[Pharo-users] UFFI with asynchronous callbacks

Hi, I would like to connect fingerprint reader to pharo - so far I am able to use C library to connect to it using UFFI, however the problem is that I can wait for fingerprint indefinitely ( blocking call to library) or register call-back for moment when fingerprint is available. The registration function returns immediately, so it is clear that the callback will be called from another thread. Is such situation supported by UFFI ? Thanks for any tip, Jan