diff --git a/server/robotserver/coroutine.cc b/server/robotserver/coroutine.cc
index dd072ae6..25d70737 100644
--- a/server/robotserver/coroutine.cc
+++ b/server/robotserver/coroutine.cc
@@ -5,12 +5,13 @@
 #include "coroutine.h"
 #include "comgr.h"
 
-void Awaiter::Await(std::shared_ptr<Awaiter> parent)
+void Awaiter::Await(std::shared_ptr<Awaiter> notifyer)
 {
-
+    notifyers_.push_back(notifyer);
+    DoAwait();
 }
 
-void Promise::Await(std::shared_ptr<Awaiter> parent)
+void Promise::DoAwait()
 {
 
 }
@@ -107,7 +108,7 @@ void Coroutine::CallExit(boost::coroutines2::coroutine<void>::push_type& sink)
     sink_ = nullptr;
 }
 
-void Coroutine::Await(std::shared_ptr<Awaiter> parent)
+void Coroutine::DoAwait()
 {
 
 }
diff --git a/server/robotserver/coroutine.h b/server/robotserver/coroutine.h
index 9f6ac2d9..b8d8a911 100644
--- a/server/robotserver/coroutine.h
+++ b/server/robotserver/coroutine.h
@@ -33,8 +33,9 @@ class Awaiter : public std::enable_shared_from_this<Awaiter>
     }
 
 protected:
-
-    virtual void Await(std::shared_ptr<Awaiter> parent);
+    std::list<std::weak_ptr<Awaiter>> notifyers_;
+    void Await(std::shared_ptr<Awaiter> notifyer);
+    virtual void DoAwait() = 0;
 
  private:
     bool done_ = false;
@@ -47,10 +48,8 @@ class Promise : public Awaiter
 {
 protected:
 
-    virtual void Await(std::shared_ptr<Awaiter> parent) override;
+    virtual void DoAwait() override;
 
- private:
-    std::shared_ptr<Awaiter> parent_;
 };
 
 class Coroutine : public Awaiter
@@ -71,7 +70,7 @@ class Coroutine : public Awaiter
     void Deatch();
     void CallEnter(boost::coroutines2::coroutine<void>::push_type& sink);
     void CallExit(boost::coroutines2::coroutine<void>::push_type& sink);
-    virtual void Await(std::shared_ptr<Awaiter> parent) override;
+    virtual void DoAwait() override;
 
  private:
     list_head co_entry_;