Thread: a noob freeing memory...

this is a snaphot of the code.i hope it helps because i can't find a point where the pointer is dereferenced.

Code:

int **gene_pricing(int run_mode,int no_of_vehicles,int gene_dim,int *gene,
		  int *edge_weight_section,int *demand,int capacity,int *fitness){
	
        //various variables
	register int i,j;
	int int_fitness,sub_cost,ext_tour_size,ext_dim;
	
	int **prev_after,count;
	
	prev_after=malloc(no_of_vehicles*sizeof(*prev_after));
	
	if(prev_after==NULL){
		 perror ("malloc");
		 exit(EXIT_FAILURE);
		  }
	
	for(i=0;i<no_of_vehicles;i++){
		prev_after[i]=malloc(gene_dim*sizeof(**prev_after));
		
                if(prev_after[i]==NULL){ //Check for memory redudancy
			 perror("malloc");
			 exit(EXIT_FAILURE);
		}
	}
		
	for(i=0;i<no_of_vehicles;i++){
		count=1;
		for(j=0;j<gene_dim;j++){
			if(gene[j]==i){
				prev_after[i][j]=count;
				count++;
			}
			else prev_after[i][j]=0;
		}
	}

  .
  . blah blah blah irrelevant stuff (nothing else allocated or used from the above)
  .
   
  *fitness=int_fitness; //some variable returned by reference externally

   return prev_after;
}


int main(){
.
.
.
        int ext_fitness,i,j;
	int **ext_matrix;
	
	ext_matrix=malloc(2*sizeof(*ext_matrix));
	for(i=0;i<2;i++){
		ext_matrix[i]=malloc(17*sizeof(**ext_matrix));
	}
			
	ext_matrix=gene_pricing(0,2,17,gene17,edges17,demand17,10,&ext_fitness);
	
        printf("\n\n%d\n\n",ext_fitness);
		
	printf("\n\n");	
	for(i=0;i<2;i++){
		for(j=0;j<17;j++) printf("%d ",ext_matrix[i][j]);
		printf("\n");
	}
		
	
	for(i=0;i<2;i++) free(ext_matrix[i]);
	free(ext_matrix);	
	
	return EXIT_SUCCESS;
}

any other suggestions???
thanx for your help and patience.

These lines in main are completely unnecessary. This allocates memory for the matrix. But then you do the exact same thing in function gene_pricing. You don't need to allocate memory for the matrix twice. Now it's up to you where to do the allocation. You can either do it down in the function, or you can do it in main, then pass the matrix as an argument to the function.

Now we know why. Since you allocated the matrix twice, you would leak twice the amount.

thanks a lot i just learned that if i want to access an already allocated pointer with another i don't have to allocate it too
pretty noob i think

thank you very much... i appreciate your help and patience...