versionbits_tests.cpp raw

   1  // Copyright (c) 2014-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 <consensus/params.h>
   8  #include <test/util/random.h>
   9  #include <test/util/common.h>
  10  #include <test/util/setup_common.h>
  11  #include <test/util/versionbits.h>
  12  #include <util/chaintype.h>
  13  #include <versionbits.h>
  14  #include <versionbits_impl.h>
  15  
  16  #include <boost/test/unit_test.hpp>
  17  
  18  /* Define a virtual block time, one block per 10 minutes after Nov 14 2014, 0:55:36am */
  19  static int32_t TestTime(int nHeight) { return 1415926536 + 600 * nHeight; }
  20  
  21  class TestConditionChecker final : public VersionBitsConditionChecker
  22  {
  23  private:
  24      mutable ThresholdConditionCache cache;
  25  
  26  public:
  27      // constructor is implicit to allow for easier initialization of vector<TestConditionChecker>
  28      explicit(false) TestConditionChecker(const Consensus::BIP9Deployment& dep) : VersionBitsConditionChecker{dep} { }
  29      ~TestConditionChecker() override = default;
  30  
  31      ThresholdState StateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, cache); }
  32      int StateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, cache); }
  33      void clear() { cache.clear(); }
  34  };
  35  
  36  namespace {
  37  struct Deployments
  38  {
  39      const Consensus::BIP9Deployment normal{
  40          .bit = 8,
  41          .nStartTime = TestTime(10000),
  42          .nTimeout = TestTime(20000),
  43          .min_activation_height = 0,
  44          .period = 1000,
  45          .threshold = 900,
  46      };
  47      Consensus::BIP9Deployment always, never, delayed;
  48      Deployments()
  49      {
  50          delayed = normal; delayed.min_activation_height = 15000;
  51          always = normal; always.nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
  52          never = normal; never.nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
  53      }
  54  };
  55  }
  56  
  57  #define CHECKERS 6
  58  
  59  class VersionBitsTester
  60  {
  61      FastRandomContext& m_rng;
  62      // A fake blockchain
  63      std::vector<CBlockIndex*> vpblock;
  64  
  65      // Used to automatically set the top bits for manual calls to Mine()
  66      const int32_t nVersionBase{0};
  67  
  68      // Setup BIP9Deployment structs for the checkers
  69      const Deployments test_deployments;
  70  
  71      // 6 independent checkers for the same bit.
  72      // The first one performs all checks, the second only 50%, the third only 25%, etc...
  73      // This is to test whether lack of cached information leads to the same results.
  74      std::vector<TestConditionChecker> checker{CHECKERS, {test_deployments.normal}};
  75      // Another 6 that assume delayed activation
  76      std::vector<TestConditionChecker> checker_delayed{CHECKERS, {test_deployments.delayed}};
  77      // Another 6 that assume always active activation
  78      std::vector<TestConditionChecker> checker_always{CHECKERS, {test_deployments.always}};
  79      // Another 6 that assume never active activation
  80      std::vector<TestConditionChecker> checker_never{CHECKERS, {test_deployments.never}};
  81  
  82      // Test counter (to identify failures)
  83      int num{1000};
  84  
  85  public:
  86      explicit VersionBitsTester(FastRandomContext& rng, int32_t nVersionBase=0) : m_rng{rng}, nVersionBase{nVersionBase} { }
  87  
  88      VersionBitsTester& Reset() {
  89          // Have each group of tests be counted by the 1000s part, starting at 1000
  90          num = num - (num % 1000) + 1000;
  91  
  92          for (unsigned int i = 0; i < vpblock.size(); i++) {
  93              delete vpblock[i];
  94          }
  95          for (unsigned int  i = 0; i < CHECKERS; i++) {
  96              checker[i].clear();
  97              checker_delayed[i].clear();
  98              checker_always[i].clear();
  99              checker_never[i].clear();
 100          }
 101          vpblock.clear();
 102          return *this;
 103      }
 104  
 105      ~VersionBitsTester() {
 106           Reset();
 107      }
 108  
 109      VersionBitsTester& Mine(unsigned int height, int32_t nTime, int32_t nVersion) {
 110          while (vpblock.size() < height) {
 111              CBlockIndex* pindex = new CBlockIndex();
 112              pindex->nHeight = vpblock.size();
