Merge #16443: refactor: have CCoins* data managed under CChainState

582d2cd74754d6b9a2394616a9c82a89d2d71976 Cover UTXO set access with lock annotations (James O'Beirne)
569353068568444a25b301bbd6513bb510157dc9 refactor: have CCoins* data managed under CChainState (James O'Beirne)
fae6ab6aed3b9fdc9201bb19a307dfc3d9b89891 refactor: pcoinsTip -> CChainState::CoinsTip() (James O'Beirne)

Pull request description:

  This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):

  Parent PR: #15606
  Issue: #15605
  Specification: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal

  ---

  This change encapsulates UTXO set data within CChainState instances, removing global data `pcoinsTip` and `pcoinsviewdb`. This is necessary if we want to maintain multiple chainstates with their own rendering of the UTXO set.

  We introduce a class CoinsViews which consolidates the construction of a CCoins* hierarchy.

  This commit could be broken into smaller pieces, but it would require more ephemeral diffs to, e.g., temporarily change CCoinsViewDB's constructor invocations.

ACKs for top commit:
  Sjors:
    reACK 582d2cd74754d6b9a2394616a9c82a89d2d71976
  MarcoFalke:
    ACK 582d2cd747

Tree-SHA512: ec9d904fe5dca8cd2dc4b7916daa5d8bab30856dd4645987300f905e0a19f9919fce4f9d1ff03eda982943ca73e6e9a746be6cf53b46510de36e8c81a1eafba1

16 files changed, 246 insertions, 99 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 25c964205a..8870f379fb 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -15,7 +15,6 @@
 #include <blockfilter.h>
 #include <chain.h>
 #include <chainparams.h>
-#include <coins.h>
 #include <compat/sanity.h>
 #include <consensus/validation.h>
 #include <fs.h>
@@ -150,7 +149,6 @@ NODISCARD static bool CreatePidFile()
 // shutdown thing.
 //
 
-static std::unique_ptr<CCoinsViewErrorCatcher> pcoinscatcher;
 static std::unique_ptr<ECCVerifyHandle> globalVerifyHandle;
 
 static boost::thread_group threadGroup;
@@ -235,8 +233,14 @@ void Shutdown(InitInterfaces& interfaces)
     }
 
     // FlushStateToDisk generates a ChainStateFlushed callback, which we should avoid missing
-    if (pcoinsTip != nullptr) {
-        ::ChainstateActive().ForceFlushStateToDisk();
+    //
+    // g_chainstate is referenced here directly (instead of ::ChainstateActive()) because it
+    // may not have been initialized yet.
+    {
+        LOCK(cs_main);
+        if (g_chainstate && g_chainstate->CanFlushToDisk()) {
+            g_chainstate->ForceFlushStateToDisk();
+        }
     }
 
     // After there are no more peers/RPC left to give us new data which may generate
@@ -251,12 +255,10 @@ void Shutdown(InitInterfaces& interfaces)
 
     {
         LOCK(cs_main);
-        if (pcoinsTip != nullptr) {
-            ::ChainstateActive().ForceFlushStateToDisk();
+        if (g_chainstate && g_chainstate->CanFlushToDisk()) {
+            g_chainstate->ForceFlushStateToDisk();
+            g_chainstate->ResetCoinsViews();
         }
-        pcoinsTip.reset();
-        pcoinscatcher.reset();
-        pcoinsdbview.reset();
         pblocktree.reset();
     }
     for (const auto& client : interfaces.chain_clients) {
@@ -1467,10 +1469,10 @@ bool AppInitMain(InitInterfaces& interfaces)
             bool is_coinsview_empty;
             try {
                 LOCK(cs_main);
+                // This statement makes ::ChainstateActive() usable.
+                g_chainstate = MakeUnique<CChainState>();
                 UnloadBlockIndex();
-                pcoinsTip.reset();
-                pcoinsdbview.reset();
-                pcoinscatcher.reset();
+
                 // new CBlockTreeDB tries to delete the existing file, which
                 // fails if it's still open from the previous loop. Close it first:
                 pblocktree.reset();
@@ -1521,9 +1523,12 @@ bool AppInitMain(InitInterfaces& interfaces)
                 // At this point we're either in reindex or we've loaded a useful
                 // block tree into BlockIndex()!
 
-                pcoinsdbview.reset(new CCoinsViewDB(nCoinDBCache, false, fReset || fReindexChainState));
-                pcoinscatcher.reset(new CCoinsViewErrorCatcher(pcoinsdbview.get()));
-                pcoinscatcher->AddReadErrCallback([]() {
+                ::ChainstateActive().InitCoinsDB(
+                    /* cache_size_bytes */ nCoinDBCache,
+                    /* in_memory */ false,
+                    /* should_wipe */ fReset || fReindexChainState);
+
+                ::ChainstateActive().CoinsErrorCatcher().AddReadErrCallback([]() {
                     uiInterface.ThreadSafeMessageBox(
                         _("Error reading from database, shutting down.").translated,
                         "", CClientUIInterface::MSG_ERROR);
@@ -1531,23 +1536,25 @@ bool AppInitMain(InitInterfaces& interfaces)
 
                 // If necessary, upgrade from older database format.
                 // This is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
-                if (!pcoinsdbview->Upgrade()) {
+                if (!::ChainstateActive().CoinsDB().Upgrade()) {
                     strLoadError = _("Error upgrading chainstate database").translated;
                     break;
                 }
 
