Merge bitcoin/bitcoin#22371: Move pblocktree global to BlockManager

faa54e375782b21cbc2761c763128131c569e903 Move pblocktree global to BlockManager (MarcoFalke)
fa27f03b4943540aa2eab283d4cf50ad4a1a01f8 Move LoadBlockIndexDB to BlockManager (MarcoFalke)

Pull request description:

  The block tree db is used within BlockManager to write and read the block index, so make the db global a member variable of BlockManager.

ACKs for top commit:
  jamesob:
    ACK faa54e375782b21cbc2761c763128131c569e903 ([`jamesob/ackr/22371.1.MarcoFalke.move_pblocktree_global_t`](https://github.com/jamesob/bitcoin/tree/ackr/22371.1.MarcoFalke.move_pblocktree_global_t))
  theStack:
    re-ACK faa54e375782b21cbc2761c763128131c569e903 🥧
  ryanofsky:
    Code review ACK faa54e375782b21cbc2761c763128131c569e903. I was thinking this looked like a change Carl would like, so no surprised he [Mega-acked](https://github.com/bitcoin/bitcoin/pull/22371#pullrequestreview-696450475)

Tree-SHA512: 1b7badbf503d53f5d4dbd9ed8f2e5c1ebfe48102665197048cc9e37bc87b5cec5f2277f3aae9f73a1095bfe879b19d288286ca3daa28031f5f1b64b1184439a9

7 files changed, 23 insertions, 28 deletions

diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
index 782e557478..cde9821f3d 100644
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -204,7 +204,7 @@ bool TxIndex::Init()
     // Attempt to migrate txindex from the old database to the new one. Even if
     // chain_tip is null, the node could be reindexing and we still want to
     // delete txindex records in the old database.
-    if (!m_db->MigrateData(*pblocktree, m_chainstate->m_chain.GetLocator())) {
+    if (!m_db->MigrateData(*m_chainstate->m_blockman.m_block_tree_db, m_chainstate->m_chain.GetLocator())) {
         return false;
     }
 
diff --git a/src/init.cpp b/src/init.cpp
index 9afd76d62d..3915fa8fcb 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -264,7 +264,6 @@ void Shutdown(NodeContext& node)
                 chainstate->ResetCoinsViews();
             }
         }
-        pblocktree.reset();
     }
     for (const auto& client : node.chain_clients) {
         client->stop();
@@ -1355,6 +1354,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
                 UnloadBlockIndex(node.mempool.get(), chainman);
 
+                auto& pblocktree{chainman.m_blockman.m_block_tree_db};
                 // new CBlockTreeDB tries to delete the existing file, which
                 // fails if it's still open from the previous loop. Close it first:
                 pblocktree.reset();
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 0083b74b33..90f7ba191d 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -518,7 +518,7 @@ void ThreadImport(ChainstateManager& chainman, std::vector<fs::path> vImportFile
                 }
                 nFile++;
             }
-            pblocktree->WriteReindexing(false);
+            WITH_LOCK(::cs_main, chainman.m_blockman.m_block_tree_db->WriteReindexing(false));
             fReindex = false;
             LogPrintf("Reindexing finished\n");
             // To avoid ending up in a situation without genesis block, re-try initializing (no-op if reindexing worked):
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index d9d236be1d..5334c4623e 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -141,12 +141,11 @@ ChainTestingSetup::ChainTestingSetup(const std::string& chainName, const std::ve
     m_node.scheduler->m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { m_node.scheduler->serviceQueue(); });
     GetMainSignals().RegisterBackgroundSignalScheduler(*m_node.scheduler);
 
-    pblocktree.reset(new CBlockTreeDB(1 << 20, true));
-
     m_node.fee_estimator = std::make_unique<CBlockPolicyEstimator>();
     m_node.mempool = std::make_unique<CTxMemPool>(m_node.fee_estimator.get(), 1);
 
     m_node.chainman = std::make_unique<ChainstateManager>();
+    m_node.chainman->m_blockman.m_block_tree_db = std::make_unique<CBlockTreeDB>(1 << 20, true);
 
