Multithreading Nsthread GCD

iOS Multithreading implementation types

Nsthread

Nsoperationqueue

NSObject
GCD

***************

1.NSThread

Threads

First Kind

Nsthread *thread1=[[nsthread alloc] initwithtarget:self selector: @selector (sum) object:nil];

//

give the thread a name

[Email protected] "thread1";

Start Thread

[Thread1 start];

End Thread

[Thread1 Cancel];

The second (does not need to be manually opened )

[Nsthread detachnewthreadselector: @selector (sum) totarget:self Withobject:nil];

2. two subcategories of nsoperation

// one .

Nsinvocationoperation *inop=[[nsinvocationoperation alloc] initwithtarget:self Selector :@selector(Invocation) object:nil];

[Inop start];

// two .

Nsblockoperation *blop=[nsblockoperation blockoperationwithblock: ^{

NSLog (@ " I am block");

}];

Create a queue

Nsoperationqueue *queue=[[nsoperationqueue alloc] init];

//Set maximum concurrent quantity

Queue.maxconcurrentoperationcount=2;

Add Event

[Queue Addoperation:inop];

[Queue addoperation:blop];

3.NSObject

[Self performselectorinbackground: @selector (sum) withobject:nil];

4.GCD

GCD (FIFO )

Serial : The previous task was completed before a task could be executed

Parallel : The task is ordered when it is dispatched , but should not begin until the first task is completed .

GCD queue in 3 : Primary queue , global queue , custom queue

1. Use the master queue for task dispatch (serial ), in the main thread

dispatch_queue_t Mainqueue=dispatch_get_main_queue ();

1.1 Adding tasks

Dispatch_async (Mainqueue, ^{

NSLog (@ " first task: current thread is%@", [Nsthread CurrentThread]);

});

Serial

2. Custom Queues

/*

dispatch_queue_t myqueue=dispatch_queue_create ("Com.lanlan.myqueue", dispatch_queue_serial);

2.1 Adding Tasks

Dispatch_async (Myqueue, ^{

NSLog (@ " first task: current thread:%@", [Nsthread CurrentThread]);

});

Parallel

3. Custom Queues

/*

dispatch_queue_t myqueue2=dispatch_queue_create ("Com.lanlan.myqueue", dispatch_queue_concurrent);

3.1 Adding tasks

Dispatch_async (MyQueue2, ^{

NSLog (@ " first task: current thread:%@", [Nsthread CurrentThread]);

});

4. Global Queue

/*

dispatch_queue_t globelqueue=dispatch_get_global_queue (dispatch_queue_priority_default, 0);

4.1 Adding Tasks

Dispatch_async (Globelqueue, ^{

NSLog (@ " first task: current thread:%@", [Nsthread CurrentThread]);

});

5. Only one execution is guaranteed

Guaranteed to execute only once

Static dispatch_once_t Oncetoken;

Dispatch_once (&oncetoken, ^{

NSLog (@ " the code here only executes once");

});

6. Delay after 5 seconds to execute

Dispatch_after (Dispatch_time (Dispatch_time_now, (int64_t) (5 * nsec_per_sec)), Dispatch_get_main_queue (), ^{

NSLog (@ " wait for me 5 seconds ...");

});

7.// Repeat execution

Dispatch_apply (5, Dispatch_get_global_queue (Dispatch_queue_priority_default, 0), ^ (size_t t) {

NSLog (@ " nice weather Today");

});

Child threads

[Nsthread detachnewthreadselector:@selector(newthead) totarget:self withobject: Nil];

//back to main thread

[self performselectoronmainthread:@selector(Mymaintherad) withobject: Self Waituntildone:NO];

-(void) Mymaintherad

{

Print Thread

NSLog (@ " I am in the mainline thread %@", [Nsthread CurrentThread]);

}

Multithreading Nsthread GCD