Merge bitcoin/bitcoin#19438: Introduce deploymentstatus

e48826ad87 tests: remove ComputeBlockVersion shortcut from versionbits tests (Anthony Towns)
c5f36725e8 [refactor] Move ComputeBlockVersion into VersionBitsCache (Anthony Towns)
4a69b4dbe0 [move-only] Move ComputeBlockVersion from validation to versionbits (Anthony Towns)
0cfd6c6a8f [refactor] versionbits: make VersionBitsCache a full class (Anthony Towns)
8ee3e0bed5 [refactor] rpc/blockchain.cpp: SoftForkPushBack (Anthony Towns)
92f48f360d deploymentinfo: Add DeploymentName() (Anthony Towns)
ea68b3a572 [move-only] Rename versionbitsinfo to deploymentinfo (Anthony Towns)
c64b2c6a0f scripted-diff: rename versionbitscache (Anthony Towns)
de55304f6e [refactor] Add versionbits deployments to deploymentstatus.h (Anthony Towns)
2b0d291da8 [refactor] Add deploymentstatus.h (Anthony Towns)
eccd736f3d versionbits: Use dedicated lock instead of cs_main (Anthony Towns)
36a4ba0aaa versionbits: correct doxygen comments (Anthony Towns)

Pull request description:

  Introduces helper functions to make it easy to bury future deployments, along the lines of the suggestion from [11398](https://github.com/bitcoin/bitcoin/pull/11398#issuecomment-335599326) "I would prefer it if a buried deployment wouldn't require all code paths that check the BIP9 status to require changing".

  This provides three functions: `DeploymentEnabled()` which tests if a deployment can ever be active, `DeploymentActiveAt()` which checks if a deployment should be enforced in the given block, and `DeploymentActiveAfter()` which checks if a deployment should be enforced in the block following the given block, and overloads all three to work both with buried deployments and versionbits deployments.

  This adds a dedicated lock for the versionbits cache, which is acquired internally by the versionbits functions, rather than relying on `cs_main`. It also moves moves versionbitscache into deploymentstatus to avoid a circular dependency with validation.

ACKs for top commit:
  jnewbery:
    ACK e48826ad87
  gruve-p:
    ACK e48826ad87
  MarcoFalke:
    re-ACK e48826ad87 🥈

Tree-SHA512: c846ba64436d36f8180046ad551d8b0d9e20509b9bc185aa2639055fc28803dd8ec2d6771ab337e80da0b40009ad959590d5772f84a0bf6199b65190d4155bed

src/Makefile.am

@@ -145,6 +145,8 @@ BITCOIN_CORE_H = \
   core_memusage.h \
   cuckoocache.h \
   dbwrapper.h \
+  deploymentinfo.h \
+  deploymentstatus.h \
   external_signer.h \
   flatfile.h \
   fs.h \
@@ -272,7 +274,6 @@ BITCOIN_CORE_H = \
   validation.h \
   validationinterface.h \
   versionbits.h \
-  versionbitsinfo.h \
   wallet/bdb.h \
   wallet/coincontrol.h \
   wallet/coinselection.h \
@@ -328,6 +329,7 @@ libbitcoin_server_a_SOURCES = \
   chain.cpp \
   consensus/tx_verify.cpp \
   dbwrapper.cpp \
+  deploymentstatus.cpp \
   flatfile.cpp \
   httprpc.cpp \
   httpserver.cpp \
@@ -540,6 +542,7 @@ libbitcoin_common_a_SOURCES = \
   compressor.cpp \
   core_read.cpp \
   core_write.cpp \
+  deploymentinfo.cpp \
   external_signer.cpp \
   init/common.cpp \
   key.cpp \
@@ -561,7 +564,6 @@ libbitcoin_common_a_SOURCES = \
   script/sign.cpp \
   script/signingprovider.cpp \
   script/standard.cpp \
-  versionbitsinfo.cpp \
   warnings.cpp \
   $(BITCOIN_CORE_H)
 

src/chainparams.cpp

@@ -7,9 +7,9 @@
 
 #include <chainparamsseeds.h>
 #include <consensus/merkle.h>
+#include <deploymentinfo.h>
 #include <hash.h> // for signet block challenge hash
 #include <util/system.h>
-#include <versionbitsinfo.h>
 
 #include <assert.h>
 

src/consensus/params.h

@@ -11,13 +11,25 @@
 
 namespace Consensus {
 
-enum DeploymentPos
+enum BuriedDeployment : int16_t
+{
+    // buried deployments get negative values to avoid overlap with DeploymentPos
+    DEPLOYMENT_HEIGHTINCB = std::numeric_limits<int16_t>::min(),
+    DEPLOYMENT_CLTV,
+    DEPLOYMENT_DERSIG,
+    DEPLOYMENT_CSV,
+    DEPLOYMENT_SEGWIT,
+};
+constexpr bool ValidDeployment(BuriedDeployment dep) { return DEPLOYMENT_HEIGHTINCB <= dep && dep <= DEPLOYMENT_SEGWIT; }
+
+enum DeploymentPos : uint16_t
 {
     DEPLOYMENT_TESTDUMMY,
     DEPLOYMENT_TAPROOT, // Deployment of Schnorr/Taproot (BIPs 340-342)
-    // NOTE: Also add new deployments to VersionBitsDeploymentInfo in versionbits.cpp
+    // NOTE: Also add new deployments to VersionBitsDeploymentInfo in deploymentinfo.cpp
     MAX_VERSION_BITS_DEPLOYMENTS
 };
+constexpr bool ValidDeployment(DeploymentPos dep) { return DEPLOYMENT_TESTDUMMY <= dep && dep <= DEPLOYMENT_TAPROOT; }
 