                 // ReplayBlocks is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
-                if (!ReplayBlocks(chainparams, pcoinsdbview.get())) {
+                if (!ReplayBlocks(chainparams, &::ChainstateActive().CoinsDB())) {
                     strLoadError = _("Unable to replay blocks. You will need to rebuild the database using -reindex-chainstate.").translated;
                     break;
                 }
 
                 // The on-disk coinsdb is now in a good state, create the cache
-                pcoinsTip.reset(new CCoinsViewCache(pcoinscatcher.get()));
+                ::ChainstateActive().InitCoinsCache();
+                assert(::ChainstateActive().CanFlushToDisk());
 
-                is_coinsview_empty = fReset || fReindexChainState || pcoinsTip->GetBestBlock().IsNull();
+                is_coinsview_empty = fReset || fReindexChainState ||
+                    ::ChainstateActive().CoinsTip().GetBestBlock().IsNull();
                 if (!is_coinsview_empty) {
-                    // LoadChainTip sets ::ChainActive() based on pcoinsTip's best block
+                    // LoadChainTip sets ::ChainActive() based on CoinsTip()'s best block
                     if (!LoadChainTip(chainparams)) {
                         strLoadError = _("Error initializing block database").translated;
                         break;
@@ -1589,7 +1596,7 @@ bool AppInitMain(InitInterfaces& interfaces)
                         break;
                     }
 
-                    if (!CVerifyDB().VerifyDB(chainparams, pcoinsdbview.get(), gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
+                    if (!CVerifyDB().VerifyDB(chainparams, &::ChainstateActive().CoinsDB(), gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
                                   gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS))) {
                         strLoadError = _("Corrupted block database detected").translated;
                         break;
diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
index bcd226edd9..fc49817502 100644
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -232,7 +232,7 @@ public:
     bool getUnspentOutput(const COutPoint& output, Coin& coin) override
     {
         LOCK(::cs_main);
-        return ::pcoinsTip->GetCoin(output, coin);
+        return ::ChainstateActive().CoinsTip().GetCoin(output, coin);
     }
     std::string getWalletDir() override
     {
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 3db460d444..520dfcbb66 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1291,11 +1291,12 @@ bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
                 LOCK(g_cs_orphans);
                 if (mapOrphanTransactions.count(inv.hash)) return true;
             }
+            const CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip();
 
             return recentRejects->contains(inv.hash) ||
                    mempool.exists(inv.hash) ||
-                   pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 0)) || // Best effort: only try output 0 and 1
-                   pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 1));
+                   coins_cache.HaveCoinInCache(COutPoint(inv.hash, 0)) || // Best effort: only try output 0 and 1
+                   coins_cache.HaveCoinInCache(COutPoint(inv.hash, 1));
         }
     case MSG_BLOCK:
     case MSG_WITNESS_BLOCK:
@@ -1844,7 +1845,7 @@ void static ProcessOrphanTx(CConnman* connman, std::set<uint256>& orphan_work_se
             EraseOrphanTx(orphanHash);
             done = true;
         }
-        mempool.check(pcoinsTip.get());
+        mempool.check(&::ChainstateActive().CoinsTip());
     }
 }
 
@@ -2497,7 +2498,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
 
         if (!AlreadyHave(inv) &&
             AcceptToMemoryPool(mempool, state, ptx, &fMissingInputs, &lRemovedTxn, false /* bypass_limits */, 0 /* nAbsurdFee */)) {
-            mempool.check(pcoinsTip.get());
+            mempool.check(&::ChainstateActive().CoinsTip());
             RelayTransaction(tx.GetHash(), *connman);
             for (unsigned int i = 0; i < tx.vout.size(); i++) {
                 auto it_by_prev = mapOrphanTransactionsByPrev.find(COutPoint(inv.hash, i));
diff --git a/src/node/coin.cpp b/src/node/coin.cpp
index bb98e63f3a..ad8d1d3af4 100644
--- a/src/node/coin.cpp
+++ b/src/node/coin.cpp
@@ -10,8 +10,7 @@
 void FindCoins(std::map<COutPoint, Coin>& coins)
 {
     LOCK2(cs_main, ::mempool.cs);
-    assert(pcoinsTip);
-    CCoinsViewCache& chain_view = *::pcoinsTip;
+    CCoinsViewCache& chain_view = ::ChainstateActive().CoinsTip();
     CCoinsViewMemPool mempool_view(&chain_view, ::mempool);
     for (auto& coin : coins) {
         if (!mempool_view.GetCoin(coin.first, coin.second)) {
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index a28136a8e8..7e8291ddc8 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -28,7 +28,7 @@ TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err
     LOCK(cs_main);
     // If the transaction is already confirmed in the chain, don't do anything
     // and return early.
-    CCoinsViewCache &view = *pcoinsTip;
+    CCoinsViewCache &view = ::ChainstateActive().CoinsTip();
     for (size_t o = 0; o < tx->vout.size(); o++) {
         const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o));
         // IsSpent doesnt mean the coin is spent, it means the output doesnt' exist.
diff --git a/src/rest.cpp b/src/rest.cpp
index eba7aae50f..2c4d475542 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -503,12 +503,12 @@ static bool rest_getutxos(HTTPRequest* req, const std::string& strURIPart)
         if (fCheckMemPool) {
             // use db+mempool as cache backend in case user likes to query mempool
             LOCK2(cs_main, mempool.cs);
-            CCoinsViewCache& viewChain = *pcoinsTip;
+            CCoinsViewCache& viewChain = ::ChainstateActive().CoinsTip();
             CCoinsViewMemPool viewMempool(&viewChain, mempool);
             process_utxos(viewMempool, mempool);
         } else {
             LOCK(cs_main);  // no need to lock mempool!
-            process_utxos(*pcoinsTip, CTxMemPool());
+            process_utxos(::ChainstateActive().CoinsTip(), CTxMemPool());
         }
 
         for (size_t i = 0; i < hits.size(); ++i) {
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index b7dcd59c6d..e3d5394a2c 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1062,7 +1062,9 @@ static UniValue gettxoutsetinfo(const JSONRPCRequest& request)
 
