去掉obi，使用自写绳索

Assets/Obi/Scripts/Common/Backends/Interface/JobHandlePool.cs

@@ -1,40 +0,0 @@
-using System.Collections.Generic;
-
-namespace Obi
-{
-
-    /**
-     * Simple pool to avoid allocating job handles at runtime. Only a small number of handles
-     * are expected, so once a handle is borrowed from the pool it cannot be individually returned: all
-     * borrowed handles are returned to the pool at the end of each step. 
-     */
-    public class JobHandlePool<T> where T : IObiJobHandle , new()
-    {
-        private List<T> pool;
-        private int borrowedHandles;
-
-        public JobHandlePool(int initialSize)
-        {
-            borrowedHandles = 0;
-            pool = new List<T>(initialSize);
-            for (int i = 0; i < initialSize; ++i)
-                pool.Add(new T());
-        }
-
-        public T Borrow()
-        {
-            // expand pool if needed (no pool doubling, simply add one extra handle).
-            if (borrowedHandles == pool.Count)
-                pool.Add(new T());
-
-            return pool[borrowedHandles++];
-        }
-
-        public void ReleaseAll()
-        {
-            borrowedHandles = 0;
-            for (int i = 0; i < pool.Count; ++i)
-                pool[i].Release();
-        }
-    }
-}