Method MaybeUpdateMempoolForReorg

src/validation.cpp:328–413

}

void CChainState::MaybeUpdateMempoolForReorg(
    DisconnectedBlockTransactions& disconnectpool,
    bool fAddToMempool)
{
    if (!m_mempool) return;

    AssertLockHeld(cs_main);
    AssertLockHeld(m_mempool->cs);
    std::vector<uint256> vHashUpdate;
    // disconnectpool's insertion_order index sorts the entries from
    // oldest to newest, but the oldest entry will be the last tx from the
    // latest mined block that was disconnected.
    // Iterate disconnectpool in reverse, so that we add transactions
    // back to the mempool starting with the earliest transaction that had
    // been previously seen in a block.
    auto it = disconnectpool.queuedTx.get<insertion_order>().rbegin();
    while (it != disconnectpool.queuedTx.get<insertion_order>().rend()) {
        // ignore validation errors in resurrected transactions
        if (!fAddToMempool || (*it)->IsCoinBase() ||
            AcceptToMemoryPool(*this, *it, GetTime(),
                /*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
                    MempoolAcceptResult::ResultType::VALID) {
            // If the transaction doesn't make it in to the mempool, remove any
            // transactions that depend on it (which would now be orphans).
            m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
        } else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) {
            vHashUpdate.push_back((*it)->GetHash());
        }
        ++it;
    }
    disconnectpool.queuedTx.clear();
    // AcceptToMemoryPool/addUnchecked all assume that new mempool entries have
    // no in-mempool children, which is generally not true when adding
    // previously-confirmed transactions back to the mempool.
    // UpdateTransactionsFromBlock finds descendants of any transactions in
    // the disconnectpool that were added back and cleans up the mempool state.
    const uint64_t ancestor_count_limit = gArgs.GetIntArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
    const uint64_t ancestor_size_limit = gArgs.GetIntArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT) * 1000;
    m_mempool->UpdateTransactionsFromBlock(vHashUpdate, ancestor_size_limit, ancestor_count_limit);

    // Predicate to use for filtering transactions in removeForReorg.
    // Checks whether the transaction is still final and, if it spends a coinbase output, mature.
    // Also updates valid entries' cached LockPoints if needed.
    // If false, the tx is still valid and its lockpoints are updated.
    // If true, the tx would be invalid in the next block; remove this entry and all of its descendants.
    const auto filter_final_and_mature = [this, flags=STANDARD_LOCKTIME_VERIFY_FLAGS](CTxMemPool::txiter it)
        EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) {
        AssertLockHeld(m_mempool->cs);
        AssertLockHeld(::cs_main);
        const CTransaction& tx = it->GetTx();

        // The transaction must be final.
        if (!CheckFinalTx(m_chain.Tip(), tx, flags)) return true;
        LockPoints lp = it->GetLockPoints();
        const bool validLP{TestLockPointValidity(m_chain, lp)};
        CCoinsViewMemPool view_mempool(&CoinsTip(), *m_mempool);
        // CheckSequenceLocks checks if the transaction will be final in the next block to be
        // created on top of the new chain. We use useExistingLockPoints=false so that, instead of