Thread: Freeing memmory - Automatic?

Hello, long time no questions, and the site was down yesterday My question will be simple today, as always haha. Hmm, I have the follow code:

Code:

#include <stdio.h>
#include <stdlib.h>

#define SIZE 10

void *pToData[100] = {NULL}; //pointer to all the data's to be free( )'ed

static void addToList( void *data ) {
	static int i = 0;

	pToData[i++] = data;
}


static int *createArray( void ) {
	int *array = malloc(SIZE * sizeof( int ) );
	int i;

	//check to see if we gain the memmory
	if( array != NULL ) {
		for( i=0; i<SIZE; i++ )
			array[i] = i;
	}

	else {
		printf( "Could not create array!\n" );
		exit( 1 );
	}
	addToList(array);
	return array;
}

static printArr( int *arr, char *label ) {
	int i;

	puts( label );
	for( i=0; i<SIZE; i++ )
		printf( "%d ", arr[i] );
}

static void freeAll( void ) {
	int i;

	for( i=0; pToData[i] != NULL; i++ )
		free( pToData[i] );
}

int main( void ) {
	int *arr1, *arr2;

	arr1 = createArray();
	arr2 = createArray();

	printArr( arr1, "Array 1: " );
	printArr( arr2, "\n\nArray 2:" );

	freeAll(); //is this really works? so easy?

	return 0;
}

As you can imagine, I'm trying to make a function that will free all the memmory I allocated by using the function createArray(); Is this really free's the memmory? If so, I'll rewrite the malloc function with some help, and then make a part that always if I malloc'ed some memmory it calls addToList() and then at the end of the program I don't need to free() every single thing, I just call freeAll and it free's for me, of course, if this works

Yeah that will work

side note:

you probably need to change the following line

Code:

int *array = malloc(SIZE * sizeof( int ) );

to

Code:

int *array = (int*)malloc(SIZE * sizeof( int ) );

you're declaring a int *, malloc return a void *...

Originally posted by Mercury_Linx
Yeah that will work

Code:

int *array = (int*)malloc(SIZE * sizeof( int ) );

you're declaring a int *, malloc return a void *...

No. You never need to type cast malloc. It is pointless. Search the forums if you're bored, for lengthy debates on why or why not to, but in short, there is no need. (Unless you're using C++, in which case, you're in the wrong forum .)

Quzah.

That may look useful at first glance, and not that it's bad code or anything, but just not a good solution to the problem. I would suggest using a simple linked list. Something that would be used like:

Code:

int main()
{
 memory_manager mm;
 mminit(&mm);
 int * i = mmalloc(&mm, 100*sizeof(int));
 //...
 mmfree(&mm); 
}

This could be used across many programs without a single static variable - and without some of the other, more glaring limitations, as well. IMO - back to the drawing board...