Use {Chain,}TestingSetup's existing {Chainstate,Block}Manager and avoid
unnecessarily creating a local one.
This also helps reduce the code diff for a later commit where we change
{Chainstate,Block}Manager's constructor signature.
After this commit, there should be no explicit instantiation of
CTxMemPool in src/test other than those in fuzz/ and setup_common
-BEGIN VERIFY SCRIPT-
find_regex="CTxMemPool\s+([^;({]+)(|\(\)|\{\});" \
&& git grep -l -E "$find_regex" -- src/test \
| grep -v -e "^src/test/util/setup_common.cpp$" \
-e "^src/test/fuzz/" \
| xargs sed -i -E "s@$find_regex@CTxMemPool\& \1 = *Assert(m_node.mempool);@g"
-END VERIFY SCRIPT-
Add an upwards reference to chainstate instances to the owning
ChainstateManager. This is necessary because there are a number
of `this_chainstate == chainman.ActiveChainstate()` checks that
will happen (as a result of assumeutxo) in functions that otherwise
don't have an easily-accessible reference to the chainstate's
ChainManager.
Since we now have multiple chainstate objects, only one of them is active at any given
time. An active chainstate has a mempool, but there's no point to others having one.
This change will simplify proposed assumeutxo semantics. See the discussion here:
https://github.com/bitcoin/bitcoin/pull/15606#pullrequestreview-692965905
Co-authored-by: Russell Yanofsky <russ@yanofsky.org>
Also adds CCoinsViewCache::ReallocateCache() to attempt to free
memory that the cacheCoins's allocator may be hanging onto when
downsizing the cache.
Adds `CChainState::m_coins{tip,db}_cache_size_bytes` data members
so that we can reference cache size on a per-chainstate basis for
flushing.
