delta.hpp

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/* Copyright 1994, LongView Technologies L.L.C. $Revision: 1.5 $ */
/* Copyright (c) 2006, Sun Microsystems, Inc.
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// A DeltaCallCache caches methods for Delta calls.
// They are primarily used to speed up performs.
//
// %todo:
//   clear all DeltaCallCache at garbage collection

class DeltaCallCache: public AllStatic {
 private:
  static DeltaCallCache* _root; // root of all DeltaCallCaches
  DeltaCallCache*        _link; // all DeltaCallCaches are linked

  // cache
  LookupKey    _key;
  LookupResult _result;

 public:
  DeltaCallCache();
  void clear();                 // clears the cache
  static void clearAll();       // clears all DeltaCallCaches (called by GC, etc.)


  bool match(klassOop klass, symbolOop selector) {
    return oop(selector) == _key.selector_or_method() 
        && klass         == _key.klass();
  }


  LookupResult lookup(klassOop klass, symbolOop selector) {
    if (!match(klass, selector)) {
      _result = interpreter_normal_lookup(klass, selector);
      if (!_result.is_empty()) {
        _key.initialize(klass, selector);
      }
    }
    return _result;
  }

  LookupResult result() { return _result; }
};


// Delta provides the following entry points for calling Delta methods

class Delta: public AllStatic {
 public:
  // The following functions return a marked oop if the selector is not a symbolOop
  static oop call_generic(DeltaCallCache* ic, oop receiver, oop selector, int nofArgs, oop* args);

  static oop call(oop receiver, oop selector);
  static oop call(oop receiver, oop selector, oop arg1);
  static oop call(oop receiver, oop selector, oop arg1, oop arg2);
  static oop call(oop receiver, oop selector, oop arg1, oop arg2, oop arg3);
  static oop call(oop receiver, oop selector, objArrayOop args);
};

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