NQMessagePool.cpp

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// NQMessagePool.cpp: implementation of the CNQMessagePool class.
//

#include "PlatformSW.h"
#include <assert.h>
#include "NQDeclarations.h"
#include "NQLogging.h"
#include "NQMessage.h"
#include "NQLockMechanism.h"
#include "NQMessagePool.h"

// Construction/Destruction

//
// constructor (basic variable initialization)
//
CNQMessagePool::CNQMessagePool(): CNQLockMechanism()
{
    m_pCMessages = NULL;
    m_pTakenBuffer = NULL;
    m_bInitialized = false;
    m_iSharedReferences = 0;
    m_iNumBuffers = 0;
}


//
// destructor (mandatory clean-up deinitialize)
//
CNQMessagePool::~CNQMessagePool()
{
    Deinitialize();
}

// CNQMessagePool::Initialize()
bool CNQMessagePool::Initialize( UINT32 numbuffers )
{
    if (m_bInitialized == true) return false;

    if (!lock()) return false;

    assert( numbuffers > 0 );

    m_pCMessages = new CNQMessage[numbuffers];
    assert( m_pCMessages != NULL);

    m_pTakenBuffer = new UINT32[numbuffers];
    assert(m_pTakenBuffer != NULL);

    for (UINT32 i=0;i<numbuffers;i++)
    {
        m_pTakenBuffer[i] = 0;
    }
    
    m_bInitialized = true;
    m_iSharedReferences = 0;
    m_iNumBuffers = numbuffers;

    unlock();

    return true;
}

//
// CNQMessagePool::Deinitialize()
bool CNQMessagePool::Deinitialize()
{
    if (m_bInitialized == true)
    {
        if (!lock()) return false;

        NQ_DEBUGMODE_ONLY(if (m_iSharedReferences>0) NQ_DBG(("clean CNQMessagePool: m_iSharedReferences=%d\n",m_iSharedReferences)));
        assert( m_iSharedReferences == 0 );

        delete [] m_pCMessages;
        delete [] m_pTakenBuffer;

        m_pCMessages = NULL;
        m_bInitialized = false;
        m_iSharedReferences = 0;
        m_iNumBuffers = 0;
        m_pTakenBuffer = NULL;
        
        unlock();
    }

    return true;
}

//
// CNQMessagePool::acquire_reference()
//
CNQMessage *CNQMessagePool::acquire_reference()
{
    if (m_bInitialized == false) return NULL;

    if (!lock()) return NULL;

    CNQMessage *retval=NULL;
    
    for (UINT32 i=0;i<m_iNumBuffers;i++)
    {
        if (m_pTakenBuffer[i] == 0) 
        {
            m_pTakenBuffer[i] = 1;
            retval = &(m_pCMessages[i]);
            m_iSharedReferences++;
            break;
        }
    }

    unlock();

    return retval; // nothing free or buffer ptr
}

//
// CNQMessagePool::increment_referencecount()
//
bool CNQMessagePool::increment_referencecount( CNQMessage *buffer_ref )
{
    bool retval = false;
    if (m_bInitialized == false) return retval;
    
    if (!lock()) return false;

    for (UINT32 i=0;i<m_iNumBuffers;i++)
    {
        if (&(m_pCMessages[i]) == buffer_ref)
        {
            assert( m_pTakenBuffer[i] > 0);
            if (m_pTakenBuffer > 0) 
            {
                m_pTakenBuffer[i]++;
                retval = true;
            }
            else retval = false;
            
            break;
        }
    }

    unlock();

    return retval; // nothing free or buffer ptr
}


//
// CNQMessagePool::putback_reference()
//
bool CNQMessagePool::putback_reference( CNQMessage *ref )
{
    if (m_bInitialized == false) return false;

    bool retval = false;

    if (!lock()) return retval;

    for (UINT32 i=0;i<m_iNumBuffers;i++)
    {
        if (&(m_pCMessages[i]) == ref)
        {
            assert( m_pTakenBuffer[i] >= 1);
            m_pTakenBuffer[i]--;

            // clear it if put back(!) important step
            if (m_pTakenBuffer[i] == 0) 
            {
                m_pCMessages[i].clear(); 
                assert(m_iSharedReferences > 0);
                m_iSharedReferences--;
            }
            
            retval = true;
        }
    }

    unlock();

    return retval;
}

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