IOS多线程（NSThread）

1.创建方法

使用NSThread创建线程主要有两个个方法，分别如下

NSThread* myThread = [[NSThread alloc] initWithTarget:self selector:@selector(doSomething:) object:nil];

[myThread start];
[NSThread detachNewThreadSelector:@selector(doSomething:) toTarget:self withObject:nil];

这两种方式的区别在于：

前一种方式尽管alloc了一个新Thread，但需要手动调用start方法来启动线程。这点与Java创建线程的方式相似。第二种方式，与上述做法1使用NSObject的类方法performSelectorInBackground:withObject:是一样的；第二种方式的可以在start真正创建线程之前对其进行设置，比如设置线程的优先级。第二种调用就会立即创建一个线程并执行selector方法。

使用NSThread创建线程时，要在执行的方法中自行管理内存，否则会有内存溢出警告。

- （void）doSomething:（id）sender

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[pool release];

}

2.线程间的通讯

与主线程通讯

[self performSelectorOnMainThread:@selector(updateUI:) withObject:image waitUntilDone:YES];

与指定的线程通讯

[viewDelegate performSelector:@selector(someMethod)

                                 onThread:[NSThread mainThread]

                               withObject:nil

                            waitUntilDone:NO]

3.线程同步
线程同步主要用
NSCondition 和 NSLock

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    tickets = ;

    count = ;

    theLock = [[NSLock alloc] init];

    // 锁对象

    ticketsCondition = [[NSCondition alloc] init];

    ticketsThreadone = [[NSThread alloc] initWithTarget:self selector:@selector(run) object:nil];

    [ticketsThreadone setName:@"Thread-1"];

    [ticketsThreadone start];

    ticketsThreadtwo = [[NSThread alloc] initWithTarget:self selector:@selector(run) object:nil];

    [ticketsThreadtwo setName:@"Thread-2"];

    [ticketsThreadtwo start];

    NSThread *ticketsThreadthree = [[NSThread alloc] initWithTarget:self selector:@selector(run3) object:nil];

    [ticketsThreadthree setName:@"Thread-3"];

    [ticketsThreadthree start];

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    // Override point for customization after application launch.

    [self.window makeKeyAndVisible];

    return YES;

    self.window.backgroundColor = [UIColor whiteColor];

    [self.window makeKeyAndVisible];

    return YES;

}

-(void)run3

{

    while (YES) {

        [ticketsCondition lock];

        [NSThread sleepForTimeInterval:];

        [ticketsCondition signal];

        [ticketsCondition unlock];

    }

}

- (void)run

{

    while (TRUE) {

        // 上锁

        [ticketsCondition lock];

        [ticketsCondition wait];

        [theLock lock];

        if(tickets >= ){

            [NSThread sleepForTimeInterval:0.09];

            count =  - tickets;

            NSLog(@"当前票数是:%d,售出:%d,线程名:%@",tickets,count,[[NSThread currentThread] name]);

            tickets--;

        }else{

            break;

        }

        [theLock unlock];

        [ticketsCondition unlock];

    }

}

巴特西

IOS多线程（NSThread）

最新文章

热门文章