iOS 各种锁

#import "ViewController.h"
#import // OSSpinLock头文件
#import // os_unfair_lock头文件
#import // pthread_mutex_t头文件
#import // pthread_rwlock_t头文件

@interface ViewController ()

@property (nonatomic, strong) UIView *bgView;

@property (nonatomic) int count;

/// 自旋锁-忙等
@property (nonatomic, assign) OSSpinLock ossLock;

/// NSLock-对pthread_mutex_t的封装
@property (nonatomic, strong) NSLock *lock;

/// 队列组
@property (nonatomic, strong) dispatch_group_t grounp;

/// os_unfair_lock-互斥锁
@property (nonatomic, assign) os_unfair_lock osUnLock;

/// 互斥锁（递归锁：允许同一个线程对一把锁进行加锁；不同线程需要等待）-需要销毁
@property (nonatomic, assign) pthread_mutex_t mutex;
@property (nonatomic, assign) pthread_cond_t cond;

/// 递归锁-对pthread_mutex_t的封装
@property (nonatomic, strong) NSRecursiveLock *reLock;

/// 条件锁-对mutex和cond的封装
@property (nonatomic, strong) NSCondition *condition;

/// 条件锁-对NSCondition的封装（设置线程依赖）
@property (nonatomic, strong) NSConditionLock *condLock;

/// 读写锁-需要销毁
@property (nonatomic, assign) pthread_rwlock_t rwLock;

/// 栅栏dispatch_barrier_async

@end

@implementation ViewController

- (void)dealloc {
    /// 销毁锁
    pthread_mutex_destroy(&_mutex);
    
    /// 销毁条件
    pthread_cond_destroy(&_cond);
    
    /// 销毁读写锁
    pthread_rwlock_destroy(&_rwLock);
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    _bgView = [[UIView alloc] init];
    _bgView.frame = CGRectMake(0, 0, 100, 100);
    _bgView.backgroundColor = UIColor.redColor;
    [self.view addSubview:_bgView];
    
    self.ossLock = OS_SPINLOCK_INIT;
    
    self.lock = [[NSLock alloc] init];
    
    self.grounp = dispatch_group_create();
    
    self.osUnLock = OS_UNFAIR_LOCK_INIT;
    
    /// 初始化属性
    pthread_mutexattr_t attr;
    pthread_mutexattr_init(&attr);
    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT);
    //pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);/// 递归锁
    /// 初始化锁
    pthread_mutex_init(&_mutex, &attr);
    /// 销毁属性
    pthread_mutexattr_destroy(&attr);
    
    /*
     /// 添加条件锁（不同线程执行任务时需要的控制条件，线程依赖，使用场景：可变数组删除和添加元素）
     pthread_cond_init(&_cond, NULL);
     /// ⚠️以下两个方法需要放在加锁解锁中间执行
     /// 根据条件，进入休眠状态，放开当前锁；被唤醒后会再次对当前线程加锁
     pthread_cond_wait(&_cond, &_mutex);
     /// 处理完成，发送信号唤醒锁
     pthread_cond_signal(&_cond);
     /// 处理完成，广播通知等待该条件的所有线程，唤醒锁，和pthread_cond_signal二选一
     pthread_cond_broadcast(&_cond);
     /// ⚠️
     */
    
    self.reLock = [[NSRecursiveLock alloc] init];
    
    self.condition = [[NSCondition alloc] init];
    
    self.condLock = [[NSConditionLock alloc] initWithCondition:1];
    
    pthread_rwlock_init(&_rwLock, NULL);
    
    /*
     /// 读锁
     pthread_rwlock_rdlock(&_rwLock);
     /// 写锁
     pthread_rwlock_wrlock(&_rwLock);
     /// 读写锁解锁
     pthread_rwlock_unlock(&_rwLock);
     */
    
    self.count = 15;
    
    [self test];
    
}

- (void)test {
    
    dispatch_queue_t queue = dispatch_get_global_queue(0, 0);

    dispatch_async(queue, ^{
        for (int i = 0; i < 5; i ++) {
            [self doSomething];
        }
    });

    dispatch_async(queue, ^{
        for (int i = 0; i < 5; i ++) {
            [self doSomething];
        }
    });

    dispatch_async(queue, ^{
        for (int i = 0; i < 5; i ++) {
            [self doSomething];
        }
    });
    
//    dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
//
//    dispatch_group_async(self.grounp, queue, ^{
//        for (int i = 0; i < 5; i ++) {
//            [self doSomething];
//        }
//    });
//
//    dispatch_group_async(self.grounp, queue, ^{
//        for (int i = 0; i < 5; i ++) {
//            [self doSomething];
//        }
//    });
//
//    dispatch_group_async(self.grounp, queue, ^{
//        for (int i = 0; i < 5; i ++) {
//            [self doSomething];
//        }
//    });
    
}

- (void)doSomething {
    
//    OSSpinLockLock(&_ossLock);
    
//    [self.lock lock];
    
//    dispatch_group_enter(self.grounp);
    
//    os_unfair_lock_lock(&_osUnLock);
    
//    pthread_mutex_lock(&_mutex);
    
//    [self.reLock lock];
    
//    [self.condition lock];
////    [self.condition wait];
    
    [self.condLock lockWhenCondition:self.condLock.condition];
    
    self.count --;
    NSLog(@"当前线程：%@ 操作剩余 = %d", [NSThread currentThread], self.count);
    
    [self.condLock unlockWithCondition:self.condLock.condition];
    
////    [self.condition signal];
////    [self.condition broadcast];
//    [self.condition unlock];
    
//    [self.reLock unlock];
    
//    pthread_mutex_unlock(&_mutex);
    
//    os_unfair_lock_unlock(&_osUnLock);
    
//    dispatch_group_leave(self.grounp);
    
//    [self.lock unlock];
    
//    OSSpinLockUnlock(&_ossLock);
    
}

@end