Command recycling and disposing during pipelined async multi-exec; enable...

Command recycling and disposing during pipelined async multi-exec; enable pipeline (via sync-over-async) for sync API

Dapper NET40/Properties/AssemblyInfo.cs

@@ -32,5 +32,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

Dapper NET40/SqlMapper.cs

@@ -884,6 +884,13 @@ private static int ExecuteImpl(this IDbConnection cnn, ref CommandDefinition com
             CacheInfo info = null;
             if (multiExec != null && !(multiExec is string))
             {
+#if ASYNC
+                if((command.Flags & CommandFlags.Pipelined) != 0)
+                {
+                    // this includes all the code for concurrent/overlapped query
+                    return ExecuteMultiImplAsync(cnn, command, multiExec).Result;
+                }
+#endif
                 bool isFirst = true;
                 int total = 0;
                 bool wasClosed = cnn.State == ConnectionState.Closed;

Dapper NET45/SqlMapperAsync.cs

@@ -72,6 +72,16 @@ public static Task<int> ExecuteAsync(this IDbConnection cnn, CommandDefinition c
             }
         }
        
+        private struct AsyncExecState
+        {
+            public readonly DbCommand Command;
+            public readonly Task<int> Task;
+            public AsyncExecState(DbCommand command, Task<int> task)
+            {
+                this.Command = command;
+                this.Task = task;
+            }
+        }
         private static async Task<int> ExecuteMultiImplAsync(IDbConnection cnn, CommandDefinition command, IEnumerable multiExec)
         {
             bool isFirst = true;
@@ -82,30 +92,55 @@ private static async Task<int> ExecuteMultiImplAsync(IDbConnection cnn, CommandD
                 if (wasClosed) await ((DbConnection)cnn).OpenAsync().ConfigureAwait(false);
                 
                 CacheInfo info = null;
+                string masterSql = null;
                 if ((command.Flags & CommandFlags.Pipelined) != 0)
                 {
                     const int MAX_PENDING = 100;
-                    var pending = new Queue<Task<int>>(MAX_PENDING);
+                    var pending = new Queue<AsyncExecState>(MAX_PENDING);
+                    DbCommand cmd = null;
+                    try
+                    {
                         foreach (var obj in multiExec)
                         {
-                        var cmd = (DbCommand)command.SetupCommand(cnn, null);
                             if (isFirst)
                             {
                                 isFirst = false;
+                                cmd = (DbCommand)command.SetupCommand(cnn, null);
+                                masterSql = cmd.CommandText;
                                 var identity = new Identity(command.CommandText, cmd.CommandType, cnn, null, obj.GetType(), null);
                                 info = GetCacheInfo(identity, obj);
+                            } else if(pending.Count >= MAX_PENDING)
+                            {
+                                var recycled = pending.Dequeue();
+                                total += await recycled.Task.ConfigureAwait(false);
+                                cmd = recycled.Command;
+                                cmd.CommandText = masterSql; // because we do magic replaces on "in" etc
+                                cmd.Parameters.Clear(); // current code is Add-tastic
+                            }
+                            else
+                            {
+                                cmd = (DbCommand)command.SetupCommand(cnn, null);
                             }
                             info.ParamReader(cmd, obj);
+
                             var task = cmd.ExecuteNonQueryAsync(command.CancellationToken);
-                        pending.Enqueue(task);
-                        if(pending.Count == MAX_PENDING)
-                        {
-                            total += await pending.Dequeue().ConfigureAwait(false);
+                            pending.Enqueue(new AsyncExecState(cmd, task));
+                            cmd = null; // note the using in the finally: this avoids a double-dispose
                         }
+                        while (pending.Count != 0)
+                        {
+                            var pair = pending.Dequeue();
+                            using (pair.Command) { } // dispose commands
+                            total += await pair.Task.ConfigureAwait(false);
                         }
-                    while(pending.Count != 0)
+                    } finally
                     {
-                        total += await pending.Dequeue().ConfigureAwait(false);
+                        // this only has interesting work to do if there are failures
+                        using (cmd) { } // dispose commands
+                        while (pending.Count != 0)
+                        { // dispose tasks even in failure
+                            using (pending.Dequeue().Command) { } // dispose commands
+                        }
                     }
                     return total;
                 }
@@ -113,7 +148,6 @@ private static async Task<int> ExecuteMultiImplAsync(IDbConnection cnn, CommandD
                 {
                     using (var cmd = (DbCommand)command.SetupCommand(cnn, null))
                     {
-                        string masterSql = null;
                         foreach (var obj in multiExec)
                         {
                             if (isFirst)

