Release guard after transaction

nano/secure/transaction.hpp

@@ -29,17 +29,18 @@ class transaction
 	virtual operator const nano::store::transaction & () const = 0;
 };
 
-class write_transaction : public transaction
+class write_transaction final : public transaction
 {
+	nano::store::write_guard guard; // Guard should be released after the transaction
 	nano::store::write_transaction txn;
-	nano::store::write_guard guard;
 	std::chrono::steady_clock::time_point start;
 
 public:
-	explicit write_transaction (nano::store::write_transaction && txn, nano::store::write_guard && guard) noexcept :
-		txn{ std::move (txn) },
-		guard{ std::move (guard) }
+	explicit write_transaction (nano::store::write_transaction && txn_a, nano::store::write_guard && guard_a) noexcept :
+		guard{ std::move (guard_a) },
+		txn{ std::move (txn_a) }
 	{
+		debug_assert (guard.is_owned ());
 		start = std::chrono::steady_clock::now ();
 	}
 
@@ -97,7 +98,7 @@ class write_transaction : public transaction
 	}
 };
 
-class read_transaction : public transaction
+class read_transaction final : public transaction
 {
 	nano::store::read_transaction txn;
 
@@ -140,4 +141,4 @@ class read_transaction : public transaction
 		return txn;
 	}
 };
-} // namespace nano::secure
+}