参考链接：iOS多线程中的几种加锁类型OSSpinLock、os_unfair_lock、pthread_mutex
1、pthread_mutex是c语言实现的跨平台互斥锁，应该是一种主流锁吧，OC多种形态的锁都是基于pthread_mutex，常见的有NSLock、NSCondition、NSConditionLock、NSRecursiveLock、@Synchronized
2、各种锁的基本使用
2.1、NSLock
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | #import "ViewController.h" #import <pthread.h> @interface ViewController () { NSLock *_lock; } @end @implementation ViewController static NSUInteger ticketCount = 20; - (void)viewDidLoad { [super viewDidLoad]; _lock = [[NSLock alloc] init]; dispatch_async(dispatch_get_global_queue(0, 0), ^{ for (int i = 0; i < 5; i++) { [self saleTickte]; } }); dispatch_async(dispatch_get_global_queue(0, 0), ^{ for (int i = 0; i < 5; i++) { [self saleTickte]; } }); } - (void)saleTickte { [_lock lock]; // lockBeforeDate:方法能在指定时间后自动解锁 // [_lock lockBeforeDate:[NSDate dateWithTimeIntervalSinceNow:3]]; NSUInteger remain = ticketCount; sleep(0.5); ticketCount = --remain; NSLog(@"%ld-%@", ticketCount, [NSThread currentThread]); [_lock unlock]; } @end |
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