diff --git a/Parallel/IpcParallel/SlaveTask.vb b/Parallel/IpcParallel/SlaveTask.vb
index dc00c75..c6088c6 100644
--- a/Parallel/IpcParallel/SlaveTask.vb
+++ b/Parallel/IpcParallel/SlaveTask.vb
@@ -2,63 +2,40 @@
 Imports System.Threading
 Imports Microsoft.VisualBasic.CommandLine.InteropService
 Imports Microsoft.VisualBasic.Language
-Imports Microsoft.VisualBasic.MIME.application.json
-Imports Microsoft.VisualBasic.MIME.application.json.BSON
-Imports Microsoft.VisualBasic.Scripting.MetaData
 
 Public Delegate Function ISlaveTask(processor As InteropService, port As Integer) As String
 
 Public Class SlaveTask
 
-    ReadOnly toBuffers As New Dictionary(Of Type, toBuffer)
-    ReadOnly loadBuffers As New Dictionary(Of Type, loadBuffer)
     ReadOnly processor As InteropService
     ReadOnly builder As ISlaveTask
     ReadOnly debugPort As Integer?
+    ReadOnly streamBuf As New StreamEmit
 
     Sub New(processor As InteropService, cli As ISlaveTask, Optional debugPort As Integer? = Nothing)
         Me.builder = cli
         Me.processor = processor
         Me.debugPort = debugPort
-
-        For Each [handle] In EmitHandler.PopulatePrimitiveHandles
-            toBuffers(handle.target) = handle.emit
-        Next
     End Sub
 
     Public Function Emit(Of T)(streamAs As Func(Of T, Stream)) As SlaveTask
-        toBuffers(GetType(T)) = Function(obj) streamAs(obj)
+        Call streamBuf.Emit(streamAs)
         Return Me
     End Function
 
     Public Function Emit(Of T)(fromStream As Func(Of Stream, T)) As SlaveTask
-        loadBuffers(GetType(T)) = Function(buf) fromStream(buf)
+        Call streamBuf.Emit(fromStream)
         Return Me
     End Function
 
     Private Function handlePOST(buf As Stream, type As Type, debugCode As Integer) As Object
         Call Console.WriteLine($"[{debugCode.ToHexString}] task finished!")
-
-        If loadBuffers.ContainsKey(type) Then
-            Return loadBuffers(type)(buf)
-        Else
-            Return BSONFormat.Load(buf).CreateObject(type)
-        End If
+        Return streamBuf.handleCreate(buf, type, StreamMethods.Auto)
     End Function
 
     Private Function handleGET(param As Object, i As Integer, debugCode As Integer) As ObjectStream
-        Dim type As Type = param.GetType
-
         Call Console.WriteLine($"[{debugCode.ToHexString}] get argument[{i + 1}]...")
-
-        If toBuffers.ContainsKey(type) Then
-            Return New ObjectStream(New TypeInfo(type, fullpath:=True), StreamMethods.Emit, toBuffers(type)(param))
-        Else
-            Dim element = type.GetJsonElement(param, New JSONSerializerOptions)
-            Dim buf As Stream = BSONFormat.SafeGetBuffer(element)
-
-            Return New ObjectStream(New TypeInfo(type, fullpath:=True), StreamMethods.BSON, buf)
-        End If
+        Return streamBuf.handleSerialize(param)
     End Function
 
     Public Function RunTask(Of T)(entry As [Delegate], ParamArray parameters As Object()) As T
@@ -102,27 +79,4 @@ Public Class SlaveTask
 
         Return result
     End Function
-
-    Private Function decomposingStdoutput(buffer As MemoryStream, type As Type, host As Integer) As Object
-        Using reader As New StreamReader(buffer)
-            Dim str As Value(Of String) = ""
-
-            Do While (str = reader.ReadLine) <> TaskBuilder.streamDelimiter
-                ' Call Console.WriteLine($"[{host.ToHexString}] {str.Value}")
-            Loop
-
-            Dim dataSize As Integer = Integer.Parse(reader.ReadLine)
-            Dim chunkBuffer As Byte() = New Byte(dataSize - 1) {}
-
-            Call Console.WriteLine($"[{host.ToHexString}] chunksize: {dataSize}/{buffer.Length}")
-
-            buffer.Seek(buffer.Length - dataSize, SeekOrigin.Begin)
-            buffer.Read(chunkBuffer, Scan0, chunkBuffer.Length)
-
-            Using resultBuffer As New MemoryStream(chunkBuffer)
-                Return handlePOST(resultBuffer, type, host)
-            End Using
-        End Using
-    End Function
-
 End Class
diff --git a/Parallel/IpcParallel/Stream/ObjectStream.vb b/Parallel/IpcParallel/Stream/ObjectStream.vb
index 0147109..b6ca5db 100644
--- a/Parallel/IpcParallel/Stream/ObjectStream.vb
+++ b/Parallel/IpcParallel/Stream/ObjectStream.vb
@@ -1,5 +1,6 @@
 Imports System.IO
 Imports System.Text
+Imports Microsoft.VisualBasic.ComponentModel.DataSourceModel
 Imports Microsoft.VisualBasic.Parallel
 Imports Microsoft.VisualBasic.Scripting.MetaData
 Imports Microsoft.VisualBasic.Serialization
@@ -14,6 +15,12 @@ Public Class ObjectStream : Inherits RawStream
     Public Property stream As Byte()
     Public Property type As TypeInfo
 
