compo_pool.c

COMPO source code for reference

/*******************************************************************************

File name   : compo_pool.c

Description : Functions of the data pool Manager

COPYRIGHT (C) STMicroelectronics 2000.

Date               Modification                               Name
----               ------------                               ----
5 May 2004        Creation                                   TM

*******************************************************************************/


/* Includes ----------------------------------------------------------------- */
#include <stdlib.h>
#include "stddefs.h"
#include <string.h>
#include "compo_pool.h"

/* Private Types ------------------------------------------------------------ */

/* Private Constants -------------------------------------------------------- */

/* Private Variables -------------------------------------------------------- */

/* Private Macros ----------------------------------------------------------- */


/* Private Function prototypes ---------------------------------------------- */


/* Functions ---------------------------------------------------------------- */
/*******************************************************************************
Name        : stcompo_InitDataPool
Description : initializes a generic datapool
Parameters  :
Assumptions :
Limitations : No error checking is performed
Returns     :
*******************************************************************************/
void stcompo_InitDataPool(
  stcompo_DataPoolDesc_t*    DataPool_p,
  U32                       NbElem,
  U32                       ElemSize,
  void*                     ElemArray_p,
  void**                    HandleArray_p)
{
  U32 i;

  DataPool_p->NbFreeElem      = NbElem;
  DataPool_p->NbElem          = NbElem;
  DataPool_p->ElemSize        = ElemSize;
  DataPool_p->ElemArray_p     = ElemArray_p;
  DataPool_p->HandleArray_p   = HandleArray_p;

  /* Initialize Handle array content*/
  for( i=0; i < NbElem; i++)
    DataPool_p->HandleArray_p[i] = (void*) ((U32)ElemArray_p + ElemSize*(NbElem - 1 -i));
}

/*******************************************************************************
Name        : stcompo_GetElement
Description : gets an element from the data pool returning its handle
Parameters  :
Assumptions :
Limitations :
Returns     :
*******************************************************************************/
ST_ErrorCode_t stcompo_GetElement( stcompo_DataPoolDesc_t* DataPool_p, void** Handle_p)
{
    if(DataPool_p->NbFreeElem > 0)
    {
        *Handle_p = (void*) DataPool_p->HandleArray_p[DataPool_p->NbFreeElem - 1];
        DataPool_p->HandleArray_p[DataPool_p->NbFreeElem - 1] = NULL;
        DataPool_p->NbFreeElem--;
        return(ST_NO_ERROR);
    }
    else
    {
        return(ST_ERROR_NO_FREE_HANDLES);
    }
}

/*******************************************************************************
Name        : stcompo_ReleaseElement
Description :
Parameters  :
Assumptions :
Limitations : upper level must ensure an handle is released only once
              upper level must also ensure handle validity
Returns     :
*******************************************************************************/
ST_ErrorCode_t stcompo_ReleaseElement(stcompo_DataPoolDesc_t*  DataPool_p,
                                      void*                    Handle)
{
    if ( Handle == NULL )
    {
        return (ST_ERROR_INVALID_HANDLE);
    }

    if (DataPool_p->NbFreeElem == DataPool_p->NbElem)
    {
        return (ST_ERROR_NO_FREE_HANDLES);
    }

    DataPool_p->NbFreeElem++;
    DataPool_p->HandleArray_p[DataPool_p->NbFreeElem - 1] = Handle;

    return(ST_NO_ERROR);
}
/* End of compo_pool.c */