VsidManager.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef PPC_COMMON_VSIDMANAGER_H
#define PPC_COMMON_VSIDMANAGER_H

#include "pedigree/kernel/process/Mutex.h"
#include "pedigree/kernel/processor/types.h"

class VsidManager
{
  public:
    typedef uint32_t Vsid;

    static VsidManager &instance();

    Vsid obtainVsid();
    void returnVsid(Vsid vsid);

  private:
    VsidManager(const VsidManager &);
    VsidManager &operator=(const VsidManager &);

    struct VsidStack
    {
        Vsid vsid;
        struct VsidStack *next;
    };
    VsidManager();
    ~VsidManager();

    Vsid m_HighWaterMark;

    VsidStack *m_pStack;

    Mutex m_Mutex;

    static VsidManager m_Instance;
};
#endif