Analysis of different queues in gcd with different functions

Two kinds of functions :

1>sync sync function ,

2>Async async function ,

Four types of queues :

1>main queue home row

2> manually created serial queues

3> Global concurrency queue

4> manually created concurrent queues

The program verifies that the two functions work together with four types of queues : A total of eight . Global concurrent queues and created concurrent queues perform the same effect, not given.

Results :

1> deadlock , the previous article has been introduced , add one thing is : The main thread in the current queue adds a task to deadlock , add to another queue does not

2> synchronization function with four queues does not open a new thread

The 3> async function does not open a new thread when mated to the home column , and other cases open the thread .

4> in the serial execution of tasks, or concurrent execution of tasks , to clarify which queue , refers to the queue after switching .

Here are eight cases of code :

The following code is the serial queue asynchronous execution, the output forgot to change:

Analysis of different queues in gcd with different functions