Merge #14963: mempool, validation: Explain cs_main locking semantics

fa5e373365 validation: Add cs_main locking annotations (MarcoFalke)
fa5c346c5a doc: Add comment to cs_main and mempool::cs (MarcoFalke)
fafe941bdd test: Add missing validation locks (MarcoFalke)
fac4558462 sync: Add RecursiveMutex type alias (MarcoFalke)

Pull request description:

  Both the chain state and the transaction pool are validation specific, but access to them is protected by two locks. The two locks have the following semantics:

  * Writing to the chain state or adding transactions to the transaction pool -> Take both `cs_main` and `mempool::cs`
  * Reading either or removing transactions from the the transaction pool -> Take only the appropriate lock

Tree-SHA512: 6f6e612ffc391904c6434a79a4f3f8de1b928bf0a3e3434b73561037b395e2b40a70a5a4bd8472dd230e9eacc8e5d5374c904a3c509910cf3971dd7ff59a626c

4 files changed, 10 insertions, 10 deletions

diff --git a/src/test/blockencodings_tests.cpp b/src/test/blockencodings_tests.cpp
index 309b8d2d06..607af8a32a 100644
--- a/src/test/blockencodings_tests.cpp
+++ b/src/test/blockencodings_tests.cpp
@@ -62,7 +62,7 @@ BOOST_AUTO_TEST_CASE(SimpleRoundTripTest)
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     pool.addUnchecked(entry.FromTx(block.vtx[2]));
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[2]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
@@ -162,7 +162,7 @@ BOOST_AUTO_TEST_CASE(NonCoinbasePreforwardRTTest)
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     pool.addUnchecked(entry.FromTx(block.vtx[2]));
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[2]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
@@ -232,7 +232,7 @@ BOOST_AUTO_TEST_CASE(SufficientPreforwardRTTest)
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     pool.addUnchecked(entry.FromTx(block.vtx[1]));
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[1]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
diff --git a/src/test/mempool_tests.cpp b/src/test/mempool_tests.cpp
index 2396aba0f1..23ca9d89ae 100644
--- a/src/test/mempool_tests.cpp
+++ b/src/test/mempool_tests.cpp
@@ -55,7 +55,7 @@ BOOST_AUTO_TEST_CASE(MempoolRemoveTest)
 
 
     CTxMemPool testPool;
-    LOCK(testPool.cs);
+    LOCK2(cs_main, testPool.cs);
 
     // Nothing in pool, remove should do nothing:
     unsigned int poolSize = testPool.size();
@@ -120,7 +120,7 @@ static void CheckSort(CTxMemPool &pool, std::vector<std::string> &sortedOrder) E
 BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
 {
     CTxMemPool pool;
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
     /* 3rd highest fee */
@@ -293,7 +293,7 @@ BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
 BOOST_AUTO_TEST_CASE(MempoolAncestorIndexingTest)
 {
     CTxMemPool pool;
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
     /* 3rd highest fee */
@@ -422,7 +422,7 @@ BOOST_AUTO_TEST_CASE(MempoolAncestorIndexingTest)
 BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest)
 {
     CTxMemPool pool;
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
     CMutableTransaction tx1 = CMutableTransaction();
@@ -595,7 +595,7 @@ BOOST_AUTO_TEST_CASE(MempoolAncestryTests)
     size_t ancestors, descendants;
 
     CTxMemPool pool;
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
     /* Base transaction */
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index f3648e2eee..5ba1df2ec2 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -99,7 +99,7 @@ static bool TestSequenceLocks(const CTransaction &tx, int flags) EXCLUSIVE_LOCKS
 // Test suite for ancestor feerate transaction selection.
 // Implemented as an additional function, rather than a separate test case,
 // to allow reusing the blockchain created in CreateNewBlock_validity.
-static void TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst) EXCLUSIVE_LOCKS_REQUIRED(::mempool.cs)
+static void TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs)
 {
     // Test the ancestor feerate transaction selection.
     TestMemPoolEntryHelper entry;
diff --git a/src/test/policyestimator_tests.cpp b/src/test/policyestimator_tests.cpp
index 431b16cfc2..7b274a1658 100644
--- a/src/test/policyestimator_tests.cpp
+++ b/src/test/policyestimator_tests.cpp
@@ -18,7 +18,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
 {
     CBlockPolicyEstimator feeEst;
     CTxMemPool mpool(&feeEst);
-    LOCK(mpool.cs);
+    LOCK2(cs_main, mpool.cs);
     TestMemPoolEntryHelper entry;
     CAmount basefee(2000);
     CAmount deltaFee(100);