This disentangles the script validation skipping from checkpoints.
A new option is introduced "assumevalid" which specifies a block whos
ancestors we assume all have valid scriptsigs and so we do not check
them when they are also burried under the best header by two weeks
worth of work.
Unlike checkpoints this has no influence on consensus unless you set
it to a block with an invalid history. Because of this it can be
easily be updated without risk of influencing the network consensus.
This results in a massive IBD speedup.
This approach was independently recommended by Peter Todd and Luke-Jr
since POW based signature skipping (see PR#9180) does not have the
verifiable properties of a specific hash and may create bad incentives.
The downside is that, like checkpoints, the defaults bitrot and older
releases will sync slower. On the plus side users can provide their
own value here, and if they set it to something crazy all that will
happen is more time will be spend validating signatures.
Checkblocks and checklevel are also moved to the hidden debug options:
Especially now that checkblocks has a low default there is little need
to change these settings, and users frequently misunderstand them as
influencing security or IBD speed. By hiding them we offset the
space added by this new option.
Previously addnodes were in competition with outbound connections
for access to the eight outbound slots.
One result of this is that frequently a node with several addnode
configured peers would end up connected to none of them, because
while the addnode loop was in its two minute sleep the automatic
connection logic would fill any free slots with random peers.
This is particularly unwelcome to users trying to maintain links
to specific nodes for fast block relay or purposes.
Another result is that a group of nine or more nodes which are
have addnode configured towards each other can become partitioned
from the public network.
This commit introduces a new limit of eight connections just for
addnode peers which is not subject to any of the other connection
limitations (including maxconnections).
The choice of eight is sufficient so that under no condition would
a user find themselves connected to fewer addnoded peers than
previously. It is also low enough that users who are confused
about the significance of more connections and have gotten too
copy-and-paste happy will not consume more than twice the slot
usage of a typical user.
Any additional load on the network resulting from this will likely
be offset by a reduction in users applying even more wasteful
workaround for the prior behavior.
The retry delays are reduced to avoid nodes sitting around without
their added peers up, but are still sufficient to prevent overly
aggressive repeated connections. The reduced delays also make
the system much more responsive to the addnode RPC.
Ban-disconnects are also exempted for peers added via addnode since
the outbound addnode logic ignores bans. Previously it would ban
an addnode then immediately reconnect to it.
A minor change was also made to CSemaphoreGrant so that it is
possible to re-acquire via an object whos grant was moved.
If the mempool is not completely full, treat the difference between
the maximum size and the actual usage as available for the coin cache.
This also changes the early flush trigger from (usage > 0.9 * space)
to (usage > 0.9 * space && usage > space - 100MB). This means we're not
permanently leaving 10% of the space unused when the space is large.
SQUASHME: Change cuckoocache to only work for powers of two, to avoid mod operator
SQUASHME: Update Documentation and simplify logarithm logic
SQUASHME: OSX Build Errors
SQUASHME: minor Feedback from sipa + bluematt
SQUASHME: DOCONLY: Clarify a few comments.
Before daemonization, just probe the data directory lock and print an
early error message if possible.
After daemonization get the data directory lock again and hold on to it until exit
This creates a slight window for a race condition to happen, however this condition is harmless: it
will at most make us exit without printing a message to console.
$ src/bitcoind -testnet -daemon
Bitcoin server starting
$ src/bitcoind -testnet -daemon
Error: Cannot obtain a lock on data directory /home/orion/.bitcoin/testnet3. Bitcoin Core is probably already running.
UnloadBlockIndex is only used during init if we end up reindexing
to clear our block state so that we can start over. However, at
that time no connections have been brought up as CConnman hasn't
been started yet, so all of the network processing state logic is
empty when its called.
Additionally, the initialization of the recentRejects set is moved
to InitPeerLogic.
This adds a new CValidationInterface subclass, defined in main.h,
to receive notifications of UpdatedBlockTip and use that to push
blocks to peers, instead of doing it directly from
ActivateBestChain.
Simplified version of #8278. Assumes that every OS that (a) is supported
by Bitcoin Core (b) supports daemonization has the `daemon()` function
in its C library.
- Removes the fallback path for operating systems that support
daemonization but not `daemon()`. This prevents never-exercised code from
ending up in the repository (see discussion here:
https://github.com/bitcoin/bitcoin/pull/8278#issuecomment-242704745).
- Removes the windows-specific path. Windows doesn't support `daemon()`,
so it don't support daemonization there, automatically.
Original code by Matthew King, adapted by Wladimir van der Laan.
Alex Morcos