guirealloc.c

ucgui的3.98版本的源代码

/*
*********************************************************************************************************
*                                             uC/GUI V3.98
*                        Universal graphic software for embedded applications
*
*                       (c) Copyright 2002, Micrium Inc., Weston, FL
*                       (c) Copyright 2002, SEGGER Microcontroller Systeme GmbH
*
*              礐/GUI is protected by international copyright laws. Knowledge of the
*              source code may not be used to write a similar product. This file may
*              only be used in accordance with a license and should not be redistributed
*              in any way. We appreciate your understanding and fairness.
*
----------------------------------------------------------------------
File        : GUIRealloc.C
Purpose     : Dynamic memory management
----------------------------------------------------------------------
*/

#include <stddef.h>           /* needed for definition of NULL */
#include <string.h>           /* for memcpy, memset */

#include "GUI_Protected.h"
#include "GUIDebug.h"

/*********************************************************************
*
*       Public routines: Using internal memory management
*
**********************************************************************
*/
/*********************************************************************
*
*       GUI_ALLOC_Realloc
*
* Purpose:
*   Reallocate a memory block. This is typically used to grow memory
*   blocks. The contents of the old memory block are copied into the
*   new block (or as much as fits in case of shrinkage).
*   In case of error the old memory block (and its handle) remain
*   unchanged.
*
*  Parameters
*    hOld       Current handle of the memory block. 0 (Invalid handle) is permitted.
*    NewSize    Number of bytes required
*
* Return value:
*   On success:    Handle of newly allocated memory block
*   On error:      0
*/
GUI_HMEM GUI_ALLOC_Realloc(GUI_HMEM hOld, int NewSize) {
  GUI_HMEM hNew;
  hNew = GUI_ALLOC_AllocNoInit(NewSize);
  if (hNew && hOld) {
    void *pNew, *pOld;
    int Size, OldSize;
    OldSize = GUI_ALLOC_GetSize(hOld);
    Size = (OldSize < NewSize) ? OldSize : NewSize;
    GUI_LOCK();
    pNew = GUI_ALLOC_h2p(hNew);
    pOld = GUI_ALLOC_h2p(hOld);
    memcpy(pNew, pOld, Size);
    GUI_UNLOCK();
    GUI_ALLOC_Free(hOld);
  }
  return hNew;
}

/*************************** End of file ****************************/