1 /*
   2  * Copyright (c) 2010, 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.nashorn.internal.objects.annotations;
  27 
  28 import java.lang.annotation.ElementType;
  29 import java.lang.annotation.Retention;
  30 import java.lang.annotation.RetentionPolicy;
  31 import java.lang.annotation.Target;
  32 
  33 /**
  34  * The Optimistic annotation is used for builtins that can throw UnwarrantedOptimism
  35  * exception if they are wrong, whose callsite is optimistic and contains a program
  36  * point. Every optimistic builtin callsite needs to bind its programPoint to an
  37  * argument of the implementation at compile time
  38  *
  39  * Typical use case would be something like: if you want to do an optimistic "push" function
  40  * in NativeArray that takes an int, write
  41  *
  42  *  <pre>
  43  *  {@literal @}SpecializedFunction {@literal @}Optimistic
  44  *  public static int push(final Object self, final int x, final int programPoint) {
  45  *    try {
  46  *    //push code assuming that this is an int array
  47  *    //return new length of array, assuming it's an int
  48  *    } catch (ArrayWasWrong e) {
  49  *       //undo any array modifications
  50  *       throw new UnwarrantedOptimismExceptionArrayType(x, programPoint);
  51  *    } catch (LengthOverFlowed e) {
  52  *       //undo any array modifications
  53  *       throw new UnwarratnedOptimismExceptionArrayLength(uint32lenThatOverFlowed, programPoint)
  54  *    }
  55  *  }
  56  *  </pre>
  57  */
  58 @Retention(RetentionPolicy.RUNTIME)
  59 @Target(ElementType.METHOD)
  60 public @interface Optimistic {
  61     //empty
  62 }