/*
* Copyright (c) 2008, 2012, 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package java.lang.invoke;
import java.util.Arrays;
import sun.invoke.empty.Empty;
import static java.lang.invoke.MethodHandleStatics.*;
import static java.lang.invoke.MethodHandleNatives.Constants.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
import static java.lang.invoke.LambdaForm.*;
/**
* Construction and caching of often-used invokers.
* @author jrose
*/
class Invokers {
// exact type (sans leading taget MH) for the outgoing call
private final MethodType targetType;
// FIXME: Get rid of the invokers that are not useful.
// exact invoker for the outgoing call
private /*lazy*/ MethodHandle exactInvoker;
// erased (partially untyped but with primitives) invoker for the outgoing call
// FIXME: get rid of
private /*lazy*/ MethodHandle erasedInvoker;
// FIXME: get rid of
/*lazy*/ MethodHandle erasedInvokerWithDrops; // for InvokeGeneric
// general invoker for the outgoing call
private /*lazy*/ MethodHandle generalInvoker;
// general invoker for the outgoing call, uses varargs
private /*lazy*/ MethodHandle varargsInvoker;
// general invoker for the outgoing call; accepts a trailing Object[]
private final /*lazy*/ MethodHandle[] spreadInvokers;
// invoker for an unbound callsite
private /*lazy*/ MethodHandle uninitializedCallSite;
/** Compute and cache information common to all collecting adapters
* that implement members of the erasure-family of the given erased type.
*/
/*non-public*/ Invokers(MethodType targetType) {
this.targetType = targetType;
this.spreadInvokers = new MethodHandle[targetType.parameterCount()+1];
}
/*non-public*/ MethodHandle exactInvoker() {
MethodHandle invoker = exactInvoker;
if (invoker != null) return invoker;
MethodType mtype = targetType;
MethodType invokerType = mtype.invokerType();
LambdaForm lform;
final int MTYPE_ARG_APPENDED = 1; // argument count for appended mtype value
if (mtype.parameterSlotCount() <= MethodType.MAX_MH_INVOKER_ARITY - MTYPE_ARG_APPENDED) {
lform = invokeForm(mtype, false, MethodTypeForm.LF_EX_INVOKER);
invoker = BoundMethodHandle.bindSingle(invokerType, lform, mtype);
} else {
// At maximum arity, we cannot afford an extra mtype argument,
// so build a fully customized (non-cached) invoker form.
lform = invokeForm(mtype, true, MethodTypeForm.LF_EX_INVOKER);
invoker = SimpleMethodHandle.make(invokerType, lform);
}
invoker = invoker.withInternalMemberName(MemberName.makeMethodHandleInvoke("invokeExact", mtype));
assert(checkInvoker(invoker));
exactInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle generalInvoker() {
MethodHandle invoker = generalInvoker;
if (invoker != null) return invoker;
MethodType mtype = targetType;
MethodType invokerType = mtype.invokerType();
LambdaForm lform;
final int MTYPE_ARG_APPENDED = 1; // argument count for appended mtype value
assert(GENERIC_INVOKER_SLOP >= MTYPE_ARG_APPENDED);
if (mtype.parameterSlotCount() <= MethodType.MAX_MH_INVOKER_ARITY - GENERIC_INVOKER_SLOP) {
prepareForGenericCall(mtype);
lform = invokeForm(mtype, false, MethodTypeForm.LF_GEN_INVOKER);
invoker = BoundMethodHandle.bindSingle(invokerType, lform, mtype);
} else {
// At maximum arity, we cannot afford an extra mtype argument,
// so build a fully customized (non-cached) invoker form.
lform = invokeForm(mtype, true, MethodTypeForm.LF_GEN_INVOKER);
invoker = SimpleMethodHandle.make(invokerType, lform);
}
invoker = invoker.withInternalMemberName(MemberName.makeMethodHandleInvoke("invoke", mtype));
assert(checkInvoker(invoker));
generalInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle makeBasicInvoker() {
MethodHandle invoker = DirectMethodHandle.make(invokeBasicMethod(targetType));
assert(targetType == targetType.basicType());
// Note: This is not cached here. It is cached by the calling MethodTypeForm.
