Free-Store vs Heap: Are They Distinct Entities in C ?

In C , the terms "free-store" and "heap" are often used interchangeably to refer to the memory region where dynamic allocations are managed. However, it's essential to understand whether there is a practical difference between these terms.

Conceptual Distinction

Historically, the free-store was the memory area reserved for dynamically allocated objects using the "new" and "delete" operators. On the other hand, the heap was a separate region used by "malloc" and "free" for allocating memory at a lower level. This distinction aimed to prevent mixing different memory management mechanisms and potential conflicts.

Compiler Perspective

In modern C implementations, the distinction between free-store and heap has become largely conceptual. Compilers typically do not make a practical distinction between the two terms. Both "new" and "malloc" allocate memory from the same underlying memory management system.

Memory Usage

While theoretically possible, it's unlikely that a compiler would allocate memory for "new" and "malloc" in separate memory spaces. Both mechanisms allocate memory within the same heap region. However, it's worth noting that some C compilers may provide compiler-specific options that allow you to allocate memory from specific heap areas.

Conclusion

In practice, the terms "free-store" and "heap" are functionally equivalent in C . Both refer to the same memory region used for dynamic memory allocation. The distinction between the two terms serves primarily as a reminder to segregate the use of "new/delete" and "malloc/free" for proper code organization. It's not a rigid division that affects the actual behavior of memory allocation in C .