* Example: In any thread, the first call of URCU_TLS(rcu_reader)
* is called from rcu_register_thread(), so we can ensure all later
* URCU_TLS(rcu_reader) in any thread is async-signal-safe.
+ *
+ * Moreover, URCU_TLS variables should not be touched from signal
+ * handlers setup with with sigaltstack(2).
*/
# define DECLARE_URCU_TLS(type, name) \