Concurrency and Multithreading Questions

Principles and practical techniques for concurrent execution and safe access to shared state across threads or execution contexts. Covers synchronization primitives (locks, mutexes, semaphores, condition variables), atomic operations and memory ordering, avoiding deadlocks, race conditions, and livelocks, designing thread safe data structures, thread pools and work scheduling, and asynchronous or event driven execution models such as coroutines, futures and promises, and reactive streams. Also covers platform and language specific concurrency tools, for example java.util.concurrent and POSIX threads on backend systems, Grand Central Dispatch and OperationQueue on iOS, coroutines and structured concurrency on Android/Kotlin, and async/await models in other languages. Evaluations focus on reasoning about correctness under concurrent access, performance trade offs (throughput, latency, contention), and preventing blocking of latency sensitive execution paths (server request handlers, UI threads, game loops) to maintain responsiveness.