A deadlock occurs when all threads remain blocked, causing the entire application to hang. It is a major debugging challenge in multithreaded programs. section 16.5
Forgetting to release a mutex
A thread enters a critical region by acquiring a mutex but fails to release it when leaving. Other threads block while trying to acquire that mutex, and the program may stop running entirely. Python’s with statement helps by releasing the mutex automatically when the region finishes. section 16.2.1
Avoid deadlock by managing synchronization carefully:
- Release every mutex or semaphore before exiting its critical region. section 16.6
- Treat mutexes, semaphores, and condition objects as synchronization tools with runtime and design costs. section 16.5
