Python's multiprocessing module enables CPU-intensive applications to bypass the Global Interpreter Lock by running separate processes. Since processes don't share memory by default, managing shared state requires specific tools: Value and Array for simple primitives, Manager for complex objects like dictionaries and lists, Lock for synchronization, and shared_memory for high-performance large data sharing. Each approach has trade-offs between flexibility and performance, with Manager being more versatile but slower due to proxying, while shared_memory offers the best performance for large binary data like numpy arrays.
Table of contents
What Is Multiprocessing?So, Why Shared State is Hard in MultiprocessingMethod 1: multiprocessing.Value and ArrayMethod 2: multiprocessing.ManagerMethod 3: Using multiprocessing.Lock and RLockAdvanced Usage: Shared Memory with multiprocessing.shared_memory (Python 3.8+)Caveats and Best PracticesSummaryFinal ThoughtsSort: