多线程 NSCondition线程同步

#import "ViewController.h"

@interface ViewController ()

{
    NSCondition *_condition;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    _condition = [[NSCondition alloc] init];
    
    //创建消费者线程 等待生产者完成任务后执行
    [self performSelectorInBackground:@selector(waitAction) withObject:nil];
    
    [self performSelector:@selector(makeProduct) withObject:nil afterDelay:3];
}

//消费者等待
-(void)waitAction
{
    NSLog(@"pay.....");
    NSLog(@"wait.....");
    //加锁
    [_condition lock];
    
    //等待
    [_condition wait];
    
    NSLog(@"drink......");
    
}

//生产者
-(void)makeProduct
{
    NSLog(@"made in china");
    
    //发送信号
    [_condition signal];
}
@end