+    Public ReadOnly Property isPrimitive As Boolean
+        Get
+            Return DataFramework.IsPrimitive(type.GetType(knownFirst:=True))
+        End Get
+    End Property
+
     Sub New(type As TypeInfo, method As StreamMethods, stream As Stream)
         Me.method = method
         Me.stream = New StreamPipe(stream).Read
@@ -37,6 +44,10 @@ Public Class ObjectStream : Inherits RawStream
         End Using
     End Sub
 
+    Public Function openMemoryBuffer() As MemoryStream
+        Return New MemoryStream(stream)
+    End Function
+
     Public Overrides Function Serialize() As Byte()
         Using ms As New MemoryStream
             Dim json As Byte() = Encoding.UTF8.GetBytes(type.GetJson)
diff --git a/Parallel/IpcParallel/Stream/StreamEmit.vb b/Parallel/IpcParallel/Stream/StreamEmit.vb
new file mode 100644
index 0000000..e6f8d90
--- /dev/null
+++ b/Parallel/IpcParallel/Stream/StreamEmit.vb
@@ -0,0 +1,58 @@
+Imports System.IO
+Imports Microsoft.VisualBasic.MIME.application.json
+Imports Microsoft.VisualBasic.MIME.application.json.BSON
+Imports Microsoft.VisualBasic.Scripting.MetaData
+
+Public Class StreamEmit
+
+    ReadOnly toBuffers As New Dictionary(Of Type, toBuffer)
+    ReadOnly loadBuffers As New Dictionary(Of Type, loadBuffer)
+
+    Sub New()
+        For Each [handle] In EmitHandler.PopulatePrimitiveHandles
+            toBuffers(handle.target) = handle.emit
+        Next
+        For Each [handle] In EmitHandler.PopulatePrimitiveParsers
+            loadBuffers(handle.target) = handle.emit
+        Next
+    End Sub
+
+    Public Function Emit(Of T)(streamAs As Func(Of T, Stream)) As StreamEmit
+        toBuffers(GetType(T)) = Function(obj) streamAs(obj)
+        Return Me
+    End Function
+
+    Public Function Emit(Of T)(fromStream As Func(Of Stream, T)) As StreamEmit
+        loadBuffers(GetType(T)) = Function(buf) fromStream(buf)
+        Return Me
+    End Function
+
+    Public Function handleCreate(buf As Stream, type As Type, emit As StreamMethods) As Object
+        If emit = StreamMethods.Auto Then
+            If loadBuffers.ContainsKey(type) Then
+                Return loadBuffers(type)(buf)
+            Else
+                Return BSONFormat.Load(buf).CreateObject(type)
+            End If
+        ElseIf emit = StreamMethods.BSON Then
+            Return BSONFormat.Load(buf).CreateObject(type)
+        ElseIf loadBuffers.ContainsKey(type) Then
+            Return loadBuffers(type)(buf)
+        Else
+            Throw New NotImplementedException
+        End If
+    End Function
+
+    Public Function handleSerialize(param As Object) As ObjectStream
+        Dim type As Type = param.GetType
+
+        If toBuffers.ContainsKey(type) Then
+            Return New ObjectStream(New TypeInfo(type, fullpath:=True), StreamMethods.Emit, toBuffers(type)(param))
+        Else
+            Dim element = type.GetJsonElement(param, New JSONSerializerOptions)
+            Dim buf As Stream = BSONFormat.SafeGetBuffer(element)
+
+            Return New ObjectStream(New TypeInfo(type, fullpath:=True), StreamMethods.BSON, buf)
+        End If
+    End Function
+End Class
diff --git a/Parallel/IpcParallel/Stream/StreamMethods.vb b/Parallel/IpcParallel/Stream/StreamMethods.vb
index a794834..d7fb5bb 100644
--- a/Parallel/IpcParallel/Stream/StreamMethods.vb
+++ b/Parallel/IpcParallel/Stream/StreamMethods.vb
@@ -1,4 +1,5 @@
 Public Enum StreamMethods
+    Auto
     BSON
     Emit
 End Enum
diff --git a/Parallel/IpcParallel/TaskBuilder.vb b/Parallel/IpcParallel/TaskBuilder.vb
index 1e2e615..db8ad42 100644
--- a/Parallel/IpcParallel/TaskBuilder.vb
+++ b/Parallel/IpcParallel/TaskBuilder.vb
@@ -1,20 +1,18 @@
 Imports System.IO
 Imports System.Reflection
-Imports System.Text
 #If netcore5 = 1 Then
 Imports Microsoft.VisualBasic.ApplicationServices.Development.NetCore5
 #End If
 Imports Microsoft.VisualBasic.ComponentModel
 Imports Microsoft.VisualBasic.MIME.application.json
-Imports Microsoft.VisualBasic.MIME.application.json.BSON
 Imports Microsoft.VisualBasic.Net.Tcp
 Imports Microsoft.VisualBasic.Parallel
-Imports Microsoft.VisualBasic.Serialization
 Imports Microsoft.VisualBasic.Serialization.JSON
 
