move-mostly: Make pindexBestHeader a ChainMan member

[META] In the next commit, we move the clearing of pindexBestHeader to
       ChainstateManager::Unload()

8 files changed, 45 insertions, 42 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 86e6ec4451..0c221ddb84 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1664,9 +1664,9 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             tip_info->block_time = chainman.ActiveChain().Tip() ? chainman.ActiveChain().Tip()->GetBlockTime() : Params().GenesisBlock().GetBlockTime();
             tip_info->verification_progress = GuessVerificationProgress(Params().TxData(), chainman.ActiveChain().Tip());
         }
-        if (tip_info && ::pindexBestHeader) {
-            tip_info->header_height = ::pindexBestHeader->nHeight;
-            tip_info->header_time = ::pindexBestHeader->GetBlockTime();
+        if (tip_info && chainman.pindexBestHeader) {
+            tip_info->header_height = chainman.pindexBestHeader->nHeight;
+            tip_info->header_time = chainman.pindexBestHeader->GetBlockTime();
         }
     }
     LogPrintf("nBestHeight = %d\n", chain_active_height);
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index ba72a11ec9..d002ec20fc 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1499,9 +1499,9 @@ bool PeerManagerImpl::BlockRequestAllowed(const CBlockIndex* pindex)
 {
     AssertLockHeld(cs_main);
     if (m_chainman.ActiveChain().Contains(pindex)) return true;
-    return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != nullptr) &&
-           (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) &&
-           (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, m_chainparams.GetConsensus()) < STALE_RELAY_AGE_LIMIT);
+    return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (m_chainman.pindexBestHeader != nullptr) &&
+           (m_chainman.pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) &&
+           (GetBlockProofEquivalentTime(*m_chainman.pindexBestHeader, *pindex, *m_chainman.pindexBestHeader, m_chainparams.GetConsensus()) < STALE_RELAY_AGE_LIMIT);
 }
 
 std::optional<std::string> PeerManagerImpl::FetchBlock(NodeId peer_id, const CBlockIndex& block_index)
@@ -1896,7 +1896,7 @@ void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv&
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
     // disconnect node in case we have reached the outbound limit for serving historical blocks
     if (m_connman.OutboundTargetReached(true) &&
-        (((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk()) &&
+        (((m_chainman.pindexBestHeader != nullptr) && (m_chainman.pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk()) &&
         !pfrom.HasPermission(NetPermissionFlags::Download) // nodes with the download permission may exceed target
     ) {
         LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom.GetId());
@@ -2173,11 +2173,11 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
         //   nUnconnectingHeaders gets reset back to 0.
         if (!m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock) && nCount < MAX_BLOCKS_TO_ANNOUNCE) {
             nodestate->nUnconnectingHeaders++;
-            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexBestHeader), uint256()));
+            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.pindexBestHeader), uint256()));
             LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n",
                     headers[0].GetHash().ToString(),
                     headers[0].hashPrevBlock.ToString(),
-                    pindexBestHeader->nHeight,
+                    m_chainman.pindexBestHeader->nHeight,
                     pfrom.GetId(), nodestate->nUnconnectingHeaders);
             // Set hashLastUnknownBlock for this peer, so that if we
             // eventually get the headers - even from a different peer -
@@ -2235,7 +2235,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
 
         if (nCount == MAX_HEADERS_RESULTS) {
             // Headers message had its maximum size; the peer may have more headers.
-            // TODO: optimize: if pindexLast is an ancestor of m_chainman.ActiveChain().Tip or pindexBestHeader, continue
+            // TODO: optimize: if pindexLast is an ancestor of m_chainman.ActiveChain().Tip or m_chainman.pindexBestHeader, continue
             // from there instead.
             LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
                                  pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height);
@@ -3102,8 +3102,8 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         }
 
         if (best_block != nullptr) {
-            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexBestHeader), *best_block));
-            LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n", pindexBestHeader->nHeight, best_block->ToString(), pfrom.GetId());
+            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.pindexBestHeader), *best_block));
+            LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n", m_chainman.pindexBestHeader->nHeight, best_block->ToString(), pfrom.GetId());
         }
 
         return;
@@ -3549,7 +3549,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         if (!m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock)) {
             // Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers
             if (!m_chainman.ActiveChainstate().IsInitialBlockDownload())
-                m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexBestHeader), uint256()));
+                m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.pindexBestHeader), uint256()));
             return;
         }
 
