refactor: Add lock annotations to Active* methods

This is a refactor, putting the burden to think about thread safety to
the caller. Otherwise, there is a risk that the caller will assume
thread safety where none exists, as is evident in the previous two
commits.

Author: MacroFake

src/bitcoin-chainstate.cpp

@@ -115,12 +115,14 @@ int main(int argc, char* argv[])
     // Main program logic starts here
     std::cout
         << "Hello! I'm going to print out some information about your datadir." << std::endl
-        << "\t" << "Path: " << gArgs.GetDataDirNet() << std::endl
+        << "\t" << "Path: " << gArgs.GetDataDirNet() << std::endl;
+    {
+        LOCK(chainman.GetMutex());
+        std::cout
         << "\t" << "Reindexing: " << std::boolalpha << node::fReindex.load() << std::noboolalpha << std::endl
         << "\t" << "Snapshot Active: " << std::boolalpha << chainman.IsSnapshotActive() << std::noboolalpha << std::endl
         << "\t" << "Active Height: " << chainman.ActiveHeight() << std::endl
         << "\t" << "Active IBD: " << std::boolalpha << chainman.ActiveChainstate().IsInitialBlockDownload() << std::noboolalpha << std::endl;
-    {
         CBlockIndex* tip = chainman.ActiveTip();
         if (tip) {
             std::cout << "\t" << tip->ToString() << std::endl;

src/init.cpp

@@ -1547,7 +1547,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     // Either install a handler to notify us when genesis activates, or set fHaveGenesis directly.
     // No locking, as this happens before any background thread is started.
     boost::signals2::connection block_notify_genesis_wait_connection;
-    if (chainman.ActiveChain().Tip() == nullptr) {
+    if (WITH_LOCK(chainman.GetMutex(), return chainman.ActiveChain().Tip() == nullptr)) {
         block_notify_genesis_wait_connection = uiInterface.NotifyBlockTip_connect(std::bind(BlockNotifyGenesisWait, std::placeholders::_2));
     } else {
         fHaveGenesis = true;

src/net_processing.cpp

@@ -2510,7 +2510,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer,
     // Consider fetching more headers.
     if (nCount == MAX_HEADERS_RESULTS) {
         // Headers message had its maximum size; the peer may have more headers.
-        if (MaybeSendGetHeaders(pfrom, m_chainman.ActiveChain().GetLocator(pindexLast), peer)) {
+        if (MaybeSendGetHeaders(pfrom, WITH_LOCK(m_chainman.GetMutex(), return m_chainman.ActiveChain().GetLocator(pindexLast)), peer)) {
             LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
                     pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height);
         }

src/qt/test/wallettests.cpp

@@ -175,14 +175,14 @@ void TestGUI(interfaces::Node& node)
         if (!wallet->AddWalletDescriptor(w_desc, provider, "", false)) assert(false);
         CTxDestination dest = GetDestinationForKey(test.coinbaseKey.GetPubKey(), wallet->m_default_address_type);
         wallet->SetAddressBook(dest, "", "receive");
-        wallet->SetLastBlockProcessed(105, node.context()->chainman->ActiveChain().Tip()->GetBlockHash());
+        wallet->SetLastBlockProcessed(105, WITH_LOCK(node.context()->chainman->GetMutex(), return node.context()->chainman->ActiveChain().Tip()->GetBlockHash()));
     }
     {
         WalletRescanReserver reserver(*wallet);
         reserver.reserve();
         CWallet::ScanResult result = wallet->ScanForWalletTransactions(Params().GetConsensus().hashGenesisBlock, /*start_height=*/0, /*max_height=*/{}, reserver, /*fUpdate=*/true, /*save_progress=*/false);
         QCOMPARE(result.status, CWallet::ScanResult::SUCCESS);
-        QCOMPARE(result.last_scanned_block, node.context()->chainman->ActiveChain().Tip()->GetBlockHash());
+        QCOMPARE(result.last_scanned_block, WITH_LOCK(node.context()->chainman->GetMutex(), return node.context()->chainman->ActiveChain().Tip()->GetBlockHash()));
         QVERIFY(result.last_failed_block.IsNull());
     }
     wallet->SetBroadcastTransactions(true);

src/test/interfaces_tests.cpp

@@ -17,6 +17,7 @@ BOOST_FIXTURE_TEST_SUITE(interfaces_tests, TestChain100Setup)
 
