我正在尝试连接到自定义 GCD 队列中的服务器。我就是这样做的。
- (void) initNetworkCommunication{
if(!self.connQueue){
self.connQueue = dispatch_queue_create("connection_queue", NULL);
}
dispatch_async(self.connQueue, ^(void) {
if(self.inputStream ==nil && self.outputStream ==nil) {
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
NSString *host= [[NSUserDefaults standardUserDefaults] objectForKey:@"ip_preference"];
NSNumber *portNum = [[NSUserDefaults standardUserDefaults] objectForKey:@"port_preference"];
int port = [portNum intValue];
CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)host, port, &readStream, &writeStream);
CFReadStreamSetProperty(readStream, kCFStreamNetworkServiceType, kCFStreamNetworkServiceTypeVoIP);
CFWriteStreamSetProperty(writeStream, kCFStreamNetworkServiceType, kCFStreamNetworkServiceTypeVoIP);
self.inputStream = (__bridge NSInputStream *)readStream;
self.outputStream = (__bridge NSOutputStream *)writeStream;
[self.inputStream setDelegate:self];
[self.outputStream setDelegate:self];
[self.inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[self.outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[self.outputStream open];
[self.inputStream open];
} else {
NSLog(@"persistant connection alerady opened");
return;
}
});
}
现在,如果我在 dispatch_sync 中编写这段代码,它会正确调用委托函数。
- (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent
但是,当我使用我想要做的 dispatch_asynch 时,它不会调用我的委托函数。
从到目前为止我所读到的内容来看,GCD 队列有一个与之关联的运行循环,但这些不是由系统运行的,我们需要自己这样做。我在理论上理解这一点,但它是如何完成的。以某种方式与此相关的调度源?
先感谢您。