     CCoinsStats stats;
     ::ChainstateActive().ForceFlushStateToDisk();
-    if (GetUTXOStats(pcoinsdbview.get(), stats)) {
+
+    CCoinsView* coins_view = WITH_LOCK(cs_main, return &ChainstateActive().CoinsDB());
+    if (GetUTXOStats(coins_view, stats)) {
         ret.pushKV("height", (int64_t)stats.nHeight);
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
         ret.pushKV("transactions", (int64_t)stats.nTransactions);
@@ -1126,19 +1128,21 @@ UniValue gettxout(const JSONRPCRequest& request)
         fMempool = request.params[2].get_bool();
 
     Coin coin;
+    CCoinsViewCache* coins_view = &::ChainstateActive().CoinsTip();
+
     if (fMempool) {
         LOCK(mempool.cs);
-        CCoinsViewMemPool view(pcoinsTip.get(), mempool);
+        CCoinsViewMemPool view(coins_view, mempool);
         if (!view.GetCoin(out, coin) || mempool.isSpent(out)) {
             return NullUniValue;
         }
     } else {
-        if (!pcoinsTip->GetCoin(out, coin)) {
+        if (!coins_view->GetCoin(out, coin)) {
             return NullUniValue;
         }
     }
 
-    const CBlockIndex* pindex = LookupBlockIndex(pcoinsTip->GetBestBlock());
+    const CBlockIndex* pindex = LookupBlockIndex(coins_view->GetBestBlock());
     ret.pushKV("bestblock", pindex->GetBlockHash().GetHex());
     if (coin.nHeight == MEMPOOL_HEIGHT) {
         ret.pushKV("confirmations", 0);
@@ -1180,7 +1184,8 @@ static UniValue verifychain(const JSONRPCRequest& request)
     if (!request.params[1].isNull())
         nCheckDepth = request.params[1].get_int();
 
-    return CVerifyDB().VerifyDB(Params(), pcoinsTip.get(), nCheckLevel, nCheckDepth);
+    return CVerifyDB().VerifyDB(
+        Params(), &::ChainstateActive().CoinsTip(), nCheckLevel, nCheckDepth);
 }
 
 /** Implementation of IsSuperMajority with better feedback */
@@ -2203,7 +2208,7 @@ UniValue scantxoutset(const JSONRPCRequest& request)
         {
             LOCK(cs_main);
             ::ChainstateActive().ForceFlushStateToDisk();
-            pcursor = std::unique_ptr<CCoinsViewCursor>(pcoinsdbview->Cursor());
+            pcursor = std::unique_ptr<CCoinsViewCursor>(::ChainstateActive().CoinsDB().Cursor());
             assert(pcursor);
         }
         bool res = FindScriptPubKey(g_scan_progress, g_should_abort_scan, count, pcursor.get(), needles, coins);
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 966c159f0f..ffbad45714 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -259,7 +259,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
 
         // Loop through txids and try to find which block they're in. Exit loop once a block is found.
         for (const auto& tx : setTxids) {
-            const Coin& coin = AccessByTxid(*pcoinsTip, tx);
+            const Coin& coin = AccessByTxid(::ChainstateActive().CoinsTip(), tx);
             if (!coin.IsSpent()) {
                 pblockindex = ::ChainActive()[coin.nHeight];
                 break;
@@ -636,7 +636,7 @@ static UniValue combinerawtransaction(const JSONRPCRequest& request)
     {
         LOCK(cs_main);
         LOCK(mempool.cs);
-        CCoinsViewCache &viewChain = *pcoinsTip;
+        CCoinsViewCache &viewChain = ::ChainstateActive().CoinsTip();
         CCoinsViewMemPool viewMempool(&viewChain, mempool);
         view.SetBackend(viewMempool); // temporarily switch cache backend to db+mempool view
 
@@ -1505,7 +1505,7 @@ UniValue utxoupdatepsbt(const JSONRPCRequest& request)
     CCoinsViewCache view(&viewDummy);
     {
         LOCK2(cs_main, mempool.cs);
-        CCoinsViewCache &viewChain = *pcoinsTip;
+        CCoinsViewCache &viewChain = ::ChainstateActive().CoinsTip();
         CCoinsViewMemPool viewMempool(&viewChain, mempool);
         view.SetBackend(viewMempool); // temporarily switch cache backend to db+mempool view
 
