#2092: message: move message around instead of copying

src/vt/collective/reduce/reduce.impl.h

@@ -78,7 +78,7 @@ void Reduce::reduceRootRecv(MsgT* msg) {
 
   auto const from_node = theContext()->getFromNodeCurrentTask();
   auto m = promoteMsg(msg);
-  runnable::makeRunnable(m, false, handler, from_node)
+  runnable::makeRunnable(std::move(m), false, handler, from_node)
     .withTDEpochFromMsg()
     .run();
 }
@@ -256,7 +256,7 @@ void Reduce::startReduce(detail::ReduceStamp id, bool use_num_contrib) {
 
       // this needs to run inline.. threaded not allowed for reduction
       // combination
-      runnable::makeRunnable(state.msgs[0], false, handler, from_node)
+      runnable::makeRunnable(std::move(state.msgs[0]), false, handler, from_node)
         .withTDEpochFromMsg()
         .run();
     }

src/vt/messaging/active.cc

@@ -500,7 +500,7 @@ EventType ActiveMessenger::doMessageSend(
       if (is_obj) {
         objgroup::dispatchObjGroup(base, han, dest, nullptr);
       } else {
-        runnable::makeRunnable(base, true, envelopeGetHandler(msg->env), dest)
+        runnable::makeRunnable(std::move(base), true, envelopeGetHandler(msg->env), dest)
           .withTDEpochFromMsg(is_term)
           .withLBData(&bare_handler_lb_data_, bare_handler_dummy_elm_id_for_lb_data_)
           .enqueue();
@@ -963,7 +963,8 @@ void ActiveMessenger::prepareActiveMsgToRun(
   if (is_obj) {
     objgroup::dispatchObjGroup(base, handler, from_node, cont);
   } else {
-    runnable::makeRunnable(base, not is_term, handler, from_node)
+    auto m = base;
+    runnable::makeRunnable(std::move(m), not is_term, handler, from_node)
       .withContinuation(cont)
       .withTDEpochFromMsg(is_term)
       .withLBData(&bare_handler_lb_data_, bare_handler_dummy_elm_id_for_lb_data_)

src/vt/messaging/message/smart_ptr.h

@@ -155,6 +155,11 @@ struct MsgSharedPtr final {
       /*N.B. retain ORIGINAL-type implementation*/ impl_);
   }
 
+  template <typename U>
+  MsgSharedPtr<U>* reinterpretAs() {
+    return reinterpret_cast<MsgSharedPtr<U>*>(this);
+  }
+
   /// [obsolete] Use to() as MsgVirtualPtr <-> MsgSharedPtr.
   /// Both methods are equivalent in funciton.
   template <typename U>

src/vt/messaging/pending_send.cc

@@ -59,17 +59,23 @@ PendingSend::PendingSend(PendingSend&& in) noexcept
   std::swap(msg_, in.msg_);
   std::swap(epoch_action_, in.epoch_action_);
   std::swap(send_action_, in.send_action_);
+  std::swap(send_move_action_, in.send_move_action_);
 }
 
 void PendingSend::sendMsg() {
-  if (send_action_ == nullptr) {
+  if (send_action_ == nullptr and send_move_action_ == nullptr) {
     theMsg()->doMessageSend(msg_);
   } else {
-    send_action_(msg_);
+    if (send_action_) {
+      send_action_(msg_);
+    } else {
+      send_move_action_(std::move(msg_));
+    }
   }
   consumeMsg();
   msg_ = nullptr;
   send_action_ = nullptr;
+  send_move_action_ = nullptr;
 }
 
 EpochType PendingSend::getProduceEpochFromMsg() const {
@@ -95,7 +101,7 @@ void PendingSend::consumeMsg() {
 }
 
 void PendingSend::release() {
-  bool send_msg = msg_ != nullptr || send_action_ != nullptr;
+  bool send_msg = msg_ != nullptr || send_action_ != nullptr || send_move_action_ != nullptr;
   vtAssert(!send_msg || !epoch_action_, "cannot have both a message and epoch action");
   if (send_msg) {
     sendMsg();

src/vt/messaging/pending_send.h

@@ -70,6 +70,7 @@ namespace vt { namespace messaging {
 struct PendingSend final {
   /// Function for complex action on send---takes a message to operate on
   using SendActionType = std::function<void(MsgSharedPtr<BaseMsgType>&)>;
+  using SendActionMoveType = std::function<void(MsgSharedPtr<BaseMsgType>&&)>;
   using EpochActionType = std::function<void()>;
 