assert(checkInvoker(invoker));
return invoker;
}
static MemberName invokeBasicMethod(MethodType type) {
type = type.basicType();
String name = "invokeBasic";
try {
//Lookup.findVirtual(MethodHandle.class, name, type);
return IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, MethodHandle.class, name, type);
} catch (ReflectiveOperationException ex) {
throw newInternalError("JVM cannot find invoker for "+type, ex);
}
}
private boolean checkInvoker(MethodHandle invoker) {
assert(targetType.invokerType().equals(invoker.type()))
: java.util.Arrays.asList(targetType, targetType.invokerType(), invoker);
assert(invoker.internalMemberName() == null ||
invoker.internalMemberName().getMethodType().equals(targetType));
assert(!invoker.isVarargsCollector());
return true;
}
// FIXME: get rid of
/*non-public*/ MethodHandle erasedInvoker() {
MethodHandle xinvoker = exactInvoker();
MethodHandle invoker = erasedInvoker;
if (invoker != null) return invoker;
MethodType erasedType = targetType.erase();
invoker = xinvoker.asType(erasedType.invokerType());
erasedInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle spreadInvoker(int leadingArgCount) {
MethodHandle vaInvoker = spreadInvokers[leadingArgCount];
if (vaInvoker != null) return vaInvoker;
int spreadArgCount = targetType.parameterCount() - leadingArgCount;
MethodType spreadInvokerType = targetType
.replaceParameterTypes(leadingArgCount, targetType.parameterCount(), Object[].class);
if (targetType.parameterSlotCount() <= MethodType.MAX_MH_INVOKER_ARITY) {
// Factor sinvoker.invoke(mh, a) into ginvoker.asSpreader().invoke(mh, a)
// where ginvoker.invoke(mh, a*) => mh.invoke(a*).
MethodHandle genInvoker = generalInvoker();
vaInvoker = genInvoker.asSpreader(Object[].class, spreadArgCount);
} else {
// Cannot build a general invoker here of type ginvoker.invoke(mh, a*[254]).
// Instead, factor sinvoker.invoke(mh, a) into ainvoker.invoke(filter(mh), a)
// where filter(mh) == mh.asSpreader(Object[], spreadArgCount)
MethodHandle arrayInvoker = MethodHandles.exactInvoker(spreadInvokerType);
MethodHandle makeSpreader;
try {
makeSpreader = IMPL_LOOKUP
.findVirtual(MethodHandle.class, "asSpreader",
MethodType.methodType(MethodHandle.class, Class.class, int.class));
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
makeSpreader = MethodHandles.insertArguments(makeSpreader, 1, Object[].class, spreadArgCount);
vaInvoker = MethodHandles.filterArgument(arrayInvoker, 0, makeSpreader);
}
assert(vaInvoker.type().equals(spreadInvokerType.invokerType()));
spreadInvokers[leadingArgCount] = vaInvoker;
return vaInvoker;
}
/*non-public*/ MethodHandle varargsInvoker() {
MethodHandle vaInvoker = varargsInvoker;
if (vaInvoker != null) return vaInvoker;
vaInvoker = spreadInvoker(0).asType(MethodType.genericMethodType(0, true).invokerType());
varargsInvoker = vaInvoker;
return vaInvoker;
}
private static MethodHandle THROW_UCS = null;
/*non-public*/ MethodHandle uninitializedCallSite() {
MethodHandle invoker = uninitializedCallSite;
if (invoker != null) return invoker;
if (targetType.parameterCount() > 0) {
MethodType type0 = targetType.dropParameterTypes(0, targetType.parameterCount());
Invokers invokers0 = type0.invokers();
invoker = MethodHandles.dropArguments(invokers0.uninitializedCallSite(),
0, targetType.parameterList());
assert(invoker.type().equals(targetType));
uninitializedCallSite = invoker;
return invoker;
}
invoker = THROW_UCS;
if (invoker == null) {
try {
THROW_UCS = invoker = IMPL_LOOKUP
.findStatic(CallSite.class, "uninitializedCallSite",
MethodType.methodType(Empty.class));
