/* * Copyright (c) 2008, 2011, 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.dyn; import sun.dyn.empty.Empty; import static java.dyn.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 // generic (untyped) invoker for the outgoing call private /*lazy*/ MethodHandle genericInvoker; // generic (untyped) invoker for the outgoing call; accepts a single 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; try { invoker = IMPL_LOOKUP.findVirtual(MethodHandle.class, "invokeExact", targetType); } catch (ReflectiveOperationException ex) { throw new InternalError("JVM cannot find invoker for "+targetType); } assert(invokerType(targetType) == invoker.type()); exactInvoker = invoker; return invoker; } /*non-public*/ MethodHandle genericInvoker() { MethodHandle invoker1 = exactInvoker(); MethodHandle invoker = genericInvoker; if (invoker != null) return invoker; MethodType genericType = targetType.generic(); invoker = MethodHandles.convertArguments(invoker1, invokerType(genericType)); genericInvoker = invoker; return invoker; } /*non-public*/ MethodHandle erasedInvoker() { MethodHandle invoker1 = exactInvoker(); MethodHandle invoker = erasedInvoker; if (invoker != null) return invoker; MethodType erasedType = targetType.erase(); if (erasedType == targetType.generic()) invoker = genericInvoker(); else invoker = MethodHandles.convertArguments(invoker1, invokerType(erasedType)); erasedInvoker = invoker; return invoker; } /*non-public*/ MethodHandle spreadInvoker(int objectArgCount) { MethodHandle vaInvoker = spreadInvokers[objectArgCount]; if (vaInvoker != null) return vaInvoker; MethodHandle gInvoker = genericInvoker(); vaInvoker = gInvoker.asSpreader(Object[].class, targetType.parameterCount() - objectArgCount); spreadInvokers[objectArgCount] = 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; } }