Processes vs. ThreadsBypassing the Global Interpreter Lock (GIL)When to Use MultiprocessingCreating and Managing ProcessesThe multiprocessing.Process ClassStarting Processes with start()Waiting for Processes to Finish with join()Custom Processes with a ClassDaemon ProcessesChecking Process InformationInter-process Communication (IPC) and Data SharingWhy Processes Don’t Share MemoryShared Memory with multiprocessing.Value and multiprocessing.ArrayExample: Using Value to Share a CounterExample: Using Array to Share a List of NumbersMessage Passing with Pipes (multiprocessing.Pipe)Example: Sending a Message from Child to ParentMessage Passing with Queues (multiprocessing.Queue and multiprocessing.SimpleQueue)Example: Multiple Processes Sending Results to a Shared QueueManagers for Shared ObjectsExample: Using a Manager to Share a DictionaryProcess Pools for Task DistributionIntroduction to multiprocessing.PoolExample: Using pool.map() to Compute Squares in ParallelSubmitting Tasks to the Pool: apply_async() and map_async()apply_async(func, args=(), kwds={}, callback=None, error_callback=None)map_async(func, iterable, chunksize=None, callback=None, error_callback=None)Example: Using apply_async() and map_async()concurrent.futures.ProcessPoolExecutor: A Modern AlternativeExample: Using ProcessPoolExecutor to Compute SquaresHandling Results and Exceptions in PoolsExample: Handling Exceptions from Worker FunctionsComparing Pool and Executor with ThreadsProcess Start Methods: Choosing the Right ApproachExplanation of Start Methods: spawn, fork, forkserverspawnforkforkserverWhen to Use Each Start Method and Platform DependenciesWhen to Choose spawnWhen to Choose forkWhen to Choose forkserverSetting the Start Method in CodeSynchronization Between ProcessesNeed for Synchronization Primitives in MultiprocessingOverview and Usage of Synchronization PrimitivesLocks and RLocks (multiprocessing.Lock, multiprocessing.RLock)Example: Protecting a Shared CounterSemaphores (multiprocessing.Semaphore, multiprocessing.BoundedSemaphore)Events (multiprocessing.Event)Example: Starting All Workers at the Same TimeConditions (multiprocessing.Condition)Example: Signaling a Consumer When a Queue Is Non-emptyBarrier (multiprocessing.Barrier)Example: Synchronizing Three ProcessesReal-World Use: Shared Locks with ManagersExample: Locking Access to a Shared DictionaryUsing Synchronization Primitives with Context ManagersShared State vs. Message PassingConclusion
