Grand Central Dispatch (GCD) in Swift.

 



In Swift, you can use the Grand Central Dispatch (GCD) framework to perform tasks concurrently. GCD allows you to execute code on different queues, which can be either serial or concurrent.

Dispatch Queues: GCD uses dispatch queues to execute code. You can create your own queues or use the predefined global queues. Global queues are concurrent queues that are automatically created for you by the system.

Dispatching to Queues: To execute code on a queue, you use the dispatchQueue.async method to add a closure to the queue. The closure will be executed as soon as a thread becomes available

For example, you can use the following code to dispatch a task to the global queue:




You can also use the following code to dispatch a task to a specific queue:




DispatchGroups: Dispatch groups allow you to group multiple tasks together and track when they have all completed. Once all the tasks in the group have completed, you can perform some additional work.




and then use the enter() and leave() methods to add tasks to the group and track their completion.




DispatchBarrier: DispatchBarrier allows to add a barrier to a concurrent queue, this means that all the tasks that were added to the queue before the barrier will be executed first and all the tasks added after the barrier will be executed after all the previous tasks have completed.

For example, you can use the following code to add a barrier to a queue:




GCD is a powerful framework that allows you to execute tasks concurrently in Swift by creating and dispatching tasks to queues, and by grouping and tracking tasks using dispatch groups and barriers. This allows your app to perform multiple tasks at the same time, improving its performance and responsiveness.




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