 BOOST_AUTO_TEST_CASE(findBlock)
 {
+    LOCK(Assert(m_node.chainman)->GetMutex());
     auto& chain = m_node.chain;
     const CChain& active = Assert(m_node.chainman)->ActiveChain();
 
@@ -61,6 +62,7 @@ BOOST_AUTO_TEST_CASE(findBlock)
 
 BOOST_AUTO_TEST_CASE(findFirstBlockWithTimeAndHeight)
 {
+    LOCK(Assert(m_node.chainman)->GetMutex());
     auto& chain = m_node.chain;
     const CChain& active = Assert(m_node.chainman)->ActiveChain();
     uint256 hash;
@@ -73,6 +75,7 @@ BOOST_AUTO_TEST_CASE(findFirstBlockWithTimeAndHeight)
 
 BOOST_AUTO_TEST_CASE(findAncestorByHeight)
 {
+    LOCK(Assert(m_node.chainman)->GetMutex());
     auto& chain = m_node.chain;
     const CChain& active = Assert(m_node.chainman)->ActiveChain();
     uint256 hash;
@@ -83,6 +86,7 @@ BOOST_AUTO_TEST_CASE(findAncestorByHeight)
 
 BOOST_AUTO_TEST_CASE(findAncestorByHash)
 {
+    LOCK(Assert(m_node.chainman)->GetMutex());
     auto& chain = m_node.chain;
     const CChain& active = Assert(m_node.chainman)->ActiveChain();
     int height = -1;
@@ -94,7 +98,7 @@ BOOST_AUTO_TEST_CASE(findAncestorByHash)
 BOOST_AUTO_TEST_CASE(findCommonAncestor)
 {
     auto& chain = m_node.chain;
-    const CChain& active = Assert(m_node.chainman)->ActiveChain();
+    const CChain& active = WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return Assert(m_node.chainman)->ActiveChain());
     auto* orig_tip = active.Tip();
     for (int i = 0; i < 10; ++i) {
         BlockValidationState state;

src/test/validation_block_tests.cpp

@@ -234,7 +234,7 @@ BOOST_AUTO_TEST_CASE(mempool_locks_reorg)
 
     // Run the test multiple times
     for (int test_runs = 3; test_runs > 0; --test_runs) {
-        BOOST_CHECK_EQUAL(last_mined->GetHash(), m_node.chainman->ActiveChain().Tip()->GetBlockHash());
+        BOOST_CHECK_EQUAL(last_mined->GetHash(), WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain().Tip()->GetBlockHash()));
 
         // Later on split from here
         const uint256 split_hash{last_mined->hashPrevBlock};
@@ -316,7 +316,7 @@ BOOST_AUTO_TEST_CASE(mempool_locks_reorg)
             ProcessBlock(b);
         }
         // Check that the reorg was eventually successful
-        BOOST_CHECK_EQUAL(last_mined->GetHash(), m_node.chainman->ActiveChain().Tip()->GetBlockHash());
+        BOOST_CHECK_EQUAL(last_mined->GetHash(), WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain().Tip()->GetBlockHash()));
 
         // We can join the other thread, which returns when the reorg was successful
         rpc_thread.join();
@@ -325,6 +325,7 @@ BOOST_AUTO_TEST_CASE(mempool_locks_reorg)
 
 BOOST_AUTO_TEST_CASE(witness_commitment_index)
 {
+    LOCK(Assert(m_node.chainman)->GetMutex());
     CScript pubKey;
     pubKey << 1 << OP_TRUE;
     auto ptemplate = BlockAssembler{m_node.chainman->ActiveChainstate(), m_node.mempool.get()}.CreateNewBlock(pubKey);

src/test/validation_chainstatemanager_tests.cpp

@@ -49,12 +49,12 @@ BOOST_AUTO_TEST_CASE(chainstatemanager)
     auto all = manager.GetAll();
     BOOST_CHECK_EQUAL_COLLECTIONS(all.begin(), all.end(), chainstates.begin(), chainstates.end());
 
-    auto& active_chain = manager.ActiveChain();
+    auto& active_chain = WITH_LOCK(manager.GetMutex(), return manager.ActiveChain());
     BOOST_CHECK_EQUAL(&active_chain, &c1.m_chain);
 
-    BOOST_CHECK_EQUAL(manager.ActiveHeight(), -1);
+    BOOST_CHECK_EQUAL(WITH_LOCK(manager.GetMutex(), return manager.ActiveHeight()), -1);
 