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 05d7f76983..c9661b730d 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -372,7 +372,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         CBlockIndex* prev = ::ChainActive().Tip();
         CBlockIndex* next = new CBlockIndex();
         next->phashBlock = new uint256(InsecureRand256());
-        pcoinsTip->SetBestBlock(next->GetBlockHash());
+        ::ChainstateActive().CoinsTip().SetBestBlock(next->GetBlockHash());
         next->pprev = prev;
         next->nHeight = prev->nHeight + 1;
         next->BuildSkip();
@@ -384,7 +384,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         CBlockIndex* prev = ::ChainActive().Tip();
         CBlockIndex* next = new CBlockIndex();
         next->phashBlock = new uint256(InsecureRand256());
-        pcoinsTip->SetBestBlock(next->GetBlockHash());
+        ::ChainstateActive().CoinsTip().SetBestBlock(next->GetBlockHash());
         next->pprev = prev;
         next->nHeight = prev->nHeight + 1;
         next->BuildSkip();
@@ -414,7 +414,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     while (::ChainActive().Tip()->nHeight > nHeight) {
         CBlockIndex* del = ::ChainActive().Tip();
         ::ChainActive().SetTip(del->pprev);
-        pcoinsTip->SetBestBlock(del->pprev->GetBlockHash());
+        ::ChainstateActive().CoinsTip().SetBestBlock(del->pprev->GetBlockHash());
         delete del->phashBlock;
         delete del;
     }
diff --git a/src/test/setup_common.cpp b/src/test/setup_common.cpp
index de877fd167..0ff081e472 100644
--- a/src/test/setup_common.cpp
+++ b/src/test/setup_common.cpp
@@ -85,8 +85,12 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
 
     mempool.setSanityCheck(1.0);
     pblocktree.reset(new CBlockTreeDB(1 << 20, true));
-    pcoinsdbview.reset(new CCoinsViewDB(1 << 23, true));
-    pcoinsTip.reset(new CCoinsViewCache(pcoinsdbview.get()));
+    g_chainstate = MakeUnique<CChainState>();
+    ::ChainstateActive().InitCoinsDB(
+        /* cache_size_bytes */ 1 << 23, /* in_memory */ true, /* should_wipe */ false);
+    assert(!::ChainstateActive().CanFlushToDisk());
+    ::ChainstateActive().InitCoinsCache();
+    assert(::ChainstateActive().CanFlushToDisk());
     if (!LoadGenesisBlock(chainparams)) {
         throw std::runtime_error("LoadGenesisBlock failed.");
     }
@@ -113,8 +117,7 @@ TestingSetup::~TestingSetup()
     g_connman.reset();
     g_banman.reset();
     UnloadBlockIndex();
-    pcoinsTip.reset();
-    pcoinsdbview.reset();
+    g_chainstate.reset();
     pblocktree.reset();
 }
 
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index f99a3748c9..e69ebcc2c3 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -97,7 +97,7 @@ BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
     BOOST_CHECK_EQUAL(mempool.size(), 0U);
 }
 
-// Run CheckInputs (using pcoinsTip) on the given transaction, for all script
+// Run CheckInputs (using CoinsTip()) on the given transaction, for all script
 // flags.  Test that CheckInputs passes for all flags that don't overlap with
 // the failing_flags argument, but otherwise fails.
 // CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY (and future NOP codes that may
@@ -125,7 +125,7 @@ static void ValidateCheckInputsForAllFlags(const CTransaction &tx, uint32_t fail
             // WITNESS requires P2SH
             test_flags |= SCRIPT_VERIFY_P2SH;
         }
-        bool ret = CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, nullptr);
+        bool ret = CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, nullptr);
         // CheckInputs should succeed iff test_flags doesn't intersect with
         // failing_flags
         bool expected_return_value = !(test_flags & failing_flags);
@@ -135,13 +135,13 @@ static void ValidateCheckInputsForAllFlags(const CTransaction &tx, uint32_t fail
         if (ret && add_to_cache) {
             // Check that we get a cache hit if the tx was valid
             std::vector<CScriptCheck> scriptchecks;
-            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
+            BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
             BOOST_CHECK(scriptchecks.empty());
         } else {
             // Check that we get script executions to check, if the transaction
             // was invalid, or we didn't add to cache.
             std::vector<CScriptCheck> scriptchecks;
-            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
+            BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
             BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
         }
     }
@@ -204,13 +204,13 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         CValidationState state;
         PrecomputedTransactionData ptd_spend_tx(spend_tx);
 
-        BOOST_CHECK(!CheckInputs(CTransaction(spend_tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
+        BOOST_CHECK(!CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
 
         // If we call again asking for scriptchecks (as happens in
         // ConnectBlock), we should add a script check object for this -- we're
         // not caching invalidity (if that changes, delete this test case).
         std::vector<CScriptCheck> scriptchecks;
-        BOOST_CHECK(CheckInputs(CTransaction(spend_tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
+        BOOST_CHECK(CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
         BOOST_CHECK_EQUAL(scriptchecks.size(), 1U);
 
         // Test that CheckInputs returns true iff DERSIG-enforcing flags are
@@ -227,7 +227,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
     block = CreateAndProcessBlock({spend_tx}, p2pk_scriptPubKey);
     LOCK(cs_main);
     BOOST_CHECK(::ChainActive().Tip()->GetBlockHash() == block.GetHash());
-    BOOST_CHECK(pcoinsTip->GetBestBlock() == block.GetHash());
+    BOOST_CHECK(::ChainstateActive().CoinsTip().GetBestBlock() == block.GetHash());
 
     // Test P2SH: construct a transaction that is valid without P2SH, and
     // then test validity with P2SH.
@@ -272,7 +272,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         CValidationState state;
         PrecomputedTransactionData txdata(invalid_with_cltv_tx);
-        BOOST_CHECK(CheckInputs(CTransaction(invalid_with_cltv_tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
+        BOOST_CHECK(CheckInputs(CTransaction(invalid_with_cltv_tx), state, ::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
     }
 
