/root/bitcoin/src/test/fuzz/versionbits.cpp

Source
// Copyright (c) 2020-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 <chain.h>
#include <chainparams.h>
#include <common/args.h>
#include <consensus/params.h>
#include <primitives/block.h>
#include <util/chaintype.h>
#include <versionbits.h>
#include <versionbits_impl.h>

#include <test/fuzz/FuzzedDataProvider.h>
#include <test/fuzz/fuzz.h>
#include <test/fuzz/util.h>
#include <test/util/versionbits.h>

#include <cstdint>
#include <limits>
#include <memory>
#include <vector>

namespace {
class TestConditionChecker : public VersionBitsConditionChecker
{
private:
    mutable ThresholdConditionCache m_cache;

public:
    TestConditionChecker(const Consensus::BIP9Deployment& dep) : VersionBitsConditionChecker{dep}
    {
        assert(dep.period > 0);
        assert(dep.threshold <= dep.period);
        assert(0 <= dep.bit && dep.bit < 32 && dep.bit < VERSIONBITS_MAX_NUM_BITS);
        assert(0 <= dep.min_activation_height);
    }

    ThresholdState GetStateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, m_cache); }
    int GetStateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, m_cache); }
};

/** Track blocks mined for test */
class Blocks
{
private:
    std::vector<std::unique_ptr<CBlockIndex>> m_blocks;
    const uint32_t m_start_time;
    const uint32_t m_interval;
    const int32_t m_signal;
    const int32_t m_no_signal;

public:
    Blocks(uint32_t start_time, uint32_t interval, int32_t signal, int32_t no_signal)
        : m_start_time{start_time}, m_interval{interval}, m_signal{signal}, m_no_signal{no_signal} {}

    size_t size() const { return m_blocks.size(); }

    CBlockIndex* tip() const
    {
        return m_blocks.empty() ? nullptr : m_blocks.back().get();
    }

    CBlockIndex* mine_block(bool signal)
    {
        CBlockHeader header;
        header.nVersion = signal ? m_signal : m_no_signal;
        header.nTime = m_start_time + m_blocks.size() * m_interval;
        header.nBits = 0x1d00ffff;

        auto current_block = std::make_unique<CBlockIndex>(header);
        current_block->pprev = tip();
        current_block->nHeight = m_blocks.size();
        current_block->BuildSkip();

        return m_blocks.emplace_back(std::move(current_block)).get();
    }
};

std::unique_ptr<const CChainParams> g_params;

void initialize()
{
    // this is actually comparatively slow, so only do it once
    g_params = CreateChainParams(ArgsManager{}, ChainType::MAIN);
    assert(g_params != nullptr);
}

constexpr uint32_t MAX_START_TIME = 4102444800; // 2100-01-01

FUZZ_TARGET(versionbits, .init = initialize)
{
    const CChainParams& params = *g_params;
    const int64_t interval = params.GetConsensus().nPowTargetSpacing;
    assert(interval > 1); // need to be able to halve it
    assert(interval < std::numeric_limits<int32_t>::max());

    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());

    // making period/max_periods larger slows these tests down significantly
    const uint32_t period = 32;
    const size_t max_periods = 16;
    const size_t max_blocks = 2 * period * max_periods;

    // too many blocks at 10min each might cause uint32_t time to overflow if
    // block_start_time is at the end of the range above
    assert(std::numeric_limits<uint32_t>::max() - MAX_START_TIME > interval * max_blocks);

    const int64_t block_start_time = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(params.GenesisBlock().nTime, MAX_START_TIME);

    // what values for version will we use to signal / not signal?
    const int32_t ver_signal = fuzzed_data_provider.ConsumeIntegral<int32_t>();
    const int32_t ver_nosignal = fuzzed_data_provider.ConsumeIntegral<int32_t>();
    if (ver_nosignal < 0) return; // negative values are uninteresting

    // Now that we have chosen time and versions, setup to mine blocks
    Blocks blocks(block_start_time, interval, ver_signal, ver_nosignal);

    const bool always_active_test = fuzzed_data_provider.ConsumeBool();
    const bool never_active_test = !always_active_test && fuzzed_data_provider.ConsumeBool();

    const Consensus::BIP9Deployment dep{[&]() {
        Consensus::BIP9Deployment dep;
        dep.period = period;

        dep.threshold = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(1, period);
        assert(0 < dep.threshold && dep.threshold <= dep.period); // must be able to both pass and fail threshold!

