iOS NSOperation

作者: 青椒辣不辣 | 来源:发表于2020-12-11 11:54 被阅读0次

iOS多线程全面解读(三)：NSOperation
iOS NSOperation
多线程 NSOperation
iOS并行开发：从NSOperation和调度队列开始
NSOperation or GCD
NSOperation
多线程的记录
iOS NSOperation的详细使用
iOS面试题：多线程有哪几种？你更倾向于哪一种？
NSOperation

$\color{rgb(0 ,139, 139)}{操作 NSOperation}$ NSInvocationOperation,NSBlockOperation,自定义

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    NSInvocationOperation *iOp = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(download) object:nil];
    [iOp start];

    NSBlockOperation *bOp = [NSBlockOperation blockOperationWithBlock:^{
        NSLog(@"NSBlockOperation----%@",[NSThread currentThread]);
    }];
    //追加任务Execution执行  当一个操作中的任务数据大于1的时候,就会开子线程并发执行任务
    [bOp addExecutionBlock:^{
        NSLog(@"NSBlockOperation_addExecutionBlock----%@",[NSThread currentThread]);
    }];
    [bOp start];

    RJOperation *rjOp = [[RJOperation alloc]init];
    [rjOp start];
}
-(void)download{
    NSLog(@"NSInvocationOperation----%@",[NSThread currentThread]);
}

NSInvocationOperation----<NSThread: 0x60000239c980>{number = 1, name = main}
NSBlockOperation----<NSThread: 0x60000239c980>{number = 1, name = main}
NSBlockOperation_addExecutionBlock----<NSThread: 0x6000023d11c0>{number = 4, name = (null)}
2020-12-11 11:17:42.582228+0800 RJCustomTool[3797:101929] RJOperation----<NSThread: 0x60000239c980>{number = 1, name = main}
2020-12-11 11:17:46.582409+0800 RJCustomTool[3797:101929] -[RJOperation dealloc]

RJOperation

#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface RJOperation : NSOperation
@end
NS_ASSUME_NONNULL_END


#import "RJOperation.h"
@implementation RJOperation
-(void)main{
    NSLog(@"RJOperation----%@",[NSThread currentThread]);
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(4 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        //4秒过后取消线程
        [self cancel];
    });
}
-(void)dealloc{
    NSLog(@"%s",__func__);
}
@end

$\color{rgb(0 ,139, 139)}{操作 + 队列NSOperationQueue}$

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    
    NSInvocationOperation *iOp = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(download) object:nil];
    
    NSBlockOperation *bOp = [NSBlockOperation blockOperationWithBlock:^{
        NSLog(@"NSBlockOperation----%@",[NSThread currentThread]);
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"addOperationWithBlock----%@",[NSThread currentThread]);
    }];

    RJOperation *rjOp = [[RJOperation alloc]init];
    
    [queue addOperation:iOp];
    [queue addOperation:bOp];
    [queue addOperation:rjOp];
}
-(void)download{
    NSLog(@"NSInvocationOperation----%@",[NSThread currentThread]);
}

addOperationWithBlock----<NSThread: 0x600003cfee00>{number = 3, name = (null)}
NSBlockOperation----<NSThread: 0x600003cfc840>{number = 4, name = (null)}
NSInvocationOperation----<NSThread: 0x600003ce5c40>{number = 9, name = (null)}
2020-12-11 11:30:27.381186+0800 RJCustomTool[3998:115346] RJOperation----<NSThread: 0x600003cfee00>{number = 3, name = (null)}
2020-12-11 11:30:31.381343+0800 RJCustomTool[3998:115106] -[RJOperation dealloc]

$\color{rgb(0 ,139, 139)}{取消|暂停|恢复}$ 队列中的任务是有状态的:暂停和取消操作不能作用于当前正处于运行状态的操作

    [queue setSuspended:YES];//暂停
    [queue setSuspended:NO];//恢复
    [queue cancelAllOperations];//取消


/*
    设置最大并发数量
    maxConcurrentOperationCount 最大并发数:同一时间最多可以处理的任务数量
    队列默认是并发队列
    maxConcurrentOperationCount == 1 串行队列
    -1 在计算机 中表示的是最大值(默认是不受限制的)*/
    queue.maxConcurrentOperationCount = -1;

$\color{rgb(0 ,139, 139)}{操作依赖}$ 不能设置循环依赖(死锁-不会执行)

    [iOp addDependency:rjOp];
    [rjOp addDependency:bOp];

NSBlockOperation----<NSThread: 0x600000870cc0>{number = 7, name = (null)}
2020-12-11 11:36:44.313473+0800 RJCustomTool[4085:121948] RJOperation----<NSThread: 0x600000870cc0>{number = 7, name = (null)}
NSInvocationOperation----<NSThread: 0x600000870cc0>{number = 7, name = (null)}
2020-12-11 11:36:48.313641+0800 RJCustomTool[4085:121654] -[RJOperation dealloc]

$\color{rgb(0 ,139, 139)}{线程间通信}$

    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    [queue addOperationWithBlock:^{
        NSLog(@"OperationQueue----%@",[NSThread currentThread]);
        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            NSLog(@"UI----%@",[NSThread currentThread]);
        }];
    }];

OperationQueue----<NSThread: 0x60000204afc0>{number = 7, name = (null)}
UI----<NSThread: 0x600002024a40>{number = 1, name = main}

$\color{rgb(0 ,139, 139)}{}$ ``