     // TEST CHECKSEQUENCEVERIFY
@@ -300,7 +300,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         CValidationState state;
         PrecomputedTransactionData txdata(invalid_with_csv_tx);
-        BOOST_CHECK(CheckInputs(CTransaction(invalid_with_csv_tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
+        BOOST_CHECK(CheckInputs(CTransaction(invalid_with_csv_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
     }
 
     // TODO: add tests for remaining script flags
@@ -362,12 +362,12 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         CValidationState state;
         PrecomputedTransactionData txdata(tx);
         // This transaction is now invalid under segwit, because of the second input.
-        BOOST_CHECK(!CheckInputs(CTransaction(tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
+        BOOST_CHECK(!CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
 
         std::vector<CScriptCheck> scriptchecks;
         // Make sure this transaction was not cached (ie because the first
         // input was valid)
-        BOOST_CHECK(CheckInputs(CTransaction(tx), state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
+        BOOST_CHECK(CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
         // Should get 2 script checks back -- caching is on a whole-transaction basis.
         BOOST_CHECK_EQUAL(scriptchecks.size(), 2U);
     }
diff --git a/src/txdb.cpp b/src/txdb.cpp
index df9851396e..18be07e6db 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -52,7 +52,7 @@ struct CoinEntry {
 
 }
 
-CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory, bool fWipe) : db(GetDataDir() / "chainstate", nCacheSize, fMemory, fWipe, true)
+CCoinsViewDB::CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory, bool fWipe) : db(ldb_path, nCacheSize, fMemory, fWipe, true)
 {
 }
 
diff --git a/src/txdb.h b/src/txdb.h
index c4ece11503..140ce2c7ff 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -48,7 +48,10 @@ class CCoinsViewDB final : public CCoinsView
 protected:
     CDBWrapper db;
 public:
-    explicit CCoinsViewDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
+    /**
+     * @param[in] ldb_path    Location in the filesystem where leveldb data will be stored.
+     */
+    explicit CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory, bool fWipe);
 
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
     bool HaveCoin(const COutPoint &outpoint) const override;
diff --git a/src/txmempool.h b/src/txmempool.h
index 7169e80da2..6e5ba445d3 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -497,7 +497,7 @@ public:
      *
      * 1. Locking both `cs_main` and `mempool.cs` will give a view of mempool
      *    that is consistent with current chain tip (`::ChainActive()` and
-     *    `pcoinsTip`) and is fully populated. Fully populated means that if the
+     *    `CoinsTip()`) and is fully populated. Fully populated means that if the
      *    current active chain is missing transactions that were present in a
      *    previously active chain, all the missing transactions will have been
      *    re-added to the mempool and should be present if they meet size and
diff --git a/src/validation.cpp b/src/validation.cpp
index b4677df62f..8f44e2565a 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -82,11 +82,17 @@ namespace {
 BlockManager g_blockman;
 } // anon namespace
 
-static CChainState g_chainstate(g_blockman);
+std::unique_ptr<CChainState> g_chainstate;
 
-CChainState& ChainstateActive() { return g_chainstate; }
+CChainState& ChainstateActive() {
+    assert(g_chainstate);
+    return *g_chainstate;
+}
 
-CChain& ChainActive() { return g_chainstate.m_chain; }
+CChain& ChainActive() {
+    assert(g_chainstate);
+    return g_chainstate->m_chain;
+}
 
 /**
  * Mutex to guard access to validation specific variables, such as reading
@@ -173,8 +179,6 @@ CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& loc
     return chain.Genesis();
 }
 
-std::unique_ptr<CCoinsViewDB> pcoinsdbview;
-std::unique_ptr<CCoinsViewCache> pcoinsTip;
 std::unique_ptr<CBlockTreeDB> pblocktree;
 
 // See definition for documentation
@@ -260,8 +264,8 @@ bool CheckSequenceLocks(const CTxMemPool& pool, const CTransaction& tx, int flag
         lockPair.second = lp->time;
     }
     else {
-        // pcoinsTip contains the UTXO set for ::ChainActive().Tip()
-        CCoinsViewMemPool viewMemPool(pcoinsTip.get(), pool);
+        // CoinsTip() contains the UTXO set for ::ChainActive().Tip()
+        CCoinsViewMemPool viewMemPool(&::ChainstateActive().CoinsTip(), pool);
         std::vector<int> prevheights;
         prevheights.resize(tx.vin.size());
         for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
@@ -310,7 +314,8 @@ bool CheckSequenceLocks(const CTxMemPool& pool, const CTransaction& tx, int flag
 // Returns the script flags which should be checked for a given block
 static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& chainparams);
 
-static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age) EXCLUSIVE_LOCKS_REQUIRED(pool.cs)
+static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age)
+    EXCLUSIVE_LOCKS_REQUIRED(pool.cs, ::cs_main)
 {
     int expired = pool.Expire(GetTime() - age);
     if (expired != 0) {
@@ -320,7 +325,7 @@ static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age)
     std::vector<COutPoint> vNoSpendsRemaining;
     pool.TrimToSize(limit, &vNoSpendsRemaining);
     for (const COutPoint& removed : vNoSpendsRemaining)
-        pcoinsTip->Uncache(removed);
+        ::ChainstateActive().CoinsTip().Uncache(removed);
 }
 
 static bool IsCurrentForFeeEstimation() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
@@ -382,7 +387,7 @@ static void UpdateMempoolForReorg(DisconnectedBlockTransactions& disconnectpool,
     mempool.UpdateTransactionsFromBlock(vHashUpdate);
 
