setup_common.cpp

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// Copyright (c) 2011-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#include <test/util/setup_common.h>
 
#include <addrman.h>
#include <banman.h>
#include <chain.h>
#include <chainparams.h>
#include <coins.h>
#include <common/system.h>
#include <consensus/amount.h>
#include <consensus/consensus.h>
#include <consensus/validation.h>
#include <crypto/hex_base.h>
#include <dbwrapper.h>
#include <init.h>
#include <interfaces/chain.h>
#include <interfaces/mining.h>
#include <kernel/caches.h>
#include <kernel/context.h>
#include <key.h>
#include <logging.h>
#include <net.h>
#include <net_processing.h>
#include <netbase.h>
#include <netgroup.h>
#include <node/blockstorage.h>
#include <node/chainstate.h>
#include <node/context.h>
#include <node/kernel_notifications.h>
#include <node/miner.h>
#include <node/mining_args.h>
#include <node/mining_types.h>
#include <node/peerman_args.h>
#include <node/warnings.h>
#include <noui.h>
#include <policy/feerate.h>
#include <policy/policy.h>
#include <pow.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <random.h>
#include <rpc/register.h>
#include <rpc/server.h>
#include <scheduler.h>
#include <script/interpreter.h>
#include <script/script.h>
#include <script/sign.h>
#include <script/signingprovider.h>
#include <serialize.h>
#include <span.h>
#include <streams.h>
#include <sync.h>
#include <test/util/coverage.h>
#include <test/util/net.h>
#include <test/util/random.h>
#include <test/util/txmempool.h>
#include <tinyformat.h>
#include <txmempool.h>
#include <uint256.h>
#include <util/chaintype.h>
#include <util/check.h>
#include <util/fs.h>
#include <util/fs_helpers.h>
#include <util/rbf.h>
#include <util/result.h>
#include <util/signalinterrupt.h>
#include <util/strencodings.h>
#include <util/task_runner.h>
#include <util/thread.h>
#include <util/threadnames.h>
#include <util/time.h>
#include <util/translation.h>
#include <util/vector.h>
#include <validation.h>
#include <validationinterface.h>
 
#include <algorithm>
#include <array>
#include <atomic>
#include <cstdlib>
#include <deque>
#include <functional>
#include <future>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <span>
#include <stdexcept>
#include <string_view>
#include <thread>
#include <tuple>
#include <utility>
 
using namespace util::hex_literals;
using node::ApplyArgsManOptions;
using node::BlockManager;
using node::KernelNotifications;
using node::LoadChainstate;
using node::RegenerateCommitments;
using node::VerifyLoadedChainstate;
 
const TranslateFn G_TRANSLATION_FUN{nullptr};
 
constexpr inline auto TEST_DIR_PATH_ELEMENT{"test_common bitcoin"}; // Includes a space to catch possible path escape issues.
static FastRandomContext g_rng_temp_path;
static const bool g_rng_temp_path_init{[] {
    // Must be initialized before any SeedRandomForTest
    Assert(!g_used_g_prng);
    (void)g_rng_temp_path.rand64();
    g_used_g_prng = false;
    ResetCoverageCounters(); // The seed strengthen in SeedStartup is not deterministic, so exclude it from coverage counts
    return true;
}()};
 
struct NetworkSetup
{
    NetworkSetup()
    {
        Assert(SetupNetworking());
    }
};
static NetworkSetup g_networksetup_instance;
 
void SetupCommonTestArgs(ArgsManager& argsman)
{
    argsman.AddArg("-testdatadir", strprintf("Custom data directory (default: %s<random_string>)", fs::PathToString(fs::temp_directory_path() / TEST_DIR_PATH_ELEMENT / "")),
                   ArgsManager::ALLOW_ANY, OptionsCategory::DEBUG_TEST);
}
 
static void ExitFailure(std::string_view str_err)
{
    std::cerr << str_err << std::endl;
    exit(EXIT_FAILURE);
}
 