@@ -4670,28 +4670,29 @@ bool PeerManagerImpl::SendMessages(CNode* pto)
         CNodeState &state = *State(pto->GetId());
 
         // Start block sync
-        if (pindexBestHeader == nullptr)
-            pindexBestHeader = m_chainman.ActiveChain().Tip();
+        if (m_chainman.pindexBestHeader == nullptr) {
+            m_chainman.pindexBestHeader = m_chainman.ActiveChain().Tip();
+        }
         bool fFetch = state.fPreferredDownload || (nPreferredDownload == 0 && !pto->fClient && !pto->IsAddrFetchConn()); // Download if this is a nice peer, or we have no nice peers and this one might do.
         if (!state.fSyncStarted && !pto->fClient && !fImporting && !fReindex) {
             // Only actively request headers from a single peer, unless we're close to today.
-            if ((nSyncStarted == 0 && fFetch) || pindexBestHeader->GetBlockTime() > GetAdjustedTime() - 24 * 60 * 60) {
+            if ((nSyncStarted == 0 && fFetch) || m_chainman.pindexBestHeader->GetBlockTime() > GetAdjustedTime() - 24 * 60 * 60) {
                 state.fSyncStarted = true;
                 state.m_headers_sync_timeout = current_time + HEADERS_DOWNLOAD_TIMEOUT_BASE +
                     (
                         // Convert HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER to microseconds before scaling
                         // to maintain precision
                         std::chrono::microseconds{HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER} *
-                        (GetAdjustedTime() - pindexBestHeader->GetBlockTime()) / consensusParams.nPowTargetSpacing
+                        (GetAdjustedTime() - m_chainman.pindexBestHeader->GetBlockTime()) / consensusParams.nPowTargetSpacing
                     );
                 nSyncStarted++;
-                const CBlockIndex *pindexStart = pindexBestHeader;
+                const CBlockIndex* pindexStart = m_chainman.pindexBestHeader;
                 /* If possible, start at the block preceding the currently
                    best known header.  This ensures that we always get a
                    non-empty list of headers back as long as the peer
                    is up-to-date.  With a non-empty response, we can initialise
                    the peer's known best block.  This wouldn't be possible
-                   if we requested starting at pindexBestHeader and
+                   if we requested starting at m_chainman.pindexBestHeader and
                    got back an empty response.  */
                 if (pindexStart->pprev)
                     pindexStart = pindexStart->pprev;
@@ -5016,7 +5017,7 @@ bool PeerManagerImpl::SendMessages(CNode* pto)
         // Check for headers sync timeouts
         if (state.fSyncStarted && state.m_headers_sync_timeout < std::chrono::microseconds::max()) {
             // Detect whether this is a stalling initial-headers-sync peer
-            if (pindexBestHeader->GetBlockTime() <= GetAdjustedTime() - 24 * 60 * 60) {
+            if (m_chainman.pindexBestHeader->GetBlockTime() <= GetAdjustedTime() - 24 * 60 * 60) {
                 if (current_time > state.m_headers_sync_timeout && nSyncStarted == 1 && (nPreferredDownload - state.fPreferredDownload >= 1)) {
                     // Disconnect a peer (without NetPermissionFlags::NoBan permission) if it is our only sync peer,
                     // and we have others we could be using instead.
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 45e7ca4796..c7a769eb33 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -81,7 +81,7 @@ const CBlockIndex* BlockManager::LookupBlockIndex(const uint256& hash) const
     return it == m_block_index.end() ? nullptr : &it->second;
 }
 
