[AccessD] Array faster in DLL?

Gustav Brock Gustav at cactus.dk
Mon Oct 31 07:32:27 CST 2005


Hi Shamil

For "redefining the interface" you mean that a Long is not enough to specify a count of loops large enough to obtain a running time of some seconds?
That's the only parameter I wish to pass.
The only needed value to return is the running duration in seconds.

If so, couldn't we expand with an additional loop to multiply the count of loops:

for (lngSequence=0; lngSequence < lngSequences; lngSequence++) {
 for (lngLoop=0; lngLoop < lngLoopMax; lngLoop++) {
  for (lngItem=0; lngItem < lngItems; lngItem++) {
   alngTmp[lngItem][0] = lngLoop * 10;
   if (alngTmp[lngItem][0] / 10 == 100) lngResult = 1;
   else lngResult = 0;
   lngCnt++;
  }
 }
}

and then add lngSequences as a separate parameter:

static long ArrayTimeLocal(long lngSequences, long lngLoopMax, long& lngTotalCnt, bool useTracePrinting = false);

That would be great.

/gustav

>>> shamil at users.mns.ru 31-10-2005 13:22:23 >>>
Gustav,

Yes, I can make a C++ dll but maybe you first (re)define your test function
call interface because even if you call very quick C++ function 1000 times
from VB6 you can loose all the advantages this C++ function gives.

Currently - here is C++ (non managed) console applications results for a
function similar to yours:

10,000,000,000 your cycles in 13 seconds (ot looks like I did some mistakes
in my previous time calculations - I have to recheck)

=====================================
Final Result = 13, Final Counter = 10000000000
=====================================

Here is the C++ code for the last test:

#include "stdafx.h"
#include <time.h>

static long ArrayTimeLocal(long lngLoopMax, long& lngTotalCnt, bool
useTracePrinting = false);
int _tmain(int argc, _TCHAR* argv[])
{
 _int64 lngTotalCnt = 0;
 long lngCnt = 0;
 time_t /*double*/ dblStart;
 time_t /*double*/ dblStop;
 long lngSeconds = 0;

 time(&dblStart);
 for (int i=1; i<=10; i++) {
    ArrayTimeLocal(10000000, lngCnt);
    lngTotalCnt += lngCnt;
 }
 time(&dblStop);
 lngSeconds = (long)difftime(dblStop,dblStart);;
 printf("Final Result = %ld, Final Counter = %I64d\n",
     lngSeconds, lngTotalCnt);
}

static long ArrayTimeLocal(long lngLoopMax, long& lngTotalCnt, bool
useTracePrinting) {
 const long lngItems = 100;
 long alngTmp[lngItems][2];
 long lngLoop;
 long lngItem;
 long lngResult = 0;
 time_t /*double*/ dblStart;
 time_t /*double*/ dblStop;
 long lngSeconds;
 long lngCnt = 0;

 if (useTracePrinting) printf("Array looping test started..\n");
 time(&dblStart);
 for (lngLoop=0; lngLoop < lngLoopMax; lngLoop++) {
  for (lngItem=0; lngItem < lngItems; lngItem++) {
   alngTmp[lngItem][0] = lngLoop * 10;
   if (alngTmp[lngItem][0] / 10 == 100) lngResult = 1;
   else lngResult = 0;
   lngCnt++;
  }
 }
 time(&dblStop);
 if (useTracePrinting) printf("Array looping test ended.\n");
 lngSeconds = (long)difftime(dblStop,dblStart);;
 if (useTracePrinting) printf("Result = %lf, Counter = %ld\n",
     lngSeconds, lngTotalCnt);
 lngTotalCnt = lngCnt;
 return lngSeconds;
}

I will try to move now all variable from stack to static memory - I expect
it may bring even more speed execution gains. We will see.

As soon as you define your final call interface I will make a test C++
.dll...

Shamil





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