@interface ViewController ()
{
//NSLock * lock;
NSCondition * condition;
}
//媒介，緩衝池
@property (nonatomic, strong) NSMutableArray * array;
@end
@implementation ViewController
- (NSMutableArray *)array
{
if (!_array)
{
_array = [NSMutableArray array];
}
return _array;
}
- (void)viewDidLoad {
[super viewDidLoad];
//創建按鈕
//初始化
condition = [[NSCondition alloc] init];
UIButton * btn = [UIButton buttonWithType:UIButtonTypeContactAdd];
btn.center = self.view.center;
[self.view addSubview:btn];
[btn addTarget:self action:@selector(_productor) forControlEvents:UIControlEventTouchUpInside];
//生產與購買
//通過多線程訪問這兩個方法
for (int i = 0; i<5; i++)
{
[self performSelectorInBackground:@selector(_consumer) withObject:nil];
}
}
//生產者
- (void)_productor
{
[condition lock];
[NSThread sleepForTimeInterval:.5];
if (self.array.count != 0)//緩衝池中一般規定只有一個，所以做一個判斷，進來之後，什麼都不做。
{
// [condition wait];
}
else
{
[self.array addObject:@"產品"];
NSLog(@"產品生產成功");
[condition signal];//隨機喚醒一個等待的消費者
//[condition broadcast];
}
[condition unlock];
}
//消費者
- (void)_consumer
{
[condition lock];
if (self.array.count <= 0)
{
NSLog(@"池子沒貨物,等待生產");
[condition wait];//wait之後，當前線程阻塞，其他線程還可以進來
}
NSLog(@"產品購買成功");
[self.array removeLastObject];
//[condition signal];
[condition unlock];
}