInterface()); return new Special(mtype, lform, member, callerClass); } case REF_invokeInterface: { // for interfaces we always need the receiver typecheck, // so we always pass 'true' to ensure we adapt if needed // to include the REF_invokeSpecial case LambdaForm lform = preparedLambdaForm(member, true); return new Interface(mtype, lform, member, refc); } default: { LambdaForm lform = preparedLambdaForm(member); return new DirectMethodHandle(mtype, lform, member); } } } else { LambdaForm lform = preparedFieldLambdaForm(member); if (member.isStatic()) { long offset = MethodHandleNatives.staticFieldOffset(member); Object base = MethodHandleNatives.staticFieldBase(member); return new StaticAccessor(mtype, lform, member, base, offset); } else { long offset = MethodHandleNatives.objectFieldOffset(member); assert(offset == (int)offset); return new Accessor(mtype, lform, member, (int)offset); } } } static DirectMethodHandle make(Class refc, MemberName member) { byte refKind = member.getReferenceKind(); if (refKind == REF_invokeSpecial) refKind = REF_invokeVirtual; return make(refKind, refc, member, null /* no callerClass context */); } static DirectMethodHandle make(MemberName member) { if (member.isConstructor()) return makeAllocator(member); return make(member.getDeclaringClass(), member); } private static DirectMethodHandle makeAllocator(MemberName ctor) { assert(ctor.isConstructor() && ctor.getName().equals("")); Class instanceClass = ctor.getDeclaringClass(); ctor = ctor.asConstructor(); assert(ctor.isConstructor() && ctor.getReferenceKind() == REF_newInvokeSpecial) : ctor; MethodType mtype = ctor.getMethodType().changeReturnType(instanceClass); LambdaForm lform = preparedLambdaForm(ctor); MemberName init = ctor.asSpecial(); assert(init.getMethodType().returnType() == void.class); return new Constructor(mtype, lform, ctor, init, instanceClass); } @Override BoundMethodHandle rebind() { return BoundMethodHandle.makeReinvoker(this); } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { assert(this.getClass() == DirectMethodHandle.class); // must override in subclasses return new DirectMethodHandle(mt, lf, member); } @Override String internalProperties() { return "\n& DMH.MN="+internalMemberName(); } //// Implementation methods. @Override @ForceInline MemberName internalMemberName() { return member; } private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory(); /** * Create a LF which can invoke the given method. * Cache and share this structure among all methods with * the same basicType and refKind. */ private static LambdaForm preparedLambdaForm(MemberName m, boolean adaptToSpecialIfc) { assert(m.isInvocable()) : m; // call preparedFieldLambdaForm instead MethodType mtype = m.getInvocationType().basicType(); assert(!m.isMethodHandleInvoke()) : m; int which; // MemberName.getReferenceKind represents the JVM optimized form of the call // as distinct from the "kind" passed to DMH.make which represents the original // bytecode-equivalent request. Specifically private/final methods that use a direct // call have getReferenceKind adapted to REF_invokeSpecial, even though the actual // invocation mode may be invokevirtual or invokeinterface. switch (m.getReferenceKind()) { case REF_invokeVirtual: which = LF_INVVIRTUAL; break; case REF_invokeStatic: which = LF_INVSTATIC; break; case REF_invokeSpecial: which = LF_INVSPECIAL; break; case REF_invokeInterface: which = LF_INVINTERFACE; break; case REF_newInvokeSpecial: which = LF_NEWINVSPECIAL; break; default: throw new InternalError(m.toString()); } if (which == LF_INVSTATIC && shouldBeInitialized(m)) { // precompute the barrier-free version: preparedLambdaForm(mtype, which); which = LF_INVSTATIC_INIT; } if (which == LF_INVSPECIAL && adaptToSpecialIfc) { which = LF_INVSPECIAL_IFC; } LambdaForm lform = preparedLambdaForm(mtype, which); maybeCompile(lform, m); assert(lform.methodType().dropParameterTypes(0, 