Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/Pool.cs

@@ -0,0 +1,56 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+namespace System.ServiceModel
+{
+    // see SynchronizedPool<T> for a threadsafe implementation
+    class Pool<T> where T : class
+    {
+        T[] items;
+        int count;
+
+        public Pool(int maxCount)
+        {
+            items = new T[maxCount];
+        }
+
+        public int Count
+        {
+            get { return count; }
+        }
+
+        public T Take()
+        {
+            if (count > 0)
+            {
+                T item = items[--count];
+                items[count] = null;
+                return item;
+            }
+            else
+            {
+                return null;
+            }
+        }
+
+        public bool Return(T item)
+        {
+            if (count < items.Length)
+            {
+                items[count++] = item;
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        public void Clear()
+        {
+            for (int i = 0; i < count; i++)
+                items[i] = null;
+            count = 0;
+        }
+    }
+}