BasicTestingSetup::BasicTestingSetup(const ChainType chainType, TestOpts opts)
    : m_args{}
{
    if (!EnableFuzzDeterminism()) {
        SeedRandomForTest(SeedRand::FIXED_SEED);
    }
 
    // Reset globals
    fDiscover = true;
    fListen = true;
    SetRPCWarmupStarting();
    g_reachable_nets.Reset();
    ClearLocal();
 
    m_node.shutdown_signal = &m_interrupt;
    m_node.shutdown_request = [this]{ return m_interrupt(); };
    m_node.args = &gArgs;
    std::vector<const char*> arguments = Cat(
        {
            "dummy",
            "-printtoconsole=0",
            "-logsourcelocations",
            "-logtimemicros",
            "-logthreadnames",
            "-loglevel=trace",
            "-debug",
            "-debugexclude=leveldb",
        },
        opts.extra_args);
    if (G_TEST_COMMAND_LINE_ARGUMENTS) {
        arguments = Cat(arguments, G_TEST_COMMAND_LINE_ARGUMENTS());
    }
    util::ThreadRename("test");
    gArgs.ClearPathCache();
    {
        SetupServerArgs(*m_node.args);
        SetupCommonTestArgs(*m_node.args);
        std::string error;
        if (!m_node.args->ParseParameters(arguments.size(), arguments.data(), error)) {
            m_node.args->ClearArgs();
            throw std::runtime_error{error};
        }
    }
 
    const std::string test_name{G_TEST_GET_FULL_NAME ? G_TEST_GET_FULL_NAME() : ""};
    if (!m_node.args->IsArgSet("-testdatadir")) {
        // To avoid colliding with a leftover prior datadir, and to allow
        // tests, such as the fuzz tests to run in several processes at the
        // same time, add a random element to the path. Keep it small enough to
        // avoid a MAX_PATH violation on Windows.
        //
        // When fuzzing with AFL++, use the shared memory ID for a deterministic
        // path. This allows for cleanup of leftover directories from timed-out
        // or crashed iterations, preventing accumulation of stale datadirs.
        if (const char* shm_id = std::getenv("__AFL_SHM_ID"); shm_id && *shm_id) {
            m_path_root = fs::temp_directory_path() / TEST_DIR_PATH_ELEMENT / test_name / shm_id;
            fs::remove_all(m_path_root);
        } else {
            const auto rand{HexStr(g_rng_temp_path.randbytes(10))};
            m_path_root = fs::temp_directory_path() / TEST_DIR_PATH_ELEMENT / test_name / rand;
        }
        TryCreateDirectories(m_path_root);
    } else {
        // Custom data directory
        m_has_custom_datadir = true;
        fs::path root_dir{m_node.args->GetPathArg("-testdatadir")};
        if (root_dir.empty()) ExitFailure("-testdatadir argument is empty, please specify a path");
 
        root_dir = fs::absolute(root_dir);
        m_path_lock = root_dir / TEST_DIR_PATH_ELEMENT / fs::PathFromString(test_name);
        m_path_root = m_path_lock / "datadir";
 
        // Try to obtain the lock; if unsuccessful don't disturb the existing test.
        TryCreateDirectories(m_path_lock);
        if (util::LockDirectory(m_path_lock, ".lock", /*probe_only=*/false) != util::LockResult::Success) {
            ExitFailure("Cannot obtain a lock on test data lock directory " + fs::PathToString(m_path_lock) + '\n' + "The test executable is probably already running.");
        }
 
        // Always start with a fresh data directory; this doesn't delete the .lock file located one level above.
        fs::remove_all(m_path_root);
        if (!TryCreateDirectories(m_path_root)) ExitFailure("Cannot create test data directory");
 
        // Print the test directory name if custom.
        std::cout << "Test directory (will not be deleted): " << m_path_root << std::endl;
    }
    m_args.ForceSetArg("-datadir", fs::PathToString(m_path_root));
    gArgs.ForceSetArg("-datadir", fs::PathToString(m_path_root));
 
    // Avoid non-loopback network traffic during tests.
    gArgs.ForceSetArg("-dnsseed", "0"); // DNS queries are usually forwarded to upstream DNS servers.
    gArgs.ForceSetArg("-natpmp", "0"); // NATPMP sends packets to the router.
 