 113              pindex->pprev = Tip();
 114              pindex->nTime = nTime;
 115              pindex->nVersion = (nVersionBase | nVersion);
 116              pindex->BuildSkip();
 117              vpblock.push_back(pindex);
 118          }
 119          return *this;
 120      }
 121  
 122      VersionBitsTester& TestStateSinceHeight(int height)
 123      {
 124          return TestStateSinceHeight(height, height);
 125      }
 126  
 127      VersionBitsTester& TestStateSinceHeight(int height, int height_delayed)
 128      {
 129          const CBlockIndex* tip = Tip();
 130          for (int i = 0; i < CHECKERS; i++) {
 131              if (m_rng.randbits(i) == 0) {
 132                  BOOST_CHECK_MESSAGE(checker[i].StateSinceHeightFor(tip) == height, strprintf("Test %i for StateSinceHeight", num));
 133                  BOOST_CHECK_MESSAGE(checker_delayed[i].StateSinceHeightFor(tip) == height_delayed, strprintf("Test %i for StateSinceHeight (delayed)", num));
 134                  BOOST_CHECK_MESSAGE(checker_always[i].StateSinceHeightFor(tip) == 0, strprintf("Test %i for StateSinceHeight (always active)", num));
 135                  BOOST_CHECK_MESSAGE(checker_never[i].StateSinceHeightFor(tip) == 0, strprintf("Test %i for StateSinceHeight (never active)", num));
 136              }
 137          }
 138          num++;
 139          return *this;
 140      }
 141  
 142      VersionBitsTester& TestState(ThresholdState exp)
 143      {
 144          return TestState(exp, exp);
 145      }
 146  
 147      VersionBitsTester& TestState(ThresholdState exp, ThresholdState exp_delayed)
 148      {
 149          if (exp != exp_delayed) {
 150              // only expected differences are that delayed stays in locked_in longer
 151              BOOST_CHECK_EQUAL(exp, ThresholdState::ACTIVE);
 152              BOOST_CHECK_EQUAL(exp_delayed, ThresholdState::LOCKED_IN);
 153          }
 154  
 155          const CBlockIndex* pindex = Tip();
 156          for (int i = 0; i < CHECKERS; i++) {
 157              if (m_rng.randbits(i) == 0) {
 158                  ThresholdState got = checker[i].StateFor(pindex);
 159                  ThresholdState got_delayed = checker_delayed[i].StateFor(pindex);
 160                  ThresholdState got_always = checker_always[i].StateFor(pindex);
 161                  ThresholdState got_never = checker_never[i].StateFor(pindex);
 162                  // nHeight of the next block. If vpblock is empty, the next (ie first)
 163                  // block should be the genesis block with nHeight == 0.
 164                  int height = pindex == nullptr ? 0 : pindex->nHeight + 1;
 165                  BOOST_CHECK_MESSAGE(got == exp, strprintf("Test %i for %s height %d (got %s)", num, StateName(exp), height, StateName(got)));
 166                  BOOST_CHECK_MESSAGE(got_delayed == exp_delayed, strprintf("Test %i for %s height %d (got %s; delayed case)", num, StateName(exp_delayed), height, StateName(got_delayed)));
 167                  BOOST_CHECK_MESSAGE(got_always == ThresholdState::ACTIVE, strprintf("Test %i for ACTIVE height %d (got %s; always active case)", num, height, StateName(got_always)));
 168                  BOOST_CHECK_MESSAGE(got_never == ThresholdState::FAILED, strprintf("Test %i for FAILED height %d (got %s; never active case)", num, height, StateName(got_never)));
 169              }
 170          }
 171          num++;
 172          return *this;
 173      }
 174  
 175      VersionBitsTester& TestDefined() { return TestState(ThresholdState::DEFINED); }
 176      VersionBitsTester& TestStarted() { return TestState(ThresholdState::STARTED); }
 177      VersionBitsTester& TestLockedIn() { return TestState(ThresholdState::LOCKED_IN); }
 178      VersionBitsTester& TestActive() { return TestState(ThresholdState::ACTIVE); }
 179      VersionBitsTester& TestFailed() { return TestState(ThresholdState::FAILED); }
 180  
 181      // non-delayed should be active; delayed should still be locked in
 182      VersionBitsTester& TestActiveDelayed() { return TestState(ThresholdState::ACTIVE, ThresholdState::LOCKED_IN); }
 183  
 184      CBlockIndex* Tip() { return vpblock.empty() ? nullptr : vpblock.back(); }
 185  };
 186  
 187  BOOST_FIXTURE_TEST_SUITE(versionbits_tests, BasicTestingSetup)
 188  
 189  BOOST_AUTO_TEST_CASE(versionbits_test)
 190  {
 191      for (int i = 0; i < 64; i++) {
