JavaScriptCore/kjs/JSGlobalData.h

/*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 */

#ifndef JSGlobalData_h
#define JSGlobalData_h

#include "ArgList.h"
#include <wtf/HashCountedSet.h>
#include <wtf/HashSet.h>
#include <wtf/Noncopyable.h>
#include <wtf/OwnPtr.h>

namespace KJS {

    class CommonIdentifiers;
    class Heap;
    class IdentifierTable;
    class JSGlobalObject;
    class Lexer;
    class Machine;
    class Parser;
    class ParserRefCounted;
    class UString;
    struct HashTable;

    // This serves as a bottleneck for accessing per-thread data structures.
    // Note that the effective instance may be different from the thread one in case of legacy
    // JavaScriptCore clients, which all share a single JSGlobalData, and thus cannot run concurrently.
    struct JSGlobalData : Noncopyable {
        static bool threadInstanceExists();
        static bool sharedInstanceExists();
        static JSGlobalData& threadInstance();
        static JSGlobalData& sharedInstance();

        Machine* machine;
        Heap* heap;

        const HashTable* arrayTable;
        const HashTable* dateTable;
        const HashTable* mathTable;
        const HashTable* numberTable;
        const HashTable* regExpTable;
        const HashTable* regExpConstructorTable;
        const HashTable* stringTable;

        IdentifierTable* identifierTable;
        CommonIdentifiers* propertyNames;
        const ArgList emptyList; // Lists are supposed to be allocated on the stack to have their elements properly marked, which is not the case here - but this list has nothing to mark.

        HashSet<ParserRefCounted*>* newParserObjects;
        HashCountedSet<ParserRefCounted*>* parserObjectExtraRefCounts;

        Lexer* lexer;
        Parser* parser;

        JSGlobalObject* head;

        bool isSharedInstance;

    private:
        JSGlobalData(bool isShared = false);
        ~JSGlobalData();

        static JSGlobalData*& threadInstanceInternal();
        static JSGlobalData*& sharedInstanceInternal();

        struct DataInstance {
            DataInstance() : m_data(0) {}
            ~DataInstance() { delete m_data; }
            operator JSGlobalData*&() { return m_data; }

            JSGlobalData* m_data;
        };
    };

}

#endif