try improve sensitive error handling

Pilz.Net/Api/ApiServer.cs

@@ -60,26 +60,34 @@ public class ApiServer(string apiUrl) : IApiServer
     }
 
     public virtual void Stop()
+    {
+        Stop(true);
+    }
+
+    public virtual void Stop(bool graceful)
     {
         Log.Info("Stopping listener");
         doListen = false;
-        httpListener.Stop();
+        if (graceful)
+            httpListener.Stop();
+        else
+            httpListener.Abort();
         Thread.Sleep(StopDelay);
         httpListener.Close();
         Log.Info("Stopped listener");
     }
 
-    public virtual void Restart()
+    public virtual void Restart(bool graceful)
     {
         Log.Info("Restarting listener");
-        Stop();
+        Stop(graceful);
         httpListener = new();
         semaphore?.Release(int.MaxValue);
         Start();
         Log.Info("Restarted listener");
     }
 
-    protected virtual bool AutoRestart()
+    protected virtual bool AutoRestart(bool graceful)
     {
         if (restartAttempts > MaxAutoRestartsPerMinute)
         {
@@ -94,7 +102,7 @@ public class ApiServer(string apiUrl) : IApiServer
 
         restartAttempts += 1;
 
-        Restart();
+        Restart(graceful);
 
         return true;
     }
@@ -192,6 +200,10 @@ public class ApiServer(string apiUrl) : IApiServer
         {
             WaitForSlot();
         }
+        catch (ObjectDisposedException)
+        {
+            return;
+        }
         catch (Exception ex)
         {
             Log.Fatal($"Too many concurent connections", ex);
@@ -205,16 +217,17 @@ public class ApiServer(string apiUrl) : IApiServer
         {
             context = httpListener.EndGetContext(result);
         }
+        catch (ObjectDisposedException)
+        {
+            return;
+        }
         catch (HttpListenerException ex)
         {
             if (ex.ErrorCode == 995 || ex.ErrorCode == 64)
             {
                 Log.Fatal($"Fatal http error retriving context with code {ex.ErrorCode}", ex);
-                if (AutoRestart()) // Try restart the server and skip this context
-                {
-                    FreeSlot();
+                if (AutoRestart(false)) // Try restart the server and skip this context
                     return;
-                }
             }
             else
                 Log.Error($"Http error retriving context with code {ex.ErrorCode}", ex);
@@ -255,9 +268,6 @@ public class ApiServer(string apiUrl) : IApiServer
             OnCheckContextCompleted?.Invoke(this, new(context));
         }
 
-        // Release slot
-        FreeSlot();
-
         // Listen for new request
         if (!AllowMultipleRequests)
         {