 192          // DEFINED -> STARTED after timeout reached -> FAILED
 193          VersionBitsTester(m_rng, VERSIONBITS_TOP_BITS).TestDefined().TestStateSinceHeight(0)
 194                             .Mine(1, TestTime(1), 0x100).TestDefined().TestStateSinceHeight(0)
 195                             .Mine(11, TestTime(11), 0x100).TestDefined().TestStateSinceHeight(0)
 196                             .Mine(989, TestTime(989), 0x100).TestDefined().TestStateSinceHeight(0)
 197                             .Mine(999, TestTime(20000), 0x100).TestDefined().TestStateSinceHeight(0) // Timeout and start time reached simultaneously
 198                             .Mine(1000, TestTime(20000), 0).TestStarted().TestStateSinceHeight(1000) // Hit started, stop signalling
 199                             .Mine(1999, TestTime(30001), 0).TestStarted().TestStateSinceHeight(1000)
 200                             .Mine(2000, TestTime(30002), 0x100).TestFailed().TestStateSinceHeight(2000) // Hit failed, start signalling again
 201                             .Mine(2001, TestTime(30003), 0x100).TestFailed().TestStateSinceHeight(2000)
 202                             .Mine(2999, TestTime(30004), 0x100).TestFailed().TestStateSinceHeight(2000)
 203                             .Mine(3000, TestTime(30005), 0x100).TestFailed().TestStateSinceHeight(2000)
 204                             .Mine(4000, TestTime(30006), 0x100).TestFailed().TestStateSinceHeight(2000)
 205  
 206          // DEFINED -> STARTED -> FAILED
 207                             .Reset().TestDefined().TestStateSinceHeight(0)
 208                             .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
 209                             .Mine(1000, TestTime(10000) - 1, 0x100).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
 210                             .Mine(2000, TestTime(10000), 0x100).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
 211                             .Mine(2051, TestTime(10010), 0).TestStarted().TestStateSinceHeight(2000) // 51 old blocks
 212                             .Mine(2950, TestTime(10020), 0x100).TestStarted().TestStateSinceHeight(2000) // 899 new blocks
 213                             .Mine(3000, TestTime(20000), 0).TestFailed().TestStateSinceHeight(3000) // 50 old blocks (so 899 out of the past 1000)
 214                             .Mine(4000, TestTime(20010), 0x100).TestFailed().TestStateSinceHeight(3000)
 215  
 216          // DEFINED -> STARTED -> LOCKEDIN after timeout reached -> ACTIVE
 217                             .Reset().TestDefined().TestStateSinceHeight(0)
 218                             .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
 219                             .Mine(1000, TestTime(10000) - 1, 0x101).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
 220                             .Mine(2000, TestTime(10000), 0x101).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
 221                             .Mine(2999, TestTime(30000), 0x100).TestStarted().TestStateSinceHeight(2000) // 999 new blocks
 222                             .Mine(3000, TestTime(30000), 0x100).TestLockedIn().TestStateSinceHeight(3000) // 1 new block (so 1000 out of the past 1000 are new)
 223                             .Mine(3999, TestTime(30001), 0).TestLockedIn().TestStateSinceHeight(3000)
 224                             .Mine(4000, TestTime(30002), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000)
 225                             .Mine(14333, TestTime(30003), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000)
 226                             .Mine(24000, TestTime(40000), 0).TestActive().TestStateSinceHeight(4000, 15000)
 227  
 228          // DEFINED -> STARTED -> LOCKEDIN before timeout -> ACTIVE
 229                             .Reset().TestDefined()
 230                             .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
 231                             .Mine(1000, TestTime(10000) - 1, 0x101).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
 232                             .Mine(2000, TestTime(10000), 0x101).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
 233                             .Mine(2050, TestTime(10010), 0x200).TestStarted().TestStateSinceHeight(2000) // 50 old blocks
 234                             .Mine(2950, TestTime(10020), 0x100).TestStarted().TestStateSinceHeight(2000) // 900 new blocks