 /**
  * Struct for each individual consensus rule change using BIP9.
@@ -100,7 +112,25 @@ struct Params {
      */
     bool signet_blocks{false};
     std::vector<uint8_t> signet_challenge;
+
+    int DeploymentHeight(BuriedDeployment dep) const
+    {
+        switch (dep) {
+        case DEPLOYMENT_HEIGHTINCB:
+            return BIP34Height;
+        case DEPLOYMENT_CLTV:
+            return BIP65Height;
+        case DEPLOYMENT_DERSIG:
+            return BIP66Height;
+        case DEPLOYMENT_CSV:
+            return CSVHeight;
+        case DEPLOYMENT_SEGWIT:
+            return SegwitHeight;
+        } // no default case, so the compiler can warn about missing cases
+        return std::numeric_limits<int>::max();
+    }
 };
+
 } // namespace Consensus
 
 #endif // BITCOIN_CONSENSUS_PARAMS_H

src/deploymentinfo.cpp

@@ -0,0 +1,36 @@
+// Copyright (c) 2016-2020 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 <deploymentinfo.h>
+
+#include <consensus/params.h>
+
+const struct VBDeploymentInfo VersionBitsDeploymentInfo[Consensus::MAX_VERSION_BITS_DEPLOYMENTS] = {
+    {
+        /*.name =*/ "testdummy",
+        /*.gbt_force =*/ true,
+    },
+    {
+        /*.name =*/ "taproot",
+        /*.gbt_force =*/ true,
+    },
+};
+
+std::string DeploymentName(Consensus::BuriedDeployment dep)
+{
+    assert(ValidDeployment(dep));
+    switch (dep) {
+    case Consensus::DEPLOYMENT_HEIGHTINCB:
+        return "bip34";
+    case Consensus::DEPLOYMENT_CLTV:
+        return "bip65";
+    case Consensus::DEPLOYMENT_DERSIG:
+        return "bip66";
+    case Consensus::DEPLOYMENT_CSV:
+        return "csv";
+    case Consensus::DEPLOYMENT_SEGWIT:
+        return "segwit";
+    } // no default case, so the compiler can warn about missing cases
+    return "";
+}

src/deploymentinfo.h

@@ -0,0 +1,29 @@
+// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_DEPLOYMENTINFO_H
+#define BITCOIN_DEPLOYMENTINFO_H
+
+#include <consensus/params.h>
+
+#include <string>
+
+struct VBDeploymentInfo {
+    /** Deployment name */
+    const char *name;
+    /** Whether GBT clients can safely ignore this rule in simplified usage */
+    bool gbt_force;
+};
+
+extern const VBDeploymentInfo VersionBitsDeploymentInfo[Consensus::MAX_VERSION_BITS_DEPLOYMENTS];
+
+std::string DeploymentName(Consensus::BuriedDeployment dep);
+
+inline std::string DeploymentName(Consensus::DeploymentPos pos)
+{
+    assert(Consensus::ValidDeployment(pos));
+    return VersionBitsDeploymentInfo[pos].name;
+}
+
+#endif // BITCOIN_DEPLOYMENTINFO_H

src/deploymentstatus.cpp

@@ -0,0 +1,17 @@
+// Copyright (c) 2020 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 <deploymentstatus.h>
+
+#include <consensus/params.h>
+#include <versionbits.h>
+
+VersionBitsCache g_versionbitscache;
+
+/* Basic sanity checking for BuriedDeployment/DeploymentPos enums and
+ * ValidDeployment check */
+
+static_assert(ValidDeployment(Consensus::DEPLOYMENT_TESTDUMMY), "sanity check of DeploymentPos failed (TESTDUMMY not valid)");
+static_assert(!ValidDeployment(Consensus::MAX_VERSION_BITS_DEPLOYMENTS), "sanity check of DeploymentPos failed (MAX value considered valid)");
+static_assert(!ValidDeployment(static_cast<Consensus::BuriedDeployment>(Consensus::DEPLOYMENT_TESTDUMMY)), "sanity check of BuriedDeployment failed (overlaps with DeploymentPos)");

src/deploymentstatus.h

@@ -0,0 +1,55 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_DEPLOYMENTSTATUS_H
+#define BITCOIN_DEPLOYMENTSTATUS_H
+
+#include <chain.h>
+#include <versionbits.h>
+
+#include <limits>
+
+/** Global cache for versionbits deployment status */
+extern VersionBitsCache g_versionbitscache;
+
+/** Determine if a deployment is active for the next block */
+inline bool DeploymentActiveAfter(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::BuriedDeployment dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return (pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1) >= params.DeploymentHeight(dep);
+}
+
+inline bool DeploymentActiveAfter(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return ThresholdState::ACTIVE == g_versionbitscache.State(pindexPrev, params, dep);
+}
+
+/** Determine if a deployment is active for this block */
+inline bool DeploymentActiveAt(const CBlockIndex& index, const Consensus::Params& params, Consensus::BuriedDeployment dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return index.nHeight >= params.DeploymentHeight(dep);
+}
+
+inline bool DeploymentActiveAt(const CBlockIndex& index, const Consensus::Params& params, Consensus::DeploymentPos dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return DeploymentActiveAfter(index.pprev, params, dep);
+}
+
+/** Determine if a deployment is enabled (can ever be active) */
+inline bool DeploymentEnabled(const Consensus::Params& params, Consensus::BuriedDeployment dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return params.DeploymentHeight(dep) != std::numeric_limits<int>::max();
+}
+
+inline bool DeploymentEnabled(const Consensus::Params& params, Consensus::DeploymentPos dep)
+{
+    assert(Consensus::ValidDeployment(dep));
+    return params.vDeployments[dep].nTimeout != 0;
+}
+
+#endif // BITCOIN_DEPLOYMENTSTATUS_H

src/init.cpp

@@ -16,6 +16,7 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <compat/sanity.h>
+#include <deploymentstatus.h>
 #include <fs.h>
 #include <hash.h>
 #include <httprpc.h>
@@ -1587,7 +1588,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         }
     }
 