1) .equals(m.getInvocationType().basicType())) : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType()); return lform; } private static LambdaForm preparedLambdaForm(MemberName m) { return preparedLambdaForm(m, false); } private static LambdaForm preparedLambdaForm(MethodType mtype, int which) { LambdaForm lform = mtype.form().cachedLambdaForm(which); if (lform != null) return lform; lform = makePreparedLambdaForm(mtype, which); return mtype.form().setCachedLambdaForm(which, lform); } static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) { boolean needsInit = (which == LF_INVSTATIC_INIT); boolean doesAlloc = (which == LF_NEWINVSPECIAL); boolean needsReceiverCheck = (which == LF_INVINTERFACE || which == LF_INVSPECIAL_IFC); String linkerName; LambdaForm.Kind kind; switch (which) { case LF_INVVIRTUAL: linkerName = "linkToVirtual"; kind = DIRECT_INVOKE_VIRTUAL; break; case LF_INVSTATIC: linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC; break; case LF_INVSTATIC_INIT:linkerName = "linkToStatic"; kind = DIRECT_INVOKE_STATIC_INIT; break; case LF_INVSPECIAL_IFC:linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL_IFC; break; case LF_INVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_INVOKE_SPECIAL; break; case LF_INVINTERFACE: linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE; break; case LF_NEWINVSPECIAL: linkerName = "linkToSpecial"; kind = DIRECT_NEW_INVOKE_SPECIAL; break; default: throw new InternalError("which="+which); } MethodType mtypeWithArg = mtype.appendParameterTypes(MemberName.class); if (doesAlloc) mtypeWithArg = mtypeWithArg .insertParameterTypes(0, Object.class) // insert newly allocated obj .changeReturnType(void.class); // returns void MemberName linker = new MemberName(MethodHandle.class, linkerName, mtypeWithArg, REF_invokeStatic); try { linker = IMPL_NAMES.resolveOrFail(REF_invokeStatic, linker, null, NoSuchMethodException.class); } catch (ReflectiveOperationException ex) { throw newInternalError(ex); } final int DMH_THIS = 0; final int ARG_BASE = 1; final int ARG_LIMIT = ARG_BASE + mtype.parameterCount(); int nameCursor = ARG_LIMIT; final int NEW_OBJ = (doesAlloc ? nameCursor++ : -1); final int GET_MEMBER = nameCursor++; final int CHECK_RECEIVER = (needsReceiverCheck ? nameCursor++ : -1); final int LINKER_CALL = nameCursor++; Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType()); assert(names.length == nameCursor); if (doesAlloc) { // names = { argx,y,z,... new C, init method } names[NEW_OBJ] = new Name(getFunction(NF_allocateInstance), names[DMH_THIS]); names[GET_MEMBER] = new Name(getFunction(NF_constructorMethod), names[DMH_THIS]); } else if (needsInit) { names[GET_MEMBER] = new Name(getFunction(NF_internalMemberNameEnsureInit), names[DMH_THIS]); } else { names[GET_MEMBER] = new Name(getFunction(NF_internalMemberName), names[DMH_THIS]); } assert(findDirectMethodHandle(names[GET_MEMBER]) == names[DMH_THIS]); Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class); if (needsReceiverCheck) { names[CHECK_RECEIVER] = new Name(getFunction(NF_checkReceiver), names[DMH_THIS], names[ARG_BASE]); outArgs[0] = names[CHECK_RECEIVER]; } assert(outArgs[outArgs.length-1] == names[GET_MEMBER]); // look, shifted args! int result = LAST_RESULT; if (doesAlloc) { assert(outArgs[outArgs.length-2] == names[NEW_OBJ]); // got to move this one System.arraycopy(outArgs, 0, outArgs, 1, outArgs.length-2); outArgs[0] = names[NEW_OBJ]; result = NEW_OBJ; } names[LINKER_CALL] = new Name(linker, outArgs); LambdaForm lform = new LambdaForm(ARG_LIMIT, names, result, kind); // This is a tricky bit of code. Don't send it through the LF interpreter. lform.compileToBytecode(); return lform; } /* assert */ static Object findDirectMethodHandle(Name name) { if (name.function.equals(getFunction(NF_internalMemberName)) || name.function.equals(getFunction(NF_internalMemberNameEnsureInit)) || name.function.equals(getFunction(NF_constructorMethod))) { assert(name.arguments.length == 1); return name.arguments[0]; } return null; } private static void maybeCompile(LambdaForm lform, MemberName m) { if (lform.vmentry == null && VerifyAccess.isSamePackage(m.getDeclaringClass(), MethodHandle.class)) // Help along bootstrapping... lform.compileToBytecode(); } /** Static wrapper for DirectMethodHandle.internalMemberName. */ @ForceInline /*non-public*/ static Object internalMemberName(Object mh) { return ((DirectMethodHandle)mh).member; } /** Static wrapper for DirectMethodHandle.internalMemberName. * This one also forces initialization. */ /*non-public*/ static Object internalMemberNameEnsureInit(Object mh) { DirectMethodHandle dmh = (DirectMethodHandle)mh; dmh.ensureInitialized(); return dmh.member; } /*non-public*/ static boolean shouldBeInitialized(MemberName member) { switch (member.getReferenceKind()) { case REF_invokeStatic: case REF_getStatic: case REF_putStatic: case REF_newInvokeSpecial: break; default: // No need to initialize the class on this kind of member. return false; } Class cls = member.getDeclaringClass(); if (cls == ValueConversions.class || cls == MethodHandleImpl.class || cls == Invokers.class) { // These guys have lots of DMH creation but we know // the MHs will not be used until the system is booted. return false; } if (VerifyAccess.isSamePackage(MethodHandle.class, cls) || VerifyAccess.isSamePackage(ValueConversions.class, cls)) { // It is a system class. It is probably in the process of // being initialized, but we will help it along just to be safe. if (UNSAFE.shouldBeInitialized(cls)) { UNSAFE.ensureClassInitialized(cls); } return false; } return UNSAFE.shouldBeInitialized(cls); } private static class EnsureInitialized extends ClassValue> { @Override protected WeakReference computeValue(Class type) { UNSAFE.ensureClassInitialized(type); if (UNSAFE.shouldBeInitialized(type)) // If the previous call didn't block, this can happen. // We are executing inside . return new WeakReference<>(Thread.currentThread()); return null; } static final EnsureInitialized INSTANCE = new EnsureInitialized(); } private void ensureInitialized() { if (checkInitialized(member)) { // The coast is clear. Delete the barrier. if (member.isField()) updateForm(preparedFieldLambdaForm(member)); else updateForm(preparedLambdaForm(member)); } } private static boolean checkInitialized(MemberName member) { Class defc = member.getDeclaringClass(); WeakReference ref = EnsureInitialized.INSTANCE.get(defc); if (ref == null) { return true; // the final state } Thread clinitThread = ref.get(); // Somebody may still be running defc.. if (clinitThread == Thread.currentThread()) { // If anybody is running defc., it is this thread. if (UNSAFE.shouldBeInitialized(defc)) // Yes, we are running it; keep the barrier for now. return false; } else { // We are in a random thread. Block. UNSAFE.ensureClassInitialized(defc); } assert(!UNSAFE.shouldBeInitialized(defc)); // put it into the final state EnsureInitialized.INSTANCE.remove(defc); return true; } /*non-public*/ static void ensureInitialized(Object mh) { ((DirectMethodHandle)mh).ensureInitialized(); } /** This subclass represents invokespecial instructions. */ static class Special extends DirectMethodHandle { private final Class caller; private Special(MethodType mtype, LambdaForm form, MemberName member, Class caller) { super(mtype, form, member); this.caller = caller; } @Override boolean isInvokeSpecial() { return true; } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { return new Special(mt, lf, member, caller); } Object checkReceiver(Object recv) { if (!caller.isInstance(recv)) { String msg = String.format("Receiver class %s is not a subclass of caller class %s", recv.getClass().getName(), caller.getName()); throw new IncompatibleClassChangeError(msg); } return recv; } } /** This subclass represents invokeinterface