mac os x - usb hid - how the receive device added / device removed callbacks?

I'm a beginner at programming on mac os x.

I am following this tutorial.

And I have this program:

#include <stdio.h>
#include <IOKit/hid/IOHIDManager.h>
#include <IOKit/hid/IOHIDKeys.h>
#include <CoreFoundation/CoreFoundation.h>

static void Handle_DeviceMatchingCallback(void *inContext, IOReturn inResult, void *inSender, IOHIDDeviceRef inIOHIDDeviceRef)
{
    puts("YAY Handle_DeviceMatchingCallback");
}

static void Handle_DeviceRemovalCallback(void *inContext, IOReturn inResult, void *inSender, IOHIDDeviceRef inIOHIDDeviceRef)
{
    puts("YAY Handle_DeviceRemovalCallback");
}

int main()
{
    IOHIDManagerRef HIDManager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
    IOHIDManagerSetDeviceMatching(HIDManager, NULL);

    IOHIDManagerRegisterDeviceMatchingCallback(HIDManager, &Handle_DeviceMatchingCallback, NULL);
    IOHIDManagerRegisterDeviceRemovalCallback(HIDManager, &Handle_DeviceRemovalCallback, NULL);

    IOHIDManagerScheduleWithRunLoop(HIDManager, CFRunLoopGetMain(), kCFRunLoopDefaultMode);

    IOReturn IOReturn = IOHIDManagerOpen(HIDManager, kIOHIDOptionsTypeNone);
    if(IOReturn) puts("IOHIDManagerOpen failed.");

    while(1)
    {
        puts("sleeping...");
        sleep(1);
    }

    return 0;
}

What I am doing wrong, because I do not get the callbacks when I insert or remove any hid device in the USB port.