-    if (chainparams.GetConsensus().SegwitHeight != std::numeric_limits<int>::max()) {
+    if (DeploymentEnabled(chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) {
         // Advertise witness capabilities.
         // The option to not set NODE_WITNESS is only used in the tests and should be removed.
         nLocalServices = ServiceFlags(nLocalServices | NODE_WITNESS);

src/miner.cpp

@@ -13,6 +13,7 @@
 #include <consensus/merkle.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
+#include <deploymentstatus.h>
 #include <policy/feerate.h>
 #include <policy/policy.h>
 #include <pow.h>
@@ -120,7 +121,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     assert(pindexPrev != nullptr);
     nHeight = pindexPrev->nHeight + 1;
 
-    pblock->nVersion = ComputeBlockVersion(pindexPrev, chainparams.GetConsensus());
+    pblock->nVersion = g_versionbitscache.ComputeBlockVersion(pindexPrev, chainparams.GetConsensus());
     // -regtest only: allow overriding block.nVersion with
     // -blockversion=N to test forking scenarios
     if (chainparams.MineBlocksOnDemand())
@@ -137,12 +138,12 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     // This is only needed in case the witness softfork activation is reverted
     // (which would require a very deep reorganization).
     // Note that the mempool would accept transactions with witness data before
-    // IsWitnessEnabled, but we would only ever mine blocks after IsWitnessEnabled
+    // the deployment is active, but we would only ever mine blocks after activation
     // unless there is a massive block reorganization with the witness softfork
     // not activated.
     // TODO: replace this with a call to main to assess validity of a mempool
     // transaction (which in most cases can be a no-op).
-    fIncludeWitness = IsWitnessEnabled(pindexPrev, chainparams.GetConsensus());
+    fIncludeWitness = DeploymentActiveAfter(pindexPrev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT);
 
     int nPackagesSelected = 0;
     int nDescendantsUpdated = 0;

src/net_processing.cpp

@@ -11,6 +11,7 @@
 #include <blockfilter.h>
 #include <chainparams.h>
 #include <consensus/validation.h>
+#include <deploymentstatus.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <merkleblock.h>
@@ -997,7 +998,7 @@ void PeerManagerImpl::FindNextBlocksToDownload(NodeId nodeid, unsigned int count
                 // We consider the chain that this peer is on invalid.
                 return;
             }
-            if (!State(nodeid)->fHaveWitness && IsWitnessEnabled(pindex->pprev, consensusParams)) {
+            if (!State(nodeid)->fHaveWitness && DeploymentActiveAt(*pindex, consensusParams, Consensus::DEPLOYMENT_SEGWIT)) {
                 // We wouldn't download this block or its descendants from this peer.
                 return;
             }
@@ -1467,7 +1468,7 @@ void PeerManagerImpl::NewPoWValidBlock(const CBlockIndex *pindex, const std::sha
         return;
     nHighestFastAnnounce = pindex->nHeight;
 
-    bool fWitnessEnabled = IsWitnessEnabled(pindex->pprev, m_chainparams.GetConsensus());
+    bool fWitnessEnabled = DeploymentActiveAt(*pindex, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT);
     uint256 hashBlock(pblock->GetHash());
 
     {
@@ -2082,7 +2083,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
             while (pindexWalk && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
                 if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
                         !IsBlockRequested(pindexWalk->GetBlockHash()) &&
-                        (!IsWitnessEnabled(pindexWalk->pprev, m_chainparams.GetConsensus()) || State(pfrom.GetId())->fHaveWitness)) {
+                        (!DeploymentActiveAt(*pindexWalk, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT) || State(pfrom.GetId())->fHaveWitness)) {
                     // We don't have this block, and it's not yet in flight.
                     vToFetch.push_back(pindexWalk);
                 }
@@ -3397,7 +3398,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             return;
         }
 
-        if (IsWitnessEnabled(pindex->pprev, m_chainparams.GetConsensus()) && !nodestate->fSupportsDesiredCmpctVersion) {
+        if (DeploymentActiveAt(*pindex, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT) && !nodestate->fSupportsDesiredCmpctVersion) {
             // Don't bother trying to process compact blocks from v1 peers
             // after segwit activates.
             return;

src/node/interfaces.cpp

@@ -6,6 +6,7 @@
 #include <banman.h>
 #include <chain.h>
 #include <chainparams.h>
+#include <deploymentstatus.h>
 #include <external_signer.h>
 #include <init.h>
 #include <interfaces/chain.h>
@@ -692,7 +693,7 @@ public:
     {
         LOCK(::cs_main);
         const CBlockIndex* tip = Assert(m_node.chainman)->ActiveChain().Tip();
-        return VersionBitsState(tip, Params().GetConsensus(), Consensus::DEPLOYMENT_TAPROOT, versionbitscache) == ThresholdState::ACTIVE;
+        return DeploymentActiveAfter(tip, Params().GetConsensus(), Consensus::DEPLOYMENT_TAPROOT);
     }
     NodeContext& m_node;
 };

src/rpc/blockchain.cpp

@@ -10,8 +10,11 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <coins.h>
+#include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
+#include <deploymentinfo.h>
+#include <deploymentstatus.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <index/coinstatsindex.h>
@@ -37,6 +40,7 @@
 #include <util/translation.h>
 #include <validation.h>
 #include <validationinterface.h>
+#include <versionbits.h>
 #include <warnings.h>
 
 #include <stdint.h>
@@ -1343,32 +1347,32 @@ static RPCHelpMan verifychain()
     };
 }
 