 Public Class TaskBuilder : Implements ITaskDriver
 
     ReadOnly masterPort As Integer
+    ReadOnly emit As New StreamEmit
 
     Sub New(port As Integer)
         masterPort = port
@@ -46,9 +44,14 @@ Public Class TaskBuilder : Implements ITaskDriver
 
         ' send debug message
         Call New TcpRequest(masterPort).SendMessage(New RequestStream(IPCSocket.Protocol, Protocols.PostStart))
-        Call PostFinished(api.Invoke(target, args.ToArray))
-        ' Call PostStdOut(api.Invoke(target, args.ToArray))
-        Call Console.WriteLine("job done!")
+
+        Try
+            Call PostFinished(api.Invoke(target, args.ToArray))
+        Catch ex As Exception
+            Call PostError(ex)
+        Finally
+            Call Console.WriteLine("job done!")
+        End Try
 
         Return 0
     End Function
@@ -78,11 +81,9 @@ Public Class TaskBuilder : Implements ITaskDriver
         Call deps.TryHandleNetCore5AssemblyBugs(package:=type)
 #End If
 
-        If stream.method = StreamMethods.BSON Then
-            Return BSONFormat.Load(stream.stream).CreateObject(type)
-        Else
-            Throw New NotImplementedException
-        End If
+        Using buf As MemoryStream = stream.openMemoryBuffer
+            Return emit.handleCreate(buf, type, stream.method)
+        End Using
     End Function
 
     Private Function PostError(err As Exception) As Integer
@@ -91,36 +92,16 @@ Public Class TaskBuilder : Implements ITaskDriver
         Return 500
     End Function
 
-    Friend Const streamDelimiter As String = "------endoftext------"
-
-    ''' <summary>
-    ''' 将结果数据写到标准输出上
-    ''' </summary>
-    ''' <param name="result"></param>
-    Private Sub PostStdOut(result As Object)
-        Dim type As Type = result.GetType
-        Dim element = type.GetJsonElement(result, New JSONSerializerOptions)
-        Dim buf As MemoryStream = BSONFormat.SafeGetBuffer(element)
-        Dim bufferSize As String = buf.Length
-        Dim outstream As Stream = Console.OpenStandardOutput
-
-        Call Console.WriteLine(streamDelimiter)
-        Call Console.WriteLine(bufferSize)
-        Call Console.Write(vbCrLf)
-
-        Using stdout As New BinaryWriter(outstream)
-            Call stdout.Write(buf.ToArray)
-            Call stdout.Flush()
-        End Using
-    End Sub
-
     Private Sub PostFinished(result As Object)
-        Dim type As Type = result.GetType
-        Dim element = type.GetJsonElement(result, New JSONSerializerOptions)
-        Dim buf As Stream = BSONFormat.SafeGetBuffer(element)
-        Dim request As New RequestStream(IPCSocket.Protocol, Protocols.PostResult, New StreamPipe(buf).Read)
-
-        Call Console.WriteLine($"post result: {type.GetObjectJson(result, indent:=False)}")
-        Call New TcpRequest(masterPort).SendMessage(request)
+        Using buf As Stream = emit.handleSerialize(result).openMemoryBuffer
+            Dim request As New RequestStream(
+                protocolCategory:=IPCSocket.Protocol,
+                protocol:=Protocols.PostResult,
+                buffer:=New StreamPipe(buf).Read
+            )
+
+            Call Console.WriteLine($"post result...")
+            Call New TcpRequest(masterPort).SendMessage(request)
+        End Using
     End Sub
 End Class
diff --git a/Parallel/Parallel.vbproj b/Parallel/Parallel.vbproj
index 4d474c3..a87b887 100644
--- a/Parallel/Parallel.vbproj
+++ b/Parallel/Parallel.vbproj
@@ -124,6 +124,7 @@
   <ItemGroup>
     <Compile Include="IpcParallel\IDelegate.vb" />
     <Compile Include="IpcParallel\IPCSocket.vb" />
+    <Compile Include="IpcParallel\Stream\StreamEmit.vb" />
     <Compile Include="IpcParallel\Stream\EmitHandler.vb" />
     <Compile Include="IpcParallel\Stream\ObjectStream.vb" />
     <Compile Include="IpcParallel\Protocols.vb" />