1. 代码如下:
@WeakObj(self)
dispatch_group_t group = dispatch_group_create();
dispatch_queue_t readQueue = dispatch_queue_create("read_config_queue",DISPATCH_QUEUE_SERIAL);// 串行队列
dispatch_semaphore_t sem = dispatch_semaphore_create(0);
__block NSNumber *serverSaveGranularity;
dispatch_group_enter(group);// 进入组
dispatch_group_async(group, readQueue, ^{
NSLog(@"-----1");
[selfWeak postArReadConfigGranularityByFinishBlock:^(NSNumber *granularity) {
NSLog(@"-----2");
serverSaveGranularity = granularity;
dispatch_group_leave(group);
dispatch_semaphore_signal(sem);
}];
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
});
__block NSArray <NSNumber *> *serverSaveFormulaCharIDsArray;
dispatch_group_enter(group);
dispatch_group_async(group, readQueue, ^{
NSLog(@"-----3");
[selfWeak postArReadConfigFormulaByFinishBlock:^(NSArray<NSNumber *> *FormulaIDs) {
NSLog(@"-----4");
serverSaveFormulaCharIDsArray = FormulaIDs;
dispatch_group_leave(group);
dispatch_semaphore_signal(sem);
}];
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
});
__block NSArray <NSNumber *> *serverSaveMetaIDsArray;
dispatch_group_enter(group);
dispatch_group_async(group, readQueue, ^{
NSLog(@"-----5");
[selfWeak postArReadConfigMetaByFinishBlock:^(NSArray<NSNumber *> *metaIDs) {
NSLog(@"-----6");
serverSaveMetaIDsArray = metaIDs;
dispatch_group_leave(group);
dispatch_semaphore_signal(sem);
}];
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
});
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
NSLog(@"-----7");
if (block) block(serverSaveGranularity,serverSaveFormulaCharIDsArray,serverSaveMetaIDsArray);
});
2.注释:
1. postArReadConfigMetaByFinishBlock 这种方法都是一些网络请求的异步回调方法
2. 打印结果
-----1
-----2
-----3
-----4
-----5
-----6
-----7
3.其实这个dispatch_group_notify形同虚设。。。。。
3. 为什么我要整这种串行异步的傻逼操作。。。???(Error Domain=NSURLErrorDomain Code=-1005 “The network connection was lost.”)
答案:
/**
1. 因为 http服务器开启了Connection: keep-alive 机制
2. 这个请求调用的很频繁,所以会导致服务器维持一个链接,
当调用很频繁的时候,会出现一个现象,
后一个http网络请求会把前一个相同url的网络请求强行终止,
返回 Error Domain=NSURLErrorDomain Code=-1005 “The network connection was lost.”
3. 因此建立了一个串行队列 用来控制相同url的网络请求,串行执行。
4. 还有个更好的办法,服务器关闭 keep-alive 机制。
可是~如果vpn服务器开启了这个Connection: keep-alive 机制,依旧会出错!!!!!
5. 。。。。。。还是想办法解决这个问题吧。。。。(先暂时先在外面加了个异步串行队列凑合~~~!!!)
6. 但是这个异步串行会大大降低效率~~~~
7. so。。要不在错误里面判断 code == -1005,重新请求???这个也很脏。。。
*/
4.这个链接可能会帮你哦~~~
点一下,可能需要的~~
网友评论