-static void BuriedForkDescPushBack(UniValue& softforks, const std::string &name, int softfork_height, int tip_height) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const Consensus::Params& params, Consensus::BuriedDeployment dep)
 {
     // For buried deployments.
     // A buried deployment is one where the height of the activation has been hardcoded into
     // the client implementation long after the consensus change has activated. See BIP 90.
     // Buried deployments with activation height value of
     // std::numeric_limits<int>::max() are disabled and thus hidden.
-    if (softfork_height == std::numeric_limits<int>::max()) return;
+    if (!DeploymentEnabled(params, dep)) return;
 
     UniValue rv(UniValue::VOBJ);
     rv.pushKV("type", "buried");
     // getblockchaininfo reports the softfork as active from when the chain height is
     // one below the activation height
-    rv.pushKV("active", tip_height + 1 >= softfork_height);
+    rv.pushKV("active", DeploymentActiveAfter(active_chain_tip, params, dep));
-    rv.pushKV("height", softfork_height);
+    rv.pushKV("height", params.DeploymentHeight(dep));
-    softforks.pushKV(name, rv);
+    softforks.pushKV(DeploymentName(dep), rv);
 }
 
-static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const std::string &name, const Consensus::Params& consensusParams, Consensus::DeploymentPos id) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const Consensus::Params& consensusParams, Consensus::DeploymentPos id)
 {
     // For BIP9 deployments.
     // Deployments that are never active are hidden.
     if (consensusParams.vDeployments[id].nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE) return;
 
     UniValue bip9(UniValue::VOBJ);
-    const ThresholdState thresholdState = VersionBitsState(active_chain_tip, consensusParams, id, versionbitscache);
+    const ThresholdState thresholdState = g_versionbitscache.State(active_chain_tip, consensusParams, id);
     switch (thresholdState) {
     case ThresholdState::DEFINED: bip9.pushKV("status", "defined"); break;
     case ThresholdState::STARTED: bip9.pushKV("status", "started"); break;
@@ -1382,12 +1386,12 @@ static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniVal
     }
     bip9.pushKV("start_time", consensusParams.vDeployments[id].nStartTime);
     bip9.pushKV("timeout", consensusParams.vDeployments[id].nTimeout);
-    int64_t since_height = VersionBitsStateSinceHeight(active_chain_tip, consensusParams, id, versionbitscache);
+    int64_t since_height = g_versionbitscache.StateSinceHeight(active_chain_tip, consensusParams, id);
     bip9.pushKV("since", since_height);
     if (ThresholdState::STARTED == thresholdState)
     {
         UniValue statsUV(UniValue::VOBJ);
-        BIP9Stats statsStruct = VersionBitsStatistics(active_chain_tip, consensusParams, id);
+        BIP9Stats statsStruct = g_versionbitscache.Statistics(active_chain_tip, consensusParams, id);
         statsUV.pushKV("period", statsStruct.period);
         statsUV.pushKV("threshold", statsStruct.threshold);
         statsUV.pushKV("elapsed", statsStruct.elapsed);
@@ -1405,7 +1409,7 @@ static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniVal
     }
     rv.pushKV("active", ThresholdState::ACTIVE == thresholdState);
 
-    softforks.pushKV(name, rv);
+    softforks.pushKV(DeploymentName(id), rv);
 }
 
 RPCHelpMan getblockchaininfo()
@@ -1502,14 +1506,14 @@ RPCHelpMan getblockchaininfo()
 
     const Consensus::Params& consensusParams = Params().GetConsensus();
     UniValue softforks(UniValue::VOBJ);
-    BuriedForkDescPushBack(softforks, "bip34", consensusParams.BIP34Height, height);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_HEIGHTINCB);
-    BuriedForkDescPushBack(softforks, "bip66", consensusParams.BIP66Height, height);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_DERSIG);
-    BuriedForkDescPushBack(softforks, "bip65", consensusParams.BIP65Height, height);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_CLTV);
-    BuriedForkDescPushBack(softforks, "csv", consensusParams.CSVHeight, height);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_CSV);
-    BuriedForkDescPushBack(softforks, "segwit", consensusParams.SegwitHeight, height);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_SEGWIT);
-    BIP9SoftForkDescPushBack(tip, softforks, "testdummy", consensusParams, Consensus::DEPLOYMENT_TESTDUMMY);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_TESTDUMMY);
-    BIP9SoftForkDescPushBack(tip, softforks, "taproot", consensusParams, Consensus::DEPLOYMENT_TAPROOT);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_TAPROOT);
-    obj.pushKV("softforks",             softforks);
+    obj.pushKV("softforks", softforks);
 
     obj.pushKV("warnings", GetWarnings(false).original);
     return obj;

src/rpc/mining.cpp

@@ -10,6 +10,8 @@
 #include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
+#include <deploymentinfo.h>
+#include <deploymentstatus.h>
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
@@ -34,7 +36,6 @@
 #include <util/translation.h>
 #include <validation.h>
 #include <validationinterface.h>
-#include <versionbitsinfo.h>
 #include <warnings.h>
 
 #include <memory>
@@ -774,7 +775,7 @@ static RPCHelpMan getblocktemplate()
     pblock->nNonce = 0;
 
     // NOTE: If at some point we support pre-segwit miners post-segwit-activation, this needs to take segwit support into consideration
-    const bool fPreSegWit = (pindexPrev->nHeight + 1 < consensusParams.SegwitHeight);
+    const bool fPreSegWit = !DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT);
 
     UniValue aCaps(UniValue::VARR); aCaps.push_back("proposal");
 