        // select deployment parameters: bit, start time, timeout
        dep.bit = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, VERSIONBITS_MAX_NUM_BITS - 1);

        if (always_active_test) {
            dep.nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
            dep.nTimeout = fuzzed_data_provider.ConsumeBool() ? Consensus::BIP9Deployment::NO_TIMEOUT : fuzzed_data_provider.ConsumeIntegral<int64_t>();
        } else if (never_active_test) {
            dep.nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
            dep.nTimeout = fuzzed_data_provider.ConsumeBool() ? Consensus::BIP9Deployment::NO_TIMEOUT : fuzzed_data_provider.ConsumeIntegral<int64_t>();
        } else {
            // pick the timestamp to switch based on a block
            // note states will change *after* these blocks because mediantime lags
            int start_block = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * (max_periods - 3));
            int end_block = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * (max_periods - 3));

            dep.nStartTime = block_start_time + start_block * interval;
            dep.nTimeout = block_start_time + end_block * interval;

            // allow for times to not exactly match a block
            if (fuzzed_data_provider.ConsumeBool()) dep.nStartTime += interval / 2;
            if (fuzzed_data_provider.ConsumeBool()) dep.nTimeout += interval / 2;
        }
        dep.min_activation_height = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * max_periods);
        return dep;
    }()};
    TestConditionChecker checker(dep);

    // Early exit if the versions don't signal sensibly for the deployment
    if (!checker.Condition(ver_signal)) return;
    if (checker.Condition(ver_nosignal)) return;

    // TOP_BITS should ensure version will be positive and meet min
    // version requirement
    assert(ver_signal > 0);
    assert(ver_signal >= VERSIONBITS_LAST_OLD_BLOCK_VERSION);

    /* Strategy:
     *  * we will mine a final period worth of blocks, with
     *    randomised signalling according to a mask
     *  * but before we mine those blocks, we will mine some
     *    randomised number of prior periods; with either all
     *    or no blocks in the period signalling
     *
     * We establish the mask first, then consume "bools" until
     * we run out of fuzz data to work out how many prior periods
     * there are and which ones will signal.
     */

    // establish the mask
    const uint32_t signalling_mask = fuzzed_data_provider.ConsumeIntegral<uint32_t>();

    // mine prior periods
    while (fuzzed_data_provider.remaining_bytes() > 0) { // early exit; no need for LIMITED_WHILE
        // all blocks in these periods either do or don't signal
        bool signal = fuzzed_data_provider.ConsumeBool();
        for (uint32_t b = 0; b < period; ++b) {
            blocks.mine_block(signal);
        }

        // don't risk exceeding max_blocks or times may wrap around
        if (blocks.size() + 2 * period > max_blocks) break;
    }
    // NOTE: fuzzed_data_provider may be fully consumed at this point and should not be used further

    // now we mine the final period and check that everything looks sane

    // count the number of signalling blocks
    uint32_t blocks_sig = 0;

    // get the info for the first block of the period
    CBlockIndex* prev = blocks.tip();
    const int exp_since = checker.GetStateSinceHeightFor(prev);
    const ThresholdState exp_state = checker.GetStateFor(prev);

    // get statistics from end of previous period, then reset
    BIP9Stats last_stats;
    last_stats.period = period;
    last_stats.threshold = dep.threshold;
    last_stats.count = last_stats.elapsed = 0;
    last_stats.possible = (period >= dep.threshold);
    std::vector<bool> last_signals{};

    int prev_next_height = (prev == nullptr ? 0 : prev->nHeight + 1);
    assert(exp_since <= prev_next_height);

    // mine (period-1) blocks and check state
    for (uint32_t b = 1; b < period; ++b) {
        const bool signal = (signalling_mask >> (b % 32)) & 1;
        if (signal) ++blocks_sig;

        CBlockIndex* current_block = blocks.mine_block(signal);

        // verify that signalling attempt was interpreted correctly
        assert(checker.Condition(current_block->nVersion) == signal);

        // state and since don't change within the period
        const ThresholdState state = checker.GetStateFor(current_block);
        const int since = checker.GetStateSinceHeightFor(current_block);
        assert(state == exp_state);
        assert(since == exp_since);

