Error at CreateProcess, after setting parentprocess with UpdateProcThreadAttribute
Hi there,
our main application is called bei a starte rapplication, which checks for updates, installs them and then calls the main application. If the starter application is called via Explorer it's running as a child process of Explorer. When the starter application calls the main application, the main application is running as a child process of the starter application until the starter application closes itself automatically. After that the main process is running seperatly and not as a child process, which causes problems later on. I tried to solve this by setting the parent process of the main application to Explorer. Therefore I've translated the following code to VB.NET, which calls Notepad with any parent process:
Code:
Imports System.Diagnostics
Imports System.IO
Imports System.Runtime.InteropServices
Public Class ProcessCreator_Test
<DllImport("kernel32.dll")> _
Private Shared Function CreateProcess(lpApplicationName As String, lpCommandLine As String, ByRef lpProcessAttributes As SECURITY_ATTRIBUTES, ByRef lpThreadAttributes As SECURITY_ATTRIBUTES, bInheritHandles As Boolean, dwCreationFlags As UInteger, _
lpEnvironment As IntPtr, lpCurrentDirectory As String, <[In]> ByRef lpStartupInfo As STARTUPINFOEX, ByRef lpProcessInformation As PROCESS_INFORMATION) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True)> _
Private Shared Function UpdateProcThreadAttribute(ByRef lpAttributeList As IntPtr, dwFlags As UInteger, Attribute As IntPtr, lpValue As IntPtr, cbSize As IntPtr, lpPreviousValue As IntPtr, _
lpReturnSize As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True)> _
Private Shared Function InitializeProcThreadAttributeList(ByRef lpAttributeList As IntPtr, dwAttributeCount As Integer, dwFlags As Integer, ByRef lpSize As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True)> _
Private Shared Sub DeleteProcThreadAttributeList(ByRef lpAttributeList As IntPtr)
End Sub
Public Shared Function CreateProcess(parentProcessId As Integer) As Boolean
Const EXTENDED_STARTUPINFO_PRESENT As UInteger = &H80000
Const PROC_THREAD_ATTRIBUTE_PARENT_PROCESS As Integer = &H20000
Dim pInfo As PROCESS_INFORMATION = New PROCESS_INFORMATION()
Dim sInfoEx As STARTUPINFOEX = New STARTUPINFOEX()
sInfoEx.StartupInfo = New STARTUPINFO()
sInfoEx.StartupInfo.cb = Marshal.SizeOf(sInfoEx)
If parentProcessId > 0 Then
Dim lpSize = IntPtr.Zero
Dim success = InitializeProcThreadAttributeList(Nothing, 1, 0, lpSize)
If success OrElse lpSize = IntPtr.Zero Then
Return False
End If
sInfoEx.lpAttributeList = Marshal.AllocHGlobal(lpSize)
If sInfoEx.lpAttributeList = IntPtr.Zero Then
Return False
End If
success = InitializeProcThreadAttributeList(sInfoEx.lpAttributeList, 1, 0, lpSize)
If Not success Then
Return False
End If
Dim parentHandle = Process.GetProcessById(parentProcessId).Handle
success = UpdateProcThreadAttribute(sInfoEx.lpAttributeList, 0, New IntPtr(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS), parentHandle, New IntPtr(Marshal.SizeOf(parentHandle)), Nothing, Nothing)
If Not success Then
Return False
End If
End If
Dim pSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
Dim tSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
pSec.nLength = Marshal.SizeOf(pSec)
tSec.nLength = Marshal.SizeOf(tSec)
Dim lpApplicationName = Path.Combine(Environment.SystemDirectory, "notepad.exe")
Return CreateProcess(lpApplicationName, Nothing, pSec, tSec, False, EXTENDED_STARTUPINFO_PRESENT, _
IntPtr.Zero, Nothing, sInfoEx, pInfo)
DeleteProcThreadAttributeList(sInfoEx.lpAttributeList)
End Function
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Private Structure STARTUPINFOEX
Public StartupInfo As STARTUPINFO
Public lpAttributeList As IntPtr
End Structure
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Private Structure STARTUPINFO
Public cb As Int32
Public lpReserved As String
Public lpDesktop As String
Public lpTitle As String
Public dwX As Int32
Public dwY As Int32
Public dwXSize As Int32
Public dwYSize As Int32
Public dwXCountChars As Int32
Public dwYCountChars As Int32
Public dwFillAttribute As Int32
Public dwFlags As Int32
Public wShowWindow As Int16
Public cbReserved2 As Int16
Public lpReserved2 As IntPtr
Public hStdInput As IntPtr
Public hStdOutput As IntPtr
Public hStdError As IntPtr
End Structure
<StructLayout(LayoutKind.Sequential)> _
Friend Structure PROCESS_INFORMATION
Public hProcess As IntPtr
Public hThread As IntPtr
Public dwProcessId As Integer
Public dwThreadId As Integer
End Structure
<StructLayout(LayoutKind.Sequential)> _
Public Structure SECURITY_ATTRIBUTES
Public nLength As Integer
Public lpSecurityDescriptor As IntPtr
Public bInheritHandle As Integer
End Structure
End Class
This code is called with Explorer as parent process like following:
Code:
ProcessCreator_test.CreateProcess(Process.GetProcessesByName("explorer")(0).Id)
Unfortunately the CreateProcess call leads to the following error (in German):
Die Laufzeit hat einen schwerwiegenden Fehler entdeckt. Fehleradresse: "0x7316d1be" in Thread "0x1718". Fehlercode: 0xc0000005. Bei diesem Fehler könnte es sich um ein Problem in der CLR oder in den unsicheren oder nicht verifizierbaren Teilen des Benutzercodes handeln. Übliche Ursachen dieses Bugs sind Marshallerfehler für COM-Interop oder PInvoke, die den Stapel beschädigen können.
Could you please help me to solve this Problem?
Thanks a lot
Re: Error at CreateProcess, after setting parentprocess with UpdateProcThreadAttribut
Windows doesn't have the concept of 'child' processes. It could be that you are relying on some environment settings that aren't getting passed; however, short of these, once one process launches another process, Windows doesn't track any interaction between the processes.