instructions. */ static class Interface extends DirectMethodHandle { private final Class refc; private Interface(MethodType mtype, LambdaForm form, MemberName member, Class refc) { super(mtype, form, member); assert refc.isInterface() : refc; this.refc = refc; } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { return new Interface(mt, lf, member, refc); } @Override Object checkReceiver(Object recv) { if (!refc.isInstance(recv)) { String msg = String.format("Receiver class %s does not implement the requested interface %s", recv.getClass().getName(), refc.getName()); throw new IncompatibleClassChangeError(msg); } return recv; } } /** Used for interface receiver type checks, by Interface and Special modes. */ Object checkReceiver(Object recv) { throw new InternalError("Should only be invoked on a subclass"); } /** This subclass handles constructor references. */ static class Constructor extends DirectMethodHandle { final MemberName initMethod; final Class instanceClass; private Constructor(MethodType mtype, LambdaForm form, MemberName constructor, MemberName initMethod, Class instanceClass) { super(mtype, form, constructor); this.initMethod = initMethod; this.instanceClass = instanceClass; assert(initMethod.isResolved()); } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { return new Constructor(mt, lf, member, initMethod, instanceClass); } } /*non-public*/ static Object constructorMethod(Object mh) { Constructor dmh = (Constructor)mh; return dmh.initMethod; } /*non-public*/ static Object allocateInstance(Object mh) throws InstantiationException { Constructor dmh = (Constructor)mh; return UNSAFE.allocateInstance(dmh.instanceClass); } /** This subclass handles non-static field references. */ static class Accessor extends DirectMethodHandle { final Class fieldType; final int fieldOffset; private Accessor(MethodType mtype, LambdaForm form, MemberName member, int fieldOffset) { super(mtype, form, member); this.fieldType = member.getFieldType(); this.fieldOffset = fieldOffset; } @Override Object checkCast(Object obj) { return fieldType.cast(obj); } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { return new Accessor(mt, lf, member, fieldOffset); } } @ForceInline /*non-public*/ static long fieldOffset(Object accessorObj) { // Note: We return a long because that is what Unsafe.getObject likes. // We store a plain int because it is more compact. return ((Accessor)accessorObj).fieldOffset; } @ForceInline /*non-public*/ static Object checkBase(Object obj) { // Note that the object's class has already been verified, // since the parameter type of the Accessor method handle // is either member.getDeclaringClass or a subclass. // This was verified in DirectMethodHandle.make. // Therefore, the only remaining check is for null. // Since this check is *not* guaranteed by Unsafe.getInt // and its siblings, we need to make an explicit one here. return Objects.requireNonNull(obj); } /** This subclass handles static field references. */ static class StaticAccessor extends DirectMethodHandle { private final Class fieldType; private final Object staticBase; private final long staticOffset; private StaticAccessor(MethodType mtype, LambdaForm form, MemberName member, Object staticBase, long staticOffset) { super(mtype, form, member); this.fieldType = member.getFieldType(); this.staticBase = staticBase; this.staticOffset = staticOffset; } @Override Object checkCast(Object obj) { return fieldType.cast(obj); } @Override MethodHandle copyWith(MethodType mt, LambdaForm lf) { return new StaticAccessor(mt, lf, member, staticBase, staticOffset); } } @ForceInline /*non-public*/ static Object nullCheck(Object obj) { return Objects.requireNonNull(obj); } @ForceInline /*non-public*/ static Object staticBase(Object accessorObj) { return ((StaticAccessor)accessorObj).staticBase; } @ForceInline /*non-public*/ static long staticOffset(Object accessorObj) { return ((StaticAccessor)accessorObj).staticOffset; } @ForceInline /*non-public*/ static Object checkCast(Object mh, Object obj) { return ((DirectMethodHandle) mh).checkCast(obj); } Object checkCast(Object obj) { return member.getReturnType().cast(obj); } // Caching machinery for field accessors: static final byte AF_GETFIELD = 0, AF_PUTFIELD = 1, AF_GETSTATIC = 2, AF_PUTSTATIC = 3, AF_GETSTATIC_INIT = 4, AF_PUTSTATIC_INIT = 5, AF_LIMIT = 6; // Enumerate the different field kinds using Wrapper, // with an extra case added for checked references. static final int FT_LAST_WRAPPER = Wrapper.COUNT-1, FT_UNCHECKED_REF = Wrapper.OBJECT.ordinal(), FT_CHECKED_REF = FT_LAST_WRAPPER+1, FT_LIMIT = FT_LAST_WRAPPER+2; private static int afIndex(byte formOp, boolean isVolatile, int ftypeKind) { return ((formOp * FT_LIMIT * 2) + (isVolatile ? FT_LIMIT : 0) + ftypeKind); } @Stable private static final LambdaForm[] ACCESSOR_FORMS = new LambdaForm[afIndex(AF_LIMIT, false, 0)]; static int ftypeKind(Class ftype) { if (ftype.isPrimitive()) return Wrapper.forPrimitiveType(ftype).ordinal(); else if (VerifyType.isNullReferenceConversion(Object.class, ftype)) return FT_UNCHECKED_REF; else return FT_CHECKED_REF; } /** * Create a LF which can access the given field. * Cache and share this structure among all fields with * the same basicType and refKind. */ private static LambdaForm preparedFieldLambdaForm(MemberName m) { Class ftype = m.getFieldType(); boolean isVolatile = m.isVolatile(); byte formOp; switch (m.getReferenceKind()) { case REF_getField: formOp = AF_GETFIELD; break; case REF_putField: formOp = AF_PUTFIELD; break; case REF_getStatic: formOp = AF_GETSTATIC; break; case REF_putStatic: formOp = AF_PUTSTATIC; break; default: throw new InternalError(m.toString()); } if (shouldBeInitialized(m)) { // precompute the barrier-free version: preparedFieldLambdaForm(formOp, isVolatile, ftype); assert((AF_GETSTATIC_INIT - AF_GETSTATIC) == (AF_PUTSTATIC_INIT - AF_PUTSTATIC)); formOp += (AF_GETSTATIC_INIT - AF_GETSTATIC); } LambdaForm lform = preparedFieldLambdaForm(formOp, isVolatile, ftype); maybeCompile(lform, m); assert(lform.methodType().dropParameterTypes(0, 1) .equals(m.getInvocationType().basicType())) : Arrays.asList(m, m.getInvocationType().basicType(), lform, lform.methodType()); return lform; } private static LambdaForm preparedFieldLambdaForm(byte formOp, boolean isVolatile, Class ftype) { int ftypeKind = ftypeKind(ftype); int afIndex = afIndex(formOp, isVolatile, ftypeKind); LambdaForm lform = ACCESSOR_FORMS[afIndex]; if (lform != null) return lform; lform = makePreparedFieldLambdaForm(formOp, isVolatile, ftypeKind); ACCESSOR_FORMS[afIndex] = lform; // don't bother with a CAS return lform; } private static final Wrapper[] ALL_WRAPPERS = Wrapper.values(); private static Kind getFieldKind(boolean isGetter, boolean isVolatile, Wrapper wrapper) { if (isGetter) { if (isVolatile) { switch (wrapper) { case BOOLEAN: return GET_BOOLEAN_VOLATILE; case BYTE: return GET_BYTE_VOLATILE; case SHORT: return GET_SHORT_VOLATILE; case CHAR: return GET_CHAR_VOLATILE; case INT: return GET_INT_VOLATILE; case LONG: return GET_LONG_VOLATILE; case FLOAT: return GET_FLOAT_VOLATILE; case DOUBLE: return GET_DOUBLE_VOLATILE; case OBJECT: return GET_OBJECT_VOLATILE; } } else { switch (wrapper) { case BOOLEAN: return GET_BOOLEAN; case BYTE: return GET_BYTE; case SHORT: return GET_SHORT; case CHAR: return GET_CHAR; case INT: return GET_INT; case LONG: return GET_LONG; case FLOAT: return GET_FLOAT; case DOUBLE: return GET_DOUBLE; case OBJECT: return GET_OBJECT; } } } else { if (isVolatile) { switch (wrapper) { case BOOLEAN: return PUT_BOOLEAN_VOLATILE; case BYTE: return PUT_BYTE_VOLATILE; case SHORT: return PUT_SHORT_VOLATILE; case CHAR: return PUT_CHAR_VOLATILE; case INT: return PUT_INT_VOLATILE; case LONG: return PUT_LONG_VOLATILE; case FLOAT: return PUT_FLOAT_VOLATILE; case DOUBLE: return PUT_DOUBLE_VOLATILE; case