-    auto active_tip = manager.ActiveTip();
+    auto active_tip = WITH_LOCK(manager.GetMutex(), return manager.ActiveTip());
     auto exp_tip = c1.m_chain.Tip();
     BOOST_CHECK_EQUAL(active_tip, exp_tip);
 
@@ -84,12 +84,12 @@ BOOST_AUTO_TEST_CASE(chainstatemanager)
     auto all2 = manager.GetAll();
     BOOST_CHECK_EQUAL_COLLECTIONS(all2.begin(), all2.end(), chainstates.begin(), chainstates.end());
 
-    auto& active_chain2 = manager.ActiveChain();
+    auto& active_chain2 = WITH_LOCK(manager.GetMutex(), return manager.ActiveChain());
     BOOST_CHECK_EQUAL(&active_chain2, &c2.m_chain);
 
-    BOOST_CHECK_EQUAL(manager.ActiveHeight(), 0);
+    BOOST_CHECK_EQUAL(WITH_LOCK(manager.GetMutex(), return manager.ActiveHeight()), 0);
 
-    auto active_tip2 = manager.ActiveTip();
+    auto active_tip2 = WITH_LOCK(manager.GetMutex(), return manager.ActiveTip());
     auto exp_tip2 = c2.m_chain.Tip();
     BOOST_CHECK_EQUAL(active_tip2, exp_tip2);
 
@@ -236,7 +236,7 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager_activate_snapshot, TestChain100Setup)
     BOOST_CHECK(WITH_LOCK(::cs_main, return !chainman.ActiveChain().Genesis()->IsAssumedValid()));
 
     const AssumeutxoData& au_data = *ExpectedAssumeutxo(snapshot_height, ::Params());
-    const CBlockIndex* tip = chainman.ActiveTip();
+    const CBlockIndex* tip = WITH_LOCK(chainman.GetMutex(), return chainman.ActiveTip());
 
     BOOST_CHECK_EQUAL(tip->nChainTx, au_data.nChainTx);
 
@@ -335,7 +335,7 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager_loadblockindex, TestChain100Setup)
     const int assumed_valid_start_idx = last_assumed_valid_idx - expected_assumed_valid;
 
     CBlockIndex* validated_tip{nullptr};
-    CBlockIndex* assumed_tip{chainman.ActiveChain().Tip()};
+    CBlockIndex* assumed_tip{WITH_LOCK(chainman.GetMutex(), return chainman.ActiveChain().Tip())};
 
     auto reload_all_block_indexes = [&]() {
         for (CChainState* cs : chainman.GetAll()) {

src/validation.h

@@ -951,9 +951,9 @@ class ChainstateManager
 
     //! The most-work chain.
     CChainState& ActiveChainstate() const;
-    CChain& ActiveChain() const { return ActiveChainstate().m_chain; }
-    int ActiveHeight() const { return ActiveChain().Height(); }
-    CBlockIndex* ActiveTip() const { return ActiveChain().Tip(); }
+    CChain& ActiveChain() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChainstate().m_chain; }
+    int ActiveHeight() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChain().Height(); }
+    CBlockIndex* ActiveTip() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChain().Tip(); }
 
     node::BlockMap& BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {

src/wallet/test/availablecoins_tests.cpp

@@ -44,6 +44,7 @@ class AvailableCoinsTestingSetup : public TestChain100Setup
         CreateAndProcessBlock({CMutableTransaction(blocktx)}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
 
         LOCK(wallet->cs_wallet);
+        LOCK(m_node.chainman->GetMutex());
         wallet->SetLastBlockProcessed(wallet->GetLastBlockHeight() + 1, m_node.chainman->ActiveChain().Tip()->GetBlockHash());
         auto it = wallet->mapWallet.find(tx->GetHash());
         BOOST_CHECK(it != wallet->mapWallet.end());

src/wallet/test/spend_tests.cpp

@@ -18,7 +18,7 @@ BOOST_FIXTURE_TEST_SUITE(spend_tests, WalletTestingSetup)
 BOOST_FIXTURE_TEST_CASE(SubtractFee, TestChain100Setup)
 {
     CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
-    auto wallet = CreateSyncedWallet(*m_node.chain, m_node.chainman->ActiveChain(), m_args, coinbaseKey);
+    auto wallet = CreateSyncedWallet(*m_node.chain, WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain()), m_args, coinbaseKey);
 
     // Check that a subtract-from-recipient transaction slightly less than the
     // coinbase input amount does not create a change output (because it would