JavaScriptCore/interpreter/RegisterFile.cpp

/*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * 1.  Redistributions of source code must retain the above copyright
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 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
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 *     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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 */

#include "config.h"
#include "RegisterFile.h"

namespace JSC {

RegisterFile::~RegisterFile()
{
#if HAVE(MMAP)
    munmap(m_buffer, ((m_max - m_start) + m_maxGlobals) * sizeof(Register));
#elif HAVE(VIRTUALALLOC)
    VirtualFree(m_buffer, 0, MEM_RELEASE);
#else
    #error "Don't know how to release virtual memory on this platform."
#endif
}

void RegisterFile::releaseExcessCapacity()
{
#if HAVE(MMAP) && HAVE(MADV_FREE) && !HAVE(VIRTUALALLOC)
    while (madvise(m_start, (m_max - m_start) * sizeof(Register), MADV_FREE) == -1 && errno == EAGAIN) { }
#elif HAVE(VIRTUALALLOC)
    VirtualFree(m_start, (m_max - m_start) * sizeof(Register), MEM_DECOMMIT);
    m_commitEnd = m_start;
#endif
    m_maxUsed = m_start;
}

} // namespace JSC