Question

When I use ObjCHiredis redis to connect to a invalid IP and Port, it will blocked.
How to set it to nonblock mode? Thx

- (void)setUp {
NSLog(@"begin setUp");
NSString *ip = @"125.124.125.125";
self.redis = [ObjCHiredis redis:ip on:[NSNumber numberWithInt:123] db:[NSNumber numberWithInt:0]];
if(self.redis == nil)
{
    NSLog(@"init redis error.");
    return ;
}
 NSLog(@"end setUp");
}

Answer 1

The easiest way to do this is probably going to be by running the connection on a separate thread and using a block to handle the response back on the main thread.

This is a helper method I regularly use to do any sort of async tasks.
I’ve adapted it so it should work for what you’re trying do:

+(void)threadedConnect:(NSString*)ip On:(int)port DB:(int)db WithResponseTask:(void(^)(ObjCHiredis *redis))task
{
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);

    dispatch_async(queue, ^{

        ObjCHiredis *redis = [ObjCHiredis redis:ip
                                on:[NSNumber numberWithInt:port]
                                db:[NSNumber numberWithInt:db]];

        // Run completion block back on main thread with result as argument
        dispatch_async(dispatch_get_main_queue(), ^{ task(redis); });
    });
}