    SelectParams(chainType);
    InitLogging(*m_node.args);
    AppInitParameterInteraction(*m_node.args);
    LogInstance().StartLogging();
    m_node.warnings = std::make_unique<node::Warnings>();
    m_node.kernel = std::make_unique<kernel::Context>();
    m_node.ecc_context = std::make_unique<ECC_Context>();
    SetupEnvironment();
 
    m_node.chain = interfaces::MakeChain(m_node);
    static bool noui_connected = false;
    if (!noui_connected) {
        noui_connect();
        noui_connected = true;
    }
}
 
BasicTestingSetup::~BasicTestingSetup()
{
    m_node.ecc_context.reset();
    m_node.kernel.reset();
    if (!EnableFuzzDeterminism()) {
        SetMockTime(0s); // Reset mocktime for following tests
    }
    LogInstance().DisconnectTestLogger();
    if (m_has_custom_datadir) {
        // Only remove the lock file, preserve the data directory.
        UnlockDirectory(m_path_lock, ".lock");
        fs::remove(m_path_lock / ".lock");
    } else {
        fs::remove_all(m_path_root);
    }
    // Clear all arguments except for -datadir, which GUI tests currently rely
    // on to be set even after the testing setup is destroyed.
    gArgs.ClearArgs();
    gArgs.ForceSetArg("-datadir", fs::PathToString(m_path_root));
}
 
ChainTestingSetup::ChainTestingSetup(const ChainType chainType, TestOpts opts)
    : BasicTestingSetup(chainType, opts)
{
    const CChainParams& chainparams = Params();
 
    // A task runner is required to prevent ActivateBestChain
    // from blocking due to queue overrun.
    if (opts.setup_validation_interface) {
        m_node.scheduler = std::make_unique<CScheduler>();
        m_node.scheduler->m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { m_node.scheduler->serviceQueue(); });
        m_node.validation_signals =
            // Use synchronous task runner while fuzzing to avoid non-determinism
            EnableFuzzDeterminism() ?
                std::make_unique<ValidationSignals>(std::make_unique<util::ImmediateTaskRunner>()) :
                std::make_unique<ValidationSignals>(std::make_unique<SerialTaskRunner>(*m_node.scheduler));
        {
            // Ensure deterministic coverage by waiting for m_service_thread to be running
            std::promise<void> promise;
            m_node.scheduler->scheduleFromNow([&promise] { promise.set_value(); }, 0ms);
            promise.get_future().wait();
        }
    }
 
    bilingual_str error{};
    m_node.mempool = std::make_unique<CTxMemPool>(MemPoolOptionsForTest(m_node), error);
    Assert(error.empty());
    m_node.warnings = std::make_unique<node::Warnings>();
 
    m_node.notifications = std::make_unique<KernelNotifications>(Assert(m_node.shutdown_request), m_node.exit_status, *Assert(m_node.warnings));
 
    m_make_chainman = [this, &chainparams, opts] {
        Assert(!m_node.chainman);
        ChainstateManager::Options chainman_opts{
            .chainparams = chainparams,
            .datadir = m_args.GetDataDirNet(),
            .check_block_index = 1,
            .notifications = *m_node.notifications,
            .signals = m_node.validation_signals.get(),
            // Use no worker threads while fuzzing to avoid non-determinism
            .worker_threads_num = EnableFuzzDeterminism() ? 0 : 2,
        };
        if (opts.min_validation_cache) {
            chainman_opts.script_execution_cache_bytes = 0;
            chainman_opts.signature_cache_bytes = 0;
        }
        const BlockManager::Options blockman_opts{
            .chainparams = chainman_opts.chainparams,
            .blocks_dir = m_args.GetBlocksDirPath(),
            .notifications = chainman_opts.notifications,
            .block_tree_db_params = DBParams{
                .path = m_args.GetDataDirNet() / "blocks" / "index",
                .cache_bytes = m_kernel_cache_sizes.block_tree_db,
                .memory_only = opts.block_tree_db_in_memory,
                .wipe_data = m_args.GetBoolArg("-reindex", false),
            },
        };
        m_node.chainman = std::make_unique<ChainstateManager>(*Assert(m_node.shutdown_signal), chainman_opts, blockman_opts);
    };
    m_make_chainman();
}
 
