fix: add std::atomic to m_cached_sml to avoid concurency updates of shared_ptr value

Co-Authored-By: PastaPastaPasta <6443210+PastaPastaPasta@users.noreply.github.com>

Author: knst

src/evo/deterministicmns.cpp

@@ -266,7 +266,7 @@ std::vector<CDeterministicMNCPtr> CDeterministicMNList::GetProjectedMNPayees(gsl
 
 gsl::not_null<std::shared_ptr<const CSimplifiedMNList>> CDeterministicMNList::to_sml() const
 {
-    if (!m_cached_sml) {
+    if (!m_cached_sml.load()) {
         std::vector<std::unique_ptr<CSimplifiedMNListEntry>> sml_entries;
         sml_entries.reserve(mnMap.size());
 
@@ -535,7 +535,7 @@ void CDeterministicMNList::UpdateMN(const CDeterministicMN& oldDmn, const std::s
 
     dmn->pdmnState = pdmnState;
     mnMap = mnMap.set(oldDmn.proTxHash, dmn);
-    if (m_cached_sml && oldDmn.to_sml_entry() != dmn->to_sml_entry()) {
+    if (m_cached_sml.load() && oldDmn.to_sml_entry() != dmn->to_sml_entry()) {
         m_cached_sml = nullptr;
     }
 }

src/evo/deterministicmns.h

@@ -179,7 +179,7 @@ class CDeterministicMNList
     // for multiple CDeterministicMNList until mnMap is actually changed.
     // Calls of AddMN, RemoveMN and (in some cases) UpdateMN reset this cache;
     // it happens also for indirect calls such as ApplyDiff
-    mutable std::shared_ptr<const CSimplifiedMNList> m_cached_sml;
+    mutable std::atomic<std::shared_ptr<const CSimplifiedMNList>> m_cached_sml;
 
 public:
     CDeterministicMNList() = default;
@@ -191,6 +191,31 @@ class CDeterministicMNList
         assert(nHeight >= 0);
     }
 
+    CDeterministicMNList(const CDeterministicMNList& other) :
+        blockHash(other.blockHash),
+        nHeight(other.nHeight),
+        nTotalRegisteredCount(other.nTotalRegisteredCount),
+        mnMap(other.mnMap),
+        mnInternalIdMap(other.mnInternalIdMap),
+        mnUniquePropertyMap(other.mnUniquePropertyMap),
+        m_cached_sml{other.m_cached_sml.load()}
+    {
+    }
+
+    CDeterministicMNList& operator=(const CDeterministicMNList& other)
+    {
+        if (this != &other) {
+            blockHash = other.blockHash;
+            nHeight = other.nHeight;
+            nTotalRegisteredCount = other.nTotalRegisteredCount;
+            mnMap = other.mnMap;
+            mnInternalIdMap = other.mnInternalIdMap;
+            mnUniquePropertyMap = other.mnUniquePropertyMap;
+            m_cached_sml = other.m_cached_sml.load();
+        }
+        return *this;
+    }
+
     template <typename Stream, typename Operation>
     inline void SerializationOpBase(Stream& s, Operation ser_action)
     {