iOS底层系列之＜40＞--多线程＜十＞-锁＜6＞NSLock、NSRecursiveLock、NSConditionLock

1、锁的封装对应关系，具体使用参考前面几篇文章

pthread_mutex_t 普通锁	NSLock
pthread_mutex_t 递归锁	NSRecursiveLock
pthread_mutex_t 条件锁	NSConditionLock

2、NSLock演示

#import "NSLockVC.h"

@interface NSLockVC ()
@property (strong, nonatomic) NSLock *lock1;
@property (strong, nonatomic) NSLock *lock2;


@end

@implementation NSLockVC

- (void)viewDidLoad {
    [super viewDidLoad];
    self.lock1 = [[NSLock alloc] init];
    self.lock2 = [[NSLock alloc] init];
    [self concurrentMoney];
    [self concurrentSaleTicket];
}



- (void)__saveMoney {
    [self.lock1 lock];
    
    [super saveMoney];
    
    [self.lock1 unlock];
    
}

- (void)__drawMoney {
    
    [self.lock1 lock];
    
    [super drawMoney];
    
    [self.lock1 unlock];
}

- (void)__saleTicket {
    
    [self.lock2 lock];
    
    [super saleTicket];
    
    [self.lock2 unlock];
}

- (void)concurrentMoney {
    dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
    
    dispatch_async(queue, ^{
        for (int i = 0; i < 10; i++) {
            [self __saveMoney];
        }
    });
    
    dispatch_async(queue, ^{
        for (int i = 0; i < 10; i++) {
            [self __drawMoney];
        }
    });
}


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

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

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

@end

3、NSRecursiveLock演示

#import "NSRecursiveLockVC.h"

@interface NSRecursiveLockVC ()
@property (strong, nonatomic) NSRecursiveLock *lock1;
@property (strong, nonatomic) NSRecursiveLock *lock2;
@end

@implementation NSRecursiveLockVC

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self test1];
}

- (void)test1 {
    [self.lock1 lock];
    static int count = 0;
    NSLog(@"%s--%d",__func__,count);
    if (count < 10) {
        count ++;
        [self test1];
    }
    
    [self.lock1 unlock];
}

@end

4、NSCondition演示

#import "NSConditioinLockVC.h"

@interface NSConditioinLockVC ()
@property (strong, nonatomic) NSCondition *condLock;
@property (strong, nonatomic) NSMutableArray *array;
@end

@implementation NSConditioinLockVC

- (void)viewDidLoad {
    [super viewDidLoad];
    self.array = [NSMutableArray array];
    self.condLock = [[NSCondition alloc] init];
    [self test];
    
}

- (void)test {
    [[[NSThread alloc] initWithTarget:self selector:@selector(removeObj) object:nil] start];
    sleep(1);
    [[[NSThread alloc] initWithTarget:self selector:@selector(addObj) object:nil] start];
}

- (void)removeObj {
    
    NSLog(@"step1---");
    [self.condLock lock];
    
    NSLog(@"step2---");
    if (self.array.count == 0) {
        NSLog(@"step3---");
        [self.condLock wait];
    }
    NSLog(@"step9---");
    // 开始删除元素
    [self.array removeLastObject];
    NSLog(@"step10--%@",self.array);
    
    [self.condLock unlock];
    NSLog(@"step11---");
}

- (void)addObj {
    NSLog(@"step4---");
    [self.condLock lock];
    NSLog(@"step5---");
    
    [self.array addObject:@"a"];
    [self.array addObject:@"b"];
    NSLog(@"step6--%@",self.array);
    
    sleep(3);
    [self.condLock signal];
    
    NSLog(@"step7---");
    [self.condLock unlock];
    NSLog(@"step8---");
}

@end

5、NSConditionLock演示

#import "NSConditionVC.h"

@interface NSConditionVC ()
@property (strong, nonatomic) NSConditionLock *condLock;
@end

@implementation NSConditionVC

- (void)viewDidLoad {
    [super viewDidLoad];
    self.condLock = [[NSConditionLock alloc] initWithCondition:1];
    [self test];
}

- (void)test {
    [[[NSThread alloc] initWithTarget:self selector:@selector(addObj2) object:nil] start];
    [[[NSThread alloc] initWithTarget:self selector:@selector(addObj) object:nil] start];
    [[[NSThread alloc] initWithTarget:self selector:@selector(removeObj) object:nil] start];
}

- (void)removeObj {
    [self.condLock lockWhenCondition:1];
    NSLog(@"removeObj---");
    [self.condLock unlockWithCondition:2];
}

- (void)addObj {
    [self.condLock lockWhenCondition:2];
    NSLog(@"addObj---");
    [self.condLock unlockWithCondition:3];
}

- (void)addObj2 {
    [self.condLock lockWhenCondition:3];
    NSLog(@"addObj2---");
    [self.condLock unlock];
}
@end