ChainTestingSetup::~ChainTestingSetup()
{
    if (m_node.scheduler) m_node.scheduler->stop();
    if (m_node.validation_signals) m_node.validation_signals->FlushBackgroundCallbacks();
    m_node.connman.reset();
    m_node.banman.reset();
    m_node.addrman.reset();
    m_node.netgroupman.reset();
    m_node.args = nullptr;
    m_node.mempool.reset();
    Assert(!m_node.fee_estimator); // Each test must create a local object, if they wish to use the fee_estimator
    m_node.chainman.reset();
    m_node.validation_signals.reset();
    m_node.scheduler.reset();
}
 
void ChainTestingSetup::LoadVerifyActivateChainstate()
{
    auto& chainman{*Assert(m_node.chainman)};
    node::ChainstateLoadOptions options;
    options.mempool = Assert(m_node.mempool.get());
    options.coins_db_in_memory = m_coins_db_in_memory;
    options.wipe_chainstate_db = m_args.GetBoolArg("-reindex", false) || m_args.GetBoolArg("-reindex-chainstate", false);
    options.prune = chainman.m_blockman.IsPruneMode();
    options.check_blocks = m_args.GetIntArg("-checkblocks", DEFAULT_CHECKBLOCKS);
    options.check_level = m_args.GetIntArg("-checklevel", DEFAULT_CHECKLEVEL);
    options.require_full_verification = m_args.IsArgSet("-checkblocks") || m_args.IsArgSet("-checklevel");
    auto [status, error] = LoadChainstate(chainman, m_kernel_cache_sizes, options);
    assert(status == node::ChainstateLoadStatus::SUCCESS);
 
    std::tie(status, error) = VerifyLoadedChainstate(chainman, options);
    assert(status == node::ChainstateLoadStatus::SUCCESS);
 
    m_node.notifications->setChainstateLoaded(true);
 
    BlockValidationState state;
    if (!chainman.ActiveChainstate().ActivateBestChain(state)) {
        throw std::runtime_error(strprintf("ActivateBestChain failed. (%s)", state.ToString()));
    }
}
 
TestingSetup::TestingSetup(
    const ChainType chainType,
    TestOpts opts)
    : ChainTestingSetup(chainType, opts)
{
    m_coins_db_in_memory = opts.coins_db_in_memory;
    m_block_tree_db_in_memory = opts.block_tree_db_in_memory;
    // Ideally we'd move all the RPC tests to the functional testing framework
    // instead of unit tests, but for now we need these here.
    RegisterAllCoreRPCCommands(tableRPC);
 
    LoadVerifyActivateChainstate();
 
    if (!opts.setup_net) return;
 
    m_node.netgroupman = std::make_unique<NetGroupManager>(NetGroupManager::NoAsmap());
    m_node.addrman = std::make_unique<AddrMan>(*m_node.netgroupman,
                                               /*deterministic=*/false,
                                               m_node.args->GetIntArg("-checkaddrman", 0));
    m_node.banman = std::make_unique<BanMan>(m_args.GetDataDirBase() / "banlist", nullptr, DEFAULT_MISBEHAVING_BANTIME);
    m_node.connman = std::make_unique<ConnmanTestMsg>(0x1337, 0x1337, *m_node.addrman, *m_node.netgroupman, Params()); // Deterministic randomness for tests.
    auto mining_args{node::ReadMiningArgs(*m_node.args)};
    Assert(mining_args);
    m_node.mining_args = std::move(*mining_args);
    PeerManager::Options peerman_opts;
    ApplyArgsManOptions(*m_node.args, peerman_opts);
    peerman_opts.deterministic_rng = true;
    m_node.peerman = PeerManager::make(*m_node.connman, *m_node.addrman,
                                       m_node.banman.get(), *m_node.chainman,
                                       *m_node.mempool, *m_node.warnings,
                                       peerman_opts);
 
