UTMutex.h

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//==================================================================================================
// Copyright (C) 2010  Brian Tietz    sdbtietz at yahoo dot com
//
// 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, version 2.0 of the
// License.
//
// 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301, USA.
//
// For commercial software, the copyright holder (Brian Tietz, email sdbtietz at yahoo dot com)
// reserves the right and is willing to waive the proprietary source code disclosure aspects of that
// license as applied to the UT library in exchange for either substantial contributions to the
// development of the UT library or other forms of compensation.  Any such waiver must be
// established in writing between the copyright holder and the commercial entity obtaining such a
// waiver.
//==================================================================================================


#ifndef _UT_MUTEX_H_
#define _UT_MUTEX_H_


//==================================================================================================
//=== Project headers
//==================================================================================================
#include "UTEvent.h"


//==================================================================================================
//=== Forward name declarations
//==================================================================================================
struct MutexPlatformInfo_t;


//==================================================================================================
class UT_EXPORT Mutex_t
//==================================================================================================
{
    //----------------------------------------------------------------------------------------------
    public:
    //----------------------------------------------------------------------------------------------
                            Mutex_t(bool allow_recursive_lock = false);

                            ~Mutex_t();

    void                    Lock();

    void                    Unlock();

    inline thread_id_t      LockedBy();

    //----------------------------------------------------------------------------------------------
    private:
    //----------------------------------------------------------------------------------------------
    MutexPlatformInfo_t*    m_info;
    volatile thread_id_t    m_owner;
    bool                    m_allow_recursive_lock;
    int                     m_locked_recursion_count;
};


//==================================================================================================
class UT_EXPORT MultiReaderMutex_t
//==================================================================================================
{
    //----------------------------------------------------------------------------------------------
    public:
    //----------------------------------------------------------------------------------------------
                    MultiReaderMutex_t();

                    ~MultiReaderMutex_t();

    void            LockRead();

    void            UnlockRead();

    void            LockWrite();

    void            UnlockWrite();

    //----------------------------------------------------------------------------------------------
    private:
    //----------------------------------------------------------------------------------------------
    inline void     DebugMRMDiag( stringliteral* what, int value ) const;

    //----------------------------------------------------------------------------------------------
    private:
    //----------------------------------------------------------------------------------------------
    Mutex_t         m_state_mutex;
    volatile bool   m_held_by_writer;
    volatile int    m_held_by_readers;
    volatile int    m_waiting_writers;
    volatile int    m_waiting_readers;
    Event_t         m_writer_wait_event;
    Event_t         m_reader_wait_event;
};




//==================================================================================================
//==================================================================================================
//===
//=== Inline function implementations: class Mutex_t
//===
//==================================================================================================
//==================================================================================================
inline thread_id_t
Mutex_t::LockedBy()
{
    return m_owner;
}


#endif // _UT_MUTEX_H_