#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <errno.h>

/* Singly linked list with a pointer to the next element and a pointer to a value. */

struct _list
{
    struct _list *next;
    void         *val;
};

typedef struct _list list;


void *mem_get( size_t size )
{
    /* Allocate a given chunk of memory to a pointer that is returned. */

    void *pt;

    assert( size > 0 );

    if ( ( pt = malloc( size ) ) == NULL )
    {
        fprintf( stderr, "ERROR: Could not allocate %zu byte(s): %s\n", size, strerror( errno ) );
        abort();
    } 

    return pt;
}


void mem_free( void *pt )
{
    /* Free memory from a given pointer. */

    void **ppt = ( void ** ) pt;
    void  *p   = *ppt;

    if ( p != NULL )
    {
        free( p );

        p = NULL;
    }

    *ppt = NULL;
}


void list_add( list **list_ppt, void *val )
{
    /* Add a new singly linked list element with a pointer. */

    list *list_pt = *list_ppt;
    list *new     = NULL;

    new = mem_get( sizeof( list ) );

    new->val  = val;
    new->next = list_pt;

    *list_ppt = new;
}


int main()
{
    int   i     = 0;
    list *new   = NULL;
    list  *next = NULL;
    list  *elem = NULL;

//    This test works nicely
//    char *test  = NULL;
//
//    test = mem_get( 100000000 );
//
//    mem_free( &test );
//
//    while( 1 )
//        ;

    fprintf( stderr, "Adding ...\n" );

    for ( i = 0; i < 10000000; i++ ) {
        list_add( &new, "TEST" );
    }

    fprintf( stderr, "Freeing ...\n" );

    next = new;

    while ( next != NULL )
    {
        elem = next;

        next = elem->next;
        mem_free( &elem );
    }

    fprintf( stderr, "Done\n" );

    while( 1 )
        ;

    return EXIT_SUCCESS;
}