     // We also need to remove any now-immature transactions
-    mempool.removeForReorg(pcoinsTip.get(), ::ChainActive().Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
+    mempool.removeForReorg(&::ChainstateActive().CoinsTip(), ::ChainActive().Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
     // Re-limit mempool size, in case we added any transactions
     LimitMempoolSize(mempool, gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
 }
@@ -414,7 +419,7 @@ static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, CValidationSt
             assert(txFrom->vout.size() > txin.prevout.n);
             assert(txFrom->vout[txin.prevout.n] == coin.out);
         } else {
-            const Coin& coinFromDisk = pcoinsTip->AccessCoin(txin.prevout);
+            const Coin& coinFromDisk = ::ChainstateActive().CoinsTip().AccessCoin(txin.prevout);
             assert(!coinFromDisk.IsSpent());
             assert(coinFromDisk.out == coin.out);
         }
@@ -514,23 +519,24 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         CCoinsViewCache view(&dummy);
 
         LockPoints lp;
-        CCoinsViewMemPool viewMemPool(pcoinsTip.get(), pool);
+        CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip();
+        CCoinsViewMemPool viewMemPool(&coins_cache, pool);
         view.SetBackend(viewMemPool);
 
         // do all inputs exist?
         for (const CTxIn& txin : tx.vin) {
-            if (!pcoinsTip->HaveCoinInCache(txin.prevout)) {
+            if (!coins_cache.HaveCoinInCache(txin.prevout)) {
                 coins_to_uncache.push_back(txin.prevout);
             }
 
             // Note: this call may add txin.prevout to the coins cache
-            // (pcoinsTip.cacheCoins) by way of FetchCoin(). It should be removed
+            // (CoinsTip().cacheCoins) by way of FetchCoin(). It should be removed
             // later (via coins_to_uncache) if this tx turns out to be invalid.
             if (!view.HaveCoin(txin.prevout)) {
                 // Are inputs missing because we already have the tx?
                 for (size_t out = 0; out < tx.vout.size(); out++) {
                     // Optimistically just do efficient check of cache for outputs
-                    if (pcoinsTip->HaveCoinInCache(COutPoint(hash, out))) {
+                    if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) {
                         return state.Invalid(ValidationInvalidReason::TX_CONFLICT, false, REJECT_DUPLICATE, "txn-already-known");
                     }
                 }
@@ -860,7 +866,7 @@ static bool AcceptToMemoryPoolWithTime(const CChainParams& chainparams, CTxMemPo
         // (`CCoinsViewCache::cacheCoins`).
 
         for (const COutPoint& hashTx : coins_to_uncache)
-            pcoinsTip->Uncache(hashTx);
+            ::ChainstateActive().CoinsTip().Uncache(hashTx);
     }
     // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits
     CValidationState stateDummy;
@@ -1040,6 +1046,40 @@ CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
     return nSubsidy;
 }
 
+CoinsViews::CoinsViews(
+    std::string ldb_name,
+    size_t cache_size_bytes,
+    bool in_memory,
+    bool should_wipe) : m_dbview(
+                            GetDataDir() / ldb_name, cache_size_bytes, in_memory, should_wipe),
+                        m_catcherview(&m_dbview) {}
+
+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() : m_blockman(g_blockman) {}
+
+
+void CChainState::InitCoinsDB(
+    size_t cache_size_bytes,
+    bool in_memory,
+    bool should_wipe,
+    std::string leveldb_name)
+{
+    m_coins_views = MakeUnique<CoinsViews>(
+        leveldb_name, cache_size_bytes, in_memory, should_wipe);
+}
+
+void CChainState::InitCoinsCache()
+{
+    assert(m_coins_views != nullptr);
+    m_coins_views->InitCache();
+}
+
 // Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which
 // is a performance-related implementation detail. This function must be marked
 // `const` so that `CValidationInterface` clients (which are given a `const CChainState*`)
@@ -1981,6 +2021,7 @@ bool CChainState::FlushStateToDisk(
 {
     int64_t nMempoolUsage = mempool.DynamicMemoryUsage();
     LOCK(cs_main);
+    assert(this->CanFlushToDisk());
     static int64_t nLastWrite = 0;
     static int64_t nLastFlush = 0;
     std::set<int> setFilesToPrune;
@@ -2014,7 +2055,7 @@ bool CChainState::FlushStateToDisk(
             nLastFlush = nNow;
         }
         int64_t nMempoolSizeMax = gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
-        int64_t cacheSize = pcoinsTip->DynamicMemoryUsage();
+        int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
         int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
         // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
         bool fCacheLarge = mode == FlushStateMode::PERIODIC && cacheSize > std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE * 1024 * 1024);
@@ -2058,17 +2099,17 @@ bool CChainState::FlushStateToDisk(
             nLastWrite = nNow;
         }
         // Flush best chain related state. This can only be done if the blocks / block index write was also done.
-        if (fDoFullFlush && !pcoinsTip->GetBestBlock().IsNull()) {
+        if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
             // Typical Coin structures on disk are around 48 bytes in size.
             // Pushing a new one to the database can cause it to be written
             // twice (once in the log, and once in the tables). This is already
             // an overestimation, as most will delete an existing entry or
             // overwrite one. Still, use a conservative safety factor of 2.
-            if (!CheckDiskSpace(GetDataDir(), 48 * 2 * 2 * pcoinsTip->GetCacheSize())) {
+            if (!CheckDiskSpace(GetDataDir(), 48 * 2 * 2 * CoinsTip().GetCacheSize())) {
                 return AbortNode(state, "Disk space is too low!", _("Error: Disk space is too low!").translated, CClientUIInterface::MSG_NOPREFIX);
             }
             // Flush the chainstate (which may refer to block index entries).
-            if (!pcoinsTip->Flush())
+            if (!CoinsTip().Flush())
                 return AbortNode(state, "Failed to write to coin database");
             nLastFlush = nNow;
             full_flush_completed = true;
@@ -2120,7 +2161,9 @@ static void AppendWarning(std::string& res, const std::string& warn)
 }
 
