1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal.reflect;
  27 
  28 import java.lang.reflect.*;
  29 
  30 import jdk.internal.misc.Strands;
  31 import jdk.internal.misc.VM;
  32 import sun.reflect.misc.ReflectUtil;
  33 
  34 /** Used only for the first few invocations of a Method; afterward,
  35     switches to bytecode-based implementation */
  36 
  37 class NativeMethodAccessorImpl extends MethodAccessorImpl {
  38     private final Method method;
  39     private DelegatingMethodAccessorImpl parent;
  40     private int numInvocations;
  41 
  42     NativeMethodAccessorImpl(Method method) {
  43         this.method = method;
  44     }
  45 
  46     public Object invoke(Object obj, Object[] args)
  47         throws IllegalArgumentException, InvocationTargetException
  48     {
  49         // We can't inflate methods belonging to vm-anonymous classes because
  50         // that kind of class can't be referred to by name, hence can't be
  51         // found from the generated bytecode.
  52         if (VM.isBooted() && (++numInvocations > ReflectionFactory.inflationThreshold()
  53                 || Strands.currentStrand() instanceof Fiber)
  54                     && !ReflectUtil.isVMAnonymousClass(method.getDeclaringClass())) {
  55             MethodAccessorImpl acc = (MethodAccessorImpl)
  56                 new MethodAccessorGenerator().
  57                     generateMethod(method.getDeclaringClass(),
  58                                    method.getName(),
  59                                    method.getParameterTypes(),
  60                                    method.getReturnType(),
  61                                    method.getExceptionTypes(),
  62                                    method.getModifiers());
  63             parent.setDelegate(acc);
  64             return acc.invoke(obj, args);
  65         }
  66 
  67         return invoke0(method, obj, args);
  68     }
  69 
  70     void setParent(DelegatingMethodAccessorImpl parent) {
  71         this.parent = parent;
  72     }
  73 
  74     private static native Object invoke0(Method m, Object obj, Object[] args);
  75 }