        // check that after mining this block stats change as expected
        std::vector<bool> signals;
        const BIP9Stats stats = checker.GetStateStatisticsFor(current_block, &signals);
        const BIP9Stats stats_no_signals = checker.GetStateStatisticsFor(current_block);
        assert(stats.period == stats_no_signals.period && stats.threshold == stats_no_signals.threshold
               && stats.elapsed == stats_no_signals.elapsed && stats.count == stats_no_signals.count
               && stats.possible == stats_no_signals.possible);

        assert(stats.period == period);
        assert(stats.threshold == dep.threshold);
        assert(stats.elapsed == b);
        assert(stats.count == last_stats.count + (signal ? 1 : 0));
        assert(stats.possible == (stats.count + period >= stats.elapsed + dep.threshold));
        last_stats = stats;

        assert(signals.size() == last_signals.size() + 1);
        assert(signals.back() == signal);
        last_signals.push_back(signal);
        assert(signals == last_signals);
    }

    if (exp_state == ThresholdState::STARTED) {
        // double check that stats.possible is sane
        if (blocks_sig >= dep.threshold - 1) assert(last_stats.possible);
    }

    // mine the final block
    bool signal = (signalling_mask >> (period % 32)) & 1;
    if (signal) ++blocks_sig;
    CBlockIndex* current_block = blocks.mine_block(signal);
    assert(checker.Condition(current_block->nVersion) == signal);

    const BIP9Stats stats = checker.GetStateStatisticsFor(current_block);
    assert(stats.period == period);
    assert(stats.threshold == dep.threshold);
    assert(stats.elapsed == period);
    assert(stats.count == blocks_sig);
    assert(stats.possible == (stats.count + period >= stats.elapsed + dep.threshold));

    // More interesting is whether the state changed.
    const ThresholdState state = checker.GetStateFor(current_block);
    const int since = checker.GetStateSinceHeightFor(current_block);

    // since is straightforward:
    assert(since % period == 0);
    assert(0 <= since && since <= current_block->nHeight + 1);
    if (state == exp_state) {
        assert(since == exp_since);
    } else {
        assert(since == current_block->nHeight + 1);
    }

    // state is where everything interesting is
    [&]() {
        switch (state) {
        case ThresholdState::DEFINED:
            assert(since == 0);
            assert(exp_state == ThresholdState::DEFINED);
            assert(current_block->GetMedianTimePast() < dep.nStartTime);
            return;
        case ThresholdState::STARTED:
            assert(current_block->GetMedianTimePast() >= dep.nStartTime);
            if (exp_state == ThresholdState::STARTED) {
                assert(blocks_sig < dep.threshold);
                assert(current_block->GetMedianTimePast() < dep.nTimeout);
            } else {
                assert(exp_state == ThresholdState::DEFINED);
            }
            return;
        case ThresholdState::LOCKED_IN:
            if (exp_state == ThresholdState::LOCKED_IN) {
                assert(current_block->nHeight + 1 < dep.min_activation_height);
            } else {
                assert(exp_state == ThresholdState::STARTED);
                assert(blocks_sig >= dep.threshold);
            }
            return;
        case ThresholdState::ACTIVE:
            assert(always_active_test || dep.min_activation_height <= current_block->nHeight + 1);
            assert(exp_state == ThresholdState::ACTIVE || exp_state == ThresholdState::LOCKED_IN);
            return;
        case ThresholdState::FAILED:
            assert(never_active_test || current_block->GetMedianTimePast() >= dep.nTimeout);
            if (exp_state == ThresholdState::STARTED) {
                assert(blocks_sig < dep.threshold);
            } else {
                assert(exp_state == ThresholdState::FAILED);
            }
            return;
        } // no default case, so the compiler can warn about missing cases
        assert(false);
    }();

    if (blocks.size() >= period * max_periods) {
        // we chose the timeout (and block times) so that by the time we have this many blocks it's all over
        assert(state == ThresholdState::ACTIVE || state == ThresholdState::FAILED);
    }

    if (always_active_test) {
        // "always active" has additional restrictions
        assert(state == ThresholdState::ACTIVE);
        assert(exp_state == ThresholdState::ACTIVE);
        assert(since == 0);
    } else if (never_active_test) {
        // "never active" does too
        assert(state == ThresholdState::FAILED);
        assert(exp_state == ThresholdState::FAILED);
        assert(since == 0);
    } else {
        // for signalled deployments, the initial state is always DEFINED
        assert(since > 0 || state == ThresholdState::DEFINED);
        assert(exp_since > 0 || exp_state == ThresholdState::DEFINED);
    }
}
} // namespace

