Without this commit:
1) read height from DB
2) add block to chain in separate thread
3) read chain for block id's and request them from peer
4) ERR in handle_response_chain_entry, peer's first block is the
one that was added to the chain, which has block idx=height from
step 1.
This commit reads the chain for height and highest block id's
in one go while holding the m_blockchain_lock to avoid the race.
update_checkpoints() makes a few DNS requests and can take up to 20-30 seconds to complete (3-6 seconds on average). It is currently called from core::handle_incoming_block() which holds m_incoming_tx_lock, so it blocks all incoming transactions and blocks processing while update_checkpoints() is running. This PR moves it to until after a new block has been processed and relayed, to avoid full monerod locking.
boosted_tcp_server: check condition before sleep too
cryptonote_protocol_handler: each instance of BlockchainLMDB requires separate thread due to private thread local fields
There are quite a few variables in the code that are no longer
(or perhaps never were) in use. These were discovered by enabling
compiler warnings for unused variables and cleaning them up.
In most cases where the unused variables were the result
of a function call the call was left but the variable
assignment removed, unless it was obvious that it was
a simple getter with no side effects.
A newly synced Alice sends a (typically quite small) list of
txids in the local tpxool to a random peer Bob, who then uses
the existing tx relay system to send Alice any tx in his txpool
which is not in the list Alice sent
