2 files changed, 12 insertions, 4 deletions
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index cd636a7127..9d7d213f6b 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -94,6 +94,8 @@ static int ComputeNextBlockAndDepth(const CBlockIndex* tip, const CBlockIndex* b
 UniValue blockheaderToJSON(const CBlockIndex* tip, const CBlockIndex* blockindex)
 {
     // Serialize passed information without accessing chain state of the active chain!
+    AssertLockNotHeld(cs_main); // For performance reasons
+
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex* pnext;
@@ -121,6 +123,8 @@ UniValue blockheaderToJSON(const CBlockIndex* tip, const CBlockIndex* blockindex
 UniValue blockToJSON(const CBlock& block, const CBlockIndex* tip, const CBlockIndex* blockindex, bool txDetails)
 {
     // Serialize passed information without accessing chain state of the active chain!
+    AssertLockNotHeld(cs_main); // For performance reasons
+
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex* pnext;
diff --git a/src/rpc/blockchain.h b/src/rpc/blockchain.h
index 55d1de453f..ff461fbcbc 100644
--- a/src/rpc/blockchain.h
+++ b/src/rpc/blockchain.h
@@ -5,9 +5,13 @@
 #ifndef BITCOIN_RPC_BLOCKCHAIN_H
 #define BITCOIN_RPC_BLOCKCHAIN_H
 
-#include <vector>
-#include <stdint.h>
 #include <amount.h>
+#include <sync.h>
+
+#include <stdint.h>
+#include <vector>
+
+extern RecursiveMutex cs_main;
 
 class CBlock;
 class CBlockIndex;
@@ -28,7 +32,7 @@ double GetDifficulty(const CBlockIndex* blockindex);
 void RPCNotifyBlockChange(bool ibd, const CBlockIndex *);
 
 /** Block description to JSON */
-UniValue blockToJSON(const CBlock& block, const CBlockIndex* tip, const CBlockIndex* blockindex, bool txDetails = false);
+UniValue blockToJSON(const CBlock& block, const CBlockIndex* tip, const CBlockIndex* blockindex, bool txDetails = false) LOCKS_EXCLUDED(cs_main);
 
 /** Mempool information to JSON */
 UniValue MempoolInfoToJSON(const CTxMemPool& pool);
@@ -37,7 +41,7 @@ UniValue MempoolInfoToJSON(const CTxMemPool& pool);
 UniValue MempoolToJSON(const CTxMemPool& pool, bool verbose = false);
 
 /** Block header to JSON */
-UniValue blockheaderToJSON(const CBlockIndex* tip, const CBlockIndex* blockindex);
+UniValue blockheaderToJSON(const CBlockIndex* tip, const CBlockIndex* blockindex) LOCKS_EXCLUDED(cs_main);
 
 /** Used by getblockstats to get feerates at different percentiles by weight  */
 void CalculatePercentilesByWeight(CAmount result[NUM_GETBLOCKSTATS_PERCENTILES], std::vector<std::pair<CAmount, int64_t>>& scores, int64_t total_weight);