 /** Check warning conditions and do some notifications on new chain tip set. */
-void static UpdateTip(const CBlockIndex *pindexNew, const CChainParams& chainParams) {
+void static UpdateTip(const CBlockIndex* pindexNew, const CChainParams& chainParams)
+    EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
+{
     // New best block
     mempool.AddTransactionsUpdated(1);
 
@@ -2162,7 +2205,7 @@ void static UpdateTip(const CBlockIndex *pindexNew, const CChainParams& chainPar
       pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, pindexNew->nVersion,
       log(pindexNew->nChainWork.getdouble())/log(2.0), (unsigned long)pindexNew->nChainTx,
       FormatISO8601DateTime(pindexNew->GetBlockTime()),
-      GuessVerificationProgress(chainParams.TxData(), pindexNew), pcoinsTip->DynamicMemoryUsage() * (1.0 / (1<<20)), pcoinsTip->GetCacheSize());
+      GuessVerificationProgress(chainParams.TxData(), pindexNew), ::ChainstateActive().CoinsTip().DynamicMemoryUsage() * (1.0 / (1<<20)), ::ChainstateActive().CoinsTip().GetCacheSize());
     if (!warningMessages.empty())
         LogPrintf(" warning='%s'", warningMessages); /* Continued */
     LogPrintf("\n");
@@ -2191,7 +2234,7 @@ bool CChainState::DisconnectTip(CValidationState& state, const CChainParams& cha
     // Apply the block atomically to the chain state.
     int64_t nStart = GetTimeMicros();
     {
-        CCoinsViewCache view(pcoinsTip.get());
+        CCoinsViewCache view(&CoinsTip());
         assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
         if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK)
             return error("DisconnectTip(): DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
@@ -2319,7 +2362,7 @@ bool CChainState::ConnectTip(CValidationState& state, const CChainParams& chainp
     int64_t nTime3;
     LogPrint(BCLog::BENCH, "  - Load block from disk: %.2fms [%.2fs]\n", (nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
     {
-        CCoinsViewCache view(pcoinsTip.get());
+        CCoinsViewCache view(&CoinsTip());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view, chainparams);
         GetMainSignals().BlockChecked(blockConnecting, state);
         if (!rv) {
@@ -2506,7 +2549,7 @@ bool CChainState::ActivateBestChainStep(CValidationState& state, const CChainPar
         // any disconnected transactions back to the mempool.
         UpdateMempoolForReorg(disconnectpool, true);
     }
-    mempool.check(pcoinsTip.get());
+    mempool.check(&CoinsTip());
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound)
@@ -3508,7 +3551,7 @@ bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams,
 {
     AssertLockHeld(cs_main);
     assert(pindexPrev && pindexPrev == ::ChainActive().Tip());
-    CCoinsViewCache viewNew(pcoinsTip.get());
+    CCoinsViewCache viewNew(&::ChainstateActive().CoinsTip());
     uint256 block_hash(block.GetHash());
     CBlockIndex indexDummy(block);
     indexDummy.pprev = pindexPrev;
@@ -3861,12 +3904,14 @@ bool static LoadBlockIndexDB(const CChainParams& chainparams) EXCLUSIVE_LOCKS_RE
 bool LoadChainTip(const CChainParams& chainparams)
 {
     AssertLockHeld(cs_main);
-    assert(!pcoinsTip->GetBestBlock().IsNull()); // Never called when the coins view is empty
+    const CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip();
+    assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty
 
-    if (::ChainActive().Tip() && ::ChainActive().Tip()->GetBlockHash() == pcoinsTip->GetBestBlock()) return true;
+    if (::ChainActive().Tip() &&
+        ::ChainActive().Tip()->GetBlockHash() == coins_cache.GetBestBlock()) return true;
 
     // Load pointer to end of best chain
-    CBlockIndex* pindex = LookupBlockIndex(pcoinsTip->GetBestBlock());
+    CBlockIndex* pindex = LookupBlockIndex(coins_cache.GetBestBlock());
     if (!pindex) {
         return false;
     }
@@ -3943,7 +3988,7 @@ bool CVerifyDB::VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview,
             }
         }
         // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
-        if (nCheckLevel >= 3 && (coins.DynamicMemoryUsage() + pcoinsTip->DynamicMemoryUsage()) <= nCoinCacheUsage) {
+        if (nCheckLevel >= 3 && (coins.DynamicMemoryUsage() + ::ChainstateActive().CoinsTip().DynamicMemoryUsage()) <= nCoinCacheUsage) {
             assert(coins.GetBestBlock() == pindex->GetBlockHash());
             DisconnectResult res = ::ChainstateActive().DisconnectBlock(block, pindex, coins);
             if (res == DISCONNECT_FAILED) {
diff --git a/src/validation.h b/src/validation.h
index d747fdbf27..65f86e3070 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -19,6 +19,7 @@
 #include <script/script_error.h>
 #include <sync.h>
 #include <txmempool.h> // For CTxMemPool::cs
+#include <txdb.h>
 #include <versionbits.h>
 