 235                             .Mine(2999, TestTime(19999), 0x200).TestStarted().TestStateSinceHeight(2000) // 49 old blocks
 236                             .Mine(3000, TestTime(29999), 0x200).TestLockedIn().TestStateSinceHeight(3000) // 1 old block (so 900 out of the past 1000)
 237                             .Mine(3999, TestTime(30001), 0).TestLockedIn().TestStateSinceHeight(3000)
 238                             .Mine(4000, TestTime(30002), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000) // delayed will not become active until height=15000
 239                             .Mine(14333, TestTime(30003), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000)
 240                             .Mine(15000, TestTime(40000), 0).TestActive().TestStateSinceHeight(4000, 15000)
 241                             .Mine(24000, TestTime(40000), 0).TestActive().TestStateSinceHeight(4000, 15000)
 242  
 243          // DEFINED multiple periods -> STARTED multiple periods -> FAILED
 244                             .Reset().TestDefined().TestStateSinceHeight(0)
 245                             .Mine(999, TestTime(999), 0).TestDefined().TestStateSinceHeight(0)
 246                             .Mine(1000, TestTime(1000), 0).TestDefined().TestStateSinceHeight(0)
 247                             .Mine(2000, TestTime(2000), 0).TestDefined().TestStateSinceHeight(0)
 248                             .Mine(3000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
 249                             .Mine(4000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
 250                             .Mine(5000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
 251                             .Mine(5999, TestTime(20000), 0).TestStarted().TestStateSinceHeight(3000)
 252                             .Mine(6000, TestTime(20000), 0).TestFailed().TestStateSinceHeight(6000)
 253                             .Mine(7000, TestTime(20000), 0x100).TestFailed().TestStateSinceHeight(6000)
 254                             .Mine(24000, TestTime(20000), 0x100).TestFailed().TestStateSinceHeight(6000) // stay in FAILED no matter how much we signal
 255          ;
 256      }
 257  }
 258  
 259  struct BlockVersionTest : BasicTestingSetup {
 260  /** Check that ComputeBlockVersion will set the appropriate bit correctly
 261   * Also checks IsActiveAfter() behaviour */
 262  void check_computeblockversion(VersionBitsCache& versionbitscache, const Consensus::Params& params, Consensus::DeploymentPos dep)
 263  {
 264      // Clear the cache every time
 265      versionbitscache.Clear();
 266  
 267      int64_t bit = params.vDeployments[dep].bit;
 268      int64_t nStartTime = params.vDeployments[dep].nStartTime;
 269      int64_t nTimeout = params.vDeployments[dep].nTimeout;
 270      int min_activation_height = params.vDeployments[dep].min_activation_height;
 271      uint32_t period = params.vDeployments[dep].period;
 272      uint32_t threshold = params.vDeployments[dep].threshold;
 273  
 274      BOOST_REQUIRE(period > 0); // no division by zero, thankyou
 275      BOOST_REQUIRE(0 < threshold); // must be able to have a window that doesn't activate
 276      BOOST_REQUIRE(threshold < period); // must be able to have a window that does activate
 277  
 278      // should not be any signalling for first block
 279      BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(nullptr, params), VERSIONBITS_TOP_BITS);
 280  
 281      // always/never active deployments shouldn't need to be tested further
 282      if (nStartTime == Consensus::BIP9Deployment::ALWAYS_ACTIVE ||
 283          nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE)
 284      {
 285          if (nStartTime == Consensus::BIP9Deployment::ALWAYS_ACTIVE) {
 286              BOOST_CHECK(versionbitscache.IsActiveAfter(nullptr, params, dep));
 287          } else {
 288              BOOST_CHECK(!versionbitscache.IsActiveAfter(nullptr, params, dep));
 289          }
 290          BOOST_CHECK_EQUAL(min_activation_height, 0);
 291          BOOST_CHECK_EQUAL(nTimeout, Consensus::BIP9Deployment::NO_TIMEOUT);
 292          return;
 293      }
 294  
 295      BOOST_REQUIRE(nStartTime < nTimeout);
 296      BOOST_REQUIRE(nStartTime >= 0);
 297      BOOST_REQUIRE(nTimeout <= std::numeric_limits<uint32_t>::max() || nTimeout == Consensus::BIP9Deployment::NO_TIMEOUT);
 298      BOOST_REQUIRE(0 <= bit && bit < 32);
 299      // Make sure that no deployment tries to set an invalid bit.