     // Start script-checking threads. Set g_parallel_script_checks to true so they are used.
     constexpr int script_check_threads = 2;
@@ -169,7 +168,6 @@ ChainTestingSetup::~ChainTestingSetup()
     m_node.scheduler.reset();
     m_node.chainman->Reset();
     m_node.chainman.reset();
-    pblocktree.reset();
 }
 
 TestingSetup::TestingSetup(const std::string& chainName, const std::vector<const char*>& extra_args)
diff --git a/src/test/validation_chainstate_tests.cpp b/src/test/validation_chainstate_tests.cpp
index 2893b412fb..315ef22599 100644
--- a/src/test/validation_chainstate_tests.cpp
+++ b/src/test/validation_chainstate_tests.cpp
@@ -20,6 +20,7 @@ BOOST_FIXTURE_TEST_SUITE(validation_chainstate_tests, TestingSetup)
 BOOST_AUTO_TEST_CASE(validation_chainstate_resize_caches)
 {
     ChainstateManager manager;
+    WITH_LOCK(::cs_main, manager.m_blockman.m_block_tree_db = std::make_unique<CBlockTreeDB>(1 << 20, true));
     CTxMemPool mempool;
 
     //! Create and add a Coin with DynamicMemoryUsage of 80 bytes to the given view.
diff --git a/src/validation.cpp b/src/validation.cpp
index 26333d7026..f81c27e8e3 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -170,8 +170,6 @@ CBlockIndex* BlockManager::FindForkInGlobalIndex(const CChain& chain, const CBlo
     return chain.Genesis();
 }
 
-std::unique_ptr<CBlockTreeDB> pblocktree;
-
 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
                        const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore,
                        bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
@@ -2075,7 +2073,7 @@ bool CChainState::FlushStateToDisk(
             if (!setFilesToPrune.empty()) {
                 fFlushForPrune = true;
                 if (!fHavePruned) {
-                    pblocktree->WriteFlag("prunedblockfiles", true);
+                    m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true);
                     fHavePruned = true;
                 }
             }
@@ -2127,7 +2125,7 @@ bool CChainState::FlushStateToDisk(
                     vBlocks.push_back(*it);
                     setDirtyBlockIndex.erase(it++);
                 }
-                if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile, vBlocks)) {
+                if (!m_blockman.m_block_tree_db->WriteBatchSync(vFiles, nLastBlockFile, vBlocks)) {
                     return AbortNode(state, "Failed to write to block index database");
                 }
             }
@@ -3700,11 +3698,11 @@ CBlockIndex * BlockManager::InsertBlockIndex(const uint256& hash)
 
 bool BlockManager::LoadBlockIndex(
     const Consensus::Params& consensus_params,
-    CBlockTreeDB& blocktree,
     std::set<CBlockIndex*, CBlockIndexWorkComparator>& block_index_candidates)
 {
-    if (!blocktree.LoadBlockIndexGuts(consensus_params, [this](const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return this->InsertBlockIndex(hash); }))
+    if (!m_block_tree_db->LoadBlockIndexGuts(consensus_params, [this](const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return this->InsertBlockIndex(hash); })) {
         return false;
+    }
 
     // Calculate nChainWork
     std::vector<std::pair<int, CBlockIndex*> > vSortedByHeight;
@@ -3764,25 +3762,25 @@ void BlockManager::Unload() {
     m_block_index.clear();
 }
 
-bool CChainState::LoadBlockIndexDB()
+bool BlockManager::LoadBlockIndexDB(std::set<CBlockIndex*, CBlockIndexWorkComparator>& setBlockIndexCandidates)
 {
-    if (!m_blockman.LoadBlockIndex(
-            m_params.GetConsensus(), *pblocktree,
+    if (!LoadBlockIndex(
+            ::Params().GetConsensus(),
             setBlockIndexCandidates)) {
         return false;
     }
 
