Assert no database operations on IO threads

nano/lib/thread_roles.cpp

@@ -191,9 +191,19 @@ std::string nano::thread_role::get_string ()
 
 void nano::thread_role::set (nano::thread_role::name role)
 {
-	auto thread_role_name_string (get_string (role));
-
-	nano::thread_role::set_os_name (thread_role_name_string);
-
+	auto thread_role_name_string = get_string (role);
+	nano::thread_role::set_os_name (thread_role_name_string); // Implementation is platform specific
 	current_thread_role = role;
 }
+
+bool nano::thread_role::is_network_io ()
+{
+	switch (get ())
+	{
+		case nano::thread_role::name::io:
+		case nano::thread_role::name::io_daemon:
+			return true;
+		default:
+			return false;
+	}
+}

nano/lib/thread_roles.hpp

@@ -84,4 +84,9 @@ std::string get_string ();
  * Internal only, should not be called directly
  */
 void set_os_name (std::string const &);
+
+/*
+ * Check if the current thread is a network IO thread
+ */
+bool is_network_io ();
 }

nano/store/transaction.cpp

@@ -9,6 +9,7 @@
 nano::store::transaction_impl::transaction_impl (nano::id_dispenser::id_t const store_id_a) :
 	store_id{ store_id_a }
 {
+	debug_assert (!nano::thread_role::is_network_io (), "database operations are not allowed to run on network IO threads");
 }
 
 /*