Why free() doesn't really frees memory?

Question

i\'m doing some tests allocating and deallocating memory. This is the code i\'m using:

#include 
#include 

#define WAVE_SIZE          


        

Answer 1

free() merely tells the allocator that your program no long needs this block. The allocator may cache it for further allocation, or it may return it to the system by change the brk pointer. It all depends on the implementation.