Grand Central Dispatch is a low-level API provided by Apple for managing concurrent operations. GCD abstracts away many of the complexities of thread management and provides a simple and efficient way to execute tasks concurrently.
It provides a set of APIs for managing tasks and executing them concurrently on multicore hardware. GCD helps developers to create responsive and scalable applications by offloading time-consuming tasks to background threads, thus keeping the main thread free to handle user interactions.
There are two types of dispatch queues:
- Serial Queues: Executes tasks one at a time in the order they are added to the queue. Tasks in a serial queue are guaranteed to run sequentially.
- Concurrent Queues: Can execute multiple tasks concurrently. Tasks may start and finish in any order.
Serial Queues
A serial queue is a type of dispatch queue in Grand Central Dispatch (GCD) that executes tasks in a FIFO (first-in, first-out) order. This means that tasks added to the queue are executed one at a time, in the order in which they were added.
Serial queues are useful when you want to ensure that tasks are executed sequentially, avoiding concurrency issues such as race conditions.
Concurrent Queues
A concurrent queue in Swift allows multiple tasks to be executed concurrently, meaning they can run simultaneously. Unlike serial queues, tasks in a concurrent queue can start and finish in any order.
