semaphore test

gistfile1.txt

- (void)viewDidLoad
{
    [super viewDidLoad];
    semaphoreTest = dispatch_semaphore_create(2);
    [NSThread detachNewThreadSelector:@selector(workThread) toTarget:self withObject:nil];
    [NSThread detachNewThreadSelector:@selector(workThread2) toTarget:self withObject:nil];
    [NSThread detachNewThreadSelector:@selector(workThread3) toTarget:self withObject:nil];
    UIButton *text = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 50, 30)];
    text.backgroundColor = [UIColor redColor];
    [text addTarget:self action:@selector(testSemaphore) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:text];
  // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void)testSemaphore
{
    dispatch_semaphore_signal(semaphoreTest);
}


-(void)workThread
{
    NSLog(@"begin1");
    int i = dispatch_semaphore_wait(semaphoreTest, dispatch_time(DISPATCH_TIME_NOW ,10000000000000));
    i ?NSLog(@"1time out"):NSLog(@"1successed");
    
}

-(void)workThread2
{
    NSLog(@"begin2");
    int i = dispatch_semaphore_wait(semaphoreTest, dispatch_time(DISPATCH_TIME_NOW ,10000000000000));
    i ?NSLog(@"2time out"):NSLog(@"2successed");
    
}

-(void)workThread3
{
    NSLog(@"begin3");
    int i = dispatch_semaphore_wait(semaphoreTest, dispatch_time(DISPATCH_TIME_NOW ,10000000000000));
    i ?NSLog(@"3time out"):NSLog(@"3successed");
    
}