iOS_多线程（一）

#import "ViewController.h"

@interface ViewController ()
{
    NSUInteger _tickets;
}
@property (weak, nonatomic) IBOutlet UITextView *textView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //初始化票数
    _tickets = 30;
    //设置textView
    self.textView.text = @"";
    //创建NSOperation
    NSInvocationOperation *operation1 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(operationSaleMethod:) object:@"售票线程-1"];
    NSInvocationOperation *operation2 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(operationSaleMethod:) object:@"售票线程-2"];
    //创建NSOperationQueue队列
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];   
    //为operation1添加依赖，只有当operation2执行完毕时，operation1才能执行。
    [operation1 addDependency:operation2];
    //将operation加入到队列
    [queue addOperation:operation1];
    [queue addOperation:operation2];  
}

#pragma mark - 更新UI
-(void)appendTextView:(NSString *)text
{
    //1.先获取原先的内容
    NSMutableString *str = [[NSMutableString alloc]initWithString:self.textView.text];
    NSRange range = NSMakeRange(str.length, 1);
    //2.追加新的内容
    [str appendString:[NSString stringWithFormat:@"%@\n",text]];
    [self.textView setText:str];
    //3.滚动textView
    [self.textView scrollRangeToVisible:range];
}
#pragma mark - 线程调用的方法
-(void)operationSaleMethod:(NSString *)name
{
    while (YES)
    {
        //判断剩余票数
        if (_tickets > 0)
        {
            @synchronized(self)
            {
                NSString *info = [NSString stringWithFormat:@"总的票数：%ld,当前线程：%@",_tickets,name];
                [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                    [self appendTextView:info];
                }];
                //卖票
                _tickets--;
            }
            if ([name isEqualToString:@"售票线程-1"])
            {
                //线程休眠
                [NSThread sleepForTimeInterval:0.3f];
            }
            else
            {
                [NSThread sleepForTimeInterval:0.2f];
            }
        }
        else
        {
            //更新UI
            NSString *info = [NSString stringWithFormat:@"已无剩余票数，当前线程：%@",name];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [self appendTextView:info];
            }];       
            break;
        }
    }
}
@end

#import "ViewController.h"

@interface ViewController ()
{
    NSInteger _tickets;
}
@property (weak, nonatomic) IBOutlet UITextView *textView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //初始化票数
    _tickets = 30;
    //设置textView
    self.textView.text = @"";
    
    //创建NSOperationQueue队列
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    //设置线程的并行数量
    [queue setMaxConcurrentOperationCount:2];
    //在队列中添加block的operation
    [queue addOperationWithBlock:^{
        [self operationSaleMethod:@"售票线程-1"];
    }];
    [queue addOperationWithBlock:^{
        [self operationSaleMethod:@"售票线程-2"];
    }];
    
    NSBlockOperation *operation = [NSBlockOperation blockOperationWithBlock:^{
        [self operationSaleMethod:@"售票线程-3"];
    }];
    //将线程添加到队列中去
    [queue addOperation:operation];
    
}

#pragma mark - 更新UI
-(void)appendTextView:(NSString *)text
{
    //1.先获取原先的内容
    NSMutableString *str = [[NSMutableString alloc]initWithString:self.textView.text];
    NSRange range = NSMakeRange(str.length, 1);
    //2.追加新的内容
    [str appendString:[NSString stringWithFormat:@"%@\n",text]];
    [self.textView setText:str];
    
    //3.滚动textView
    [self.textView scrollRangeToVisible:range];
}
#pragma mark - 线程调用的方法
-(void)operationSaleMethod:(NSString *)name
{
    while (YES)
    {
        //判断剩余票数
        if (_tickets > 0)
        {
            @synchronized(self)
            {
                NSString *info = [NSString stringWithFormat:@"总的票数：%ld,当前线程：%@",_tickets,name];
                [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                    [self appendTextView:info];
                }];
                //卖票
                _tickets--;
            }
            if ([name isEqualToString:@"售票线程-1"])
            {
                //线程休眠
                [NSThread sleepForTimeInterval:0.3f];
            }
            else
            {
                [NSThread sleepForTimeInterval:0.2f];
            }
        }
        else
        {
            //更新UI
            NSString *info = [NSString stringWithFormat:@"已无剩余票数，当前线程：%@",name];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [self appendTextView:info];
            }];
            
            break;
        }
    }
}
@end

//为operation1添加依赖，只有当operation2执行完毕时，operation1才能执行。
    [operation1 addDependency:operation2];