In the case of (for example) an already-running bitcoind, the shutdown sequence
begins before CConnman has been created, leading to a null-pointer dereference
when g_connman->Stop() is called.
Instead, Just let the CConnman dtor take care of stopping.
CConnman then passes the current best height into CNode at creation time.
This way CConnman/CNode have no dependency on main for height, and the signals
only move in one direction.
This also helps to prevent identity leakage a tiny bit. Before this change, an
attacker could theoretically make 2 connections on different interfaces. They
would connect fully on one, and only establish the initial connection on the
other. Once they receive a new block, they would relay it to your first
connection, and immediately commence the version handshake on the second. Since
the new block height is reflected immediately, they could attempt to learn
whether the two connections were correlated.
This is, of course, incredibly unlikely to work due to the small timings
involved and receipt from other senders. But it doesn't hurt to lock-in
nBestHeight at the time of connection, rather than letting the remote choose
the time.
waitfornewblock waits until a new block is received, or the timeout expires, then
returns the current block height/hash.
waitforblock waits for a specific blockhash, or until the timeout expires, then
returns the current block height/hash. If the target blockhash is the current
tip, it will return immediately.
waitforblockheight waits until the tip has reached a certain height or higher,
then returns the current height and hash.
waitforblockheight is used to avoid polling in the rpc tests.
Also cap the allocation for the leveldb-specific cache for the UTXO set
to 8MiB.
This avoids that the extra cache memory goes to the much less effective
leveldb cache instead of our application-level cache.
As per meeting 2016-03-31
https://bitcoincore.org/en/meetings/2016/03/31/#bad-chain-alerts
The partition checker was producing huge number of false-positives
and was disabled in 0.12.1 on the understanding it would either be
fixed in 0.13 or removed entirely from master if not.
Putting the build date in the executable is a practice that has no place
in these days, now that deterministic building is increasingly common.
Continues #7732 which did this for the GUI.