Question

I had the habit for a while to call malloc on anything. Then it dawned to me if there’s no performance critical section of the code, why not use a couple of kilobytes more on an automatic and lose the accuracy of the amount of memory I need (potentially) of the malloc procedure? That way with no noticeable impact one can make much more readable code. e.g. copying temporarily a string for manipulating it in a function that is called very rarely.

Is my logic sound?

Answer 1

Local variables are stored on the stack, which is limited. malloc() allocates memory from the heap, which is also limited but contains far more memory.

I generally do not use malloc() unless the amount of memory would exceed what I could safely store on the stack.

For Windows development, the stacks are normally pretty large. You could store a buffer of up to a couple of hundred bytes without too much trouble (assuming the function would never be called recursively).

But, generally, if I need more than, say, 50 bytes, I would normally use malloc().