From 01b1b51804cac347d826333b3458fce5d6fb11fe Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@loria.fr>
Date: Wed, 15 Aug 2018 01:02:20 +0200
Subject: [PATCH] make the code of an s4u::actor copyiable in all cases to fix
 autorestart

---
 ChangeLog                                     |  4 +++
 include/simgrid/s4u/Actor.hpp                 | 30 ++++++-------------
 .../actor-autorestart/actor-autorestart.tesh  |  4 +--
 3 files changed, 15 insertions(+), 23 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 39946e8de7..7686dc26db 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,10 @@ S4U new features:
        activity.
      - read_async(sg_size_t) and write_async(sg_size_t) which are wrappers on 
        io_init() + start()
+ - When creating an actor from a function and its parameters,
+   move-only parameters are not allowed anymore, as it would prevent
+   the actor to be restartable it its parameters are consumed during
+   the first run.
 
 Tracing:
  - Rename 'power' and 'power_used' variables into 'speed' and 'speed_used'
diff --git a/include/simgrid/s4u/Actor.hpp b/include/simgrid/s4u/Actor.hpp
index cf5f0f10ef..026b326dd4 100644
--- a/include/simgrid/s4u/Actor.hpp
+++ b/include/simgrid/s4u/Actor.hpp
@@ -129,17 +129,10 @@ class XBT_PUBLIC Actor : public simgrid::xbt::Extendable<Actor> {
 #endif
   kernel::actor::ActorImpl* pimpl_ = nullptr;
 
-  /** Wrap a (possibly non-copyable) single-use task into a `std::function` */
-  template<class F, class... Args>
-  static std::function<void()> wrap_task(F f, Args... args)
-  {
-    typedef decltype(f(std::move(args)...)) R;
-    auto task = std::make_shared<simgrid::xbt::Task<R()>>(simgrid::xbt::make_task(std::move(f), std::move(args)...));
-    return [task] { (*task)(); };
-  }
-
   explicit Actor(smx_actor_t pimpl) : pimpl_(pimpl) {}
 
+  typedef std::function<void()> callback_type;
+
 public:
 
   // ***** No copy *****
@@ -171,35 +164,30 @@ public:
   /** Signal indicating that the given actor is about to disappear */
   static simgrid::xbt::signal<void(simgrid::s4u::ActorPtr)> on_destruction;
 
-  /** Create an actor from a std::function
+  /** Create an actor from a std::function<void()>
    *
    *  If the actor is restarted, the actor has a fresh copy of the function.
    */
-  static ActorPtr create(std::string name, s4u::Host* host, std::function<void()> code);
+  static ActorPtr create(std::string name, s4u::Host* host, callback_type code);
 
   /** Create an actor from a std::function
    *
    *  If the actor is restarted, the actor has a fresh copy of the function.
    */
-  static ActorPtr create(std::string name, s4u::Host* host, std::function<void(std::vector<std::string>*)> code,
-                         std::vector<std::string>* args)
+  template <class F> static ActorPtr create(std::string name, s4u::Host* host, F code)
   {
-    return create(name, host, [code](std::vector<std::string>* args) { code(args); }, args);
+    return create(name, host, callback_type(std::move(code)));
   }
 
-  /** Create an actor using code
+  /** Create an actor using a callable thing and its arguments.
    *
-   *  Using this constructor, move-only type can be used. The consequence is
-   *  that we cannot copy the value and restart the actor in its initial
-   *  state. In order to use auto-restart, an explicit `function` must be passed
-   *  instead.
-   */
+   * Note that the arguments will be copied, so move-only parameters are forbidden */
   template <class F, class... Args,
             // This constructor is enabled only if the call code(args...) is valid:
             typename = typename std::result_of<F(Args...)>::type>
   static ActorPtr create(std::string name, s4u::Host* host, F code, Args... args)
   {
-    return create(name, host, wrap_task(std::move(code), std::move(args)...));
+    return create(name, host, std::bind(std::move(code), std::move(args)...));
   }
 
   // Create actor from function name:
diff --git a/teshsuite/s4u/actor-autorestart/actor-autorestart.tesh b/teshsuite/s4u/actor-autorestart/actor-autorestart.tesh
index e2ecd26e0e..a835b8cc72 100644
--- a/teshsuite/s4u/actor-autorestart/actor-autorestart.tesh
+++ b/teshsuite/s4u/actor-autorestart/actor-autorestart.tesh
@@ -3,6 +3,6 @@ $ ./actor-autorestart ${platfdir}/small_platform.xml
 > [Fafard:Dummy:(2) 0.000000] [s4u_test/INFO] I start
 > [Tremblay:Autostart:(1) 50.000000] [s4u_test/INFO] powering off Fafard
 > [Tremblay:Autostart:(1) 60.000000] [s4u_test/INFO] powering on Fafard
-> [Fafard:Dummy:(2) 60.000000] [s4u_test/INFO] I start
-> [Fafard:Dummy:(2) 260.000000] [s4u_test/INFO] I stop
+> [Fafard:Dummy:(3) 60.000000] [s4u_test/INFO] I start
+> [Fafard:Dummy:(3) 260.000000] [s4u_test/INFO] I stop
 > [260.000000] [s4u_test/INFO] Simulation time 260
-- 
2.20.1