Chapter 22
What is the difference in memory management between Python and C++?
C++ associates a variable to its value by simply writing the value to the memory location of the variable; Python has its variables reference point to the memory location of the values that they hold. For this reason, Python needs to maintain a reference count for every value in its memory space.
What problem does the GIL solve for Python?
To avoid race conditions, and consequently, the corruption of value reference counts, the GIL is implemented so that only one thread can access and mutate the counts at any given time.
What problem does the GIL create for Python?
The GIL effectively prevents multiple threads from taking advantage of the CPU and executing CPU-bound instructions at the same time. This means that if multiple threads that are meant to be executed concurrently are CPU-bound, they will actually be executed sequentially.
What are some of the approaches to circumventing the GIL in Python programs?
There are a few ways to deal with the GIL in your Python applications; namely, implementing multiprocessing instead of multithreading, and utilizing other, alternative Python interpreters.
