Why Python is not better in multiprocessing or multithreading applications than Java?

Question

Since Python has some issues with GIL, Java is better for developing multiprocessing applications. Could you please justify the exact reasoning of java's effective processing than python in your way?

Answer 1

The biggest problem in multithreading in CPython is the Global Interpreter Lock (GIL) (note that other Python implementations don't necessarily share this problem!)

The GIL is an implementation detail that effectively prevents parallel (simultaneous) execution of separate threads in Python. The problem is that whenever Python byte code is to be executed, then the current thread must have acquired the GIL and only a single thread can have the GIL at any given moment.

So if 5 threads are trying to execute some Python byte code, then they will effectively run interleaved, because each one will have to wait for the GIL to become available. This is not usually a problem with single-core computers, as the physical constraints have the same effect: only a single thread can run at a time.

In multi-core/SMP computers, however this becomes a bottleneck. These days almost everthing is running on multiple cores, including effectively all smartphones and even many embedded systems.

Java has no such restrictions, so multiple threads can execute at the exact same time.