7032323: code changes for JSR 292 EG adjustments to API, through Public Review
Summary: API code changes and javadoc changes following JSR 292 Public Review comments, through PFD
Reviewed-by: never
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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 sun.invoke.empty.Empty;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
/**
* 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;
// exact invoker for the outgoing call
private /*lazy*/ MethodHandle exactInvoker;
// erased (partially untyped but with primitives) invoker for the outgoing call
private /*lazy*/ MethodHandle erasedInvoker;
/*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*/ static MethodType invokerType(MethodType targetType) {
return targetType.insertParameterTypes(0, MethodHandle.class);
}
/*non-public*/ MethodHandle exactInvoker() {
MethodHandle invoker = exactInvoker;
if (invoker != null) return invoker;
invoker = lookupInvoker("invokeExact");
exactInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle generalInvoker() {
MethodHandle invoker = generalInvoker;
if (invoker != null) return invoker;
invoker = lookupInvoker("invoke");
generalInvoker = invoker;
return invoker;
}
private MethodHandle lookupInvoker(String name) {
MethodHandle invoker;
try {
invoker = IMPL_LOOKUP.findVirtual(MethodHandle.class, name, targetType);
} catch (ReflectiveOperationException ex) {
throw new InternalError("JVM cannot find invoker for "+targetType);
}
assert(invokerType(targetType) == invoker.type());
assert(!invoker.isVarargsCollector());
return invoker;
}
/*non-public*/ MethodHandle erasedInvoker() {
MethodHandle xinvoker = exactInvoker();
MethodHandle invoker = erasedInvoker;
if (invoker != null) return invoker;
MethodType erasedType = targetType.erase();
invoker = xinvoker.asType(invokerType(erasedType));
erasedInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle spreadInvoker(int leadingArgCount) {
MethodHandle vaInvoker = spreadInvokers[leadingArgCount];
if (vaInvoker != null) return vaInvoker;
MethodHandle gInvoker = generalInvoker();
int spreadArgCount = targetType.parameterCount() - leadingArgCount;
vaInvoker = gInvoker.asSpreader(Object[].class, spreadArgCount);
spreadInvokers[leadingArgCount] = vaInvoker;
return vaInvoker;
}
/*non-public*/ MethodHandle varargsInvoker() {
MethodHandle vaInvoker = varargsInvoker;
if (vaInvoker != null) return vaInvoker;
vaInvoker = spreadInvoker(0).asType(invokerType(MethodType.genericMethodType(0, true)));
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;
}
if (THROW_UCS == null) {
try {
THROW_UCS = IMPL_LOOKUP
.findStatic(CallSite.class, "uninitializedCallSite",
MethodType.methodType(Empty.class));
} catch (ReflectiveOperationException ex) {
throw new RuntimeException(ex);
}
}
invoker = AdapterMethodHandle.makeRetypeRaw(targetType, THROW_UCS);
assert(invoker.type().equals(targetType));
uninitializedCallSite = invoker;
return invoker;
}
public String toString() {
return "Invokers"+targetType;
}
}