- (void)defaulTimer1{
    NSTimer *_time1=[NSTimer timerWithTimeInterval:1 repeats:YES block:^(NSTimer * _Nonnull timer) {
        NSLog(@"%@",[NSRunLoop currentRunLoop].currentMode);
    }];
    [[NSRunLoop currentRunLoop] addTimer:_time1 forMode:NSDefaultRunLoopMode];
}

- (void)defaulTimer2{//scrollview滑動定時器也運行
    NSTimer *_time1=[NSTimer timerWithTimeInterval:1 repeats:YES block:^(NSTimer * _Nonnull timer) {
        NSLog(@"%@",[NSRunLoop currentRunLoop].currentMode);
    }];
    [[NSRunLoop currentRunLoop] addTimer:_time1 forMode:NSRunLoopCommonModes];
}


- (void)defaulTimer3{//schedule開頭的都默認加到defaultMode中
    NSTimer * _timer=[NSTimer scheduledTimerWithTimeInterval:1 repeats:YES block:^(NSTimer * _Nonnull timer) {
        NSLog(@"%@",[NSRunLoop currentRunLoop].currentMode);
    }];
    [_timer fire];
}

//為了不阻礙主線程，再開一個子線程創(chuàng)建定時器
//創(chuàng)建子線程的RunLoop直接調用[NSRunLoop currentRunLoop];
//一定要讓子線程的runLoop跑起來, 不然的話, 子線程一結束, 運行循環(huán)立馬銷毀
- (void)defaulTimer4{
   dispatch_async(dispatch_get_global_queue(0, 0), ^{
       NSTimer *_time1=[NSTimer timerWithTimeInterval:1 repeats:YES block:^(NSTimer * _Nonnull timer) {
           NSLog(@"%@",[NSRunLoop currentRunLoop].currentMode);
       }];
       //NSRunLoop * mainRunLoop=[NSRunLoop mainRunLoop];
       NSRunLoop *currentRunLoop = [NSRunLoop currentRunLoop];
       [currentRunLoop addTimer:_time1 forMode:NSRunLoopCommonModes];
       [currentRunLoop run];
   });
}

//并發(fā)調多個接口，都返回更新UI
dispatch_group_enter(_group);
    [_userOtherViewModel getPublish:_userID minID:@"" callback:^(NSInteger state, NSString *msg) {
        dispatch_group_leave(_group);
    }];
    dispatch_group_enter(_group);
    [_userOtherViewModel getMyComment:_userID minID:@"" callback:^(NSInteger state, NSString *msg) {
        dispatch_group_leave(_group);
    }];
    dispatch_group_notify(_group, dispatch_get_main_queue(), ^{
        [ self updateUI];
    });

- (void)semaphore{
    //對有限資源的約束
    dispatch_semaphore_t semaphore=dispatch_semaphore_create(1);
    //value約束幾個線程訪問資源  getdtablesize()取得程序所有線程的個數
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);//如果有人占用資源微猖，我一直等待
        NSLog(@"我有了資源");
        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);//如果有人占用資源绣夺，我一直等待
        NSLog(@"我有了資源1");
    });
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        sleep(2);
         NSLog(@"在做事");//比如對文件操作或播視頻
        //訪問資源的這個人走時發(fā)送一個信息量
        dispatch_semaphore_signal(semaphore);
    });
}