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

1 files changed, 2 insertions, 2 deletions

diff --git a/src/bench/mempool_eviction.cpp b/src/bench/mempool_eviction.cpp
index 49ea6e88b5..ac8a182358 100644
--- a/src/bench/mempool_eviction.cpp
+++ b/src/bench/mempool_eviction.cpp
@@ -9,7 +9,7 @@
 #include <list>
 #include <vector>
 
-static void AddTx(const CTransactionRef& tx, const CAmount& nFee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(pool.cs)
+static void AddTx(const CTransactionRef& tx, const CAmount& nFee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
 {
     int64_t nTime = 0;
     unsigned int nHeight = 1;
@@ -108,7 +108,7 @@ static void MempoolEviction(benchmark::State& state)
     tx7.vout[1].nValue = 10 * COIN;
 
     CTxMemPool pool;
-    LOCK(pool.cs);
+    LOCK2(cs_main, pool.cs);
     // Create transaction references outside the "hot loop"
     const CTransactionRef tx1_r{MakeTransactionRef(tx1)};
     const CTransactionRef tx2_r{MakeTransactionRef(tx2)};