/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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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package jdk.internal.reflect;

import sun.reflect.misc.ReflectUtil;

import java.lang.reflect.*;
import jdk.internal.misc.Unsafe;

Used only for the first few invocations of a Method; afterward, switches to bytecode-based implementation
/** Used only for the first few invocations of a Method; afterward, switches to bytecode-based implementation */
class NativeMethodAccessorImpl extends MethodAccessorImpl { private static final Unsafe U = Unsafe.getUnsafe(); private static final long GENERATED_OFFSET = U.objectFieldOffset(NativeMethodAccessorImpl.class, "generated"); private final Method method; private DelegatingMethodAccessorImpl parent; private int numInvocations; private volatile int generated; NativeMethodAccessorImpl(Method method) { this.method = method; } public Object invoke(Object obj, Object[] args) throws IllegalArgumentException, InvocationTargetException { // We can't inflate methods belonging to vm-anonymous classes because // that kind of class can't be referred to by name, hence can't be // found from the generated bytecode. if (++numInvocations > ReflectionFactory.inflationThreshold() && !method.getDeclaringClass().isHidden() && !ReflectUtil.isVMAnonymousClass(method.getDeclaringClass()) && generated == 0 && U.compareAndSetInt(this, GENERATED_OFFSET, 0, 1)) { try { MethodAccessorImpl acc = (MethodAccessorImpl) new MethodAccessorGenerator(). generateMethod(method.getDeclaringClass(), method.getName(), method.getParameterTypes(), method.getReturnType(), method.getExceptionTypes(), method.getModifiers()); parent.setDelegate(acc); } catch (Throwable t) { // Throwable happens in generateMethod, restore generated to 0 generated = 0; throw t; } } return invoke0(method, obj, args); } void setParent(DelegatingMethodAccessorImpl parent) { this.parent = parent; } private static native Object invoke0(Method m, Object obj, Object[] args); }