CPP Memory Management & Performance Optimization 2

Question 1

What is a dangling pointer?

Accepted Answer

A pointer that points to freed or invalid memory

Answer

A dangling pointer references memory that has already been freed, leading to undefined behavior if dereferenced.

Question 2

Which profiling technique samples the call stack at regular intervals to identify hotspots?

Accepted Answer

Sampling profiling

Answer

Sampling profilers periodically capture the call stack to approximate where a program spends most of its time with low overhead.

Question 3

What is the purpose of lazy initialization?

Accepted Answer

Defer object creation until the first time it is actually needed

Answer

Lazy initialization avoids expensive setup until it's necessary, improving startup time and avoiding unnecessary resource use.

Question 4

What causes a stack overflow error?

Accepted Answer

Excessive recursion or very large local variables exhausting the call stack

Answer

A stack overflow occurs when the call stack grows beyond its fixed size limit, typically due to infinite or very deep recursion.

Question 5

What is memory fragmentation and how does it affect performance?

Accepted Answer

Free memory blocks scattered throughout the heap making it hard to allocate large contiguous blocks

Answer

Heap fragmentation results in wasted memory and allocation failures even when total free memory is sufficient but not contiguous.

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