Question

What is the Best Pattern or Topology for avoid Memory Leaks in Projects

Answer 1

There are two problems -
One is memory leak and another is memory corruption which are similar in the nature and we should always use the following topology -
1. Always nullify the pointer after free.
2. While free first check if it is null.
3. Use the smart pointer in C++ to avoid the dangling pointer (http://ootips.org/yonat/4dev/smart-pointers.html )
4. Always check the return of malloc to see if was succeeded
5. You can create a wrapper over malloc and free to to keep the track of count i.e. free count and allocated count on the following lines -

void *my_alloc (size_t size)
{
    void *p;

    p = malloc(size);
    if (p)
    {
        my_count_alloc++;
    }
    else
        return null;

    return (p);
}

void my_free (void *p)
{
    if (p)
    {
        free(p);
        my_count_free++;
    }
}

and at the end u can match the free count to the allocated count.

Answer 2

there are three parts -
1. why/when/where you are allocating,
2. what is the lifetime of object
3. and last why/when/where you want to free it.

Before allocating you should be very clear about these three parts.
To work in multi-threaded application, there is reference counting, weak pointers etc
(http://www.codingwisdom.com/codingwisdom/2012/09/reference-counted-smart-pointers-are-for-retards.html).
(do read the discussions also)