1 /*
   2  * Copyright (c) 2010, 2014, 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.runtime;
  27 
  28 import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
  29 import jdk.nashorn.internal.objects.annotations.SpecializedFunction.LinkLogic;
  30 
  31 /**
  32  * This is an interface for classes that need custom linkage logic. This means Native objects
  33  * that contain optimistic native methods, that need special/extra rules for linking, guards and
  34  * SwitchPointing, known and internal to the Native object for its linkage
  35  */
  36 public interface OptimisticBuiltins {
  37 
  38     /**
  39      * Return an instance of the linking logic we need for a particular LinkLogic
  40      * subclass, gotten from the compile time annotation of a specialized builtin method
  41      * No assumptions can be made about the lifetime of the instance. The receiver may
  42      * keep it as a perpetual final instance field or create new linking logic depending
  43      * on its current state for each call, depending on if the global state has changed
  44      * or other factors
  45      *
  46      * @param clazz linking logic class
  47      * @return linking logic instance for this class
  48      */
  49     public SpecializedFunction.LinkLogic getLinkLogic(final Class<? extends LinkLogic> clazz);
  50 
  51     /**
  52      * Does this link logic vary depending on which instance we are working with.
  53      * Then we have to sort out certain primitives, as they are created as new
  54      * objects in the wrapFilter by JavaScript semantics. An example of instance only
  55      * assumptions are switchPoints per instance, as in NativeArray. NativeString is
  56      * fine, as it's only static.
  57      *
  58      * TODO: finer granularity on this, on the function level so certain functions
  59      * are forbidden only. Currently we don't have enough specialization to bump into this
  60      *
  61      * @return true if there are per instance assumptions for the optimism
  62      */
  63     public boolean hasPerInstanceAssumptions();
  64 
  65 }