Coverage Report

Created: 2026-06-09 19:51

Line	Count	Source
1		// Copyright (c) 2020-present The Bitcoin Core developers
2		// Distributed under the MIT software license, see the accompanying
3		// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5		#include <chain.h>
6		#include <chainparams.h>
7		#include <common/args.h>
8		#include <consensus/params.h>
9		#include <primitives/block.h>
10		#include <util/chaintype.h>
11		#include <versionbits.h>
12		#include <versionbits_impl.h>
13
14		#include <test/fuzz/FuzzedDataProvider.h>
15		#include <test/fuzz/fuzz.h>
16		#include <test/fuzz/util.h>
17		#include <test/util/versionbits.h>
18
19		#include <cstdint>
20		#include <limits>
21		#include <memory>
22		#include <vector>
23
24		namespace {
25		class TestConditionChecker : public VersionBitsConditionChecker
26		{
27		private:
28		mutable ThresholdConditionCache m_cache;
29
30		public:
31	0	TestConditionChecker(const Consensus::BIP9Deployment& dep) : VersionBitsConditionChecker{dep}
32	0	{
33	0	assert(dep.period > 0); Branch (33:9): [True: 0, False: 0]
34	0	assert(dep.threshold <= dep.period); Branch (34:9): [True: 0, False: 0]
35	0	assert(0 <= dep.bit && dep.bit < 32 && dep.bit < VERSIONBITS_MAX_NUM_BITS); Branch (35:9): [True: 0, False: 0] Branch (35:9): [True: 0, False: 0] Branch (35:9): [True: 0, False: 0] Branch (35:9): [True: 0, False: 0]
36	0	assert(0 <= dep.min_activation_height); Branch (36:9): [True: 0, False: 0]
37	0	}
38
39	0	ThresholdState GetStateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, m_cache); }
40	0	int GetStateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, m_cache); }
41		};
42
43		/** Track blocks mined for test */
44		class Blocks
45		{
46		private:
47		std::vector<std::unique_ptr<CBlockIndex>> m_blocks;
48		const uint32_t m_start_time;
49		const uint32_t m_interval;
50		const int32_t m_signal;
51		const int32_t m_no_signal;
52
53		public:
54		Blocks(uint32_t start_time, uint32_t interval, int32_t signal, int32_t no_signal)
55	0	: m_start_time{start_time}, m_interval{interval}, m_signal{signal}, m_no_signal{no_signal} {}
56
57	0	size_t size() const { return m_blocks.size(); }
58
59		CBlockIndex* tip() const
60	0	{
61	0	return m_blocks.empty() ? nullptr : m_blocks.back().get(); Branch (61:16): [True: 0, False: 0]
62	0	}
63
64		CBlockIndex* mine_block(bool signal)
65	0	{
66	0	CBlockHeader header;
67	0	header.nVersion = signal ? m_signal : m_no_signal; Branch (67:27): [True: 0, False: 0]
68	0	header.nTime = m_start_time + m_blocks.size() * m_interval;
69	0	header.nBits = 0x1d00ffff;
70
71	0	auto current_block = std::make_unique<CBlockIndex>(header);
72	0	current_block->pprev = tip();
73	0	current_block->nHeight = m_blocks.size();
74	0	current_block->BuildSkip();
75
76	0	return m_blocks.emplace_back(std::move(current_block)).get();
77	0	}
78		};
79
80		std::unique_ptr<const CChainParams> g_params;
81
82		void initialize()
83	0	{
84		// this is actually comparatively slow, so only do it once
85	0	g_params = CreateChainParams(ArgsManager{}, ChainType::MAIN);
86	0	assert(g_params != nullptr); Branch (86:5): [True: 0, False: 0]
87	0	}
88
89		constexpr uint32_t MAX_START_TIME = 4102444800; // 2100-01-01
90
91		FUZZ_TARGET(versionbits, .init = initialize)
92	0	{
93	0	const CChainParams& params = *g_params;
94	0	const int64_t interval = params.GetConsensus().nPowTargetSpacing;
95	0	assert(interval > 1); // need to be able to halve it Branch (95:5): [True: 0, False: 0]
96	0	assert(interval < std::numeric_limits<int32_t>::max()); Branch (96:5): [True: 0, False: 0]
97
98	0	FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
99
100		// making period/max_periods larger slows these tests down significantly