    {
        CConnman::Options options;
        options.m_msgproc = m_node.peerman.get();
        m_node.connman->Init(options);
    }
}
 
TestChain100Setup::TestChain100Setup(
    const ChainType chain_type,
    TestOpts opts)
    : TestingSetup{ChainType::REGTEST, opts}
{
    constexpr std::array<unsigned char, 32> vchKey = {
        {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}};
    coinbaseKey.Set(vchKey.begin(), vchKey.end(), true);
 
    // Generate a 100-block chain:
    this->mineBlocks(COINBASE_MATURITY);
 
    {
        LOCK(::cs_main);
        assert(
            m_node.chainman->ActiveChain().Tip()->GetBlockHash().ToString() ==
            "0ee6e270d6594249e548110619f7bd690695beb219b915da4a2e84e2b61ed60f");
    }
}
 
void TestChain100Setup::mineBlocks(int num_blocks)
{
    CScript scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
    for (int i = 0; i < num_blocks; i++) {
        std::vector<CMutableTransaction> noTxns;
        CBlock b = CreateAndProcessBlock(noTxns, scriptPubKey);
        m_clock += 1s;
        m_coinbase_txns.push_back(b.vtx[0]);
    }
}
 
CBlock TestChain100Setup::CreateBlock(
    const std::vector<CMutableTransaction>& txns,
    const CScript& scriptPubKey)
{
    auto mining{interfaces::MakeMining(m_node)};
    auto block_template{mining->createNewBlock({
        .use_mempool = false,
        .coinbase_output_script = scriptPubKey,
    }, /*cooldown=*/false)};
    Assert(block_template);
    CBlock block{block_template->getBlock()};
 
    Assert(block.vtx.size() == 1);
    for (const CMutableTransaction& tx : txns) {
        block.vtx.push_back(MakeTransactionRef(tx));
    }
    RegenerateCommitments(block, *Assert(m_node.chainman));
 
    while (!CheckProofOfWork(block.GetHash(), block.nBits, m_node.chainman->GetConsensus())) ++block.nNonce;
 
    return block;
}
 
CBlock TestChain100Setup::CreateAndProcessBlock(
    const std::vector<CMutableTransaction>& txns,
    const CScript& scriptPubKey)
{
    CBlock block = this->CreateBlock(txns, scriptPubKey);
    std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
    Assert(m_node.chainman)->ProcessNewBlock(shared_pblock, true, true, nullptr);
 
    return block;
}
 
std::pair<CMutableTransaction, CAmount> TestChain100Setup::CreateValidTransaction(const std::vector<CTransactionRef>& input_transactions,
                                                                                  const std::vector<COutPoint>& inputs,
                                                                                  int input_height,
                                                                                  const std::vector<CKey>& input_signing_keys,
                                                                                  const std::vector<CTxOut>& outputs,
                                                                                  const std::optional<CFeeRate>& feerate,
                                                                                  const std::optional<uint32_t>& fee_output)
{
    CMutableTransaction mempool_txn;
    mempool_txn.vin.reserve(inputs.size());
    mempool_txn.vout.reserve(outputs.size());
 
    for (const auto& outpoint : inputs) {
        mempool_txn.vin.emplace_back(outpoint, CScript(), MAX_BIP125_RBF_SEQUENCE);
    }
    mempool_txn.vout = outputs;
 
