From 4cee907912fadc945840e27a60bb90a71b964f29 Mon Sep 17 00:00:00 2001
From: Volker Birk <vb@pep-project.org>
Date: Tue, 30 Jun 2020 22:41:15 +0200
Subject: [PATCH] singleton

---
 callback_dispatcher.cc | 8 ++++++++
 callback_dispatcher.hh | 5 ++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/callback_dispatcher.cc b/callback_dispatcher.cc
index c6098a8..6a29946 100644
--- a/callback_dispatcher.cc
+++ b/callback_dispatcher.cc
@@ -3,8 +3,16 @@
 #include <cassert>
 
 namespace pEp {
+    bool CallbackDispatcher::once = true;
     CallbackDispatcher dispatcher;
 
+    CallbackDispatcher::CallbackDispatcher()
+    {
+        if (!once)
+            throw std::out_of_range("CallbackDispatcher is a singleton");
+        once = false;
+    }
+
     PEP_STATUS CallbackDispatcher::messageToSend(::message *msg)
     {
         return dispatcher._messageToSend(msg);
diff --git a/callback_dispatcher.hh b/callback_dispatcher.hh
index 8a25303..76e997e 100644
--- a/callback_dispatcher.hh
+++ b/callback_dispatcher.hh
@@ -9,10 +9,13 @@ namespace pEp {
             ::messageToSend_t messageToSend;
             ::notifyHandshake_t notifyHandshake;
         };
-
         std::vector<callbacks> targets;
 
+        static bool once;
+
     public:
+        CallbackDispatcher();
+
         static PEP_STATUS messageToSend(::message *msg);
         static PEP_STATUS notifyHandshake(::pEp_identity *me,
                 ::pEp_identity *partner, ::sync_handshake_signal signal);