RE: [DEV-C++] BUG: Dev-C 4.9.20 consolprogram has only access to 1MB memory.

[Ioannis V. <no...@ho...>]

Your code fixed:

#include <iostream>
//-->Not needed
// #include <stdio.h>
#include <stdlib.h>

//--> You do not use argc,  argv[] so why you declare them?
int main(int argc, char *argv[])
{
  using namespace std; // --> necessary
  
  const long MEGA_BYTE = 1024*1024;
  
  long nMBSize = 1;
  
  while (nMBSize != 0 ){
    cout << "Give MB size: ";
    cin >> nMBSize;

    //--> Illegal in ANSI C++. The sizes of arrays in the stack must be
constants
    //--> char narrBig[nMBSize * MEGA_BYTE];
    
    char *narrBig=new char[nMBSize*MEGA_BYTE];


    //--> Useless. sizeof(char) is always 1 byte
   //cout << "char size: " << sizeof(char) << " Bytes." <<  endl;

   //-->You can't do that on an array on the free store. 
   // Here it returns the size of char *   
   //   cout << "Array size: " << sizeof(narrBig)<< " Bytes." << endl;
   //See if initializing each element makes a difference
   for (unsigned long i = 0; i<nMBSize*MEGA_BYTE;i++){
      narrBig[i] = 'A';
   }//i
   //--> Useless. cout << "Array size: " << sizeof(narrBig) << endl;
   //If you store objects in the array remember to use:
   delete [] narrBig;
//--> This could be disastrous when applied on a built in array as you
had done


}//while (nMB..
//To have a breake before window closes, use:
  system("PAUSE");
  return 0;
}


====


How i would do it in your case:


#include <iostream>
#include <cstdlib>
#include <vector>


int main()
{
  using namespace std;
  
  const unsigned long MEGA_BYTE = 1024*1024;

  long nMBSize;

  do
  {
    cout << "\nGive MB size: ";
    cin >> nMBSize;

    vector<char> narrBig(nMBSize*MEGA_BYTE);

    cout << "Array contents size: " << narrBig.size()<< " Bytes." <<
endl;
   
    for (unsigned long i = 0; i<nMBSize*MEGA_BYTE;i++)
       narrBig[i] = 'A';

    cout << "Array contents size: " << narrBig.size()<< " Bytes." <<
endl;

    // vector is destroyed at the end of its scope, and its contents are
cleared
   }while (nMBSize!=0);

//To have a break before window closes, use:
  system("PAUSE");
  
  return 0;
}


Ioannis

* Ioannis Vranos
* Programming pages: http://www.noicys.cjb.net
* Alternative URL: http://run.to/noicys


> -----Original Message-----
> From: dev...@li... 
> [mailto:dev...@li...] On Behalf Of staale
> Sent: Friday, May 10, 2002 4:46 AM
> To: jar...@be...; ha...@bl...; Dev-Cpp
> Subject: [DEV-C++] BUG: Dev-C 4.9.20 consolprogram has only 
> access to 1MB memory.
> 
> 
> Se also thread:
>     [Dev-C++] not enough memory - how to configure Win2000
> on the mailing list. Test code below
> 
> Hi Helmuth,
> 
> Turns out this has somthing to do with Dev-C 4.9.20.
> 
> This is what I did to verify the problem:
> 1: Tried your file on both w2k (Clean system) or NT4-Sp6. It 
> failed on both
> machins.
> 
> 2: I installed DEV-C 4.9.20 (downloaded today) on a clean w2k 
> machine and
> encountered the same problem when I compiled and ran the code.
> 
> 3: Tried to uninstall DEV-C 4.9.20. Uninstal DOES NOT work. 
> Delete the fiels
> manualy. Search for dev-c in regedit.exe and then run 
> RegClean.exe just
> search for RegClean and you should be well of (Might not nead 
> this see pkt
> 5)
> 
> 4: Installed DEV-C 4.0 on the w2k machine  Compiled and 
> tested OK to 31MB.
> 
> 5: Installed Dev-c 4.9.20 on top of the 4.0 and It still 
> worked nicely..:o)
> 
> 6: Installed Dev-C 4.9.20 on NT4-SP6 (Only Winzip appart from 
> OS). Added
> shlwapi.dll and wininet.dll to system32 folder. Tried to run 
> the code but
> no. Same failure.
> 
> 7: Installed Dev-C 4.0 on top of the 4.9.20. This did not 
> help. Brobably
> because both installers does not overwrite existing header 
> files (?). So you
> should delete the 4.9.x installaation. Install 4.0 and then 
> 4.9.x (if you
> nead it. It is a must if you want to use the wxWindows lib, 
> if I understand
> right)
> 
> 
> I'm not a seasoned C developer but would gues there are 
> somthing wrong with
> a header file or reference making dev-c 4.9.x compile to 
> 16bit code(???)
> 
> Best regards
> Staale Flock
> 
> ------------------- Code
> Start --------------------------------------------------------
> //////////////////////////////////////////////////////////////
> //////////////
> ///////////////////////////////////////////////////
> // this code fails if you install Dev-C 4.9.20 on a new w2k 
> machine and try
> to access
> // more than 1MB memory. (Enter any number higher than 1).
> //////////////////////////////////////////////////////////////
> //////////////
> ///////////////////////////////////////////////////
> 
> #include <iostream>
> #include <stdio.h>
> #include <stdlib.h>
> 
> 
> int main(int argc, char *argv[])
> {
> const long MEGA_BYTE = 1024*1024;
> long nMBSize = 1;
> while (nMBSize != 0 ){
>    cout << "Give MB size: ";
>    cin >> nMBSize;
>    char narrBig[nMBSize * MEGA_BYTE];
>    cout << "char size: " << sizeof(char) << " Bytes." <<  endl;
>    cout << "Array size: " << sizeof(narrBig)<< " Bytes." << endl;
>    //See if initializing each element makes a difference
>    for (unsigned long i = 0; i<nMBSize*MEGA_BYTE;i++){
>       narrBig[i] = 'A';
>    }//i
>    cout << "Array size: " << sizeof(narrBig) << endl;
>    //If you store objects in the array remember to use:
>    delete []narrBig;
> }//while (nMB..
> //To have a breake before window closes, use:
>   system("PAUSE");
>   return 0;
> }
> 
> ------------------- Code end --------------------------------->