    // - Add the signing key to a keystore
    FillableSigningProvider keystore;
    for (const auto& input_signing_key : input_signing_keys) {
        keystore.AddKey(input_signing_key);
    }
    // - Populate a CoinsViewCache with the unspent output
    CCoinsViewCache coins_cache{&CoinsViewEmpty::Get()};
    for (const auto& input_transaction : input_transactions) {
        AddCoins(coins_cache, *input_transaction.get(), input_height);
    }
    // Build Outpoint to Coin map for SignTransaction
    std::map<COutPoint, Coin> input_coins;
    CAmount inputs_amount{0};
    for (const auto& outpoint_to_spend : inputs) {
        // Use GetCoin to properly populate utxo_to_spend
        auto utxo_to_spend{coins_cache.GetCoin(outpoint_to_spend).value()};
        input_coins.insert({outpoint_to_spend, utxo_to_spend});
        inputs_amount += utxo_to_spend.out.nValue;
    }
    // - Default signature hashing type
    int nHashType = SIGHASH_ALL;
    std::map<int, bilingual_str> input_errors;
    assert(SignTransaction(mempool_txn, &keystore, input_coins, {.sighash_type = nHashType}, input_errors));
    CAmount current_fee = inputs_amount - std::accumulate(outputs.begin(), outputs.end(), CAmount(0),
        [](const CAmount& acc, const CTxOut& out) {
        return acc + out.nValue;
    });
    // Deduct fees from fee_output to meet feerate if set
    if (feerate.has_value()) {
        assert(fee_output.has_value());
        assert(fee_output.value() < mempool_txn.vout.size());
        CAmount target_fee = feerate.value().GetFee(GetVirtualTransactionSize(CTransaction{mempool_txn}));
        CAmount deduction = target_fee - current_fee;
        if (deduction > 0) {
            // Only deduct fee if there's anything to deduct. If the caller has put more fees than
            // the target feerate, don't change the fee.
            mempool_txn.vout[fee_output.value()].nValue -= deduction;
            // Re-sign since an output has changed
            input_errors.clear();
            assert(SignTransaction(mempool_txn, &keystore, input_coins, {.sighash_type = nHashType}, input_errors));
            current_fee = target_fee;
        }
    }
    return {mempool_txn, current_fee};
}
 
CMutableTransaction TestChain100Setup::CreateValidMempoolTransaction(const std::vector<CTransactionRef>& input_transactions,
                                                                     const std::vector<COutPoint>& inputs,
                                                                     int input_height,
                                                                     const std::vector<CKey>& input_signing_keys,
                                                                     const std::vector<CTxOut>& outputs,
                                                                     bool submit)
{
    CMutableTransaction mempool_txn = CreateValidTransaction(input_transactions, inputs, input_height, input_signing_keys, outputs, std::nullopt, std::nullopt).first;
    // If submit=true, add transaction to the mempool.
    if (submit) {
        LOCK(cs_main);
        const MempoolAcceptResult result = m_node.chainman->ProcessTransaction(MakeTransactionRef(mempool_txn));
        assert(result.m_result_type == MempoolAcceptResult::ResultType::VALID);
    }
    return mempool_txn;
}
 
CMutableTransaction TestChain100Setup::CreateValidMempoolTransaction(CTransactionRef input_transaction,
                                                                     uint32_t input_vout,
                                                                     int input_height,
                                                                     CKey input_signing_key,
                                                                     CScript output_destination,
                                                                     CAmount output_amount,
                                                                     bool submit)
{
    COutPoint input{input_transaction->GetHash(), input_vout};
    CTxOut output{output_amount, output_destination};
    return CreateValidMempoolTransaction(/*input_transactions=*/{input_transaction},
                                         /*inputs=*/{input},
                                         /*input_height=*/input_height,
                                         /*input_signing_keys=*/{input_signing_key},
                                         /*outputs=*/{output},
                                         /*submit=*/submit);
}
 