 300      BOOST_REQUIRE(((1 << bit) & VERSIONBITS_TOP_MASK) == 0);
 301      BOOST_REQUIRE(min_activation_height >= 0);
 302      // Check min_activation_height is on a retarget boundary
 303      BOOST_REQUIRE_EQUAL(min_activation_height % period, 0U);
 304  
 305      // In the first chain, test that the bit is set by CBV until it has failed.
 306      // In the second chain, test the bit is set by CBV while STARTED and
 307      // LOCKED-IN, and then no longer set while ACTIVE.
 308      VersionBitsTester firstChain{m_rng}, secondChain{m_rng};
 309  
 310      int64_t nTime = nStartTime;
 311  
 312      const CBlockIndex *lastBlock = nullptr;
 313  
 314      // Before MedianTimePast of the chain has crossed nStartTime, the bit
 315      // should not be set.
 316      if (nTime == 0) {
 317          // since CBlockIndex::nTime is uint32_t we can't represent any
 318          // earlier time, so will transition from DEFINED to STARTED at the
 319          // end of the first period by mining blocks at nTime == 0
 320          lastBlock = firstChain.Mine(period - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 321          BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 322          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 323          lastBlock = firstChain.Mine(period, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 324          BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 325          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 326          // then we'll keep mining at nStartTime...
 327      } else {
 328          // use a time 1s earlier than start time to check we stay DEFINED
 329          --nTime;
 330  
 331          // Start generating blocks before nStartTime
 332          lastBlock = firstChain.Mine(period, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 333          BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 334          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 335  
 336          // Mine more blocks (4 less than the adjustment period) at the old time, and check that CBV isn't setting the bit yet.
 337          for (uint32_t i = 1; i < period - 4; i++) {
 338              lastBlock = firstChain.Mine(period + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 339              BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 340              BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 341          }
 342          // Now mine 5 more blocks at the start time -- MTP should not have passed yet, so
 343          // CBV should still not yet set the bit.
 344          nTime = nStartTime;
 345          for (uint32_t i = period - 4; i <= period; i++) {
 346              lastBlock = firstChain.Mine(period + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 347              BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 348              BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 349          }
 350          // Next we will advance to the next period and transition to STARTED,
 351      }
 352  
 353      lastBlock = firstChain.Mine(period * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 354      // so ComputeBlockVersion should now set the bit,
 355      BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 356      // and should also be using the VERSIONBITS_TOP_BITS.
 357      BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
 358      BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 359  
 360      // Check that ComputeBlockVersion will set the bit until nTimeout
 361      nTime += 600;
 362      uint32_t blocksToMine = period * 2; // test blocks for up to 2 time periods
 363      uint32_t nHeight = period * 3;
 364      // These blocks are all before nTimeout is reached.
 365      while (nTime < nTimeout && blocksToMine > 0) {
 366          lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 367          BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 368          BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
 369          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 370          blocksToMine--;
 371          nTime += 600;
 372          nHeight += 1;
 373      }
 374  
 375      if (nTimeout != Consensus::BIP9Deployment::NO_TIMEOUT) {
 376          // can reach any nTimeout other than NO_TIMEOUT due to earlier BOOST_REQUIRE
 377  
 378          nTime = nTimeout;
 379  
 380          // finish the last period before we start timing out
 381          while (nHeight % period != 0) {
 382              lastBlock = firstChain.Mine(nHeight+1, nTime - 1, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 383              BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 384              BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 385              nHeight += 1;
 386          }
 387  
 388          // FAILED is only triggered at the end of a period, so CBV should be setting
 389          // the bit until the period transition.
 390          for (uint32_t i = 0; i < period - 1; i++) {
 391              lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 392              BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 393              BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 394              nHeight += 1;
 395          }
 396          // The next block should trigger no longer setting the bit.
 397          lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 398          BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 399          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 400      }
 401  
 402      // On a new chain:
 403      // verify that the bit will be set after lock-in, and then stop being set
 404      // after activation.
 405      nTime = nStartTime;
 406  
 407      // Mine one period worth of blocks, and check that the bit will be on for the
 408      // next period.
 409      lastBlock = secondChain.Mine(period, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 410      BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 411      BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 412  
 413      // Mine another period worth of blocks, signaling the new bit.
 414      lastBlock = secondChain.Mine(period * 2, nTime, VERSIONBITS_TOP_BITS | (1<<bit)).Tip();
 415      // After one period of setting the bit on each block, it should have locked in.
 416      // We keep setting the bit for one more period though, until activation.