@@ -840,7 +841,7 @@ static RPCHelpMan getblocktemplate()
     UniValue vbavailable(UniValue::VOBJ);
     for (int j = 0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
         Consensus::DeploymentPos pos = Consensus::DeploymentPos(j);
-        ThresholdState state = VersionBitsState(pindexPrev, consensusParams, pos, versionbitscache);
+        ThresholdState state = g_versionbitscache.State(pindexPrev, consensusParams, pos);
         switch (state) {
             case ThresholdState::DEFINED:
             case ThresholdState::FAILED:
@@ -848,7 +849,7 @@ static RPCHelpMan getblocktemplate()
                 break;
             case ThresholdState::LOCKED_IN:
                 // Ensure bit is set in block version
-                pblock->nVersion |= VersionBitsMask(consensusParams, pos);
+                pblock->nVersion |= g_versionbitscache.Mask(consensusParams, pos);
                 // FALL THROUGH to get vbavailable set...
             case ThresholdState::STARTED:
             {
@@ -857,7 +858,7 @@ static RPCHelpMan getblocktemplate()
                 if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
                     if (!vbinfo.gbt_force) {
                         // If the client doesn't support this, don't indicate it in the [default] version
-                        pblock->nVersion &= ~VersionBitsMask(consensusParams, pos);
+                        pblock->nVersion &= ~g_versionbitscache.Mask(consensusParams, pos);
                     }
                 }
                 break;

src/test/versionbits_tests.cpp

@@ -5,6 +5,7 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <consensus/params.h>
+#include <deploymentstatus.h>
 #include <test/util/setup_common.h>
 #include <validation.h>
 #include <versionbits.h>
@@ -258,8 +259,8 @@ BOOST_AUTO_TEST_CASE(versionbits_test)
 /** Check that ComputeBlockVersion will set the appropriate bit correctly */
 static void check_computeblockversion(const Consensus::Params& params, Consensus::DeploymentPos dep)
 {
-    // This implicitly uses versionbitscache, so clear it every time
+    // This implicitly uses g_versionbitscache, so clear it every time
-    versionbitscache.Clear();
+    g_versionbitscache.Clear();
 
     int64_t bit = params.vDeployments[dep].bit;
     int64_t nStartTime = params.vDeployments[dep].nStartTime;
@@ -267,7 +268,7 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
     int min_activation_height = params.vDeployments[dep].min_activation_height;
 
     // should not be any signalling for first block
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(nullptr, params), VERSIONBITS_TOP_BITS);
+    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 ||
@@ -287,7 +288,7 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
     // Check min_activation_height is on a retarget boundary
     BOOST_REQUIRE_EQUAL(min_activation_height % params.nMinerConfirmationWindow, 0U);
 
-    const uint32_t bitmask{VersionBitsMask(params, dep)};
+    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.
@@ -306,9 +307,9 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
         // 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(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+        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((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+        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
@@ -316,28 +317,28 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
 
         // Start generating blocks before nStartTime
         lastBlock = firstChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+        BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 
         // Mine more blocks (4 less than the adjustment period) at the old time, and check that CBV isn't setting the bit yet.
         for (uint32_t i = 1; i < params.nMinerConfirmationWindow - 4; i++) {
             lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-            BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+            BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
         }
         // Now mine 5 more blocks at the start time -- MTP should not have passed yet, so
         // CBV should still not yet set the bit.
         nTime = nStartTime;
         for (uint32_t i = params.nMinerConfirmationWindow - 4; i <= params.nMinerConfirmationWindow; i++) {
             lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-            BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+            BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
         }
         // Next we will advance to the next period and transition to STARTED,
     }
 
     lastBlock = firstChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
     // so ComputeBlockVersion should now set the bit,
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+    BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
     // and should also be using the VERSIONBITS_TOP_BITS.
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
+    BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
 
     // Check that ComputeBlockVersion will set the bit until nTimeout
     nTime += 600;
@@ -346,8 +347,8 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
     // These blocks are all before nTimeout is reached.
     while (nTime < nTimeout && blocksToMine > 0) {
         lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+        BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
+        BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
         blocksToMine--;
         nTime += 600;
         nHeight += 1;
@@ -361,7 +362,7 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
         // finish the last period before we start timing out
         while (nHeight % params.nMinerConfirmationWindow != 0) {
             lastBlock = firstChain.Mine(nHeight+1, nTime - 1, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-            BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+            BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
             nHeight += 1;
         }
 
@@ -369,12 +370,12 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
         // the bit until the period transition.
         for (uint32_t i = 0; i < params.nMinerConfirmationWindow - 1; i++) {
             lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-            BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+            BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
             nHeight += 1;
         }
         // The next block should trigger no longer setting the bit.
         lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+        BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
     }
 
     // On a new chain:
@@ -385,30 +386,30 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
     // Mine one period worth of blocks, and check that the bit will be on for the
     // next period.
     lastBlock = secondChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+    BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 
     // Mine another period worth of blocks, signaling the new bit.
     lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 2, nTime, VERSIONBITS_TOP_BITS | (1<<bit)).Tip();
     // After one period of setting the bit on each block, it should have locked in.
     // We keep setting the bit for one more period though, until activation.
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+    BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
 
     // Now check that we keep mining the block until the end of this period, and
     // then stop at the beginning of the next period.
     lastBlock = secondChain.Mine((params.nMinerConfirmationWindow * 3) - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
+    BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
     lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
 
     if (lastBlock->nHeight + 1 < min_activation_height) {
         // check signalling continues while min_activation_height is not reached
         lastBlock = secondChain.Mine(min_activation_height - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
+        BOOST_CHECK((g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
         // then reach min_activation_height, which was already REQUIRE'd to start a new period
         lastBlock = secondChain.Mine(min_activation_height, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
     }
 
     // Check that we don't signal after activation
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
+    BOOST_CHECK_EQUAL(g_versionbitscache.ComputeBlockVersion(lastBlock, params) & (1 << bit), 0);
 }
 
 BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
@@ -425,7 +426,7 @@ BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
             // not take precedence over STARTED/LOCKED_IN. So all softforks on
             // the same bit might overlap, even when non-overlapping start-end
             // times are picked.
-            const uint32_t dep_mask{VersionBitsMask(chainParams->GetConsensus(), dep)};
+            const uint32_t dep_mask{g_versionbitscache.Mask(chainParams->GetConsensus(), dep)};
             BOOST_CHECK(!(chain_all_vbits & dep_mask));
             chain_all_vbits |= dep_mask;
             check_computeblockversion(chainParams->GetConsensus(), dep);

src/validation.cpp

@@ -15,6 +15,7 @@
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <cuckoocache.h>
+#include <deploymentstatus.h>
 #include <flatfile.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
@@ -683,9 +684,8 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     }
 
     // Check for non-standard pay-to-script-hash in inputs
-    const auto& params = args.m_chainparams.GetConsensus();
+    const bool taproot_active = DeploymentActiveAfter(m_active_chainstate.m_chain.Tip(), args.m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_TAPROOT);
-    auto taproot_state = VersionBitsState(m_active_chainstate.m_chain.Tip(), params, Consensus::DEPLOYMENT_TAPROOT, versionbitscache);
+    if (fRequireStandard && !AreInputsStandard(tx, m_view, taproot_active)) {
-    if (fRequireStandard && !AreInputsStandard(tx, m_view, taproot_state == ThresholdState::ACTIVE)) {
         return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs");
     }
 
@@ -1606,23 +1606,6 @@ void StopScriptCheckWorkerThreads()
     scriptcheckqueue.StopWorkerThreads();
 }
 
-VersionBitsCache versionbitscache GUARDED_BY(cs_main);
-
-int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params)
-{
-    LOCK(cs_main);
-    int32_t nVersion = VERSIONBITS_TOP_BITS;
-
-    for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
-        ThresholdState state = VersionBitsState(pindexPrev, params, static_cast<Consensus::DeploymentPos>(i), versionbitscache);
-        if (state == ThresholdState::LOCKED_IN || state == ThresholdState::STARTED) {
-            nVersion |= VersionBitsMask(params, static_cast<Consensus::DeploymentPos>(i));
-        }
-    }
-
-    return nVersion;
-}
-
 /**
  * Threshold condition checker that triggers when unknown versionbits are seen on the network.
  */
@@ -1644,24 +1627,14 @@ public:
         return pindex->nHeight >= params.MinBIP9WarningHeight &&
                ((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) &&
                ((pindex->nVersion >> bit) & 1) != 0 &&
-               ((ComputeBlockVersion(pindex->pprev, params) >> bit) & 1) == 0;
+               ((g_versionbitscache.ComputeBlockVersion(pindex->pprev, params) >> bit) & 1) == 0;
     }
 };
 
 static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS] GUARDED_BY(cs_main);
 
-// 0.13.0 was shipped with a segwit deployment defined for testnet, but not for
+static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& consensusparams)
-// mainnet. We no longer need to support disabling the segwit deployment
-// except for testing purposes, due to limitations of the functional test
-// environment. See test/functional/p2p-segwit.py.
-static bool IsScriptWitnessEnabled(const Consensus::Params& params)
 {
-    return params.SegwitHeight != std::numeric_limits<int>::max();
-}
-
-static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& consensusparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
-    AssertLockHeld(cs_main);
-
     unsigned int flags = SCRIPT_VERIFY_NONE;
 
     // BIP16 didn't become active until Apr 1 2012 (on mainnet, and
@@ -1678,32 +1651,32 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consens
 
     // Enforce WITNESS rules whenever P2SH is in effect (and the segwit
     // deployment is defined).
-    if (flags & SCRIPT_VERIFY_P2SH && IsScriptWitnessEnabled(consensusparams)) {
+    if (flags & SCRIPT_VERIFY_P2SH && DeploymentEnabled(consensusparams, Consensus::DEPLOYMENT_SEGWIT)) {
         flags |= SCRIPT_VERIFY_WITNESS;
     }
 
-    // Start enforcing the DERSIG (BIP66) rule
+    // Enforce the DERSIG (BIP66) rule
-    if (pindex->nHeight >= consensusparams.BIP66Height) {
+    if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_DERSIG)) {
         flags |= SCRIPT_VERIFY_DERSIG;
     }
 
-    // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule
+    // Enforce CHECKLOCKTIMEVERIFY (BIP65)
-    if (pindex->nHeight >= consensusparams.BIP65Height) {
+    if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_CLTV)) {
         flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
     }
 
-    // Start enforcing BIP112 (CHECKSEQUENCEVERIFY)
+    // Enforce CHECKSEQUENCEVERIFY (BIP112)
-    if (pindex->nHeight >= consensusparams.CSVHeight) {
+    if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_CSV)) {
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
-    // Start enforcing Taproot using versionbits logic.
+    // Enforce Taproot (BIP340-BIP342)
-    if (VersionBitsState(pindex->pprev, consensusparams, Consensus::DEPLOYMENT_TAPROOT, versionbitscache) == ThresholdState::ACTIVE) {
+    if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_TAPROOT)) {
         flags |= SCRIPT_VERIFY_TAPROOT;
     }
 
-    // Start enforcing BIP147 NULLDUMMY (activated simultaneously with segwit)
+    // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit)
-    if (IsWitnessEnabled(pindex->pprev, consensusparams)) {
+    if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_SEGWIT)) {
         flags |= SCRIPT_VERIFY_NULLDUMMY;
     }
 
@@ -1893,9 +1866,9 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state,
         }
     }
 
-    // Start enforcing BIP68 (sequence locks)
+    // Enforce BIP68 (sequence locks)
     int nLockTimeFlags = 0;
-    if (pindex->nHeight >= m_params.GetConsensus().CSVHeight) {
+    if (DeploymentActiveAt(*pindex, m_params.GetConsensus(), Consensus::DEPLOYMENT_CSV)) {
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
@@ -2988,7 +2961,7 @@ void CChainState::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pi
     pindexNew->nDataPos = pos.nPos;
     pindexNew->nUndoPos = 0;
     pindexNew->nStatus |= BLOCK_HAVE_DATA;
-    if (IsWitnessEnabled(pindexNew->pprev, m_params.GetConsensus())) {
+    if (DeploymentActiveAt(*pindexNew, m_params.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) {
         pindexNew->nStatus |= BLOCK_OPT_WITNESS;
     }
     pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS);
@@ -3109,17 +3082,11 @@ bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensu
     return true;
 }
 
-bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)
-{
-    int height = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
-    return (height >= params.SegwitHeight);
-}
-
 void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams)
 {
     int commitpos = GetWitnessCommitmentIndex(block);
     static const std::vector<unsigned char> nonce(32, 0x00);
-    if (commitpos != NO_WITNESS_COMMITMENT && IsWitnessEnabled(pindexPrev, consensusParams) && !block.vtx[0]->HasWitness()) {
+    if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) {
         CMutableTransaction tx(*block.vtx[0]);
         tx.vin[0].scriptWitness.stack.resize(1);
         tx.vin[0].scriptWitness.stack[0] = nonce;
@@ -3132,7 +3099,7 @@ std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBloc
     std::vector<unsigned char> commitment;
     int commitpos = GetWitnessCommitmentIndex(block);
     std::vector<unsigned char> ret(32, 0x00);
-    if (consensusParams.SegwitHeight != std::numeric_limits<int>::max()) {
+    if (DeploymentEnabled(consensusParams, Consensus::DEPLOYMENT_SEGWIT)) {
         if (commitpos == NO_WITNESS_COMMITMENT) {
             uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr);
             CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot);
@@ -3210,13 +3177,13 @@ static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidatio
     if (block.GetBlockTime() > nAdjustedTime + MAX_FUTURE_BLOCK_TIME)
         return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future");
 
-    // Reject outdated version blocks when 95% (75% on testnet) of the network has upgraded:
+    // Reject blocks with outdated version
-    // check for version 2, 3 and 4 upgrades
+    if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_HEIGHTINCB)) ||
-    if((block.nVersion < 2 && nHeight >= consensusParams.BIP34Height) ||
+        (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_DERSIG)) ||
-       (block.nVersion < 3 && nHeight >= consensusParams.BIP66Height) ||
+        (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_CLTV))) {
-       (block.nVersion < 4 && nHeight >= consensusParams.BIP65Height))
             return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion),
                                  strprintf("rejected nVersion=0x%08x block", block.nVersion));
+    }
 
     return true;
 }
@@ -3231,9 +3198,9 @@ static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& stat
 {
     const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
 
-    // Start enforcing BIP113 (Median Time Past).
+    // Enforce BIP113 (Median Time Past).
     int nLockTimeFlags = 0;
-    if (nHeight >= consensusParams.CSVHeight) {
+    if (DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_CSV)) {
         assert(pindexPrev != nullptr);
         nLockTimeFlags |= LOCKTIME_MEDIAN_TIME_PAST;
     }
@@ -3250,7 +3217,7 @@ static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& stat
     }
 
     // Enforce rule that the coinbase starts with serialized block height
-    if (nHeight >= consensusParams.BIP34Height)
+    if (DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_HEIGHTINCB))
     {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
@@ -3268,7 +3235,7 @@ static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& stat
     //   {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are
     //   multiple, the last one is used.
     bool fHaveWitness = false;
-    if (nHeight >= consensusParams.SegwitHeight) {
+    if (DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT)) {
         int commitpos = GetWitnessCommitmentIndex(block);
         if (commitpos != NO_WITNESS_COMMITMENT) {
             bool malleated = false;
@@ -4098,9 +4065,8 @@ bool CChainState::NeedsRedownload() const
 
     // At and above m_params.SegwitHeight, segwit consensus rules must be validated
     CBlockIndex* block{m_chain.Tip()};
-    const int segwit_height{m_params.GetConsensus().SegwitHeight};
 
-    while (block != nullptr && block->nHeight >= segwit_height) {
+    while (block != nullptr && DeploymentActiveAt(*block, m_params.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) {
         if (!(block->nStatus & BLOCK_OPT_WITNESS)) {
             // block is insufficiently validated for a segwit client
             return true;
@@ -4130,7 +4096,7 @@ void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman)
     nLastBlockFile = 0;
     setDirtyBlockIndex.clear();
     setDirtyFileInfo.clear();
-    versionbitscache.Clear();
+    g_versionbitscache.Clear();
     for (int b = 0; b < VERSIONBITS_NUM_BITS; b++) {
         warningcache[b].clear();
     }
@@ -5002,7 +4968,7 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
 
         // Fake BLOCK_OPT_WITNESS so that CChainState::NeedsRedownload()
         // won't ask to rewind the entire assumed-valid chain on startup.
-        if (index->pprev && ::IsWitnessEnabled(index->pprev, ::Params().GetConsensus())) {
+        if (index->pprev && DeploymentActiveAt(*index, ::Params().GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) {
             index->nStatus |= BLOCK_OPT_WITNESS;
         }
     }

src/validation.h

@@ -24,7 +24,6 @@
 #include <sync.h>
 #include <txmempool.h> // For CTxMemPool::cs
 #include <txdb.h>
-#include <versionbits.h>
 #include <serialize.h>
 #include <util/check.h>
 #include <util/hasher.h>
@@ -345,10 +344,6 @@ bool TestBlockValidity(BlockValidationState& state,
                        bool fCheckPOW = true,
                        bool fCheckMerkleRoot = true) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-/** Check whether witness commitments are required for a block, and whether to enforce NULLDUMMY (BIP 147) rules.
- *  Note that transaction witness validation rules are always enforced when P2SH is enforced. */
-bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params);
-
 /** Update uncommitted block structures (currently: only the witness reserved value). This is safe for submitted blocks. */
 void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams);
 
