Merge #780: Change elements mode to activating BIP9 signaling based on height

6fc3fe04e Change elements mode to activating BIP9 signaling based on height (Gregory Sanders)

Pull request description:

  When based on block time, it's really hard to engineer principled tests for activation of consensus changes.

  resolves https://github.com/ElementsProject/elements/issues/779

Tree-SHA512: c5672d54a3a906d1318c82197022b9effd39e951e3f9e5ca4dc92055f2fa638a6359797662014c4928be25795ddd6b3f401769d53a967cf08d4f564210926773

src/chainparams.cpp

@@ -135,6 +135,7 @@ public:
         g_con_elementsmode = false;
         g_con_blockheightinheader = false;
         consensus.total_valid_epochs = 0;
+        consensus.elements_mode = g_con_elementsmode;
 
         /**
          * The message start string is designed to be unlikely to occur in normal data.
@@ -265,6 +266,7 @@ public:
         g_con_elementsmode = false;
         g_con_blockheightinheader = false;
         consensus.total_valid_epochs = 0;
+        consensus.elements_mode = g_con_elementsmode;
 
         pchMessageStart[0] = 0x0b;
         pchMessageStart[1] = 0x11;
@@ -367,6 +369,7 @@ public:
         consensus.has_parent_chain = false;
         g_signed_blocks = false;
         g_con_elementsmode = false;
+        consensus.elements_mode = g_con_elementsmode;
         g_con_blockheightinheader = false;
         consensus.total_valid_epochs = 0;
 
@@ -552,6 +555,7 @@ class CCustomParams : public CRegTestParams {
         // Default to true for custom chains.
         g_con_blockheightinheader = args.GetBoolArg("-con_blockheightinheader", true);
         g_con_elementsmode = args.GetBoolArg("-con_elementsmode", true);
+        consensus.elements_mode = g_con_elementsmode;
 
         // No subsidy for custom chains by default
         consensus.genesis_subsidy = args.GetArg("-con_blocksubsidy", 0);
@@ -726,6 +730,7 @@ public:
 
         g_con_blockheightinheader = true;
         g_con_elementsmode = true;
+        consensus.elements_mode = g_con_elementsmode;
         // TODO: Pick appropriate value for this network.
         consensus.total_valid_epochs = 2;
 

src/consensus/params.h

@@ -108,6 +108,7 @@ struct Params {
     // Used to allow M-epoch-old peg-in addresses as deposits
     // default 1 to not break legacy chains implicitly.
     size_t total_valid_epochs = 1;
+    bool elements_mode = false;
 };
 } // namespace Consensus
 

src/versionbits.cpp

@@ -5,10 +5,20 @@
 #include <versionbits.h>
 #include <consensus/params.h>
 
+// Elements: We use height, not time!
+int64_t GetBIP9Time(const CBlockIndex* pindexPrev, const Consensus::Params& params) {
+    if (params.elements_mode) {
+        return pindexPrev->nHeight;
+    } else {
+        return pindexPrev->GetMedianTimePast();
+    }
+}
+
 ThresholdState AbstractThresholdConditionChecker::GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const
 {
     int nPeriod = Period(params);
     int nThreshold = Threshold(params);
+    // ELEMENTS: We interpret this as block height, not block time!
     int64_t nTimeStart = BeginTime(params);
     int64_t nTimeTimeout = EndTime(params);
 
@@ -30,7 +40,7 @@ ThresholdState AbstractThresholdConditionChecker::GetStateFor(const CBlockIndex*
             cache[pindexPrev] = ThresholdState::DEFINED;
             break;
         }
-        if (pindexPrev->GetMedianTimePast() < nTimeStart) {
+        if (GetBIP9Time(pindexPrev, params) < nTimeStart) {
             // Optimization: don't recompute down further, as we know every earlier block will be before the start time
             cache[pindexPrev] = ThresholdState::DEFINED;
             break;
@@ -51,15 +61,15 @@ ThresholdState AbstractThresholdConditionChecker::GetStateFor(const CBlockIndex*
 
         switch (state) {
             case ThresholdState::DEFINED: {
-                if (pindexPrev->GetMedianTimePast() >= nTimeTimeout) {
+                if (GetBIP9Time(pindexPrev, params) >= nTimeTimeout) {
                     stateNext = ThresholdState::FAILED;
-                } else if (pindexPrev->GetMedianTimePast() >= nTimeStart) {
+                } else if (GetBIP9Time(pindexPrev, params) >= nTimeStart) {
                     stateNext = ThresholdState::STARTED;
                 }
                 break;
             }
             case ThresholdState::STARTED: {
-                if (pindexPrev->GetMedianTimePast() >= nTimeTimeout) {
+                if (GetBIP9Time(pindexPrev, params) >= nTimeTimeout) {
                     stateNext = ThresholdState::FAILED;
                     break;
                 }

test/functional/feature_dynafed.py

@@ -63,7 +63,7 @@ class DynaFedTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 2
         # We want to test activation of dynafed
-        self.extra_args = [["-con_dyna_deploy_start=0", "-enforce_pak=1", "-con_parent_chain_signblockscript=51", "-peginconfirmationdepth=1", "-parentscriptprefix=75", "-parent_bech32_hrp=ert"] for i in range(self.num_nodes)]
+        self.extra_args = [["-con_dyna_deploy_start=1000", "-enforce_pak=1", "-con_parent_chain_signblockscript=51", "-peginconfirmationdepth=1", "-parentscriptprefix=75", "-parent_bech32_hrp=ert"] for i in range(self.num_nodes)]
         # second node will not mine transactions
         self.extra_args[1].append("-blocksonly=1")
 
@@ -105,8 +105,18 @@ class DynaFedTest(BitcoinTestFramework):
     def test_dynafed_activation(self):
         self.log.info("Testing dynafed versionbits activation...")
 
+        # Signaling window is in height, not time, so first block that will signal is
+        # at height 1008 which is evenly disible by 144(regtest bip9 window size)
+        # Giving funds to node 1 to avoid a transaction size blowup when sweeping later
+        blocks = self.nodes[0].generatetoaddress(1006, self.nodes[1].getnewaddress())
+        assert_equal(self.nodes[0].getblockchaininfo()["bip9_softforks"]["dynafed"]["status"], "defined")
+        blocks += self.nodes[0].generatetoaddress(1, self.nodes[0].getnewaddress())
+        assert_equal(self.nodes[0].getblockchaininfo()["bip9_softforks"]["dynafed"]["status"], "started")
+        blocks += self.nodes[0].generatetoaddress(144, self.nodes[0].getnewaddress())
+        assert_equal(self.nodes[0].getblockchaininfo()["bip9_softforks"]["dynafed"]["status"], "locked_in")
+
         # Move chain forward to activation, any new blocks will be enforced
-        blocks = self.nodes[0].generatetoaddress(431, self.nodes[0].getnewaddress())
+        blocks += self.nodes[0].generatetoaddress(144, self.nodes[0].getnewaddress())
         self.sync_all()
         assert_equal(self.nodes[0].getblockchaininfo()["bip9_softforks"]["dynafed"]["status"], "active")