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
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| #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 |
#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
输出结果：[……]
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