When cancelling, SeedQueue deadlocked if HttpQueue refused to accept items from SeedQueue because HttpQueue already was "too full" and simultaneously stopped processing any of the remaining ones because it already tried to close. HttpQueue now always allows SeedQueue to send items while it cancels.
When cancelling, SeedQueue deadlocked if HttpQueue refused to accept items from SeedQueue because HttpQueue already was "too full" and simultaneously stopped processing any of the remaining ones because it already tried to close. HttpQueue now always allows SeedQueue to send items while it cancels.