_GetHandSize( ) API Library Routine Example

The following example allocates memory blocks of various size from 1 to 2¹⁵ and shows the value returned by _GetHandSize( ) for these allocations. Notice that the value returned by _GetHandSize( ) is only sometimes exactly equal to the size requested by _AllocHand( ); usually it's a bit more.

Visual FoxPro Code

SET LIBRARY TO GETHANDS

C Code

#include <pro_ext.h>

void putLong(long n)
{
   Value val;

   val.ev_type = 'I';
   val.ev_long = n;
   val.ev_width = 5;

   _PutValue(&val);
}

void FAR Example(ParamBlk FAR *parm)
{
   MHANDLE mh;
   unsigned int allocSize;

   for (allocSize = 1;; allocSize *= 2)
   {
      if ((mh = _AllocHand(allocSize)) == 0)
      {
         _Error(182);  // "Insufficient memory"
      }
      _PutStr("\n_AllocHand("); putLong(allocSize); _PutStr(")");
      _PutStr("\n_GetHandSize() ="); putLong(_GetHandSize(mh));
      _FreeHand(mh);
      if (allocSize == 32768)
      {
         break;
      }
   }
}

FoxInfo myFoxInfo[] = {
   {"ONLOAD", (FPFI) Example, CALLONLOAD, ""},
};
FoxTable _FoxTable = {
   (FoxTable FAR *) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo
};