问iOS - CFSocket未收到回调

EN

int sock;
int err;
CFRunLoopSourceRef rls;
const CFSocketContext   context = { 0, self, NULL, NULL, NULL };

sock = socket(AF_INET, SOCK_DGRAM, 0);

# Setup address struct and bind to socket for broadcast
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_len = sizeof(addr);
addr.sin_family = AF_INET;
addr.sin_port = 51234;
addr.sin_addr.s_addr = INADDR_ANY;
err = bind(sock, (const struct sockaddr *) &addr, sizeof(addr));

# Set flags to non-blocking
int flags;
flags = fcntl(sock,F_GETFL);
err = fcntl(sock, F_SETFL, flags | O_NONBLOCK);

# CFSocket is created, stored in the object
self->_cfSocket = CFSocketCreateWithNative(NULL,sock,kCFSocketReadCallBack,   
                                           SocketReadCallback, &context);
sock = -1;
# CFSocket is added to the Main RunLoop
rls = CFSocketCreateRunLoopSource(NULL,self->_cfSocket,0);
CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, kCFRunLoopDefaultMode);
CFRelease(rls);

static void SocketReadCallback(CFSocketRef s, CFSocketCallBackType type, CFDataRef address, const void *data, void *info){
    DataListener* obj;
    obj = (DataListener*) info;
    NSLog(@"Got callback in C");
    [obj readData];
}