   /**
@@ -91,6 +92,21 @@ struct PendingSend final {
     produceMsg();
   }
 
+  /**
+   * \brief Construct a pending send.
+   *
+   * \param[in] in_msg the message to send
+   * \param[in] in_move_action the action to run, where the msg is moved.
+   */
+  PendingSend(
+    MsgSharedPtr<BaseMsgType>&& in_msg,
+    SendActionMoveType in_move_action = nullptr
+  ) : msg_(std::move(in_msg))
+    , send_move_action_(in_move_action)
+  {
+    produceMsg();
+  }
+
   /**
    * \brief Construct a pending send that invokes a callback.
    *
@@ -182,6 +198,7 @@ struct PendingSend final {
 private:
   MsgPtr<BaseMsgType> msg_ = nullptr;
   SendActionType send_action_ = {};
+  SendActionMoveType send_move_action_ = {};
   EpochActionType epoch_action_ = {};
   EpochType epoch_produced_ = no_epoch;
 };

src/vt/objgroup/manager.static.h

@@ -91,7 +91,7 @@ void invoke(messaging::MsgPtrThief<MsgT> msg, HandlerType han, NodeType dest_nod
   auto const& elm_id = holder->getElmID();
   auto elm = holder->getPtr();
   auto lb_data = &holder->getLBData();
-  runnable::makeRunnable(msg.msg_, false, han, this_node)
+  runnable::makeRunnable(std::move(msg.msg_), false, han, this_node)
     .withObjGroup(elm)
     .withTDEpochFromMsg()
     .withLBData(lb_data, elm_id)
@@ -107,13 +107,13 @@ namespace detail {
 
 template <typename MsgT, typename ObjT>
 void dispatchImpl(
-  MsgSharedPtr<MsgT> const& msg, HandlerType han, NodeType from_node,
+  MsgSharedPtr<MsgT> msg, HandlerType han, NodeType from_node,
   ActionType cont, ObjT* obj
 ) {
   auto holder = detail::getHolderBase(han);
   auto const& elm_id = holder->getElmID();
   auto lb_data = &holder->getLBData();
-  runnable::makeRunnable(msg, true, han, from_node)
+  runnable::makeRunnable(std::move(msg), true, han, from_node)
     .withContinuation(cont)
     .withObjGroup(obj)
     .withLBData(lb_data, elm_id)

src/vt/pipe/callback/handler_send/callback_send_tl.impl.h

@@ -71,7 +71,7 @@ void CallbackSendTypeless::trigger(MsgT* msg, PipeType const& pipe) {
   );
   auto pmsg = promoteMsg(msg);
   if (this_node == send_node_) {
-    runnable::makeRunnable(pmsg, true, handler_, this_node)
+    runnable::makeRunnable(std::move(pmsg), true, handler_, this_node)
       .withTDEpochFromMsg()
       .enqueue();
   } else {

src/vt/runnable/make_runnable.h

@@ -67,19 +67,18 @@ struct RunnableMaker {
    * \internal \brief Construct the builder. Shall not be called directly.
    *
    * \param[in] in_impl the runnable
-   * \param[in] in_msg the associated message
+   * \param[in] in_has_msg whether we have a message
    * \param[in] in_handler the handler
    * \param[in] in_han_type the type of handler
    * \param[in] in_from_node the from node for the runnable
    */
   RunnableMaker(
-    RunnableNew* in_impl, MsgSharedPtr<MsgT> const& in_msg,
+    RunnableNew* in_impl, bool in_has_msg,
     HandlerType in_handler, NodeType in_from_node
   ) : impl_(in_impl),
-      msg_(in_msg),
+      has_msg_(in_has_msg),
       handler_(in_handler),
-      from_node_(in_from_node),
-      has_msg_(in_msg != nullptr)
+      from_node_(in_from_node)
   { }
   RunnableMaker(RunnableMaker const&) = delete;
   RunnableMaker(RunnableMaker&&) = default;
@@ -119,7 +118,7 @@ struct RunnableMaker {
   RunnableMaker&& withTDEpochFromMsg(bool is_term = false) {
     is_term_ = is_term;
     if (not is_term) {
-      impl_->addContextTD(msg_);
+      impl_->addContextTD(impl_->getMsg());
     }
     return std::move(*this);
   }
@@ -219,7 +218,7 @@ struct RunnableMaker {
   template <typename ElmT>
   RunnableMaker&& withLBData(ElmT* elm) {
 #if vt_check_enabled(lblite)
-    impl_->addContextLB(elm, msg_.get());
+    impl_->addContextLB(elm, impl_->getMsg().get());
 #endif
     return std::move(*this);
   }
@@ -239,7 +238,7 @@ struct RunnableMaker {
     uint64_t idx1, uint64_t idx2, uint64_t idx3, uint64_t idx4
   ) {
     impl_->addContextTrace(
-      msg_, trace_event, handler_, from_node_, idx1, idx2, idx3, idx4
+      impl_->getMsg(), trace_event, handler_, from_node_, idx1, idx2, idx3, idx4
     );
     return std::move(*this);
   }
@@ -309,13 +308,12 @@ struct RunnableMaker {
 
