Grand Central Dispatch

What is Grand central dispatch.

What is Concurrency?

• Doing multiple things at the same time.

• Taking advantage of number of cores available in multicore CPUs.

• Running multiple programs in parallel.

Objectives of Concurrency

• Running program in background without hogging CPU.

Define Tasks, Define Rules and let the system take the responsibility of performing them.

Improve responsiveness by ensuring that the main thread is free to respond to user events.

DISPATCH QUEUES

Grand central dispatch – dispatch queues allows us to execute arbitrary blocks of code either asynchronously or synchronously All Dispatch Queues are first in – first out All the tasks added to dispatch queue are started in the order they were added to the dispatch queue.