Changeset 2571 for trunk/eraser/Eraser.Manager/EntropyPoller.cs

Timestamp:

3/22/2012 2:58:33 AM (14 months ago)

Author:

lowjoel

Message:

Use our MemoryXor? function to invert the pool, instead of writing another loop. Performance for this code is about 10% faster than the unsafe loop, on average, on x64.

File:

• trunk/eraser/Eraser.Manager/EntropyPoller.cs (modified) (3 diffs)

trunk/eraser/Eraser.Manager/EntropyPoller.cs

@@ -46 +46 @@
         public EntropyPoller()
         {
-            //Create the pool.
+            //Create the pool and its complement.
             Pool = new byte[sizeof(uint) << 7];
+            PoolInvert = new byte[Pool.Length];
+            for (uint i = 0, j = (uint)PoolInvert.Length; i < j; ++i)
+                PoolInvert[i] = byte.MaxValue;
 
             //Handle the Entropy Source Registered event.
@@ -162 +165 @@
 
         /// <summary>
-        /// Inverts the contents of the pool
+        /// Inverts the contents of the pool.
         /// </summary>
         private void InvertPool()
         {
             lock (PoolLock)
-                unsafe
-                {
-                    fixed (byte* fPool = Pool)
-                    {
-                        uint* pPool = (uint*)fPool;
-                        uint poolLength = (uint)(Pool.Length / sizeof(uint));
-                        while (poolLength-- != 0)
-                            *pPool = (uint)(*pPool++ ^ uint.MaxValue);
-                    }
-                }
+            {
+                MemoryXor(PoolInvert, 0, Pool, 0, Pool.Length);
+            }
         }
 
@@ -323 +319 @@
 
         /// <summary>
+        /// A pool, the same size as <see cref="Pool"/>, but containing all bitwise 1's
+        /// for XOR for pool inversion
+        /// </summary>
+        private byte[] PoolInvert;
+
+        /// <summary>
         /// The next position where entropy will be added to the pool.
         /// </summary>