What is the concept of multiprocessing and what are its main advantages and disadvantages?

Multithreading is a concept where a program uses multiple processes to perform tasks in parallel. In Python, this is especially relevant due to the limitations of GIL (Global Interpreter Lock), which prevents effective use of multithreading for CPU-bound tasks.

Advantages of multiprocessing:

• Actual parallel execution of code on multiple CPU cores.
• Process isolation: failure of one process does not directly affect others.
• Bypassing GIL limitations in Python.

Disadvantages:

• Higher resource consumption (each process has its own memory).
• Difficulties in data exchange between processes (requires IPC mechanisms).
• More complex process management compared to threads.

Example of using the multiprocessing module in Python:

from multiprocessing import Pool

def f(x):
    return x * x

if __name__ == '__main__':
    with Pool(4) as p:
        results = p.map(f, [1, 2, 3, 4])
    print(results)  # [1, 4, 9, 16]

Here, a pool of 4 processes is created, which compute the function f in parallel for different input data.