use ChainstateManager to initialize chainstate

This allows us to easily initialize multiple chainstates on startup in future
commits. It retires the g_chainstate global in lieu of g_chainman.

1 files changed, 32 insertions, 36 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 9d4cdf6eb9..77b6e7c051 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -77,20 +77,17 @@ bool CBlockIndexWorkComparator::operator()(const CBlockIndex *pa, const CBlockIn
     return false;
 }
 
-namespace {
-BlockManager g_blockman;
-} // anon namespace
-
-std::unique_ptr<CChainState> g_chainstate;
+ChainstateManager g_chainman;
 
-CChainState& ChainstateActive() {
-    assert(g_chainstate);
-    return *g_chainstate;
+CChainState& ChainstateActive()
+{
+    assert(g_chainman.m_active_chainstate);
+    return *g_chainman.m_active_chainstate;
 }
 
-CChain& ChainActive() {
-    assert(g_chainstate);
-    return g_chainstate->m_chain;
+CChain& ChainActive()
+{
+    return ::ChainstateActive().m_chain;
 }
 
 /**
@@ -152,8 +149,8 @@ namespace {
 CBlockIndex* LookupBlockIndex(const uint256& hash)
 {
     AssertLockHeld(cs_main);
-    BlockMap::const_iterator it = g_blockman.m_block_index.find(hash);
-    return it == g_blockman.m_block_index.end() ? nullptr : it->second;
+    BlockMap::const_iterator it = g_chainman.BlockIndex().find(hash);
+    return it == g_chainman.BlockIndex().end() ? nullptr : it->second;
 }
 
 CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator)
@@ -1243,13 +1240,10 @@ void CoinsViews::InitCache()
     m_cacheview = MakeUnique<CCoinsViewCache>(&m_catcherview);
 }
 
-// NOTE: for now m_blockman is set to a global, but this will be changed
-// in a future commit.
-CChainState::CChainState(uint256 from_snapshot_blockhash)
-    : m_blockman(g_blockman),
+CChainState::CChainState(BlockManager& blockman, uint256 from_snapshot_blockhash)
+    : m_blockman(blockman),
       m_from_snapshot_blockhash(from_snapshot_blockhash) {}
 
-
 void CChainState::InitCoinsDB(
     size_t cache_size_bytes,
     bool in_memory,
@@ -1301,7 +1295,7 @@ static CBlockIndex *pindexBestForkTip = nullptr, *pindexBestForkBase = nullptr;
 
 BlockMap& BlockIndex()
 {
-    return g_blockman.m_block_index;
+    return g_chainman.m_blockman.m_block_index;
 }
 
 static void AlertNotify(const std::string& strMessage)
@@ -3471,7 +3465,7 @@ static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidatio
     if (fCheckpointsEnabled) {
         // Don't accept any forks from the main chain prior to last checkpoint.
         // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's in our
-        // g_blockman.m_block_index.
+        // BlockIndex().
         CBlockIndex* pcheckpoint = GetLastCheckpoint(params.Checkpoints());
         if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
             LogPrintf("ERROR: %s: forked chain older than last checkpoint (height %d)\n", __func__, nHeight);
@@ -3679,7 +3673,8 @@ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, BlockValid
         LOCK(cs_main);
         for (const CBlockHeader& header : headers) {
             CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast
-            bool accepted = g_blockman.AcceptBlockHeader(header, state, chainparams, &pindex);
+            bool accepted = g_chainman.m_blockman.AcceptBlockHeader(
+                header, state, chainparams, &pindex);
             ::ChainstateActive().CheckBlockIndex(chainparams.GetConsensus());
 
             if (!accepted) {
@@ -3881,7 +3876,7 @@ void PruneOneBlockFile(const int fileNumber)
 {
     LOCK(cs_LastBlockFile);
 