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
}
invoker = MethodHandles.explicitCastArguments(invoker, MethodType.methodType(targetType.returnType()));
invoker = invoker.dropArguments(targetType, 0, targetType.parameterCount());
assert(invoker.type().equals(targetType));
uninitializedCallSite = invoker;
return invoker;
}
public String toString() {
return "Invokers"+targetType;
}
static MemberName exactInvokerMethod(MethodType mtype, Object[] appendixResult) {
LambdaForm lform;
final int MTYPE_ARG_APPENDED = 1; // argument count for appended mtype value
if (mtype.parameterSlotCount() <= MethodType.MAX_MH_ARITY - MTYPE_ARG_APPENDED) {
lform = invokeForm(mtype, false, MethodTypeForm.LF_EX_LINKER);
appendixResult[0] = mtype;
} else {
lform = invokeForm(mtype, true, MethodTypeForm.LF_EX_LINKER);
}
return lform.vmentry;
}
static MemberName genericInvokerMethod(MethodType mtype, Object[] appendixResult) {
LambdaForm lform;
final int MTYPE_ARG_APPENDED = 1; // argument count for appended mtype value
if (mtype.parameterSlotCount() <= MethodType.MAX_MH_ARITY - (MTYPE_ARG_APPENDED + GENERIC_INVOKER_SLOP)) {
lform = invokeForm(mtype, false, MethodTypeForm.LF_GEN_LINKER);
appendixResult[0] = mtype;
prepareForGenericCall(mtype);
} else {
lform = invokeForm(mtype, true, MethodTypeForm.LF_GEN_LINKER);
}
return lform.vmentry;
}
private static LambdaForm invokeForm(MethodType mtype, boolean customized, int which) {
boolean isCached;
if (!customized) {
mtype = mtype.basicType(); // normalize Z to I, String to Object, etc.
isCached = true;
} else {
isCached = false; // maybe cache if mtype == mtype.basicType()
}
boolean isLinker, isGeneric;
String debugName;
switch (which) {
case MethodTypeForm.LF_EX_LINKER: isLinker = true; isGeneric = false; debugName = "invokeExact_MT"; break;
case MethodTypeForm.LF_EX_INVOKER: isLinker = false; isGeneric = false; debugName = "exactInvoker"; break;
case MethodTypeForm.LF_GEN_LINKER: isLinker = true; isGeneric = true; debugName = "invoke_MT"; break;
case MethodTypeForm.LF_GEN_INVOKER: isLinker = false; isGeneric = true; debugName = "invoker"; break;
default: throw new InternalError();
}
LambdaForm lform;
if (isCached) {
lform = mtype.form().cachedLambdaForm(which);
if (lform != null) return lform;
}
// exactInvokerForm (Object,Object)Object
// link with java.lang.invoke.MethodHandle.invokeBasic(MethodHandle,Object,Object)Object/invokeSpecial
final int THIS_MH = 0;
final int CALL_MH = THIS_MH + (isLinker ? 0 : 1);
final int ARG_BASE = CALL_MH + 1;
final int OUTARG_LIMIT = ARG_BASE + mtype.parameterCount();
final int INARG_LIMIT = OUTARG_LIMIT + (isLinker && !customized ? 1 : 0);
int nameCursor = OUTARG_LIMIT;
final int MTYPE_ARG = customized ? -1 : nameCursor++; // might be last in-argument
final int CHECK_TYPE = nameCursor++;
final int LINKER_CALL = nameCursor++;
MethodType invokerFormType = mtype.invokerType();
if (isLinker) {
if (!customized)
invokerFormType = invokerFormType.appendParameterTypes(MemberName.class);
} else {
invokerFormType = invokerFormType.invokerType();
}
Name[] names = arguments(nameCursor - INARG_LIMIT, invokerFormType);
assert(names.length == nameCursor)
: Arrays.asList(mtype, customized, which, nameCursor, names.length);
if (MTYPE_ARG >= INARG_LIMIT) {
assert(names[MTYPE_ARG] == null);
names[MTYPE_ARG] = BoundMethodHandle.getSpeciesData("L").getterName(names[THIS_MH], 0);
// else if isLinker, then MTYPE is passed in from the caller (e.g., the JVM)
}
// Make the final call. If isGeneric, then prepend the result of type checking.
