What this topic actually controls

Dynamic allocation is a lifecycle problem: allocate, initialize, use, transfer ownership if needed, then free exactly once. Most runtime memory faults trace back to broken lifecycle bookkeeping.

Heap allocation can fail; null returns are part of normal control flow on constrained systems.

realloc can move memory and invalidate old pointers on success.

Ownership ambiguity creates both leaks and use-after-free defects.

Quantitative behavior you should be able to compute

Heap bytes for n objects:

Where:

• $B$: heap bytes requested
• $n$: object count
• $T$: object type

Leak ratio in a run:

Where:

• $L$: leak ratio estimate

Design path from requirement to implementation

1. Define ownership at API boundaries in comments and function names.
2. Use overflow-safe size calculations before allocation.
3. Centralize cleanup in one exit path to reduce leak branches.
4. Instrument allocation and free counts in debug builds.

Where real projects usually break

• Never assign realloc result directly over the original pointer without temporary variable.
• Do not free memory from unknown allocator source.
• A non-null pointer is not proof of valid lifetime.
• Run sanitizer/memory tools before trusting stress-test success.

When ownership is explicit and cleanup paths are systematic, dynamic memory becomes predictable instead of fragile.