/*

 * 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.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 *

 */

#ifndef WTFThreadData_h

#define WTFThreadData_h

#include <wtf/HashMap.h>

#include <wtf/HashSet.h>

#include <wtf/Noncopyable.h>

#include <wtf/text/StringHash.h>

// This was ENABLE(WORKERS) in WebCore, but this is not defined when compiling JSC.

// However this check was not correct anyway, re this comment:

//    // FIXME: Workers are not necessarily the only feature that make per-thread global data necessary.

//    // We need to check for e.g. database objects manipulating strings on secondary threads.

// Always enabling this is safe, and should be a better option until we can come up

// with a better define.

#define WTFTHREADDATA_MULTITHREADED 1

#if WTFTHREADDATA_MULTITHREADED

#include <wtf/ThreadSpecific.h>

#include <wtf/Threading.h>

#endif

// FIXME: This is a temporary layering violation while we move more string code to WTF.

namespace WebCore {

class AtomicStringTable;

class StringImpl;

}

using WebCore::StringImpl;

typedef void (*AtomicStringTableDestructor)(WebCore::AtomicStringTable*);

#if USE(JSC)

// FIXME: This is a temporary layering violation while we move more string code to WTF.

namespace JSC {

typedef HashMap<const char*, RefPtr<StringImpl>, PtrHash<const char*> > LiteralIdentifierTable;

class IdentifierTable : public FastAllocBase {

public:

    ~IdentifierTable();

    std::pair<HashSet<StringImpl*>::iterator, bool> add(StringImpl* value);

    template<typename U, typename V>

    std::pair<HashSet<StringImpl*>::iterator, bool> add(U value);

    void remove(StringImpl* r) { m_table.remove(r); }

    LiteralIdentifierTable& literalTable() { return m_literalTable; }

private:

    HashSet<StringImpl*> m_table;

    LiteralIdentifierTable m_literalTable;

};

}

#endif

namespace WTF {

class WTFThreadData : public Noncopyable {

public:

    WTFThreadData();

    ~WTFThreadData();

    WebCore::AtomicStringTable* atomicStringTable()

    {

        return m_atomicStringTable;

    }

#if USE(JSC)

    void initializeIdentifierTable(JSC::IdentifierTable* identifierTable)

    {

        m_defaultIdentifierTable = identifierTable;

        m_currentIdentifierTable = identifierTable;

    }

    JSC::IdentifierTable* currentIdentifierTable()

    {

        return m_currentIdentifierTable;

    }

    JSC::IdentifierTable* setCurrentIdentifierTable(JSC::IdentifierTable* identifierTable)

    {

        JSC::IdentifierTable* oldIdentifierTable = m_currentIdentifierTable;

        m_currentIdentifierTable = identifierTable;

        return oldIdentifierTable;

    }

    void resetCurrentIdentifierTable()

    {

        m_currentIdentifierTable = m_defaultIdentifierTable;

    }

#endif

private:

    WebCore::AtomicStringTable* m_atomicStringTable;

    AtomicStringTableDestructor m_atomicStringTableDestructor;

#if USE(JSC)

    JSC::IdentifierTable* m_defaultIdentifierTable;

    JSC::IdentifierTable* m_currentIdentifierTable;

#endif

#if WTFTHREADDATA_MULTITHREADED

    static JS_EXPORTDATA ThreadSpecific<WTFThreadData>* staticData;

#else

    static JS_EXPORTDATA WTFThreadData* staticData;

#endif

    friend WTFThreadData& wtfThreadData();

    friend class WebCore::AtomicStringTable;

};

inline WTFThreadData& wtfThreadData()

{

#if WTFTHREADDATA_MULTITHREADED

    // WRT WebCore:

    //    WTFThreadData is used on main thread before it could possibly be used

    //    on secondary ones, so there is no need for synchronization here.

    // WRT JavaScriptCore:

    //    wtfThreadData() is initially called from initializeThreading(), ensuring

    //    this is initially called in a pthread_once locked context.

    if (!WTFThreadData::staticData)

        WTFThreadData::staticData = new ThreadSpecific<WTFThreadData>;

    return **WTFThreadData::staticData;

#else

    if (!WTFThreadData::staticData) {

        WTFThreadData::staticData = static_cast<WTFThreadData*>(fastMalloc(sizeof(WTFThreadData)));

        // WTFThreadData constructor indirectly uses staticData, so we need to set up the memory before invoking it.

        new (WTFThreadData::staticData) WTFThreadData;

    }

    return *WTFThreadData::staticData;

#endif

}

} // namespace WTF

using WTF::WTFThreadData;

using WTF::wtfThreadData;

#endif // WTFThreadData_h