Subscribers to the BlockChecked validation interface event may need
access to the block outside of the callback scope. Currently, this
is only possible by copying the block, which makes exposing this
validation interface event publicly either cumbersome or with significant
copy overhead.
By using shared_ptr, we make the shared ownership explicit and allow
users to safely use the block outside of the callback scope.
04528054fc [bench] BlockAssembler with mempool packages (glozow)
6ce265acf4 [test util] lock cs_main before pool.cs in PopulateMempool (glozow)
8791410662 [test util] randomize fee in PopulateMempool (glozow)
cba5934eb6 [miner] allow bypassing TestBlockValidity (glozow)
c058852308 [refactor] parameterize BlockAssembler::Options in PrepareBlock (glozow)
a2de971ba1 [refactor] add helper to apply ArgsManager to BlockAssembler::Options (glozow)
Pull request description:
Performance of block template building matters as miners likely want to be able to start mining on a block with transactions asap after a block is found. We would want to know if a mempool PR accidentally caused, for example, a 100x slowdown. An `AssembleBlock()` bench exists, but it operates on a mempool with 101 transactions, each with 0 ancestors or descendants and with the same fee. Adding a bench with a more complex mempool is useful because (1) it's more realistic (2) updating packages can potentially cause the algorithm to take a long time.
ACKs for top commit:
kevkevinpal:
Tested ACK [0452805](04528054fc)
achow101:
ACK 04528054fc
stickies-v:
ACK 04528054f
Tree-SHA512: 38c138d6a75616651f9b1faf4e3a1cd833437a486f4e84308fbee958e8462bb570582c88f7ba7ab99d80191e97855ac2cf27c43cc21585d3e4b0e227effe2fb5
In order to prevent memory DoS, we must ensure that we don't accept a new
header into memory until we've performed anti-DoS checks, such as verifying
that the header is part of a sufficiently high work chain. This commit adds a
new argument to AcceptBlockHeader() so that we can ensure that all call-sites
which might cause a new header to be accepted into memory have to grapple with
the question of whether the header is safe to accept, or needs further
validation.
This patch also fixes two places where low-difficulty-headers could have been
processed without such validation (processing an unrequested block from the
network, and processing a compact block).
Credit to Niklas Gögge for noticing this issue, and thanks to Sjors Provoost
for test code.
...also adjust callers
Changes:
- In BlockAssembler::CreateNewBlock, we now only lock m_mempool->cs and
call addPackageTxs if m_mempool is not nullptr
- BlockAssembler::addPackageTxs now takes in a mempool reference, and is
annotated to require that mempool's lock.
- In TestChain100Setup::CreateBlock and generateblock, don't construct
an empty mempool, just pass in a nullptr for mempool
The utility is primarily useful to dereference pointer types, which are
known to be not null at that time.
For example, the ArgsManager is known to exist when the wallets are
started. Instead of silently relying on that assumption, Assert can be
used to abort the program and avoid UB should the assumption ever be
violated.