@@ -1024,13 +1019,6 @@ public:
 /** Global variable that points to the active block tree (protected by cs_main) */
 extern std::unique_ptr<CBlockTreeDB> pblocktree;
 
-extern VersionBitsCache versionbitscache;
-
-/**
- * Determine what nVersion a new block should use.
- */
-int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
-
 using FopenFn = std::function<FILE*(const fs::path&, const char*)>;
 
 /** Dump the mempool to disk. */

src/versionbits.cpp

@@ -190,29 +190,48 @@ public:
 
 } // namespace
 
-ThresholdState VersionBitsState(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache)
+ThresholdState VersionBitsCache::State(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos)
 {
-    return VersionBitsConditionChecker(pos).GetStateFor(pindexPrev, params, cache.caches[pos]);
+    LOCK(m_mutex);
+    return VersionBitsConditionChecker(pos).GetStateFor(pindexPrev, params, m_caches[pos]);
 }
 
-BIP9Stats VersionBitsStatistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos)
+BIP9Stats VersionBitsCache::Statistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos)
 {
     return VersionBitsConditionChecker(pos).GetStateStatisticsFor(pindexPrev, params);
 }
 
-int VersionBitsStateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache)
+int VersionBitsCache::StateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos)
 {
-    return VersionBitsConditionChecker(pos).GetStateSinceHeightFor(pindexPrev, params, cache.caches[pos]);
+    LOCK(m_mutex);
+    return VersionBitsConditionChecker(pos).GetStateSinceHeightFor(pindexPrev, params, m_caches[pos]);
 }
 
-uint32_t VersionBitsMask(const Consensus::Params& params, Consensus::DeploymentPos pos)
+uint32_t VersionBitsCache::Mask(const Consensus::Params& params, Consensus::DeploymentPos pos)
 {
     return VersionBitsConditionChecker(pos).Mask(params);
 }
 
+int32_t VersionBitsCache::ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params)
+{
+    LOCK(m_mutex);
+    int32_t nVersion = VERSIONBITS_TOP_BITS;
+
+    for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
+        Consensus::DeploymentPos pos = static_cast<Consensus::DeploymentPos>(i);
+        ThresholdState state = VersionBitsConditionChecker(pos).GetStateFor(pindexPrev, params, m_caches[pos]);
+        if (state == ThresholdState::LOCKED_IN || state == ThresholdState::STARTED) {
+            nVersion |= Mask(params, pos);
+        }
+    }
+
+    return nVersion;
+}
+
 void VersionBitsCache::Clear()
 {
+    LOCK(m_mutex);
     for (unsigned int d = 0; d < Consensus::MAX_VERSION_BITS_DEPLOYMENTS; d++) {
-        caches[d].clear();
+        m_caches[d].clear();
     }
 }

src/versionbits.h

@@ -6,6 +6,8 @@
 #define BITCOIN_VERSIONBITS_H
 
 #include <chain.h>
+#include <sync.h>
+
 #include <map>
 
 /** What block version to use for new blocks (pre versionbits) */
@@ -71,21 +73,31 @@ public:
     int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
 };
 
-/** BIP 9 allows multiple softforks to be deployed in parallel. We cache per-period state for every one of them
+/** BIP 9 allows multiple softforks to be deployed in parallel. We cache
- *  keyed by the bit position used to signal support. */
+ *  per-period state for every one of them. */
-struct VersionBitsCache
+class VersionBitsCache
 {
-    ThresholdConditionCache caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS];
+private:
+    Mutex m_mutex;
+    ThresholdConditionCache m_caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS] GUARDED_BY(m_mutex);
+
+public:
+    /** Get the numerical statistics for a given deployment for the signalling period that includes the block after pindexPrev. */
+    static BIP9Stats Statistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
+
+    static uint32_t Mask(const Consensus::Params& params, Consensus::DeploymentPos pos);
+
+    /** Get the BIP9 state for a given deployment for the block after pindexPrev. */
+    ThresholdState State(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
+
+    /** Get the block height at which the BIP9 deployment switched into the state for the block after pindexPrev. */
+    int StateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
+
+    /** Determine what nVersion a new block should use
+     */
+    int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
 
     void Clear();
 };
 
-/** Get the BIP9 state for a given deployment at the current tip. */
-ThresholdState VersionBitsState(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache);
-/** Get the numerical statistics for the BIP9 state for a given deployment at the current tip. */
-BIP9Stats VersionBitsStatistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
-/** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */
-int VersionBitsStateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache);
-uint32_t VersionBitsMask(const Consensus::Params& params, Consensus::DeploymentPos pos);
-
 #endif // BITCOIN_VERSIONBITS_H

src/versionbitsinfo.cpp

@@ -1,18 +0,0 @@
-// Copyright (c) 2016-2020 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 <versionbitsinfo.h>
-
-#include <consensus/params.h>
-
-const struct VBDeploymentInfo VersionBitsDeploymentInfo[Consensus::MAX_VERSION_BITS_DEPLOYMENTS] = {
-    {
-        /*.name =*/ "testdummy",
-        /*.gbt_force =*/ true,
-    },
-    {
-        /*.name =*/ "taproot",
-        /*.gbt_force =*/ true,
-    },
-};

src/versionbitsinfo.h

@@ -1,17 +0,0 @@
-// Copyright (c) 2016-2018 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#ifndef BITCOIN_VERSIONBITSINFO_H
-#define BITCOIN_VERSIONBITSINFO_H
-
-struct VBDeploymentInfo {
-    /** Deployment name */
-    const char *name;
-    /** Whether GBT clients can safely ignore this rule in simplified usage */
-    bool gbt_force;
-};
-
-extern const struct VBDeploymentInfo VersionBitsDeploymentInfo[];
-
-#endif // BITCOIN_VERSIONBITSINFO_H