iOS 多线程

参考链接

iOS多线程
iOS 多线程：『GCD』详尽总结
iOS简单优雅的实现复杂情况下的串行需求(各种锁、GCD 、NSOperationQueue...)

GCD组合结果

区别	并发队列	串行队列	主队列
同步（sync）	没有开启新线程，串行执行任务	没有开启新线程，串行执行任务	主线程调用：死锁卡住不执行。其他线程调用：没有开启新线程，串行执行任务
异步（async）	有开启新线程，并发执行任务	有开启新线程(1条)，串行执行任务	没有开启新线程，串行执行任务

应用

顺序网络请求

互斥锁实现

#import <pthread.h>

/**
 pthread_mutex 互斥锁
 */
-(void)usePthred{
    static pthread_mutex_t pLock;
    pthread_mutex_init(&pLock, NULL);

    pthread_mutex_lock(&pLock);
    NSLog(@"1上锁");
    [self doSomeThingForFlag:1 finish:^{
        NSLog(@"1解锁");
        pthread_mutex_unlock(&pLock);
    }];

    pthread_mutex_lock(&pLock);
    NSLog(@"2上锁");
    [self doSomeThingForFlag:2 finish:^{
        NSLog(@"2解锁");
        pthread_mutex_unlock(&pLock);
    }];

    pthread_mutex_lock(&pLock);
    NSLog(@"3上锁");
    [self doSomeThingForFlag:3 finish:^{
        NSLog(@"3解锁");
        pthread_mutex_unlock(&pLock);
    }];

    pthread_mutex_lock(&pLock);
    NSLog(@"4上锁");
    [self doSomeThingForFlag:4 finish:^{
        NSLog(@"4解锁");
        pthread_mutex_unlock(&pLock);
    }];
}
--------------------- 
作者：spicyShrimp 
来源：CSDN 
原文：https://blog.csdn.net/spicyshrimp/article/details/70845822 
版权声明：本文为博主原创文章，转载请附上博文链接！

OSSpinLock 自旋锁

#import <libkern/OSAtomic.h>

/**
 OSSpinLock 自旋锁
 */
-(void)useOSSpinLock{
    __block OSSpinLock oslock = OS_SPINLOCK_INIT;

    OSSpinLockLock(&oslock);
    NSLog(@"1上锁");
    [self doSomeThingForFlag:1 finish:^{
        NSLog(@"1解锁");
        OSSpinLockUnlock(&oslock);
    }];

    OSSpinLockLock(&oslock);
    NSLog(@"2上锁");
    [self doSomeThingForFlag:2 finish:^{
        NSLog(@"2解锁");
        OSSpinLockUnlock(&oslock);
    }];


    OSSpinLockLock(&oslock);
    NSLog(@"3上锁");
    [self doSomeThingForFlag:3 finish:^{
        NSLog(@"3解锁");
        OSSpinLockUnlock(&oslock);
    }];

    OSSpinLockLock(&oslock);
    NSLog(@"4上锁");
    [self doSomeThingForFlag:4 finish:^{
        NSLog(@"4解锁");
        OSSpinLockUnlock(&oslock);
    }];
}
--------------------- 
作者：spicyShrimp 
来源：CSDN 
原文：https://blog.csdn.net/spicyshrimp/article/details/70845822 
版权声明：本文为博主原创文章，转载请附上博文链接！

GCD实现信号量实现

/**
 GCD single
 */
-(void)useGCDSingle{
    dispatch_semaphore_t semaphore = dispatch_semaphore_create(1);

    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    NSLog(@"1阻塞线程");
    [self doSomeThingForFlag:1 finish:^{
        NSLog(@"1释放线程");
        dispatch_semaphore_signal(semaphore);
    }];

    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    NSLog(@"2阻塞线程");
    [self doSomeThingForFlag:2 finish:^{
        NSLog(@"2释放线程");
        dispatch_semaphore_signal(semaphore);
    }];

    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    NSLog(@"3阻塞线程");
    [self doSomeThingForFlag:3 finish:^ {
        NSLog(@"3释放线程");
        dispatch_semaphore_signal(semaphore);
    }];

    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    NSLog(@"4阻塞线程");
    [self doSomeThingForFlag:4 finish:^{
        NSLog(@"4释放线程");
        dispatch_semaphore_signal(semaphore);
    }];
}
--------------------- 
作者：spicyShrimp 
来源：CSDN 
原文：https://blog.csdn.net/spicyshrimp/article/details/70845822 
版权声明：本文为博主原创文章，转载请附上博文链接！

GCD队列的暂停和恢复

/**
 GCD队列的暂停和恢复
 */
-(void)useGCDSuspendAndResume{
//串行队列
    dispatch_queue_t myqueue = dispatch_queue_create("com.charles.queue", NULL);

    dispatch_async(myqueue, ^{
        dispatch_suspend(myqueue);
        [self doSomeThingForFlag:1 finish:^(NSInteger flag) {
            dispatch_resume(myqueue);
        }];
    });

    dispatch_async(myqueue, ^{
        dispatch_suspend(myqueue);
        [self doSomeThingForFlag:2 finish:^(NSInteger flag) {
            dispatch_resume(myqueue);
        }];
    });

    dispatch_async(myqueue, ^{
        dispatch_suspend(myqueue);
        [self doSomeThingForFlag:3 finish:^(NSInteger flag) {
            dispatch_resume(myqueue);
        }];
    });

    dispatch_async(myqueue, ^{
        dispatch_suspend(myqueue);
        [self doSomeThingForFlag:4 finish:^(NSInteger flag) {
            dispatch_resume(myqueue);
        }];
    });
}
--------------------- 
作者：spicyShrimp 
来源：CSDN 
原文：https://blog.csdn.net/spicyshrimp/article/details/70845822 
版权声明：本文为博主原创文章，转载请附上博文链接！

NSOperationQueue

/**
 operationQueue的暂停和恢复
 */
-(void)useOperationQueue{
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue setMaxConcurrentOperationCount:1];

    __weak typeof(self)weakSelf = self;
    NSBlockOperation * operation1 = [NSBlockOperation blockOperationWithBlock:^{
        [queue setSuspended:YES];
        [weakSelf doSomeThingForFlag:1 finish:^(NSInteger flag) {
            [queue setSuspended:NO];
        }];
    }];

    NSBlockOperation * operation2 = [NSBlockOperation blockOperationWithBlock:^{
        [queue setSuspended:YES];
        [weakSelf doSomeThingForFlag:2 finish:^(NSInteger flag) {
            [queue setSuspended:NO];
        }];
    }];

    NSBlockOperation * operation3 = [NSBlockOperation blockOperationWithBlock:^{
        [queue setSuspended:YES];
        [weakSelf doSomeThingForFlag:3 finish:^(NSInteger flag) {
            [queue setSuspended:NO];
        }];
    }];

    NSBlockOperation * operation4 = [NSBlockOperation blockOperationWithBlock:^{
        [queue setSuspended:YES];
        [weakSelf doSomeThingForFlag:4 finish:^(NSInteger flag) {
            [queue setSuspended:NO];
        }];
    }];

    [operation4 addDependency:operation3];
    [operation3 addDependency:operation2];
    [operation2 addDependency:operation1];

    [queue addOperation:operation1];
    [queue addOperation:operation2];
    [queue addOperation:operation3];
    [queue addOperation:operation4];
}
--------------------- 
作者：spicyShrimp 
来源：CSDN 
原文：https://blog.csdn.net/spicyshrimp/article/details/70845822 
版权声明：本文为博主原创文章，转载请附上博文链接！