General C++ questions, Signal Processing questions like convolution

Difference between macro and inline function. Call the main function from the cmd line and pass two arguments to it and with these arguments call macro and inline function defined above. Whose execution will be faster? Find the size of int in C without using sizeof() operator. Inter-Process Communication OOPs concepts Virtual function and virtual class Function overriding and function overloading difference How to implement function overriding in C Extern keyword related questions Some other questions related to operating systems like threads, semaphores, mutex, spinlocks, scheduling algos, etc.