-CBlockIndex* BlockManager::AddToBlockIndex(const CBlockHeader& block)
+CBlockIndex* BlockManager::AddToBlockIndex(const CBlockHeader& block, CBlockIndex*& best_header)
 {
     AssertLockHeld(cs_main);
 
@@ -106,8 +106,9 @@ CBlockIndex* BlockManager::AddToBlockIndex(const CBlockHeader& block)
     pindexNew->nTimeMax = (pindexNew->pprev ? std::max(pindexNew->pprev->nTimeMax, pindexNew->nTime) : pindexNew->nTime);
     pindexNew->nChainWork = (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) + GetBlockProof(*pindexNew);
     pindexNew->RaiseValidity(BLOCK_VALID_TREE);
-    if (pindexBestHeader == nullptr || pindexBestHeader->nChainWork < pindexNew->nChainWork)
-        pindexBestHeader = pindexNew;
+    if (best_header == nullptr || best_header->nChainWork < pindexNew->nChainWork) {
+        best_header = pindexNew;
+    }
 
     m_dirty_blockindex.insert(pindexNew);
 
diff --git a/src/node/blockstorage.h b/src/node/blockstorage.h
index a051e90808..3a95e321f7 100644
--- a/src/node/blockstorage.h
+++ b/src/node/blockstorage.h
@@ -147,7 +147,7 @@ public:
     /** Clear all data members. */
     void Unload() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-    CBlockIndex* AddToBlockIndex(const CBlockHeader& block) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+    CBlockIndex* AddToBlockIndex(const CBlockHeader& block, CBlockIndex*& best_header) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /** Create a new block index entry for a given block hash */
     CBlockIndex* InsertBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 73d15652b1..96e0e365a4 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -212,9 +212,10 @@ public:
     bool getHeaderTip(int& height, int64_t& block_time) override
     {
         LOCK(::cs_main);
-        if (::pindexBestHeader) {
-            height = ::pindexBestHeader->nHeight;
-            block_time = ::pindexBestHeader->GetBlockTime();
+        auto best_header = chainman().pindexBestHeader;
+        if (best_header) {
+            height = best_header->nHeight;
+            block_time = best_header->GetBlockTime();
             return true;
         }
         return false;
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index a124e0267c..1c8718ffba 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1207,7 +1207,7 @@ RPCHelpMan getblockchaininfo()
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("chain",                 Params().NetworkIDString());
     obj.pushKV("blocks",                height);
-    obj.pushKV("headers",               pindexBestHeader ? pindexBestHeader->nHeight : -1);
+    obj.pushKV("headers", chainman.pindexBestHeader ? chainman.pindexBestHeader->nHeight : -1);
     obj.pushKV("bestblockhash",         tip->GetBlockHash().GetHex());
     obj.pushKV("difficulty",            (double)GetDifficulty(tip));
     obj.pushKV("time",                  (int64_t)tip->nTime);
diff --git a/src/validation.cpp b/src/validation.cpp
index 677159ddfe..9a68f8591a 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -120,7 +120,6 @@ const std::vector<std::string> CHECKLEVEL_DOC {
  */
 RecursiveMutex cs_main;
 
-CBlockIndex *pindexBestHeader = nullptr;
 Mutex g_best_block_mutex;
 std::condition_variable g_best_block_cv;
 uint256 g_best_block;
@@ -280,8 +279,9 @@ static bool IsCurrentForFeeEstimation(CChainState& active_chainstate) EXCLUSIVE_
         return false;
     if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE))
         return false;
-    if (active_chainstate.m_chain.Height() < pindexBestHeader->nHeight - 1)
+    if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.pindexBestHeader->nHeight - 1) {
         return false;
+    }
     return true;
 }
 
@@ -1602,8 +1602,8 @@ void CChainState::InvalidChainFound(CBlockIndex* pindexNew)
     if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
         m_chainman.m_best_invalid = pindexNew;
     }
-    if (pindexBestHeader != nullptr && pindexBestHeader->GetAncestor(pindexNew->nHeight) == pindexNew) {
-        pindexBestHeader = m_chain.Tip();
+    if (m_chainman.pindexBestHeader != nullptr && m_chainman.pindexBestHeader->GetAncestor(pindexNew->nHeight) == pindexNew) {
+        m_chainman.pindexBestHeader = m_chain.Tip();
     }
 
