I need to embed billing into the libtorrent. So I need to know when node B successfully uploads a block to node A. But according to libtorrent docs, alert block-uploaded-alert is posted when a block intended to be sent to a peer is placed in the send buffer. So in fact the block is not yet uploaded when this alert is posted. Is there a way to know whether the upload was successful?
P.S. Can I limit the number of blocks which are uploaded to the same peer at the same time?