     // Load block file info
-    pblocktree->ReadLastBlockFile(nLastBlockFile);
+    m_block_tree_db->ReadLastBlockFile(nLastBlockFile);
     vinfoBlockFile.resize(nLastBlockFile + 1);
     LogPrintf("%s: last block file = %i\n", __func__, nLastBlockFile);
     for (int nFile = 0; nFile <= nLastBlockFile; nFile++) {
-        pblocktree->ReadBlockFileInfo(nFile, vinfoBlockFile[nFile]);
+        m_block_tree_db->ReadBlockFileInfo(nFile, vinfoBlockFile[nFile]);
     }
     LogPrintf("%s: last block file info: %s\n", __func__, vinfoBlockFile[nLastBlockFile].ToString());
     for (int nFile = nLastBlockFile + 1; true; nFile++) {
         CBlockFileInfo info;
-        if (pblocktree->ReadBlockFileInfo(nFile, info)) {
+        if (m_block_tree_db->ReadBlockFileInfo(nFile, info)) {
             vinfoBlockFile.push_back(info);
         } else {
             break;
@@ -3792,7 +3790,7 @@ bool CChainState::LoadBlockIndexDB()
     // Check presence of blk files
     LogPrintf("Checking all blk files are present...\n");
     std::set<int> setBlkDataFiles;
-    for (const std::pair<const uint256, CBlockIndex*>& item : m_blockman.m_block_index) {
+    for (const std::pair<const uint256, CBlockIndex*>& item : m_block_index) {
         CBlockIndex* pindex = item.second;
         if (pindex->nStatus & BLOCK_HAVE_DATA) {
             setBlkDataFiles.insert(pindex->nFile);
@@ -3807,13 +3805,13 @@ bool CChainState::LoadBlockIndexDB()
     }
 
     // Check whether we have ever pruned block & undo files
-    pblocktree->ReadFlag("prunedblockfiles", fHavePruned);
+    m_block_tree_db->ReadFlag("prunedblockfiles", fHavePruned);
     if (fHavePruned)
         LogPrintf("LoadBlockIndexDB(): Block files have previously been pruned\n");
 
     // Check whether we need to continue reindexing
     bool fReindexing = false;
-    pblocktree->ReadReindexing(fReindexing);
+    m_block_tree_db->ReadReindexing(fReindexing);
     if(fReindexing) fReindex = true;
 
     return true;
@@ -4114,7 +4112,7 @@ bool ChainstateManager::LoadBlockIndex()
     // Load block index from databases
     bool needs_init = fReindex;
     if (!fReindex) {
-        bool ret = ActiveChainstate().LoadBlockIndexDB();
+        bool ret = m_blockman.LoadBlockIndexDB(ActiveChainstate().setBlockIndexCandidates);
         if (!ret) return false;
         needs_init = m_blockman.m_block_index.empty();
     }
diff --git a/src/validation.h b/src/validation.h
index 9a2be3ad97..18a09d4aa3 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -446,6 +446,10 @@ public:
      */
     std::multimap<CBlockIndex*, CBlockIndex*> m_blocks_unlinked;
 
+    std::unique_ptr<CBlockTreeDB> m_block_tree_db GUARDED_BY(::cs_main);
+
+    bool LoadBlockIndexDB(std::set<CBlockIndex*, CBlockIndexWorkComparator>& setBlockIndexCandidates) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+
     /**
      * Load the blocktree off disk and into memory. Populate certain metadata
      * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as peripheral
@@ -456,7 +460,6 @@ public:
      */
     bool LoadBlockIndex(
         const Consensus::Params& consensus_params,
-        CBlockTreeDB& blocktree,
         std::set<CBlockIndex*, CBlockIndexWorkComparator>& block_index_candidates)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
@@ -798,8 +801,6 @@ private:
     void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void InvalidChainFound(CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-    bool LoadBlockIndexDB() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
-
     //! Indirection necessary to make lock annotations work with an optional mempool.
     RecursiveMutex* MempoolMutex() const LOCK_RETURNED(m_mempool->cs)
     {
@@ -1047,9 +1048,6 @@ public:
     }
 };
 
-/** Global variable that points to the active block tree (protected by cs_main) */
-extern std::unique_ptr<CBlockTreeDB> pblocktree;
-
 using FopenFn = std::function<FILE*(const fs::path&, const char*)>;
 
 /** Dump the mempool to disk. */