     LogPrintf("%s: invalid block=%s  height=%d  log2_work=%f  date=%s\n", __func__,
@@ -2029,8 +2029,8 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state,
         BlockMap::const_iterator  it = m_blockman.m_block_index.find(hashAssumeValid);
         if (it != m_blockman.m_block_index.end()) {
             if (it->second.GetAncestor(pindex->nHeight) == pindex &&
-                pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
-                pindexBestHeader->nChainWork >= nMinimumChainWork) {
+                m_chainman.pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
+                m_chainman.pindexBestHeader->nChainWork >= nMinimumChainWork) {
                 // This block is a member of the assumed verified chain and an ancestor of the best header.
                 // Script verification is skipped when connecting blocks under the
                 // assumevalid block. Assuming the assumevalid block is valid this
@@ -2045,7 +2045,7 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state,
                 //  artificially set the default assumed verified block further back.
                 // The test against nMinimumChainWork prevents the skipping when denied access to any chain at
                 //  least as good as the expected chain.
-                fScriptChecks = (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, m_params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
+                fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.pindexBestHeader, *pindex, *m_chainman.pindexBestHeader, m_params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
             }
         }
     }
@@ -2904,7 +2904,7 @@ static bool NotifyHeaderTip(CChainState& chainstate) LOCKS_EXCLUDED(cs_main) {
     CBlockIndex* pindexHeader = nullptr;
     {
         LOCK(cs_main);
-        pindexHeader = pindexBestHeader;
+        pindexHeader = chainstate.m_chainman.pindexBestHeader;
 
         if (pindexHeader != pindexHeaderOld) {
             fNotify = true;
@@ -3621,7 +3621,7 @@ bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValida
             }
         }
     }
-    CBlockIndex* pindex{m_blockman.AddToBlockIndex(block)};
+    CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, pindexBestHeader)};
 
     if (ppindex)
         *ppindex = pindex;
@@ -4122,7 +4122,7 @@ void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman)
 {
     AssertLockHeld(::cs_main);
     chainman.Unload();
-    pindexBestHeader = nullptr;
+    chainman.pindexBestHeader = nullptr;
     if (mempool) mempool->clear();
     g_versionbitscache.Clear();
     for (int b = 0; b < VERSIONBITS_NUM_BITS; b++) {
@@ -4239,7 +4239,7 @@ bool CChainState::LoadGenesisBlock()
         if (blockPos.IsNull()) {
             return error("%s: writing genesis block to disk failed", __func__);
         }
-        CBlockIndex *pindex = m_blockman.AddToBlockIndex(block);
+        CBlockIndex* pindex = m_blockman.AddToBlockIndex(block, m_chainman.pindexBestHeader);
         ReceivedBlockTransactions(block, pindex, blockPos);
     } catch (const std::runtime_error& e) {
         return error("%s: failed to write genesis block: %s", __func__, e.what());
diff --git a/src/validation.h b/src/validation.h
index 53ea2d4aea..7959766d1d 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -131,9 +131,6 @@ extern uint256 hashAssumeValid;
 /** Minimum work we will assume exists on some valid chain. */
 extern arith_uint256 nMinimumChainWork;
 
-/** Best header we've seen so far (used for getheaders queries' starting points). */
-extern CBlockIndex *pindexBestHeader;
-
 /** Documentation for argument 'checklevel'. */
 extern const std::vector<std::string> CHECKLEVEL_DOC;
 
@@ -883,6 +880,9 @@ public:
      */
     std::set<CBlockIndex*> m_failed_blocks;
 
+    /** Best header we've seen so far (used for getheaders queries' starting points). */
+    CBlockIndex* pindexBestHeader = nullptr;
+
     //! The total number of bytes available for us to use across all in-memory
     //! coins caches. This will be split somehow across chainstates.
     int64_t m_total_coinstip_cache{0};