CWE-ou-minkata/Sources/Plasma/NucleusLib/pnUtils/pnUtSync.h

/*==LICENSE==*

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Additional permissions under GNU GPL version 3 section 7

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*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtSync.h
*   
***/

#ifndef PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTSYNC_H
#define PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTSYNC_H

#include "Pch.h"

/****************************************************************************
*
*   Atomic operations
*
***/

// *value += increment; return original value of *value; thread safe
long AtomicAdd (long * value, long increment);

// *value = value; return original value of *value; thread safe
long AtomicSet (long * value, long set);


#define ATOMIC_ONCE(code) {     \
    static long s_count = 1;    \
    if (AtomicSet(&s_count, 0)) \
        code;                   \
}                               //


/****************************************************************************
*
*   CLock
*   (reader/writer lock)
*
***/

class CLockWaitSet;

class CLock {
private:
    CLockWaitSet *  m_waitSet;
    long            m_spinLock;
    unsigned        m_readerCount;
    unsigned        m_writerCount;

public:
    CLock ();
    ~CLock ();
    void EnterRead ();
    void EnterWrite ();
    void LeaveRead ();
    void LeaveWrite ();
};

#endif