PODArena.h   [plain text]

/*
 * Copyright (C) 2010 Google 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 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
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef PODArena_h
#define PODArena_h

#include <stdint.h>
#include <wtf/Assertions.h>
#include <wtf/FastMalloc.h>
#include <wtf/Noncopyable.h>
#include <wtf/OwnPtr.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/Vector.h>

namespace WebCore {

// An arena which allocates only Plain Old Data (POD), or classes and
// structs bottoming out in Plain Old Data. NOTE: the constructors of
// the objects allocated in this arena are called, but _not_ their
// destructors.

class PODArena : public RefCounted<PODArena> {
protected:
    virtual ~PODArena() { }
    friend class WTF::RefCounted<PODArena>;

    // Returns the alignment requirement for classes and structs on the
    // current platform.
    template <class T> static size_t minAlignment()
    {
        return WTF_ALIGN_OF(T);
    }

    // Rounds up the given allocation size to the specified alignment.
    size_t roundUp(size_t size, size_t alignment)
    {
        ASSERT(!(alignment % 2));
        return (size + alignment - 1) & ~(alignment - 1);
    }
};

} // namespace WebCore

#endif // PODArena_h