/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

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

#ifdef PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTSYNC_H
#error "Header $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtSync.h included more than once"
#endif
#define PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTSYNC_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 ();
};


/*****************************************************************************
*
*   CEvent
*
***/

#ifdef HS_BUILD_FOR_WIN32
typedef HANDLE EventHandle;
#else
# error "CEvent: Not implemented on this platform"
#endif

const unsigned  kEventWaitForever   = (unsigned)-1;

enum ECEventResetBehavior {
    kEventManualReset,
    kEventAutoReset,
};

class CEvent {
    EventHandle     m_handle;
public:
    CEvent (
        ECEventResetBehavior resetType,
        bool        initialSet = false
    );
    ~CEvent ();

    void Signal ();
    void Reset ();
    bool Wait (unsigned waitMs);
    
    const EventHandle & Handle () const { return m_handle; }
};