 private:
   RunnableNew* impl_ = nullptr;
-  MsgSharedPtr<MsgT> const& msg_;
+  bool has_msg_ = false;
   HandlerType handler_ = uninitialized_handler;
   bool set_handler_ = false;
   NodeType from_node_ = uninitialized_destination;
   bool is_done_ = false;
   bool is_term_ = false;
-  bool has_msg_ = true;
 };
 
 /**
@@ -331,19 +329,19 @@ struct RunnableMaker {
  */
 template <typename U>
 RunnableMaker<U> makeRunnable(
-  MsgSharedPtr<U> const& msg, bool is_threaded, HandlerType handler, NodeType from
+  MsgSharedPtr<U>&& msg, bool is_threaded, HandlerType handler, NodeType from
 ) {
-  auto r = new RunnableNew(msg, is_threaded);
+  auto r = new RunnableNew(std::move(msg), is_threaded);
 #if vt_check_enabled(trace_enabled)
   auto const han_type = HandlerManager::getHandlerRegistryType(handler);
   if (han_type == auto_registry::RegistryTypeEnum::RegVrt or
       han_type == auto_registry::RegistryTypeEnum::RegGeneral or
       han_type == auto_registry::RegistryTypeEnum::RegObjGroup) {
-    r->addContextTrace(msg, handler, from);
+    r->addContextTrace(r->getMsg(), handler, from);
   }
 #endif
   r->addContextSetContext(r, from);
-  return RunnableMaker<U>{r, msg, handler, from};
+  return RunnableMaker<U>{r, true, handler, from};
 }
 
 /**
@@ -362,7 +360,7 @@ inline RunnableMaker<BaseMsgType> makeRunnableVoid(
   auto r = new RunnableNew(is_threaded);
   // @todo: figure out how to trace this?
   r->addContextSetContext(r, from);
-  return RunnableMaker<BaseMsgType>{r, nullptr, handler, from};
+  return RunnableMaker<BaseMsgType>{r, false, handler, from};
 }
 
 }} /* end namespace vt::runnable */

src/vt/runnable/runnable.h

@@ -106,8 +106,8 @@ struct RunnableNew {
    * \param[in] in_is_threaded whether the handler can be run with a thread
    */
   template <typename U>
-  RunnableNew(MsgSharedPtr<U> const& in_msg, bool in_is_threaded)
-    : msg_(in_msg.template to<BaseMsgType>())
+  RunnableNew(MsgSharedPtr<U>&& in_msg, bool in_is_threaded)
+    :  msg_(std::move(*in_msg.template reinterpretAs<BaseMsgType>()))
 #if vt_check_enabled(fcontext)
     , is_threaded_(in_is_threaded)
 #endif
@@ -130,6 +130,8 @@ struct RunnableNew {
   RunnableNew& operator=(RunnableNew&&) = default;
 
 public:
+  MsgSharedPtr<BaseMsgType> const& getMsg() { return msg_; }
+
   /**
    * \brief Add a new \c SetContext for this handler
    *