101	0	const uint32_t period = 32;
102	0	const size_t max_periods = 16;
103	0	const size_t max_blocks = 2 * period * max_periods;
104
105		// too many blocks at 10min each might cause uint32_t time to overflow if
106		// block_start_time is at the end of the range above
107	0	assert(std::numeric_limits<uint32_t>::max() - MAX_START_TIME > interval * max_blocks); Branch (107:5): [True: 0, False: 0]
108
109	0	const int64_t block_start_time = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(params.GenesisBlock().nTime, MAX_START_TIME);
110
111		// what values for version will we use to signal / not signal?
112	0	const int32_t ver_signal = fuzzed_data_provider.ConsumeIntegral<int32_t>();
113	0	const int32_t ver_nosignal = fuzzed_data_provider.ConsumeIntegral<int32_t>();
114	0	if (ver_nosignal < 0) return; // negative values are uninteresting Branch (114:9): [True: 0, False: 0]
115
116		// Now that we have chosen time and versions, setup to mine blocks
117	0	Blocks blocks(block_start_time, interval, ver_signal, ver_nosignal);
118
119	0	const bool always_active_test = fuzzed_data_provider.ConsumeBool();
120	0	const bool never_active_test = !always_active_test && fuzzed_data_provider.ConsumeBool(); Branch (120:36): [True: 0, False: 0] Branch (120:59): [True: 0, False: 0]
121
122	0	const Consensus::BIP9Deployment dep{[&]() {
123	0	Consensus::BIP9Deployment dep;
124	0	dep.period = period;
125
126	0	dep.threshold = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(1, period);
127	0	assert(0 < dep.threshold && dep.threshold <= dep.period); // must be able to both pass and fail threshold! Branch (127:9): [True: 0, False: 0] Branch (127:9): [True: 0, False: 0] Branch (127:9): [True: 0, False: 0]
128
129		// select deployment parameters: bit, start time, timeout
130	0	dep.bit = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, VERSIONBITS_MAX_NUM_BITS - 1);
131
132	0	if (always_active_test) { Branch (132:13): [True: 0, False: 0]
133	0	dep.nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
134	0	dep.nTimeout = fuzzed_data_provider.ConsumeBool() ? Consensus::BIP9Deployment::NO_TIMEOUT : fuzzed_data_provider.ConsumeIntegral<int64_t>(); Branch (134:28): [True: 0, False: 0]
135	0	} else if (never_active_test) { Branch (135:20): [True: 0, False: 0]
136	0	dep.nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
137	0	dep.nTimeout = fuzzed_data_provider.ConsumeBool() ? Consensus::BIP9Deployment::NO_TIMEOUT : fuzzed_data_provider.ConsumeIntegral<int64_t>(); Branch (137:28): [True: 0, False: 0]
138	0	} else {
139		// pick the timestamp to switch based on a block
140		// note states will change after these blocks because mediantime lags
141	0	int start_block = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * (max_periods - 3));
142	0	int end_block = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * (max_periods - 3));
143
144	0	dep.nStartTime = block_start_time + start_block * interval;
145	0	dep.nTimeout = block_start_time + end_block * interval;
146
147		// allow for times to not exactly match a block
148	0	if (fuzzed_data_provider.ConsumeBool()) dep.nStartTime += interval / 2; Branch (148:17): [True: 0, False: 0]
149	0	if (fuzzed_data_provider.ConsumeBool()) dep.nTimeout += interval / 2; Branch (149:17): [True: 0, False: 0]
150	0	}
151	0	dep.min_activation_height = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, period * max_periods);
152	0	return dep;
153	0	}()};
154	0	TestConditionChecker checker(dep);
155
156		// Early exit if the versions don't signal sensibly for the deployment
157	0	if (!checker.Condition(ver_signal)) return; Branch (157:9): [True: 0, False: 0]
