NSOperationqueue的一些感悟

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor redColor];
    
    NSOperationQueue *queue=[[NSOperationQueue alloc]init];
    
    NSOperationQueue *queue2=[[NSOperationQueue alloc]init];
    
    NSBlockOperation *operation1=[NSBlockOperation blockOperationWithBlock:^(){
        NSLog(@"执行第一次:%@",[NSThread currentThread]);
    }];

    
    NSBlockOperation *operation2=[NSBlockOperation blockOperationWithBlock:^(){
        NSLog(@"执行第二次:%@",[NSThread currentThread]);
    }];
    
    [operation1 addDependency:operation2];
    [queue addOperation:operation1];
    [queue addOperation:operation2 ];
    
    NSBlockOperation *operation3=[NSBlockOperation blockOperationWithBlock:^(){
        NSLog(@"执行第三次:%@",[NSThread currentThread]);
    }];
    NSBlockOperation *operation4=[NSBlockOperation blockOperationWithBlock:^(){
        NSLog(@"执行第四次:%@",[NSThread currentThread]);
    }];
    
    [queue2 addOperation:operation4];
    [queue2 addOperation:operation3];

2016-05-10 17:00:00.552 testobjectc[2305:152414] 执行第四次:<NSThread: 0x78e89910>{number = 2, name = (null)}
2016-05-10 17:00:00.552 testobjectc[2305:152410] 执行第二次:<NSThread: 0x78e60090>{number = 3, name = (null)}
2016-05-10 17:00:00.553 testobjectc[2305:152415] 执行第三次:<NSThread: 0x78fa4280>{number = 4, name = (null)}
2016-05-10 17:00:00.559 testobjectc[2305:152414] 执行第一次:<NSThread: 0x78e89910>{number = 2, name = (null)}