From 6e4193f4a8a6b94bf32b593730719b7bc6d56c64 Mon Sep 17 00:00:00 2001
From: Ben Adams <thundercat@illyriad.co.uk>
Date: Mon, 15 Feb 2016 13:00:23 +0000
Subject: [PATCH] ValueTask

---
 dnx/Program.cs   | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 dnx/project.json |  9 ++---
 2 files changed, 91 insertions(+), 4 deletions(-)

diff --git a/dnx/Program.cs b/dnx/Program.cs
index fd85054..31e0330 100644
--- a/dnx/Program.cs
+++ b/dnx/Program.cs
@@ -50,6 +50,18 @@ private static void Run(bool output)
             }
             CleanUp();
 
+            sw.Restart();
+            var x5 = skynetValueTaskAsync(0, limit, 10).Result;
+            sw.Stop();
+            var t5 = sw.Elapsed.TotalMilliseconds;
+
+            if (output)
+            {
+                Console.WriteLine(x5);
+                Console.WriteLine($"1 Thread - ValueTask Async: {t5:0.000}ms");
+            }
+            CleanUp();
+
             sw.Restart();
             var x3 = skynetThreadpoolAsync(0, limit, 10).Result;
             sw.Stop();
@@ -62,6 +74,18 @@ private static void Run(bool output)
             }
             CleanUp();
 
+            sw.Restart();
+            var x6 = skynetThreadpoolValueTaskAsync(0, limit, 10).Result;
+            sw.Stop();
+            var t6 = sw.Elapsed.TotalMilliseconds;
+
+            if (output)
+            {
+                Console.WriteLine(x5);
+                Console.WriteLine($"Parallel - ValueTask Async: {t6:0.000}ms");
+            }
+            CleanUp();
+
             sw.Restart();
             var x4 = skynetParallel(0, limit, 10);
             sw.Stop();
@@ -73,6 +97,7 @@ private static void Run(bool output)
                 Console.WriteLine($"Parallel Sync: {t4:0.000}ms");
             }
             CleanUp();
+
         }
 
         private static long skynetSync(long num, long size, long div)
@@ -142,6 +167,67 @@ static long skynetAggregator(Task<long[]> children)
             return sumAsync;
         }
 
+
+        private static ValueTask<long> skynetValueTaskAsync(long num, long size, long div)
+        {
+            if (size == 1)
+            {
+                return num;
+            }
+            else
+            {
+                long subtotal = 0;
+                List<Task<long>> tasks = null;
+                
+                for (var i = 0; i < div; i++)
+                {
+                    var sub_num = num + i * (size / div);
+                    var task = skynetValueTaskAsync(sub_num, size / div, div);
+                    if (task.IsCompleted)
+                    {
+                        subtotal += task.Result;
+                    }
+                    else
+                    {
+                        if (tasks == null)
+                        {
+                            tasks = new List<Task<long>>((int)div);
+                        }
+                        tasks.Add(task.AsTask());
+                    }
+                }
+
+                if (tasks == null)
+                {
+                    return subtotal;
+                }
+                else if (subtotal > 0)
+                {
+                    tasks.Add(Task.FromResult(subtotal));
+                }
+                return Task.WhenAll(tasks).ContinueWith(skynetAggregator);
+            }
+        }
+
+        private static Task<long> skynetThreadpoolValueTaskAsync(long num, long size, long div)
+        {
+            if (size == 1)
+            {
+                return Task.FromResult(num);
+            }
+            else
+            {
+                var tasks = new List<Task<long>>((int)div);
+                for (var i = 0; i < div; i++)
+                {
+                    var sub_num = num + i * (size / div);
+                    var task = Task.Run(() => skynetValueTaskAsync(sub_num, size / div, div).AsTask());
+                    tasks.Add(task);
+                }
+                return Task.WhenAll(tasks).ContinueWith(skynetAggregator);
+            }
+        }
+
         private static long skynetParallel(long num, long size, long div)
         {
             if (size == 1)
diff --git a/dnx/project.json b/dnx/project.json
index 36eb6d7..0cb015b 100644
--- a/dnx/project.json
+++ b/dnx/project.json
@@ -4,10 +4,11 @@
         "emitEntryPoint": true
     },
 
-    "dependencies": {
-        "NETStandard.Library": "1.0.0-rc2-23811",
-        "System.Threading.Tasks.Parallel": "4.0.1-rc2-23805"
-    },
+  "dependencies": {
+    "NETStandard.Library": "1.0.0-rc2-23811",
+    "System.Threading.Tasks.Extensions": "4.0.0-rc2-23812",
+    "System.Threading.Tasks.Parallel": "4.0.1-rc2-23805"
+  },
 
     "frameworks": {
         "dnxcore50": { }