src/vt/serialization/messaging/serialized_messenger.impl.h

@@ -95,7 +95,7 @@ template <typename UserMsgT>
       user_msg.template to<BaseMsgType>(), handler, sys_msg->from_node, nullptr
     );
   } else {
-    runnable::makeRunnable(user_msg, true, handler, sys_msg->from_node)
+    runnable::makeRunnable(std::move(user_msg), true, handler, sys_msg->from_node)
       .withTDEpochFromMsg()
       .enqueue();
   }
@@ -146,7 +146,7 @@ template <typename UserMsgT>
           msg.template to<BaseMsgType>(), handler, node, action
         );
       } else {
-        runnable::makeRunnable(msg, true, handler, node)
+        runnable::makeRunnable(std::move(msg), true, handler, node)
           .withTDEpoch(epoch, not is_valid_epoch)
           .withContinuation(action)
           .enqueue();
@@ -195,7 +195,7 @@ template <typename UserMsgT, typename BaseEagerMsgT>
       user_msg.template to<BaseMsgType>(), handler, sys_msg->from_node, nullptr
     );
   } else {
-    runnable::makeRunnable(user_msg, true, handler, sys_msg->from_node)
+    runnable::makeRunnable(std::move(user_msg), true, handler, sys_msg->from_node)
       .withTDEpochFromMsg()
       .enqueue();
   }
@@ -428,14 +428,14 @@ template <typename MsgT, typename BaseT>
         );
 
         auto base_msg = user_msg.template to<BaseMsgType>();
-        return messaging::PendingSend(base_msg, [=](MsgPtr<BaseMsgType> in) {
+        return messaging::PendingSend(std::move(base_msg), [=](MsgPtr<BaseMsgType>&& in) mutable {
           bool const is_obj = HandlerManager::isHandlerObjGroup(typed_handler);
           if (is_obj) {
             objgroup::dispatchObjGroup(
               user_msg.template to<BaseMsgType>(), typed_handler, node, nullptr
             );
           } else {
-            runnable::makeRunnable(user_msg, true, typed_handler, node)
+            runnable::makeRunnable(std::move(user_msg), true, typed_handler, node)
               .withTDEpochFromMsg()
               .enqueue();
           }

src/vt/topos/location/location.h

@@ -244,7 +244,7 @@ struct EntityLocationCoord : LocationCoord {
   template <typename MessageT, ActiveTypedFnType<MessageT> *f>
   void routeMsgHandler(
     EntityID const& id, NodeType const& home_node,
-    MsgSharedPtr<MessageT> const& msg
+    MsgSharedPtr<MessageT>&& msg
   );
 
   /**
@@ -253,15 +253,15 @@ struct EntityLocationCoord : LocationCoord {
    * \param[in] m message shared pointer
    */
   template <typename MessageT, ActiveTypedFnType<MessageT> *f>
-  void routePreparedMsgHandler(MsgSharedPtr<MessageT> const& msg);
+  void routePreparedMsgHandler(MsgSharedPtr<MessageT>&& msg);
 
   /**
    * \brief Route a message with a custom handler
    *
    * \param[in] m message shared pointer
    */
   template <typename MessageT>
-  void routePreparedMsg(MsgSharedPtr<MessageT> const& msg);
+  void routePreparedMsg(MsgSharedPtr<MessageT>&& msg);
 
   /**
    * \brief Route a message with a custom handler where the element is local
@@ -270,7 +270,7 @@ struct EntityLocationCoord : LocationCoord {
    * \param[in] obj the object pointer
    */
   template <typename MessageT, ActiveTypedFnType<MessageT> *f>
-  void routeMsgHandlerLocal(MsgSharedPtr<MessageT> const& msg, void* obj);
+  void routeMsgHandlerLocal(MsgSharedPtr<MessageT>&& msg, void* obj);
 
   /**
    * \brief Route a message to the default handler
@@ -283,7 +283,7 @@ struct EntityLocationCoord : LocationCoord {
   template <typename MessageT>
   void routeMsg(
     EntityID const& id, NodeType const& home_node,
-    MsgSharedPtr<MessageT> const& msg,
+    MsgSharedPtr<MessageT>&& msg,
     NodeType from_node = uninitialized_destination
   );
 
@@ -410,7 +410,7 @@ struct EntityLocationCoord : LocationCoord {
   template <typename MessageT>
   void routeMsgEager(
     EntityID const& id, NodeType const& home_node,
-    MsgSharedPtr<MessageT> const& msg
+    MsgSharedPtr<MessageT>&& msg
   );
 
   /**
@@ -424,7 +424,7 @@ struct EntityLocationCoord : LocationCoord {
   template <typename MessageT>
   void routeMsgNode(
     EntityID const& id, NodeType const& home_node, NodeType const& to_node,
-    MsgSharedPtr<MessageT> const& msg
+    MsgSharedPtr<MessageT>&& msg
   );
 
   /**