What mechanism of dispatching provides the minimum delay time when executing tasks?

In iOS, the minimum delay time when executing tasks is provided by the dispatching mechanism using Dispatch Queues from Grand Central Dispatch (GCD).

For minimal delay, the following are typically used:

• Main Dispatch Queue — for tasks related to UI updates, executed on the main thread.
• Concurrent Dispatch Queues with high priority (QoS) — for background tasks requiring quick response.

Example of creating and using a high-priority queue:

let queue = DispatchQueue.global(qos: .userInitiated)
queue.async {
    // Fast task execution
}

Using GCD allows efficient thread management and minimizes delays in task execution.