NSCondition用法

使用NSCondition，实现多线程同步。。。举个列子消费者跟生产者。。。

现在传言6s要出了。。

消费者想买6s。现在还没有6s。消费者等待6s生产。
生产了一个产品，唤起消费者去买6s。解锁

 1 @interface ViewController ()

 2 /*

 3  创建一个数组盛放生产的数据，创建一个线程锁

 4  */

 5 @property (nonatomic, strong) NSCondition *condition;

 6 @property (nonatomic, strong) NSMutableArray *products;

 7

 8 @end

 9

10 @implementation ViewController

11 #pragma mark - event reponse

12 /*

13  拖拽一个点击事件，创建两个线程

14  */

15 - (IBAction)coditionTest:(id)sender {

16     NSLog(@"condiction 开始");

17      [NSThread detachNewThreadSelector:@selector(createConsumenr) toTarget:self withObject:nil];

18     [NSThread detachNewThreadSelector:@selector(createProducter) toTarget:self withObject:nil];

19 }

20

21 #pragma mark - provate methods

22 - (void)createConsumenr

23 {

24     [self.condition lock];

25     while(self.products.count == 0){

26         NSLog(@"等待产品");

27         [_condition wait];

28     }

29     [self.products removeObject:0];

30      NSLog(@"消费产品");

31     [_condition unlock];

32 }

33

34 - (void)createProducter

35 {

36     [self.condition lock];

37     [self.products addObject:[[NSObject alloc] init]];

38     NSLog(@"生产了一个产品");

39     [_condition signal];

40     [_condition unlock];

41 }

42

43 #pragma mark - getters and setters

44 - (NSMutableArray *)products

45 {

46     if(_products == nil){

47         _products = [[NSMutableArray alloc] initWithCapacity:30];

48     }

49     return _products;

50 }

51

52 - (NSCondition *)condition

53 {

54     if(_condition == nil){

55         _condition = [[NSCondition alloc] init];

56     }

57     return _condition;

58 }

59

60 @end

最后附上运行结果

2015-05-27 10:14:32.283 Test-NSCondition[43215:1648129] condiction 开始

2015-05-27 10:14:37.051 Test-NSCondition[43215:1648533] 等待产品

2015-05-27 10:14:37.056 Test-NSCondition[43215:1648534] 生产了一个产品

2015-05-27 10:14:37.056 Test-NSCondition[43215:1648533] 消费产品