General Protection Exception

[akmkat]

I have encoutered a problem "General Protection Exception" when trying to run this program, I need a help on a urgent basis:

the code:

#include <stdio.h>
#include <stdlib.h>
 
#define L 20
#define V 30
#define O 2
#define N 4
 
struct Element
 {
    unsigned int c[L];
    int value ;
 };
 
struct Variable
 {
    struct Element e[V] ;
    double y[V] ;
    double f[O] ;
 };
 
void initializeElement(struct Element*);
 
void main(void)
 {
    Variable *x ;
    int i,j ;
    x = (struct Variable*)malloc(sizeof(struct Variable) * N);
 
    for( i = 0 ; i < N ; i++ )
        {
          for( j = 0 ; j < V ; j++ )
              {
                 initializeElement(&(x[i].e[j]));
                 x[i].y[j] = 0 ;
                 x[i].f[j] = 0 ;
              }
 
          for( j = 0 ; j < O ; j++ )
              x[i].f[j] = 0 ;
        }
 }
 
 
void initializeElement( struct Element *e)
 {
    int i, r ;
    for( i = 0 ; i < L ; i++ )
        {
          r = rand() % 1000 ;
          if( r < 500 )
              e -> c[i] = 0 ;
          else
              e -> c[i] = 1 ;
        }
    e -> value = 0 ;
 }
 

Plz help anyone as soon as possible.

[AdrianH]

              {
                 initializeElement(&(x[i].e[j]));
                 x[i].y[j] = 0 ;
                 x[i].f[j] = 0 ;
              }
 

Just by inspection, I would say it is the x[i].f[j] = 0 ; line, since j could be between 0 and V which is defined as 30 and f has only O elements which you defined O as 2.

You've been looking at the code too long. :)


Adrian

[DeMan]

You've been looking at the code too long. :-)

Ain't that the truth way too often

[akmkat]

I have encoutered a problem "General Protection Exception" when trying to run this program, I need a help on a urgent basis:

the code:

#include <stdio.h>
#include <stdlib.h>
 
#define L 20
#define V 30
#define O 2
#define N 1024
 
struct Element
 {
    unsigned int c[L];
    int value ;
 };
 
struct Variable
 {
    struct Element e[V] ;
    double y[V] ;
    double f[O] ;
 };
 
void initializeElement(struct Element*);
 
void main(void)
 {
    Variable *x ;
    int i,j ;
    x = (struct Variable*)malloc(sizeof(struct Variable) * N);
 
    for( i = 0 ; i < N ; i++ )
        {
          for( j = 0 ; j < V ; j++ )
              {
                 initializeElement(&(x[i].e[j]));
                 x[i].y[j] = 0 ;
                 //x[i].f[j] = 0 ;
              }
 
          for( j = 0 ; j < O ; j++ )
              x[i].f[j] = 0 ;
        }
 }
 
 
void initializeElement( struct Element *e)
 {
    int i, r ;
    for( i = 0 ; i < L ; i++ )
        {
          r = rand() % 1000 ;
          if( r < 500 )
              e -> c[i] = 0 ;
          else
              e -> c[i] = 1 ;
        }
    e -> value = 0 ;
 }
 

Plz help anyone as soon as possible.

If I ommit that line, still the problem exists. if N < 40 then it is ok, but when I put N = 1024, same General Protection Exception occurs. What'll I do?

[AdrianH]

If I ommit that line, still the problem exists. if N < 40 then it is ok, but when I put N = 1024, same General Protection Exception occurs. What'll I do?

Are you using g++? Perhaps you have gdb installed there as well? Try looking at this post. It will briefly explain how to use it to debug your programme. You may try and run the programme in the debugger, and if the exception occurs, depending on the severity, it may tell you where the problem is. Otherwise a stepping approch as describe there may be your only way.

If you still have problems, I will try and help you further.


Adrian

[akmkat]

Are you using g++? Perhaps you have gdb installed there as well? Try looking at this post. It will briefly explain how to use it to debug your programme. You may try and run the programme in the debugger, and if the exception occurs, depending on the severity, it may tell you where the problem is. Otherwise a stepping approch as describe there may be your only way.

If you still have problems, I will try and help you further.


Adrian

Thanx, I think my problem is finished. I found no exception now using g++/gcc

[AdrianH]

Thanx, I think my problem is finished. I found no exception now using g++/gcc

Ohh, problems that go away by themselves. I hate those. I never know if the problem has truely gone away or just not showing itself.

If you recompiled a clean copy, it could be that you had a phase error in your compilation. This happens when one source file that depends on another source or header file doesn't get recompiled when the files it depends on have been.

I hate that when it happens.


Adrian