NSThread sleepfortimeinterval blocks main thread

Question

I want to simulate a communication with a server. As the remote server will have some delays I want to use a background thread that has on it ``` [NSThread sleepForTimeInterval:timeoutTillAnswer]; ``` The thread is created with NSThread sub classing and started ... However I noticed that sleepForTimeInterval is blocking the main thread... Why??? Isn't a NSThread a backgroundThread by default? This is how the thread is created: ``` self.botThread = [[PSBotThread alloc] init]; [self.botThread start]; ``` Further info: This is the bot thread subclas ``` - (void)main { @autoreleasepool { self.gManager = [[PSGameManager alloc] init]; self.comManager = [[PSComManager alloc] init]; self.bot = [[PSBotPlayer alloc] initWithName:@"Botus" andXP:[NSNumber numberWithInteger:1500]]; self.gManager.localPlayer = self.bot; self.gManager.comDelegate = self.comManager; self.gManager.tillTheEndGame = NO; self.gManager.localDelegate = self.bot; self.comManager.gameManDelegate = self.gManager; self.comMana…

Accepted Answer

It blocks whatever thread sleepForTimeInterval is running on. Run it on another thread to simulate your server delay like this:

```
dispatch_queue_t serverDelaySimulationThread = dispatch_queue_create("com.xxx.serverDelay", nil);
dispatch_async(serverDelaySimulationThread, ^{
     [NSThread sleepForTimeInterval:10.0];
     dispatch_async(dispatch_get_main_queue(), ^{
            //Your server communication code here
    }); 
});
```

NSThread sleepfortimeinterval blocks main thread

Solution

Problem