OBJECT: return PUT_OBJECT_VOLATILE; } } else { switch (wrapper) { case BOOLEAN: return PUT_BOOLEAN; case BYTE: return PUT_BYTE; case SHORT: return PUT_SHORT; case CHAR: return PUT_CHAR; case INT: return PUT_INT; case LONG: return PUT_LONG; case FLOAT: return PUT_FLOAT; case DOUBLE: return PUT_DOUBLE; case OBJECT: return PUT_OBJECT; } } } throw new AssertionError("Invalid arguments"); } static LambdaForm makePreparedFieldLambdaForm(byte formOp, boolean isVolatile, int ftypeKind) { boolean isGetter = (formOp & 1) == (AF_GETFIELD & 1); boolean isStatic = (formOp >= AF_GETSTATIC); boolean needsInit = (formOp >= AF_GETSTATIC_INIT); boolean needsCast = (ftypeKind == FT_CHECKED_REF); Wrapper fw = (needsCast ? Wrapper.OBJECT : ALL_WRAPPERS[ftypeKind]); Class ft = fw.primitiveType(); assert(ftypeKind(needsCast ? String.class : ft) == ftypeKind); // getObject, putIntVolatile, etc. Kind kind = getFieldKind(isGetter, isVolatile, fw); MethodType linkerType; if (isGetter) linkerType = MethodType.methodType(ft, Object.class, long.class); else linkerType = MethodType.methodType(void.class, Object.class, long.class, ft); MemberName linker = new MemberName(Unsafe.class, kind.methodName, linkerType, REF_invokeVirtual); try { linker = IMPL_NAMES.resolveOrFail(REF_invokeVirtual, linker, null, NoSuchMethodException.class); } catch (ReflectiveOperationException ex) { throw newInternalError(ex); } // What is the external type of the lambda form? MethodType mtype; if (isGetter) mtype = MethodType.methodType(ft); else mtype = MethodType.methodType(void.class, ft); mtype = mtype.basicType(); // erase short to int, etc. if (!isStatic) mtype = mtype.insertParameterTypes(0, Object.class); final int DMH_THIS = 0; final int ARG_BASE = 1; final int ARG_LIMIT = ARG_BASE + mtype.parameterCount(); // if this is for non-static access, the base pointer is stored at this index: final int OBJ_BASE = isStatic ? -1 : ARG_BASE; // if this is for write access, the value to be written is stored at this index: final int SET_VALUE = isGetter ? -1 : ARG_LIMIT - 1; int nameCursor = ARG_LIMIT; final int F_HOLDER = (isStatic ? nameCursor++ : -1); // static base if any final int F_OFFSET = nameCursor++; // Either static offset or field offset. final int OBJ_CHECK = (OBJ_BASE >= 0 ? nameCursor++ : -1); final int U_HOLDER = nameCursor++; // UNSAFE holder final int INIT_BAR = (needsInit ? nameCursor++ : -1); final int PRE_CAST = (needsCast && !isGetter ? nameCursor++ : -1); final int LINKER_CALL = nameCursor++; final int POST_CAST = (needsCast && isGetter ? nameCursor++ : -1); final int RESULT = nameCursor-1; // either the call or the cast Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType()); if (needsInit) names[INIT_BAR] = new Name(getFunction(NF_ensureInitialized), names[DMH_THIS]); if (needsCast && !isGetter) names[PRE_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[SET_VALUE]); Object[] outArgs = new Object[1 + linkerType.parameterCount()]; assert(outArgs.length == (isGetter ? 3 : 4)); outArgs[0] = names[U_HOLDER] = new Name(getFunction(NF_UNSAFE)); if (isStatic) { outArgs[1] = names[F_HOLDER] = new Name(getFunction(NF_staticBase), names[DMH_THIS]); outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_staticOffset), names[DMH_THIS]); } else { outArgs[1] = names[OBJ_CHECK] = new Name(getFunction(NF_checkBase), names[OBJ_BASE]); outArgs[2] = names[F_OFFSET] = new Name(getFunction(NF_fieldOffset), names[DMH_THIS]); } if (!isGetter) { outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]); } for (Object a : outArgs) assert(a != null); names[LINKER_CALL] = new Name(linker, outArgs); if (needsCast && isGetter) names[POST_CAST] = new Name(getFunction(NF_checkCast), names[DMH_THIS], names[LINKER_CALL]); for (Name n : names) assert(n != null); LambdaForm form; if (needsCast || needsInit) { // can't use the pre-generated form when casting and/or initializing form = new