Dapper.Contrib.Tests/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

Dapper.Contrib/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

Dapper.SqlBuilder/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

DapperTests NET35/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

DapperTests NET45/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

DapperTests NET45/Tests.cs

@@ -209,10 +209,10 @@ public void LiteralIn()
         }
 
 
-        public void RunSequentialVersusParallel()
+        public void RunSequentialVersusParallelAsync()
         {
 
-            var ids = Enumerable.Range(1, 2000).Select(id => new { id }).ToArray();
+            var ids = Enumerable.Range(1, 20000).Select(id => new { id }).ToArray();
             using (var connection = Program.GetOpenConnection(true))
             {
                 connection.ExecuteAsync(new CommandDefinition("select @id", ids.Take(5), flags: CommandFlags.None)).Wait();
@@ -228,6 +228,26 @@ public void RunSequentialVersusParallel()
                 System.Console.WriteLine("Pipeline: {0}ms", watch.ElapsedMilliseconds);
             }
         }
+
+        public void RunSequentialVersusParallelSync()
+        {
+
+            var ids = Enumerable.Range(1, 20000).Select(id => new { id }).ToArray();
+            using (var connection = Program.GetOpenConnection(true))
+            {
+                connection.Execute(new CommandDefinition("select @id", ids.Take(5), flags: CommandFlags.None));
+
+                var watch = Stopwatch.StartNew();
+                connection.Execute(new CommandDefinition("select @id", ids, flags: CommandFlags.None));
+                watch.Stop();
+                System.Console.WriteLine("No pipeline: {0}ms", watch.ElapsedMilliseconds);
+
+                watch = Stopwatch.StartNew();
+                connection.Execute(new CommandDefinition("select @id", ids, flags: CommandFlags.Pipelined));
+                watch.Stop();
+                System.Console.WriteLine("Pipeline: {0}ms", watch.ElapsedMilliseconds);
+            }
+        }
         class Product
         {
             public int Id { get; set; }

Tests/Properties/AssemblyInfo.cs

@@ -31,5 +31,5 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.24.0.0")]
-[assembly: AssemblyFileVersion("1.24.0.0")]
+[assembly: AssemblyVersion("1.25.0.0")]
+[assembly: AssemblyFileVersion("1.25.0.0")]

dapper.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
   <metadata schemaVersion="2">
     <id>Dapper</id>
-    <version>1.24</version>
+    <version>1.25</version>
     <title>Dapper dot net</title>
     <authors>Sam Saffron,Marc Gravell</authors>
     <owners>Sam Saffron,Marc Gravell</owners>
@@ -19,6 +19,7 @@
       <frameworkAssembly assemblyName="Microsoft.CSharp" targetFramework=".NETFramework4.0-Client, .NETFramework4.0" />
     </frameworkAssemblies>
     <releaseNotes>
+      * 1.25    - Command recycling and disposing during pipelined async multi-exec; enable pipeline (via sync-over-async) for sync API
       * 1.24    - Implement pipelined async multi-exec, when flag is specified (only - requires MARS etc)
       * 1.23    - Improved support for optimize hints (@foo unknown) with list expansions
       * 1.22    - Literal support now extends to enumerable types (for "in" etc usage); move to command-flags model for "buffered" etc