我有以下代码:-(void)test_with_running_runLoop{dispatch_semaphore_tsemaphore=dispatch_semaphore_create(0);NSTimeIntervalcheckEveryInterval=0.05;NSLog(@"Ismainqueue?:%d",dispatch_get_current_queue()==dispatch_get_main_queue());dispatch_async(dispatch_get_main_queue(),^{sleep(1);NSLog(@"Iwillreachhere,be