In iOS env, is it possible to make current thread sleep for seconds, then execute my code? NSTimer, GDC or any technique is okay for me.
it depends how you are creating (spawning) your threads. For example if you are creating your thread with NSThread
class, you can use the two class methods :
sleepUntilDate:
sleepForTimeInterval:
But generally it's a bad idea to handle the threading management yourself, because multithreading programming is very hard. You can use GCD or operations queues for example to handle the multithreading in your application.