Martin Ling 743b2c76e2 Replace per-transfer flags with a count of active transfers.
This simplifies the code required to wait for cancellations to complete.
The condition variable now reflects whether `active_transfers == 0`, and
the associated lock must be held to decrement that count to zero.
2022-06-15 00:48:47 +01:00
..
2015-07-21 17:01:07 +01:00