158	0	if (checker.Condition(ver_nosignal)) return; Branch (158:9): [True: 0, False: 0]
159
160		// TOP_BITS should ensure version will be positive and meet min
161		// version requirement
162	0	assert(ver_signal > 0); Branch (162:5): [True: 0, False: 0]
163	0	assert(ver_signal >= VERSIONBITS_LAST_OLD_BLOCK_VERSION); Branch (163:5): [True: 0, False: 0]
164
165		/* Strategy:
166		* * we will mine a final period worth of blocks, with
167		* randomised signalling according to a mask
168		* * but before we mine those blocks, we will mine some
169		* randomised number of prior periods; with either all
170		* or no blocks in the period signalling
171		*
172		* We establish the mask first, then consume "bools" until
173		* we run out of fuzz data to work out how many prior periods
174		* there are and which ones will signal.
175		*/
176
177		// establish the mask
178	0	const uint32_t signalling_mask = fuzzed_data_provider.ConsumeIntegral<uint32_t>();
179
180		// mine prior periods
181	0	while (fuzzed_data_provider.remaining_bytes() > 0) { // early exit; no need for LIMITED_WHILE Branch (181:12): [True: 0, False: 0]
182		// all blocks in these periods either do or don't signal
183	0	bool signal = fuzzed_data_provider.ConsumeBool();
184	0	for (uint32_t b = 0; b < period; ++b) { Branch (184:30): [True: 0, False: 0]
185	0	blocks.mine_block(signal);
186	0	}
187
188		// don't risk exceeding max_blocks or times may wrap around
189	0	if (blocks.size() + 2 * period > max_blocks) break; Branch (189:13): [True: 0, False: 0]
190	0	}
191		// NOTE: fuzzed_data_provider may be fully consumed at this point and should not be used further
192
193		// now we mine the final period and check that everything looks sane
194
195		// count the number of signalling blocks
196	0	uint32_t blocks_sig = 0;
197
198		// get the info for the first block of the period
199	0	CBlockIndex* prev = blocks.tip();
200	0	const int exp_since = checker.GetStateSinceHeightFor(prev);
201	0	const ThresholdState exp_state = checker.GetStateFor(prev);
202
203		// get statistics from end of previous period, then reset
204	0	BIP9Stats last_stats;
205	0	last_stats.period = period;
206	0	last_stats.threshold = dep.threshold;
207	0	last_stats.count = last_stats.elapsed = 0;
208	0	last_stats.possible = (period >= dep.threshold);
209	0	std::vector<bool> last_signals{};
210
211	0	int prev_next_height = (prev == nullptr ? 0 : prev->nHeight + 1); Branch (211:29): [True: 0, False: 0]
212	0	assert(exp_since <= prev_next_height); Branch (212:5): [True: 0, False: 0]
213
214		// mine (period-1) blocks and check state
215	0	for (uint32_t b = 1; b < period; ++b) { Branch (215:26): [True: 0, False: 0]
216	0	const bool signal = (signalling_mask >> (b % 32)) & 1;
217	0	if (signal) ++blocks_sig; Branch (217:13): [True: 0, False: 0]
218
219	0	CBlockIndex* current_block = blocks.mine_block(signal);
220
221		// verify that signalling attempt was interpreted correctly
222	0	assert(checker.Condition(current_block->nVersion) == signal); Branch (222:9): [True: 0, False: 0]
223
224		// state and since don't change within the period
225	0	const ThresholdState state = checker.GetStateFor(current_block);
226	0	const int since = checker.GetStateSinceHeightFor(current_block);
227	0	assert(state == exp_state); Branch (227:9): [True: 0, False: 0]
228	0	assert(since == exp_since); Branch (228:9): [True: 0, False: 0]
229
230		// check that after mining this block stats change as expected
231	0	std::vector<bool> signals;
232	0	const BIP9Stats stats = checker.GetStateStatisticsFor(current_block, &signals);
233	0	const BIP9Stats stats_no_signals = checker.GetStateStatisticsFor(current_block);