MethodType outCallType;
Object[] outArgs;
Object mtypeArg = (customized ? mtype : names[MTYPE_ARG]);
if (!isGeneric) {
names[CHECK_TYPE] = new Name(NF_checkExactType, names[CALL_MH], mtypeArg);
// mh.invokeExact(a*):R => checkExactType(mh, TYPEOF(a*:R)); mh.invokeBasic(a*)
outArgs = Arrays.copyOfRange(names, CALL_MH, OUTARG_LIMIT, Object[].class);
outCallType = mtype;
} else if (customized) {
names[CHECK_TYPE] = new Name(NF_asType, names[CALL_MH], mtypeArg);
// mh.invokeGeneric(a*):R =>
// let mt=TYPEOF(a*:R), tmh=asType(mh, mt);
// tmh.invokeBasic(a*)
outArgs = Arrays.copyOfRange(names, CALL_MH, OUTARG_LIMIT, Object[].class);
outCallType = mtype;
} else {
names[CHECK_TYPE] = new Name(NF_checkGenericType, names[CALL_MH], mtypeArg);
// mh.invokeGeneric(a*):R =>
// let mt=TYPEOF(a*:R), gamh=checkGenericType(mh, mt);
// gamh.invokeBasic(mt, mh, a*)
final int PREPEND_GAMH = 0, PREPEND_MT = 1, PREPEND_COUNT = 2;
assert(GENERIC_INVOKER_SLOP == PREPEND_COUNT);
outArgs = Arrays.copyOfRange(names, CALL_MH, OUTARG_LIMIT + PREPEND_COUNT, Object[].class);
// prepend arguments:
System.arraycopy(outArgs, 0, outArgs, PREPEND_COUNT, outArgs.length - PREPEND_COUNT);
outArgs[PREPEND_GAMH] = names[CHECK_TYPE];
outArgs[PREPEND_MT] = mtypeArg;
outCallType = mtype.insertParameterTypes(0, MethodType.class, MethodHandle.class);
}
names[LINKER_CALL] = new Name(invokeBasicMethod(outCallType), outArgs);
lform = new LambdaForm(debugName, INARG_LIMIT, names);
if (isLinker)
lform.compileToBytecode(); // JVM needs a real methodOop
if (isCached)
lform = mtype.form().setCachedLambdaForm(which, lform);
return lform;
}
private static final int GENERIC_INVOKER_SLOP = 2; // used elsewhere to avoid arity problems
/*non-public*/ static
WrongMethodTypeException newWrongMethodTypeException(MethodType actual, MethodType expected) {
// FIXME: merge with JVM logic for throwing WMTE
return new WrongMethodTypeException("expected "+expected+" but found "+actual);
}
/** Static definition of MethodHandle.invokeExact checking code. */
/*non-public*/ static
@ForceInline
void checkExactType(Object mhObj, Object expectedObj) {
MethodHandle mh = (MethodHandle) mhObj;
MethodType expected = (MethodType) expectedObj;
MethodType actual = mh.type();
if (actual != expected)
throw newWrongMethodTypeException(expected, actual);
}
/** Static definition of MethodHandle.invokeGeneric checking code. */
/*non-public*/ static
@ForceInline
Object checkGenericType(Object mhObj, Object expectedObj) {
MethodHandle mh = (MethodHandle) mhObj;
MethodType expected = (MethodType) expectedObj;
//MethodType actual = mh.type();
MethodHandle gamh = expected.form().genericInvoker;
if (gamh != null) return gamh;
return prepareForGenericCall(expected);
}
/**
* Returns an adapter GA for invoking a MH with type adjustments.
