winmidi: fixes, fix double notification in constructor

Author: jcelerier

include/libremidi/backends/winmidi/midi_in.hpp

@@ -186,10 +186,16 @@ class midi_in_impl final
 
   stdx::error close_port() override
   {
+    if(!m_endpoint)
+      return std::errc::not_connected;
+
 #if !LIBREMIDI_WINMIDI_HAS_COM_EXTENSIONS
     m_endpoint.MessageReceived(m_revoke_token);
 #else
-    m_raw_endpoint->RemoveMessagesReceivedCallback();
+    if(m_raw_endpoint) {
+      m_raw_endpoint->RemoveMessagesReceivedCallback();
+      m_raw_endpoint = nullptr;
+    }
 #endif
     m_session.DisconnectEndpointConnection(m_endpoint.ConnectionId());
     return stdx::error{};

include/libremidi/backends/winmidi/midi_out.hpp

@@ -57,6 +57,9 @@ class midi_out_impl final
 
   stdx::error close_port() override
   {
+    if(!m_endpoint)
+      return std::errc::not_connected;
+
     m_session.DisconnectEndpointConnection(m_endpoint.ConnectionId());
     return stdx::error{};
   }

include/libremidi/backends/winmidi/observer.hpp

@@ -29,25 +29,19 @@ class observer_impl final
   std::map<hstring, std::vector<input_port>> m_known_input_devices;
   std::map<hstring, std::vector<output_port>> m_known_output_devices;
   std::mutex m_devices_mtx;
+  std::atomic_bool m_in_constructor{true};
 
   explicit observer_impl(
       libremidi::observer_configuration&& conf, winmidi::observer_configuration&& apiconf)
       : configuration{std::move(conf), std::move(apiconf)}
   {
+    struct on_delete { observer_impl& self; ~on_delete() { self.m_in_constructor = false; } } on_delete{*this};
+
     if (!configuration.has_callbacks())
       return;
 
-    if (configuration.notify_in_constructor)
-    {
-      if (configuration.input_added)
-        for (const auto& p : get_input_ports())
-          configuration.input_added(p);
-
-      if (configuration.output_added)
-        for (const auto& p : get_output_ports())
-          configuration.output_added(p);
-    }
-
+    // Note: winmidi also notifies for existing devices, so the "notify in constructor"
+    // is handled in the callbacks
     if ((watcher = MidiEndpointDeviceWatcher::Create()))
     {
       namespace enumeration = winrt::Windows::Devices::Enumeration;
@@ -204,7 +198,9 @@ class observer_impl final
               std::lock_guard _{m_devices_mtx};
               m_known_input_devices[ep.EndpointDeviceId()].push_back(ip);
             }
-            configuration.input_added(std::move(ip));
+
+            if(!m_in_constructor || configuration.notify_in_constructor)
+              configuration.input_added(std::move(ip));
           }
           if (configuration.output_added)
           {
@@ -213,7 +209,9 @@ class observer_impl final
               std::lock_guard _{m_devices_mtx};
               m_known_output_devices[ep.EndpointDeviceId()].push_back(op);
             }
-            configuration.output_added(std::move(op));
+
+            if(!m_in_constructor || configuration.notify_in_constructor)
+              configuration.output_added(std::move(op));
           }
           break;
         }
@@ -225,7 +223,9 @@ class observer_impl final
               std::lock_guard _{m_devices_mtx};
               m_known_input_devices[ep.EndpointDeviceId()].push_back(ip);
             }
-            configuration.input_added(std::move(ip));
+
+            if(!m_in_constructor || configuration.notify_in_constructor)
+              configuration.input_added(std::move(ip));
           }
           break;
         case MidiGroupTerminalBlockDirection::BlockOutput:
@@ -236,12 +236,15 @@ class observer_impl final
               std::lock_guard _{m_devices_mtx};
               m_known_output_devices[ep.EndpointDeviceId()].push_back(op);
             }
-            configuration.output_added(std::move(op));
+
+            if(!m_in_constructor || configuration.notify_in_constructor)
+              configuration.output_added(std::move(op));
           }
           break;
       }
     }
   }
+
   void remove_device(hstring eid)
   {
     std::vector<input_port> to_remove_in;