 #include <algorithm>
@@ -37,7 +38,6 @@ class CBlockIndex;
 class CBlockTreeDB;
 class CBlockUndo;
 class CChainParams;
-class CCoinsViewDB;
 class CInv;
 class CConnman;
 class CScriptCheck;
@@ -506,6 +506,41 @@ public:
 };
 
 /**
+ * A convenience class for constructing the CCoinsView* hierarchy used
+ * to facilitate access to the UTXO set.
+ *
+ * This class consists of an arrangement of layered CCoinsView objects,
+ * preferring to store and retrieve coins in memory via `m_cacheview` but
+ * ultimately falling back on cache misses to the canonical store of UTXOs on
+ * disk, `m_dbview`.
+ */
+class CoinsViews {
+
+public:
+    //! The lowest level of the CoinsViews cache hierarchy sits in a leveldb database on disk.
+    //! All unspent coins reside in this store.
+    CCoinsViewDB m_dbview GUARDED_BY(cs_main);
+
+    //! This view wraps access to the leveldb instance and handles read errors gracefully.
+    CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main);
+
+    //! This is the top layer of the cache hierarchy - it keeps as many coins in memory as
+    //! can fit per the dbcache setting.
+    std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main);
+
+    //! This constructor initializes CCoinsViewDB and CCoinsViewErrorCatcher instances, but it
+    //! *does not* create a CCoinsViewCache instance by default. This is done separately because the
+    //! presence of the cache has implications on whether or not we're allowed to flush the cache's
+    //! state to disk, which should not be done until the health of the database is verified.
+    //!
+    //! All arguments forwarded onto CCoinsViewDB.
+    CoinsViews(std::string ldb_name, size_t cache_size_bytes, bool in_memory, bool should_wipe);
+
+    //! Initialize the CCoinsViewCache member.
+    void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+};
+
+/**
  * CChainState stores and provides an API to update our local knowledge of the
  * current best chain.
  *
@@ -553,12 +588,39 @@ private:
     //! easily as opposed to referencing a global.
     BlockManager& m_blockman;
 
+    //! Manages the UTXO set, which is a reflection of the contents of `m_chain`.
+    std::unique_ptr<CoinsViews> m_coins_views;
+
 public:
-    CChainState(BlockManager& blockman) : m_blockman(blockman) { }
+    CChainState(BlockManager& blockman) : m_blockman(blockman) {}
+    CChainState();
+
+    /**
+     * Initialize the CoinsViews UTXO set database management data structures. The in-memory
+     * cache is initialized separately.
+     *
+     * All parameters forwarded to CoinsViews.
+     */
+    void InitCoinsDB(
+        size_t cache_size_bytes,
+        bool in_memory,
+        bool should_wipe,
+        std::string leveldb_name = "chainstate");
+
+    //! Initialize the in-memory coins cache (to be done after the health of the on-disk database
+    //! is verified).
+    void InitCoinsCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+
+    //! @returns whether or not the CoinsViews object has been fully initialized and we can
+    //!          safely flush this object to disk.
+    bool CanFlushToDisk() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
+        return m_coins_views && m_coins_views->m_cacheview;
+    }
 
     //! The current chain of blockheaders we consult and build on.
     //! @see CChain, CBlockIndex.
     CChain m_chain;
+
     /**
      * The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for itself and all ancestors) and
      * as good as our current tip or better. Entries may be failed, though, and pruning nodes may be
@@ -566,6 +628,29 @@ public:
      */
     std::set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexCandidates;
 
+    //! @returns A reference to the in-memory cache of the UTXO set.
+    CCoinsViewCache& CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+    {
+        assert(m_coins_views->m_cacheview);
+        return *m_coins_views->m_cacheview.get();
+    }
+
+    //! @returns A reference to the on-disk UTXO set database.
+    CCoinsViewDB& CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+    {
+        return m_coins_views->m_dbview;
+    }
+
+    //! @returns A reference to a wrapped view of the in-memory UTXO set that
+    //!     handles disk read errors gracefully.
+    CCoinsViewErrorCatcher& CoinsErrorCatcher() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+    {
+        return m_coins_views->m_catcherview;
+    }
+
+    //! Destructs all objects related to accessing the UTXO set.
+    void ResetCoinsViews() { m_coins_views.reset(); }
+
     /**
      * Update the on-disk chain state.
      * The caches and indexes are flushed depending on the mode we're called with
@@ -597,7 +682,7 @@ public:
     bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex,
                       CCoinsViewCache& view, const CChainParams& chainparams, bool fJustCheck = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-    // Block disconnection on our pcoinsTip:
+    // Apply the effects of a block disconnection on the UTXO set.
     bool DisconnectTip(CValidationState& state, const CChainParams& chainparams, DisconnectedBlockTransactions* disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs);
 
     // Manual block validity manipulation:
@@ -659,11 +744,10 @@ CChain& ChainActive();
 /** @returns the global block index map. */
 BlockMap& BlockIndex();
 
-/** Global variable that points to the coins database (protected by cs_main) */
-extern std::unique_ptr<CCoinsViewDB> pcoinsdbview;
-
-/** Global variable that points to the active CCoinsView (protected by cs_main) */
-extern std::unique_ptr<CCoinsViewCache> pcoinsTip;
+// Most often ::ChainstateActive() should be used instead of this, but some code
+// may not be able to assume that this has been initialized yet and so must use it
+// directly, e.g. init.cpp.
+extern std::unique_ptr<CChainState> g_chainstate;
 
 /** Global variable that points to the active block tree (protected by cs_main) */
 extern std::unique_ptr<CBlockTreeDB> pblocktree;