LambdaForm(ARG_LIMIT, names, RESULT); } else { form = new LambdaForm(ARG_LIMIT, names, RESULT, kind); } if (LambdaForm.debugNames()) { // add some detail to the lambdaForm debugname, // significant only for debugging StringBuilder nameBuilder = new StringBuilder(kind.methodName); if (isStatic) { nameBuilder.append("Static"); } else { nameBuilder.append("Field"); } if (needsCast) { nameBuilder.append("Cast"); } if (needsInit) { nameBuilder.append("Init"); } LambdaForm.associateWithDebugName(form, nameBuilder.toString()); } return form; } /** * Pre-initialized NamedFunctions for bootstrapping purposes. */ static final byte NF_internalMemberName = 0, NF_internalMemberNameEnsureInit = 1, NF_ensureInitialized = 2, NF_fieldOffset = 3, NF_checkBase = 4, NF_staticBase = 5, NF_staticOffset = 6, NF_checkCast = 7, NF_allocateInstance = 8, NF_constructorMethod = 9, NF_UNSAFE = 10, NF_checkReceiver = 11, NF_LIMIT = 12; private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT]; private static NamedFunction getFunction(byte func) { NamedFunction nf = NFS[func]; if (nf != null) { return nf; } // Each nf must be statically invocable or we get tied up in our bootstraps. nf = NFS[func] = createFunction(func); assert(InvokerBytecodeGenerator.isStaticallyInvocable(nf)); return nf; } private static final MethodType OBJ_OBJ_TYPE = MethodType.methodType(Object.class, Object.class); private static final MethodType LONG_OBJ_TYPE = MethodType.methodType(long.class, Object.class); private static NamedFunction createFunction(byte func) { try { switch (func) { case NF_internalMemberName: return getNamedFunction("internalMemberName", OBJ_OBJ_TYPE); case NF_internalMemberNameEnsureInit: return getNamedFunction("internalMemberNameEnsureInit", OBJ_OBJ_TYPE); case NF_ensureInitialized: return getNamedFunction("ensureInitialized", MethodType.methodType(void.class, Object.class)); case NF_fieldOffset: return getNamedFunction("fieldOffset", LONG_OBJ_TYPE); case NF_checkBase: return getNamedFunction("checkBase", OBJ_OBJ_TYPE); case NF_staticBase: return getNamedFunction("staticBase", OBJ_OBJ_TYPE); case NF_staticOffset: return getNamedFunction("staticOffset", LONG_OBJ_TYPE); case NF_checkCast: return getNamedFunction("checkCast", MethodType.methodType(Object.class, Object.class, Object.class)); case NF_allocateInstance: return getNamedFunction("allocateInstance", OBJ_OBJ_TYPE); case NF_constructorMethod: return getNamedFunction("constructorMethod", OBJ_OBJ_TYPE); case NF_UNSAFE: MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getField); return new NamedFunction( MemberName.getFactory() .resolveOrFail(REF_getField, member, DirectMethodHandle.class, NoSuchMethodException.class)); case NF_checkReceiver: member = new MemberName(DirectMethodHandle.class, "checkReceiver", OBJ_OBJ_TYPE, REF_invokeVirtual); return new NamedFunction( MemberName.getFactory() .resolveOrFail(REF_invokeVirtual, member, DirectMethodHandle.class, NoSuchMethodException.class)); default: throw newInternalError("Unknown function: " + func); } } catch (ReflectiveOperationException ex) { throw newInternalError(ex); } } private static NamedFunction getNamedFunction(String name, MethodType type) throws ReflectiveOperationException { MemberName member = new MemberName(DirectMethodHandle.class, name, type, REF_invokeStatic); return new NamedFunction( MemberName.getFactory() .resolveOrFail(REF_invokeStatic, member, DirectMethodHandle.class, NoSuchMethodException.class)); } static { // The Holder class will contain pre-generated DirectMethodHandles resolved // speculatively using MemberName.getFactory().resolveOrNull. However, that // doesn't initialize the class, which subtly breaks inlining etc. By forcing // initialization of the Holder class we avoid these issues. UNSAFE.ensureClassInitialized(Holder.class); } /* Placeholder class for DirectMethodHandles generated ahead of time */ final class Holder {} }