标签:test 利用 inter read operation 结果 specified upload finish
//
// ViewController.m
// OperationTest0108
//
// Created by LongMa on 2020/1/8.
//
#import "ViewController.h"
#import <AFNetworking/AFNetworking.h>
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self testQueue];
}
- (void)testQueue{
NSOperationQueue *lQ = [[NSOperationQueue alloc] init];
//任务最大并发数,与是否开启子线程无关。
// lQ.maxConcurrentOperationCount = 1;
NSBlockOperation *lOp0 = [NSBlockOperation blockOperationWithBlock:^{
AFHTTPSessionManager *lMng = [AFHTTPSessionManager manager];
[lMng POST:@"https://www.baidu.com" parameters:@{
@"mapId" : @"1"
} progress:^(NSProgress * _Nonnull uploadProgress) {
} success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
NSLog(@"0 suc");
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
NSLog(@"0 error");
}];
NSLog(@"0 %@", [NSThread currentThread]);
}];
NSBlockOperation *lOp1 = [NSBlockOperation blockOperationWithBlock:^{
AFHTTPSessionManager *lMng = [AFHTTPSessionManager manager];
[lMng POST:@"https://www.baidu.com" parameters:@{
@"mapId" : @"1"
} progress:^(NSProgress * _Nonnull uploadProgress) {
} success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
NSLog(@"1 suc");
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
NSLog(@"1 error");
}];
NSLog(@"1 %@", [NSThread currentThread]);
}];
NSBlockOperation *lOp2 = [NSBlockOperation blockOperationWithBlock:^{
NSLog(@"2 %@", [NSThread currentThread]);
}];
[lOp0 addDependency:lOp1];
NSLog(@"before add op");
[lQ addOperations:@[lOp0] waitUntilFinished:NO];
[lQ addOperations:@[lOp1] waitUntilFinished:NO];
[lQ addOperations:@[lOp2] waitUntilFinished:NO];
}
@end
执行结果
2020-01-08 18:02:31.378260+0800 OperationTest0108[1583:527022] before add op
2020-01-08 18:02:31.378635+0800 OperationTest0108[1583:527045] 2 <NSThread: 0x283db43c0>{number = 4, name = (null)}
2020-01-08 18:02:31.379722+0800 OperationTest0108[1583:527047] 1 <NSThread: 0x283db4240>{number = 5, name = (null)}
2020-01-08 18:02:31.380265+0800 OperationTest0108[1583:527047] 0 <NSThread: 0x283db4240>{number = 5, name = (null)}
2020-01-08 18:02:31.915236+0800 OperationTest0108[1583:527022] 0 error
2020-01-08 18:02:31.921841+0800 OperationTest0108[1583:527022] 1 error
由上面log可知:任务结束判定以发起请求为准!数据返回是异步的,不受依赖关系影响!
当把上面代码
[lQ addOperations:@[lOp0] waitUntilFinished:NO];
改为
[lQ addOperations:@[lOp0] waitUntilFinished:YES];
时,
log如下,没有正常执行操作:
2020-01-08 18:03:55.308276+0800 OperationTest0108[1587:527738] before add op
分析:
waitUntilFinished方法定义为:
If YES, the current thread is blocked until all of the specified operations finish executing. If NO, the operations are added to the queue and control returns immediately to the caller.
当为YES时,当前线程被阻塞,直到被添加的操作执行完毕。上面代码使线程依赖于lOp0执行完毕,而lOp0的执行依赖于lOp1执行完毕。由于lOp1比lOp0加入队列更晚。当上面代码被执行时,线程在等lOp0执行完毕,而此时lOp1还没被加入队列中,即lOp1还没开始执行,所以线程一直处于阻塞状态!当然,合理利用waitUntilFinished方法,也能实现想要的特殊效果。
标签:test 利用 inter read operation 结果 specified upload finish
原文地址:https://www.cnblogs.com/Dast1/p/12168103.html