From 7932a6bed7bad4849fc5f4e30be34ccd9b7886f6 Mon Sep 17 00:00:00 2001
From: Francisco Paisana <paisanaf@tcd.ie>
Date: Wed, 8 Apr 2020 14:00:40 +0100
Subject: [PATCH] allow the use of move_tasks in procedures

---
 lib/include/srslte/common/multiqueue.h      | 14 ++++++++------
 lib/include/srslte/common/stack_procedure.h | 15 ++++++++-------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/lib/include/srslte/common/multiqueue.h b/lib/include/srslte/common/multiqueue.h
index 2bbc52dc4..fb8db8923 100644
--- a/lib/include/srslte/common/multiqueue.h
+++ b/lib/include/srslte/common/multiqueue.h
@@ -250,25 +250,26 @@ private:
  * Specialization for tasks with content that is move-only
  **********************************************************/
 
-class move_task_t
+template <typename... Args>
+class move_function
 {
 public:
-  move_task_t() = default;
+  move_function() = default;
   template <typename Func>
-  move_task_t(Func&& f) : task_ptr(new derived_task<Func>(std::forward<Func>(f)))
+  move_function(Func&& f) : task_ptr(new derived_task<Func>(std::forward<Func>(f)))
   {
   }
-  void operator()() { (*task_ptr)(); }
+  void operator()(Args&&... args) { (*task_ptr)(std::forward<Args>(args)...); }
 
 private:
   struct base_task {
     virtual ~base_task() {}
-    virtual void operator()() = 0;
+    virtual void operator()(Args&&...) = 0;
   };
   template <typename Func>
   struct derived_task : public base_task {
     derived_task(Func&& f_) : f(std::forward<Func>(f_)) {}
-    void operator()() final { f(); }
+    void operator()(Args&&... args) final { f(std::forward<Args>(args)...); }
 
   private:
     Func f;
@@ -277,6 +278,7 @@ private:
   std::unique_ptr<base_task> task_ptr;
 };
 
+using move_task_t     = move_function<>;
 using task_multiqueue = multiqueue_handler<move_task_t>;
 
 } // namespace srslte
diff --git a/lib/include/srslte/common/stack_procedure.h b/lib/include/srslte/common/stack_procedure.h
index 626e29ea2..9f57272da 100644
--- a/lib/include/srslte/common/stack_procedure.h
+++ b/lib/include/srslte/common/stack_procedure.h
@@ -19,6 +19,7 @@
  *
  */
 
+#include "srslte/common/multiqueue.h"
 #include <functional>
 #include <list>
 #include <memory>
@@ -73,7 +74,7 @@ class callback_group_t
 {
 public:
   using callback_id_t = uint32_t;
-  using callback_t    = std::function<void(Args...)>;
+  using callback_t    = srslte::move_function<Args...>;
 
   //! register callback, that gets called once
   callback_id_t on_next_call(callback_t f_)
@@ -93,11 +94,11 @@ public:
 
   // call all callbacks
   template <typename... ArgsRef>
-  void operator()(const ArgsRef&... args)
+  void operator()(ArgsRef&&... args)
   {
     for (auto& f : func_list) {
       if (f.active) {
-        f.func(args...);
+        f.func(std::forward<ArgsRef>(args)...);
         if (not f.call_always) {
           f.active = false;
         }
@@ -274,7 +275,7 @@ public:
   using result_type          = ResultType;
   using proc_result_type     = proc_result_t<result_type>;
   using proc_future_type     = proc_future_t<result_type>;
-  using then_callback_list_t = callback_group_t<proc_result_type>;
+  using then_callback_list_t = callback_group_t<const proc_result_type&>;
   using callback_t           = typename then_callback_list_t::callback_t;
   using callback_id_t        = typename then_callback_list_t::callback_id_t;
 
@@ -312,8 +313,8 @@ public:
   }
 
   //! methods to schedule continuation tasks
-  callback_id_t then(const callback_t& c) { return complete_callbacks.on_next_call(c); }
-  callback_id_t then_always(const callback_t& c) { return complete_callbacks.on_every_call(c); }
+  callback_id_t then(callback_t c) { return complete_callbacks.on_next_call(std::move(c)); }
+  callback_id_t then_always(callback_t c) { return complete_callbacks.on_every_call(std::move(c)); }
 
   //! launch a procedure, returning true if successful or running and false if it error or it failed to launch
   template <class... Args>
@@ -363,7 +364,7 @@ protected:
     // call T::then() if it exists
     proc_detail::optional_then(proc_ptr.get(), &result);
     // signal continuations
-    complete_callbacks(result);
+    complete_callbacks(std::move(result));
     // back to inactive
     proc_detail::optional_clear(proc_ptr.get());
     proc_state = proc_status_t::idle;