-    for (const auto& entry : g_blockman.m_block_index) {
+    for (const auto& entry : g_chainman.BlockIndex()) {
         CBlockIndex* pindex = entry.second;
         if (pindex->nFile == fileNumber) {
             pindex->nStatus &= ~BLOCK_HAVE_DATA;
@@ -3895,12 +3890,12 @@ void PruneOneBlockFile(const int fileNumber)
             // to be downloaded again in order to consider its chain, at which
             // point it would be considered as a candidate for
             // m_blocks_unlinked or setBlockIndexCandidates.
-            auto range = g_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
+            auto range = g_chainman.m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator _it = range.first;
                 range.first++;
                 if (_it->second == pindex) {
-                    g_blockman.m_blocks_unlinked.erase(_it);
+                    g_chainman.m_blockman.m_blocks_unlinked.erase(_it);
                 }
             }
         }
@@ -4137,9 +4132,11 @@ void BlockManager::Unload() {
 
 bool static LoadBlockIndexDB(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
-    if (!g_blockman.LoadBlockIndex(
-            chainparams.GetConsensus(), *pblocktree, ::ChainstateActive().setBlockIndexCandidates))
+    if (!g_chainman.m_blockman.LoadBlockIndex(
+            chainparams.GetConsensus(), *pblocktree,
+            ::ChainstateActive().setBlockIndexCandidates)) {
         return false;
+    }
 
     // Load block file info
     pblocktree->ReadLastBlockFile(nLastBlockFile);
@@ -4161,7 +4158,7 @@ bool static LoadBlockIndexDB(const CChainParams& chainparams) EXCLUSIVE_LOCKS_RE
     // 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 : g_blockman.m_block_index)
+    for (const std::pair<const uint256, CBlockIndex*>& item : g_chainman.BlockIndex())
     {
         CBlockIndex* pindex = item.second;
         if (pindex->nStatus & BLOCK_HAVE_DATA) {
@@ -4564,8 +4561,7 @@ void CChainState::UnloadBlockIndex() {
 void UnloadBlockIndex()
 {
     LOCK(cs_main);
-    ::ChainActive().SetTip(nullptr);
-    g_blockman.Unload();
+    g_chainman.Unload();
     pindexBestInvalid = nullptr;
     pindexBestHeader = nullptr;
     mempool.clear();
@@ -4578,8 +4574,6 @@ void UnloadBlockIndex()
         warningcache[b].clear();
     }
     fHavePruned = false;
-
-    ::ChainstateActive().UnloadBlockIndex();
 }
 
 bool LoadBlockIndex(const CChainParams& chainparams)
@@ -4589,7 +4583,7 @@ bool LoadBlockIndex(const CChainParams& chainparams)
     if (!fReindex) {
         bool ret = LoadBlockIndexDB(chainparams);
         if (!ret) return false;
-        needs_init = g_blockman.m_block_index.empty();
+        needs_init = g_chainman.m_blockman.m_block_index.empty();
     }
 
     if (needs_init) {
@@ -5135,10 +5129,10 @@ public:
     CMainCleanup() {}
     ~CMainCleanup() {
         // block headers
-        BlockMap::iterator it1 = g_blockman.m_block_index.begin();
-        for (; it1 != g_blockman.m_block_index.end(); it1++)
+        BlockMap::iterator it1 = g_chainman.BlockIndex().begin();
+        for (; it1 != g_chainman.BlockIndex().end(); it1++)
             delete (*it1).second;
-        g_blockman.m_block_index.clear();
+        g_chainman.BlockIndex().clear();
     }
 };
 static CMainCleanup instance_of_cmaincleanup;
@@ -5176,7 +5170,7 @@ CChainState& ChainstateManager::InitializeChainstate(const uint256& snapshot_blo
         throw std::logic_error("should not be overwriting a chainstate");
     }
 
-    to_modify.reset(new CChainState(snapshot_blockhash));
+    to_modify.reset(new CChainState(m_blockman, snapshot_blockhash));
 
     // Snapshot chainstates and initial IBD chaintates always become active.
     if (is_snapshot || (!is_snapshot && !m_active_chainstate)) {
@@ -5220,6 +5214,8 @@ void ChainstateManager::Unload()
         chainstate->m_chain.SetTip(nullptr);
         chainstate->UnloadBlockIndex();
     }
+
+    m_blockman.Unload();
 }
 
 void ChainstateManager::Reset()