refactor: remove RecursiveMutex cs_nBlockSequenceId

The RecursiveMutex cs_nBlockSequenceId is only used at one place in
CChainState::ReceivedBlockTransactions() to atomically read-and-increment the
nBlockSequenceId member. At this point, the cs_main lock is set, hence we can
use a plain int for the member and mark it as guarded by cs_main.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index ec457da5cc..9944e31557 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2970,10 +2970,7 @@ void CChainState::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pi
             CBlockIndex *pindex = queue.front();
             queue.pop_front();
             pindex->nChainTx = (pindex->pprev ? pindex->pprev->nChainTx : 0) + pindex->nTx;
-            {
-                LOCK(cs_nBlockSequenceId);
-                pindex->nSequenceId = nBlockSequenceId++;
-            }
+            pindex->nSequenceId = nBlockSequenceId++;
             if (m_chain.Tip() == nullptr || !setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
                 setBlockIndexCandidates.insert(pindex);
             }