* The MethodType of the generic invocation site is prepended to MH
* and its arguments as follows:
* {@code (R)MH.invoke(A*) => GA.invokeBasic(TYPEOF<A*,R>, MH, A*)}
*/
/*non-public*/ static MethodHandle prepareForGenericCall(MethodType mtype) {
// force any needed adapters to be preconstructed
MethodTypeForm form = mtype.form();
MethodHandle gamh = form.genericInvoker;
if (gamh != null) return gamh;
try {
// Trigger adapter creation.
gamh = InvokeGeneric.generalInvokerOf(form.erasedType);
form.genericInvoker = gamh;
return gamh;
} catch (Exception ex) {
throw newInternalError("Exception while resolving inexact invoke", ex);
}
}
static MemberName linkToCallSiteMethod(MethodType mtype) {
LambdaForm lform = callSiteForm(mtype);
return lform.vmentry;
}
private static LambdaForm callSiteForm(MethodType mtype) {
mtype = mtype.basicType(); // normalize Z to I, String to Object, etc.
LambdaForm lform = mtype.form().cachedLambdaForm(MethodTypeForm.LF_CS_LINKER);
if (lform != null) return lform;
// exactInvokerForm (Object,Object)Object
// link with java.lang.invoke.MethodHandle.invokeBasic(MethodHandle,Object,Object)Object/invokeSpecial
final int ARG_BASE = 0;
final int OUTARG_LIMIT = ARG_BASE + mtype.parameterCount();
final int INARG_LIMIT = OUTARG_LIMIT + 1;
int nameCursor = OUTARG_LIMIT;
final int CSITE_ARG = nameCursor++; // the last in-argument
final int CALL_MH = nameCursor++; // result of getTarget
final int LINKER_CALL = nameCursor++;
MethodType invokerFormType = mtype.appendParameterTypes(CallSite.class);
Name[] names = arguments(nameCursor - INARG_LIMIT, invokerFormType);
assert(names.length == nameCursor);
assert(names[CSITE_ARG] != null);
names[CALL_MH] = new Name(NF_getCallSiteTarget, names[CSITE_ARG]);
// (site.)invokedynamic(a*):R => mh = site.getTarget(); mh.invokeBasic(a*)
final int PREPEND_MH = 0, PREPEND_COUNT = 1;
Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, OUTARG_LIMIT + PREPEND_COUNT, Object[].class);
// prepend MH argument:
System.arraycopy(outArgs, 0, outArgs, PREPEND_COUNT, outArgs.length - PREPEND_COUNT);
outArgs[PREPEND_MH] = names[CALL_MH];
names[LINKER_CALL] = new Name(invokeBasicMethod(mtype), outArgs);
lform = new LambdaForm("linkToCallSite", INARG_LIMIT, names);
lform.compileToBytecode(); // JVM needs a real methodOop
lform = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_CS_LINKER, lform);
return lform;
}
/** Static definition of MethodHandle.invokeGeneric checking code. */
/*non-public*/ static
@ForceInline
Object getCallSiteTarget(Object site) {
return ((CallSite)site).getTarget();
}
// Local constant functions:
private static final NamedFunction NF_checkExactType;
private static final NamedFunction NF_checkGenericType;
private static final NamedFunction NF_asType;
private static final NamedFunction NF_getCallSiteTarget;
static {
try {
NF_checkExactType = new NamedFunction(Invokers.class
.getDeclaredMethod("checkExactType", Object.class, Object.class));
NF_checkGenericType = new NamedFunction(Invokers.class
.getDeclaredMethod("checkGenericType", Object.class, Object.class));
NF_asType = new NamedFunction(MethodHandle.class
.getDeclaredMethod("asType", MethodType.class));
NF_getCallSiteTarget = new NamedFunction(Invokers.class
.getDeclaredMethod("getCallSiteTarget", Object.class));
NF_checkExactType.resolve();
NF_checkGenericType.resolve();
NF_getCallSiteTarget.resolve();
// bound
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
}
}