234	0	assert(stats.period == stats_no_signals.period && stats.threshold == stats_no_signals.threshold Branch (234:9): [True: 0, False: 0] Branch (234:9): [True: 0, False: 0] Branch (234:9): [True: 0, False: 0] Branch (234:9): [True: 0, False: 0] Branch (234:9): [True: 0, False: 0] Branch (234:9): [True: 0, False: 0]
235	0	&& stats.elapsed == stats_no_signals.elapsed && stats.count == stats_no_signals.count
236	0	&& stats.possible == stats_no_signals.possible);
237
238	0	assert(stats.period == period); Branch (238:9): [True: 0, False: 0]
239	0	assert(stats.threshold == dep.threshold); Branch (239:9): [True: 0, False: 0]
240	0	assert(stats.elapsed == b); Branch (240:9): [True: 0, False: 0]
241	0	assert(stats.count == last_stats.count + (signal ? 1 : 0)); Branch (241:9): [True: 0, False: 0] Branch (241:9): [True: 0, False: 0]
242	0	assert(stats.possible == (stats.count + period >= stats.elapsed + dep.threshold)); Branch (242:9): [True: 0, False: 0]
243	0	last_stats = stats;
244
245	0	assert(signals.size() == last_signals.size() + 1); Branch (245:9): [True: 0, False: 0]
246	0	assert(signals.back() == signal); Branch (246:9): [True: 0, False: 0]
247	0	last_signals.push_back(signal);
248	0	assert(signals == last_signals); Branch (248:9): [True: 0, False: 0]
249	0	}
250
251	0	if (exp_state == ThresholdState::STARTED) { Branch (251:9): [True: 0, False: 0]
252		// double check that stats.possible is sane
253	0	if (blocks_sig >= dep.threshold - 1) assert(last_stats.possible); Branch (253:13): [True: 0, False: 0] Branch (253:46): [True: 0, False: 0]
254	0	}
255
256		// mine the final block
257	0	bool signal = (signalling_mask >> (period % 32)) & 1;
258	0	if (signal) ++blocks_sig; Branch (258:9): [True: 0, False: 0]
259	0	CBlockIndex* current_block = blocks.mine_block(signal);
260	0	assert(checker.Condition(current_block->nVersion) == signal); Branch (260:5): [True: 0, False: 0]
261
262	0	const BIP9Stats stats = checker.GetStateStatisticsFor(current_block);
263	0	assert(stats.period == period); Branch (263:5): [True: 0, False: 0]
264	0	assert(stats.threshold == dep.threshold); Branch (264:5): [True: 0, False: 0]
265	0	assert(stats.elapsed == period); Branch (265:5): [True: 0, False: 0]
266	0	assert(stats.count == blocks_sig); Branch (266:5): [True: 0, False: 0]
267	0	assert(stats.possible == (stats.count + period >= stats.elapsed + dep.threshold)); Branch (267:5): [True: 0, False: 0]
268
269		// More interesting is whether the state changed.
270	0	const ThresholdState state = checker.GetStateFor(current_block);
271	0	const int since = checker.GetStateSinceHeightFor(current_block);
272
273		// since is straightforward:
274	0	assert(since % period == 0); Branch (274:5): [True: 0, False: 0]
275	0	assert(0 <= since && since <= current_block->nHeight + 1); Branch (275:5): [True: 0, False: 0] Branch (275:5): [True: 0, False: 0] Branch (275:5): [True: 0, False: 0]
276	0	if (state == exp_state) { Branch (276:9): [True: 0, False: 0]
277	0	assert(since == exp_since); Branch (277:9): [True: 0, False: 0]
278	0	} else {
279	0	assert(since == current_block->nHeight + 1); Branch (279:9): [True: 0, False: 0]
280	0	}
281
282		// state is where everything interesting is
283	0	[&]() {
284	0	switch (state) { Branch (284:17): [True: 0, False: 0]
285	0	case ThresholdState::DEFINED: Branch (285:9): [True: 0, False: 0]
286	0	assert(since == 0); Branch (286:13): [True: 0, False: 0]
287	0	assert(exp_state == ThresholdState::DEFINED); Branch (287:13): [True: 0, False: 0]
288	0	assert(current_block->GetMedianTimePast() < dep.nStartTime); Branch (288:13): [True: 0, False: 0]
289	0	return;
290	0	case ThresholdState::STARTED: Branch (290:9): [True: 0, False: 0]
