Added null-check for destructor and health-checker

Added null-check for creator in validate
Simlivied constructor using default values

ManagedPool/Pool_T_.cs

@@ -40,35 +40,6 @@ namespace eu.railduction.netcore.dll.ManagedPool
         /// <summary>If more items are in the pool that the buffer, it will delete/kill the overflowing items</summary>
         public int DecreaseBuffer { get => decreaseBuffer; set => decreaseBuffer = value; }
 
-        /// <summary>
-        /// Creates a managed pool<para/>
-        /// Will automatically spawn <paramref name="min"/> items
-        /// </summary>
-        /// <param name="min">The minimum amount of items in the pool</param>
-        /// <param name="max">The maximum amount of items in the pool</param>
-        /// <param name="batch">Amount if items being spawned at a time if needed</param>
-        /// <param name="increaseBuffer">If less items are in the pool than the <paramref name="increaseBuffer"/>, it will spawn <paramref name="batch"/>-amount</param>
-        /// <param name="decreaseBuffer">If more items are in the pool than the <paramref name="decreaseBuffer"/>, it will delete/kill the overflowing items</param>
-        /// <param name="creator">Method to handle item-spawning (needs to return the item-type)</param>
-        /// <param name="destructor">Method to handle item-deleting/killing (needs to take the item-type as parameter)</param>
-        public Pool(int min, int max, int batch, int increaseBuffer, int decreaseBuffer, Func<T> creator, Action<T> destructor)
-        {
-            this.min = min;
-            this.max = max;
-            this.batch = batch;
-            this.increaseBuffer = increaseBuffer;
-            this.decreaseBuffer = decreaseBuffer;
-
-            // Validate objects state
-            validate();
-
-            this.creator = creator;
-            this.destructor = destructor;
-
-            // Create the minimum amount of objects
-            Task.Run(() => createNewObjects(min));
-        }
-
         /// <summary>
         /// Creates a managed pool<para/>
         /// Will automatically spawn <paramref name="min"/> items<para/>
@@ -83,7 +54,7 @@ namespace eu.railduction.netcore.dll.ManagedPool
         /// <param name="destructor">Method to handle item-deleting/killing</param>
         /// <param name="healthChecker">Method to handle item-health-checking (useful for unstable items)
         /// <para/>While running the health-check, the Thread will be blocked!</param>
-        public Pool(int min, int max, int batch, int increaseBuffer, int decreaseBuffer, Func<T> creator, Action<T> destructor, Func<T, bool> healthChecker)
+        public Pool(int min, int max, int batch, int increaseBuffer, int decreaseBuffer, Func<T> creator, Action<T> destructor = null, Func<T, bool> healthChecker = null)
         {
             this.min = min;
             this.max = max;
@@ -109,6 +80,7 @@ namespace eu.railduction.netcore.dll.ManagedPool
             if (batch <= 0) throw new InvalidOperationException($"Invalid parameter batch='{batch}'. Must be at least '1'!");
             if (increaseBuffer <= 0) throw new InvalidOperationException($"Invalid parameter increaseBuffer='{increaseBuffer}'. Must be at least '1'!");
             if (decreaseBuffer <= 0) throw new InvalidOperationException($"Invalid parameter decreaseBuffer='{decreaseBuffer}'. Must be at least '1'!");
+            if(creator == null) throw new InvalidOperationException($"Invalid parameter creator. Cannot be null!");
         }
 
         /// <summary>
@@ -133,7 +105,11 @@ namespace eu.railduction.netcore.dll.ManagedPool
 
                 if (popped)
                 {
-                    if (healthChecker(item))  // Check for item-health
+                    // Only run healthChecker if its set
+                    bool healthy = true;
+                    if (healthChecker != null) healthy = healthChecker(item);
+
+                    if (healthy)  // Check for item-health
                     {
                         return item;    // Item is healthy, return it
                     }
@@ -218,8 +194,8 @@ namespace eu.railduction.netcore.dll.ManagedPool
         {
             // decrease counter
             current--;
-            // Destruct it
-            destructor(item);
+            // Destruct it when we have a descructor (otherwise the garbage-collector will take care)
+            if(destructor != null) destructor(item);
         }
 
         /// <summary>