Add chaser_validate::parallel<> helper and use common macro.

Author: evoskuil

include/bitcoin/node/chasers/chaser.hpp

@@ -163,9 +163,6 @@ class BCN_API chaser
 #define SUBSCRIBE_EVENTS(method, ...) \
     subscribe_events(BIND(method, __VA_ARGS__))
 
-#define PARALLEL(method, ...) \
-    boost::asio::post(threadpool_.service(), BIND(method, __VA_ARGS__));
-
 } // namespace node
 } // namespace libbitcoin
 

include/bitcoin/node/chasers/chaser_validate.hpp

@@ -42,6 +42,14 @@ class BCN_API chaser_validate
     void stop() NOEXCEPT override;
 
 protected:
+    /// Post a method in base or derived class in parallel (use PARALLEL).
+    template <class Derived, typename Method, typename... Args>
+    inline auto parallel(Method&& method, Args&&... args) NOEXCEPT
+    {
+        return boost::asio::post(threadpool_.service(),
+            BIND_THIS(method, args));
+    }
+
     typedef network::race_unity<const code&, const database::tx_link&> race;
 
     virtual bool handle_event(const code& ec, chase event_,