 417      BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 418      BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 419  
 420      // Now check that we keep mining the block until the end of this period, and
 421      // then stop at the beginning of the next period.
 422      lastBlock = secondChain.Mine((period * 3) - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 423      BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 424      BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 425      lastBlock = secondChain.Mine(period * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 426  
 427      if (lastBlock->nHeight + 1 < min_activation_height) {
 428          // check signalling continues while min_activation_height is not reached
 429          lastBlock = secondChain.Mine(min_activation_height - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 430          BOOST_CHECK((versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 431          BOOST_CHECK(!versionbitscache.IsActiveAfter(lastBlock, params, dep));
 432          // then reach min_activation_height, which was already REQUIRE'd to start a new period
 433          lastBlock = secondChain.Mine(min_activation_height, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 434      }
 435  
 436      // Check that we don't signal after activation
 437      BOOST_CHECK_EQUAL(versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 438      BOOST_CHECK(versionbitscache.IsActiveAfter(lastBlock, params, dep));
 439  }
 440  }; // struct BlockVersionTest
 441  
 442  BOOST_FIXTURE_TEST_CASE(versionbits_computeblockversion, BlockVersionTest)
 443  {
 444      VersionBitsCache vbcache;
 445  
 446      // check that any deployment on any chain can conceivably reach both
 447      // ACTIVE and FAILED states in roughly the way we expect
 448      for (const auto& chain_type: {ChainType::MAIN, ChainType::TESTNET, ChainType::TESTNET4, ChainType::SIGNET, ChainType::REGTEST}) {
 449          const auto chainParams = CreateChainParams(*m_node.args, chain_type);
 450          uint32_t chain_all_vbits{0};
 451          for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++i) {
 452              const auto dep = static_cast<Consensus::DeploymentPos>(i);
 453              // Check that no bits are reused (within the same chain). This is
 454              // disallowed because the transition to FAILED (on timeout) does
 455              // not take precedence over STARTED/LOCKED_IN. So all softforks on
 456              // the same bit might overlap, even when non-overlapping start-end
 457              // times are picked.
 458              const auto& dep_info = chainParams->GetConsensus().vDeployments[dep];
 459              const uint32_t dep_mask{uint32_t{1} << dep_info.bit};
 460              BOOST_CHECK(!(chain_all_vbits & dep_mask));
 461              chain_all_vbits |= dep_mask;
 462              BOOST_CHECK(0 <= dep_info.bit && dep_info.bit < VERSIONBITS_MAX_NUM_BITS);
 463              if (chain_type != ChainType::REGTEST) {
 464                  if (dep == Consensus::DEPLOYMENT_TESTDUMMY) {
 465                      BOOST_CHECK_EQUAL(dep_info.nStartTime, Consensus::BIP9Deployment::NEVER_ACTIVE);
 466                      BOOST_CHECK_EQUAL(dep_info.nTimeout, Consensus::BIP9Deployment::NO_TIMEOUT);
 467                  } else {
 468                      BOOST_CHECK(dep_info.bit < VERSIONBITS_NUM_BITS);
 469                  }
 470              }
 471              check_computeblockversion(vbcache, chainParams->GetConsensus(), dep);
 472          }
 473      }
 474  
 475      {
 476          // Use regtest/testdummy to ensure we always exercise some
 477          // deployment that's not always/never active
 478          ArgsManager args;
 479          args.ForceSetArg("-vbparams", "testdummy:1199145601:1230767999"); // January 1, 2008 - December 31, 2008
 480          const auto chainParams = CreateChainParams(args, ChainType::REGTEST);
 481          check_computeblockversion(vbcache, chainParams->GetConsensus(), Consensus::DEPLOYMENT_TESTDUMMY);
 482      }
 483  
 484      {
 485          // Use regtest/testdummy to ensure we always exercise the
 486          // min_activation_height test, even if we're not using that in a
 487          // live deployment
 488          ArgsManager args;
 489          args.ForceSetArg("-vbparams", "testdummy:1199145601:1230767999:403200"); // January 1, 2008 - December 31, 2008, min act height 403200
 490          const auto chainParams = CreateChainParams(args, ChainType::REGTEST);
 491          check_computeblockversion(vbcache, chainParams->GetConsensus(), Consensus::DEPLOYMENT_TESTDUMMY);
 492      }
 493  }
 494  
 495  BOOST_AUTO_TEST_SUITE_END()
 496