when in shutdown exit this loop

Adapter.cc

@@ -144,5 +144,14 @@ namespace pEp {
         {
             return _sync_thread != nullptr;
         }
+
+        bool in_shutdown()
+        {
+            SYNC_EVENT ev = q.back();
+            if (ev)
+                return false;
+            else
+                return true;
+        }
     }
 }

Adapter.hh

@@ -51,6 +51,7 @@ namespace pEp {
         void shutdown();
 
         bool is_sync_running();
+        bool in_shutdown();
     }
 }
 

callback_dispatcher.cc

@@ -94,6 +94,9 @@ namespace pEp {
         if (Adapter::on_sync_thread() && !msg) {
             semaphore.try_wait();
 
+            if (Adapter::in_shutdown())
+                return PEP_SYNC_NO_CHANNEL;
+
             PEP_STATUS status = PassphraseCache::config_next_passphrase();
 
             // if the cache has no valid passphrase ask the app

locked_queue.hh

@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include <list>
+#include <deque>
 #include <condition_variable>
 #include <mutex>
 
@@ -17,7 +17,7 @@ namespace utility
         
         Mutex  _mtx;
         std::condition_variable_any  _cv;
-        std::list<T> _q;
+        std::deque<T> _q;
 
     public:
         ~locked_queue()
@@ -39,14 +39,14 @@ namespace utility
         }
 
         // undefined behavior when queue empty
-        T& back()
+        T back()
         {
             Lock lg(_mtx);
             return _q.back();
         }
 
         // undefined behavior when queue empty
-        T& front()
+        T front()
         {
             Lock lg(_mtx);
             return _q.front();

pc_container.hh

@@ -17,7 +17,7 @@ enum class PC_State { Illegal = 0, Created = 1, Deleted = 2, Changed = 3 };
 
 // Producer/Consumer container.
 // 
-// The "Producer" works on a std::list: inserts, changes, erases elements and 
+// The "Producer" works on a std::deque: inserts, changes, erases elements and 
 // informs a "Consumer" via a queue about the changes.
 //
 // The "Consumer" can poll for changes and process them asynchronously.
@@ -36,7 +36,7 @@ public:
         PC_State state() const noexcept { return PC_State((pdata!=nullptr) + (cdata!=nullptr)*2); }
     };
     
-    typedef std::list<PC> Container;
+    typedef std::deque<PC> Container;
     
     typename Container::const_iterator cbegin() const noexcept { return c.cbegin(); }
     typename Container::const_iterator cend()   const noexcept { return c.cend();   }