Function check_computeblockversion

src/test/versionbits_tests.cpp:260–413

Check that ComputeBlockVersion will set the appropriate bit correctly */

/** Check that ComputeBlockVersion will set the appropriate bit correctly */
static void check_computeblockversion(const Consensus::Params& params, Consensus::DeploymentPos dep)
{
    // This implicitly uses g_versionbitscache, so clear it every time
    g_versionbitscache.Clear();

    int64_t bit = params.vDeployments[dep].bit;
    int64_t nStartTime = params.vDeployments[dep].nStartTime;
    int64_t nTimeout = params.vDeployments[dep].nTimeout;
    int min_activation_height = params.vDeployments[dep].min_activation_height;

    // should not be any signalling for first block
    BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(nullptr, params), VERSIONBITS_TOP_BITS);

    // always/never active deployments shouldn't need to be tested further
    if (nStartTime == Consensus::BIP9Deployment::ALWAYS_ACTIVE ||
        nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE)
    {
        BOOST_CHECK_EQUAL(min_activation_height, 0);
        return;
    }

    BOOST_REQUIRE(nStartTime < nTimeout);
    BOOST_REQUIRE(nStartTime >= 0);
    BOOST_REQUIRE(nTimeout <= std::numeric_limits<uint32_t>::max() || nTimeout == Consensus::BIP9Deployment::NO_TIMEOUT);
    BOOST_REQUIRE(0 <= bit && bit < 32);
    // Make sure that no deployment tries to set an invalid bit.
    BOOST_REQUIRE(((1 << bit) & VERSIONBITS_TOP_MASK) == 0);
    BOOST_REQUIRE(min_activation_height >= 0);
    // Check min_activation_height is on a retarget boundary
    BOOST_REQUIRE_EQUAL(min_activation_height % params.nMinerConfirmationWindow, 0U);

    const uint32_t bitmask{g_versionbitscache.Mask(params, dep)};
    BOOST_CHECK_EQUAL(bitmask, uint32_t{1} << bit);

    // In the first chain, test that the bit is set by CBV until it has failed.
    // In the second chain, test the bit is set by CBV while STARTED and
    // LOCKED-IN, and then no longer set while ACTIVE.
    VersionBitsTester firstChain, secondChain;

    int64_t nTime = nStartTime;

    const CBlockIndex *lastBlock = nullptr;

    // Before MedianTimePast of the chain has crossed nStartTime, the bit
    // should not be set.
    if (nTime == 0) {
        // since CBlockIndex::nTime is uint32_t we can't represent any
        // earlier time, so will transition from DEFINED to STARTED at the
        // end of the first period by mining blocks at nTime == 0
        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
        // then we'll keep mining at nStartTime...
    } else {
        // use a time 1s earlier than start time to check we stay DEFINED
        --nTime;