test: add basic tests for ChainstateManager

Summary:
Partial backport (4/5) of core [[bitcoin/bitcoin#17737 | PR17737]]:
bitcoin/bitcoin@2b081c4

Depends on D8539.

Test Plan:
  ninja check

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D8540

src/test/CMakeLists.txt

@@ -213,6 +213,7 @@ add_boost_unit_tests_to_suite(bitcoin test_bitcoin
 		util_tests.cpp
 		util_threadnames_tests.cpp
 		validation_block_tests.cpp
+		validation_chainstatemanager_tests.cpp
 		validation_tests.cpp
 		validationinterface_tests.cpp
 		versionbits_tests.cpp

src/test/util/setup_common.cpp

@@ -147,6 +147,7 @@ TestingSetup::TestingSetup(const std::string &chainName)
     GetMainSignals().RegisterBackgroundSignalScheduler(*m_node.scheduler);
 
     pblocktree.reset(new CBlockTreeDB(1 << 20, true));
+
     g_chainman.InitializeChainstate();
     ::ChainstateActive().InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true,

src/test/validation_chainstatemanager_tests.cpp

@@ -0,0 +1,107 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+//
+#include <chainparams.h>
+#include <config.h>
+#include <consensus/validation.h>
+#include <random.h>
+#include <sync.h>
+#include <test/util/setup_common.h>
+#include <validation.h>
+
+#include <vector>
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(validation_chainstatemanager_tests, TestingSetup)
+
+//! Basic tests for ChainstateManager.
+//!
+//! First create a legacy (IBD) chainstate, then create a snapshot chainstate.
+BOOST_AUTO_TEST_CASE(chainstatemanager) {
+    ChainstateManager manager;
+    std::vector<CChainState *> chainstates;
+    const CChainParams &chainparams = Params();
+
+    // Create a legacy (IBD) chainstate.
+    //
+    ENTER_CRITICAL_SECTION(cs_main);
+    CChainState &c1 = manager.InitializeChainstate();
+    LEAVE_CRITICAL_SECTION(cs_main);
+    chainstates.push_back(&c1);
+    c1.InitCoinsDB(
+        /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
+        /* should_wipe */ false);
+    WITH_LOCK(::cs_main, c1.InitCoinsCache());
+
+    BOOST_CHECK(!manager.IsSnapshotActive());
+    BOOST_CHECK(!manager.IsSnapshotValidated());
+    BOOST_CHECK(!manager.IsBackgroundIBD(&c1));
+    auto all = manager.GetAll();
+    BOOST_CHECK_EQUAL_COLLECTIONS(all.begin(), all.end(), chainstates.begin(),
+                                  chainstates.end());
+
+    auto &active_chain = manager.ActiveChain();
+    BOOST_CHECK_EQUAL(&active_chain, &c1.m_chain);
+
+    BOOST_CHECK_EQUAL(manager.ActiveHeight(), -1);
+
+    auto active_tip = manager.ActiveTip();
+    auto exp_tip = c1.m_chain.Tip();
+    BOOST_CHECK_EQUAL(active_tip, exp_tip);
+
+    auto &validated_cs = manager.ValidatedChainstate();
+    BOOST_CHECK_EQUAL(&validated_cs, &c1);
+
+    // Create a snapshot-based chainstate.
+    //
+    ENTER_CRITICAL_SECTION(cs_main);
+    CChainState &c2 = manager.InitializeChainstate(BlockHash(GetRandHash()));
+    LEAVE_CRITICAL_SECTION(cs_main);
+    chainstates.push_back(&c2);
+    c2.InitCoinsDB(
+        /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
+        /* should_wipe */ false);
+    WITH_LOCK(::cs_main, c2.InitCoinsCache());
+    // Unlike c1, which doesn't have any blocks. Gets us different tip, height.
+    c2.LoadGenesisBlock(chainparams);
+    BlockValidationState _;
+    BOOST_CHECK(c2.ActivateBestChain(GetConfig(), _, nullptr));
+
+    BOOST_CHECK(manager.IsSnapshotActive());
+    BOOST_CHECK(!manager.IsSnapshotValidated());
+    BOOST_CHECK(manager.IsBackgroundIBD(&c1));
+    BOOST_CHECK(!manager.IsBackgroundIBD(&c2));
+    auto all2 = manager.GetAll();
+    BOOST_CHECK_EQUAL_COLLECTIONS(all2.begin(), all2.end(), chainstates.begin(),
+                                  chainstates.end());
+
+    auto &active_chain2 = manager.ActiveChain();
+    BOOST_CHECK_EQUAL(&active_chain2, &c2.m_chain);
+
+    BOOST_CHECK_EQUAL(manager.ActiveHeight(), 0);
+
+    auto active_tip2 = manager.ActiveTip();
+    auto exp_tip2 = c2.m_chain.Tip();
+    BOOST_CHECK_EQUAL(active_tip2, exp_tip2);
+
+    // Ensure that these pointers actually correspond to different
+    // CCoinsViewCache instances.
+    BOOST_CHECK(exp_tip != exp_tip2);
+
+    auto &validated_cs2 = manager.ValidatedChainstate();
+    BOOST_CHECK_EQUAL(&validated_cs2, &c1);
+
+    auto &validated_chain = manager.ValidatedChain();
+    BOOST_CHECK_EQUAL(&validated_chain, &c1.m_chain);
+
+    auto validated_tip = manager.ValidatedTip();
+    exp_tip = c1.m_chain.Tip();
+    BOOST_CHECK_EQUAL(validated_tip, exp_tip);
+
+    // Avoid triggering the address sanitizer.
+    WITH_LOCK(::cs_main, manager.Unload());
+}
+
+BOOST_AUTO_TEST_SUITE_END()