291	0	assert(current_block->GetMedianTimePast() >= dep.nStartTime); Branch (291:13): [True: 0, False: 0]
292	0	if (exp_state == ThresholdState::STARTED) { Branch (292:17): [True: 0, False: 0]
293	0	assert(blocks_sig < dep.threshold); Branch (293:17): [True: 0, False: 0]
294	0	assert(current_block->GetMedianTimePast() < dep.nTimeout); Branch (294:17): [True: 0, False: 0]
295	0	} else {
296	0	assert(exp_state == ThresholdState::DEFINED); Branch (296:17): [True: 0, False: 0]
297	0	}
298	0	return;
299	0	case ThresholdState::LOCKED_IN: Branch (299:9): [True: 0, False: 0]
300	0	if (exp_state == ThresholdState::LOCKED_IN) { Branch (300:17): [True: 0, False: 0]
301	0	assert(current_block->nHeight + 1 < dep.min_activation_height); Branch (301:17): [True: 0, False: 0]
302	0	} else {
303	0	assert(exp_state == ThresholdState::STARTED); Branch (303:17): [True: 0, False: 0]
304	0	assert(blocks_sig >= dep.threshold); Branch (304:17): [True: 0, False: 0]
305	0	}
306	0	return;
307	0	case ThresholdState::ACTIVE: Branch (307:9): [True: 0, False: 0]
308	0	assert(always_active_test \|\| dep.min_activation_height <= current_block->nHeight + 1); Branch (308:13): [True: 0, False: 0] Branch (308:13): [True: 0, False: 0] Branch (308:13): [True: 0, False: 0]
309	0	assert(exp_state == ThresholdState::ACTIVE \|\| exp_state == ThresholdState::LOCKED_IN); Branch (309:13): [True: 0, False: 0] Branch (309:13): [True: 0, False: 0] Branch (309:13): [True: 0, False: 0]
310	0	return;
311	0	case ThresholdState::FAILED: Branch (311:9): [True: 0, False: 0]
312	0	assert(never_active_test \|\| current_block->GetMedianTimePast() >= dep.nTimeout); Branch (312:13): [True: 0, False: 0] Branch (312:13): [True: 0, False: 0] Branch (312:13): [True: 0, False: 0]
313	0	if (exp_state == ThresholdState::STARTED) { Branch (313:17): [True: 0, False: 0]
314	0	assert(blocks_sig < dep.threshold); Branch (314:17): [True: 0, False: 0]
315	0	} else {
316	0	assert(exp_state == ThresholdState::FAILED); Branch (316:17): [True: 0, False: 0]
317	0	}
318	0	return;
319	0	} // no default case, so the compiler can warn about missing cases
320	0	assert(false); Branch (320:9): [Folded - Ignored]
321	0	}();
322
323	0	if (blocks.size() >= period * max_periods) { Branch (323:9): [True: 0, False: 0]
324		// we chose the timeout (and block times) so that by the time we have this many blocks it's all over
325	0	assert(state == ThresholdState::ACTIVE \|\| state == ThresholdState::FAILED); Branch (325:9): [True: 0, False: 0] Branch (325:9): [True: 0, False: 0] Branch (325:9): [True: 0, False: 0]
326	0	}
327
328	0	if (always_active_test) { Branch (328:9): [True: 0, False: 0]
329		// "always active" has additional restrictions
330	0	assert(state == ThresholdState::ACTIVE); Branch (330:9): [True: 0, False: 0]
331	0	assert(exp_state == ThresholdState::ACTIVE); Branch (331:9): [True: 0, False: 0]
332	0	assert(since == 0); Branch (332:9): [True: 0, False: 0]
333	0	} else if (never_active_test) { Branch (333:16): [True: 0, False: 0]
334		// "never active" does too
335	0	assert(state == ThresholdState::FAILED); Branch (335:9): [True: 0, False: 0]
336	0	assert(exp_state == ThresholdState::FAILED); Branch (336:9): [True: 0, False: 0]
337	0	assert(since == 0); Branch (337:9): [True: 0, False: 0]
338	0	} else {
339		// for signalled deployments, the initial state is always DEFINED
340	0	assert(since > 0 \|\| state == ThresholdState::DEFINED); Branch (340:9): [True: 0, False: 0] Branch (340:9): [True: 0, False: 0] Branch (340:9): [True: 0, False: 0]
341	0	assert(exp_since > 0 \|\| exp_state == ThresholdState::DEFINED); Branch (341:9): [True: 0, False: 0] Branch (341:9): [True: 0, False: 0] Branch (341:9): [True: 0, False: 0]
342	0	}
343	0	}
344		} // namespace