Minimal first-fit memory allocator implementation
janitor is a minimal memory allocator implementation that relies on a singly linked-list in order to store blocks of allocated memory. This works similarly in a way a mark-sweek garbage collector would work, except for the fact that C does not utilize automatic memory deallocation.
$ gcc -o test test.c janitor.c
jmalloc - using a first-fit approach, check if our list already contains free blocks that haven't been marked. if not, set the program break of the heap and set the head to the new block.
jcalloc - works like jmalloc, but instead implements memset to zero out the newly allocated block
jrealloc - allocates new block with jmalloc if block does not exist. Otherwise, allocate an empty block of specified size, and copy specified block into newly created block with new size.
jfree - checks if specified block and size of all blocks meet at program break. NULL out the block until that point. Set new program break and mark block as deallocated.