Thread Explosion in iOS: GCD and Swift Concurrency

Thread explosion occurs when multiple threads run simultaneously, causing performance degradation and memory overhead. In Grand Central Dispatch (GCD), thread explosion can happen in both concurrent and serial queues. GCD doesn't have a built-in mechanism to prevent thread explosion, which can lead to deadlocks. Deadlocks can occur when multiple queues are waiting for each other to release resources. To prevent thread explosion in GCD, three possible solutions are available: using OperationQueue to limit simultaneous tasks, using DispatchSemaphore to limit simultaneous tasks, and using Swift Concurrency. Swift Concurrency can manage thread explosion by prioritizing tasks and limiting concurrency based on available resources. In Swift Concurrency, tasks are assigned priorities, including .userInitiated, .utility, and .background. The system limits the number of threads to the number of CPU cores, preventing thread explosion. Swift Concurrency also allows tasks with different priorities to run concurrently without negatively impacting performance. Swift Concurrency's approach to concurrency management reduces the risk of thread explosion and optimizes performance. By prioritizing tasks and limiting concurrency, Swift Concurrency ensures that multiple tasks can run concurrently without overwhelming the system. This approach improves upon GCD's concurrency management, offering a more structured and efficient way to handle concurrent tasks. Swift Concurrency's ability to handle tasks with different priorities efficiently maintains a balance even when tasks run concurrently. The system can process multiple threads simultaneously, and introducing delays between task groups can impact their execution. Overall, Swift Concurrency provides a more efficient and structured approach to concurrency management, reducing the risk of thread explosion and optimizing performance.