std::vector<CTransactionRef> TestChain100Setup::PopulateMempool(FastRandomContext& det_rand, size_t num_transactions, bool submit)
{
    std::vector<CTransactionRef> mempool_transactions;
    std::deque<std::pair<COutPoint, CAmount>> unspent_prevouts, undo_info;
    std::transform(m_coinbase_txns.begin(), m_coinbase_txns.end(), std::back_inserter(unspent_prevouts),
        [](const auto& tx){ return std::make_pair(COutPoint(tx->GetHash(), 0), tx->vout[0].nValue); });
    while (num_transactions > 0 && !unspent_prevouts.empty()) {
        // The number of inputs and outputs are randomly chosen, between 1-5
        // and 1-25 respectively.
        CMutableTransaction mtx = CMutableTransaction();
        const size_t num_inputs = det_rand.randrange(5) + 1;
        CAmount total_in{0};
        for (size_t n{0}; n < num_inputs; ++n) {
            if (unspent_prevouts.empty()) break;
            const auto& [prevout, amount] = unspent_prevouts.front();
            undo_info.emplace_back(prevout, amount);
            mtx.vin.emplace_back(prevout, CScript());
            total_in += amount;
            unspent_prevouts.pop_front();
        }
        const size_t num_outputs = det_rand.randrange(25) + 1;
        const CAmount fee = 100 * det_rand.randrange(30);
        const CAmount amount_per_output = (total_in - fee) / num_outputs;
        for (size_t n{0}; n < num_outputs; ++n) {
            CScript spk = CScript() << CScriptNum(num_transactions + n);
            mtx.vout.emplace_back(amount_per_output, spk);
        }
        CTransactionRef ptx = MakeTransactionRef(mtx);
        bool success{true};
        if (submit) {
            LOCK2(cs_main, m_node.mempool->cs);
            LockPoints lp;
            auto changeset = m_node.mempool->GetChangeSet();
            changeset->StageAddition(ptx, /*fee=*/(total_in - num_outputs * amount_per_output),
                    /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0,
                    /*spends_coinbase=*/false, /*sigops_cost=*/4, lp);
            if (changeset->CheckMemPoolPolicyLimits()) {
                changeset->Apply();
                --num_transactions;
            } else {
                success = false;
                // Add the inputs back to unspent prevouts
                for (const auto& [prevout, amount] : undo_info) {
                    unspent_prevouts.emplace_back(prevout, amount);
                    std::swap(unspent_prevouts.back(), unspent_prevouts[det_rand.randrange(unspent_prevouts.size())]);
                }
            }
        }
        if (success) {
            mempool_transactions.push_back(ptx);
            if (amount_per_output > 3000) {
                // If the value is high enough to fund another transaction + fees, keep track of it so
                // it can be used to build a more complex transaction graph. Insert randomly into
                // unspent_prevouts for extra randomness in the resulting structures.
                for (size_t n{0}; n < num_outputs; ++n) {
                    unspent_prevouts.emplace_back(COutPoint(ptx->GetHash(), n), amount_per_output);
                    std::swap(unspent_prevouts.back(), unspent_prevouts[det_rand.randrange(unspent_prevouts.size())]);
                }
            }
        }
        undo_info.clear();
    }
    return mempool_transactions;
}
 
SocketTestingSetup::SocketTestingSetup()
{
    // "back up" the current CreateSock() so we can restore it after the test
    m_create_sock_orig = CreateSock;
 
    CreateSock = [this](int, int, int) {
        // This is a mock Listening Socket that a server can "bind" to and
        // listen to for incoming connections. We won't need to access its I/O
        // pipes because we don't read or write directly to it. It will return
        // Connected Sockets from the queue via its Accept() method.
        return std::make_unique<DynSock>(std::make_shared<DynSock::Pipes>(), &m_accepted_sockets);
    };
};
 
SocketTestingSetup::~SocketTestingSetup()
{
    CreateSock = m_create_sock_orig;
}
 
CBlock getBlock13b8a()
{
    CBlock block;
    DataStream stream{
        "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"_hex,
    };
    stream >> TX_WITH_WITNESS(block);
    return block;
}