diff --git a/Parallel/IPCSocket.vb b/Parallel/IPCSocket.vb
index 5355527..8cab67e 100644
--- a/Parallel/IPCSocket.vb
+++ b/Parallel/IPCSocket.vb
@@ -63,6 +63,7 @@ Public Class IPCSocket : Implements ITaskDriver
 
     <Protocol(Protocols.GetTask)>
     Public Function GetTask(request As RequestStream, remoteAddress As System.Net.IPEndPoint) As BufferPipe
+        Call Console.WriteLine($"[{GetHashCode.ToHexString}] get parallel task entry.")
         Return New DataPipe(Encoding.UTF8.GetBytes(target.GetJson))
     End Function
 
@@ -75,6 +76,12 @@ Public Class IPCSocket : Implements ITaskDriver
         Return pipe
     End Function
 
+    <Protocol(Protocols.PostStart)>
+    Public Function PostStart(request As RequestStream, remoteAddress As System.Net.IPEndPoint) As BufferPipe
+        Call Console.WriteLine($"[{GetHashCode.ToHexString}] started!")
+        Return New DataPipe(Encoding.UTF8.GetBytes("OK!"))
+    End Function
+
     <Protocol(Protocols.GetArgumentNumber)>
     Public Function GetArgumentNumber(request As RequestStream, remoteAddress As System.Net.IPEndPoint) As BufferPipe
         Return New DataPipe(BitConverter.GetBytes(nargs))
diff --git a/Parallel/Protocols.vb b/Parallel/Protocols.vb
index 5ce6078..2ae25f7 100644
--- a/Parallel/Protocols.vb
+++ b/Parallel/Protocols.vb
@@ -2,5 +2,6 @@
     GetTask
     GetArgumentNumber
     GetArgumentByIndex
+    PostStart
     PostResult
 End Enum
diff --git a/Parallel/SlaveTask.vb b/Parallel/SlaveTask.vb
index ab6b3ce..4bfe1d7 100644
--- a/Parallel/SlaveTask.vb
+++ b/Parallel/SlaveTask.vb
@@ -31,7 +31,9 @@ Public Class SlaveTask
         Return Me
     End Function
 
-    Private Function handlePOST(buf As Stream, type As Type) As Object
+    Private Function handlePOST(buf As Stream, type As Type, debugCode As Integer) As Object
+        Call Console.WriteLine($"[{debugCode.ToHexString}] task finished!")
+
         If fromBuffer.ContainsKey(type) Then
             Return fromBuffer(type)(buf)
         Else
@@ -39,9 +41,11 @@ Public Class SlaveTask
         End If
     End Function
 
-    Private Function handleGET(param As Object) As ObjectStream
+    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
@@ -55,12 +59,16 @@ Public Class SlaveTask
     Public Function RunTask(entry As [Delegate], ParamArray parameters As Object()) As Object
         Dim target As New IDelegate(entry)
         Dim result As Object = Nothing
-        Dim host As New IPCSocket(target, debugPort) With {
-            .handlePOSTResult = Sub(buf) result = handlePOST(buf, entry.Method.ReturnType),
+        Dim host As IPCSocket = Nothing
+
+        host = New IPCSocket(target, debugPort) With {
+            .handlePOSTResult = Sub(buf) result = handlePOST(buf, entry.Method.ReturnType, host.GetHashCode),
             .nargs = parameters.Length,
-            .handleGetArgument = Function(i) handleGET(parameters(i))
+            .handleGetArgument = Function(i) handleGET(parameters(i), i, host.GetHashCode)
         }
 
+        Call Console.WriteLine($"[{host.GetHashCode.ToHexString}] port:{host.HostPort}")
+
         Call New Thread(AddressOf host.Run).Start()
         Call Thread.Sleep(100)
 
diff --git a/Parallel/TaskBuilder.vb b/Parallel/TaskBuilder.vb
index 4c5702d..f7bdda6 100644
--- a/Parallel/TaskBuilder.vb
+++ b/Parallel/TaskBuilder.vb
@@ -35,6 +35,8 @@ Public Class TaskBuilder : Implements ITaskDriver
             End If
         Next
 
+        ' send debug message
+        Call New TcpRequest(masterPort).SendMessage(New RequestStream(IPCSocket.Protocol, Protocols.PostStart))
         Call PostFinished(api.Invoke(Nothing, args.ToArray))
 
         Return 0