Re: Simple COM EXE Server question [More queries]
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Hi it's virat here. and i was trying to create a MTA out-process server. =
i took help from the article
http://support.microsoft.com/kb/244495
and created my Exe Com server as MTA and then tried to call my exe from =
..NET using multiple threads at same time. i have following function in =
my COM Exe Server which i am calling from .NET.
STDMETHODIMP CMain::Check(BSTR bsInput, VARIANT *Result)
{
LogToFile(_T("Entered ... ")+(_bstr_t) (long) this =
+_T("\n"),_T("C:\\Chk.Log"));
_bstr_t bstMain = _T("");
try{
for (unsigned long a =0; a < 80000 ; a ++)
{
for (int x=0;x <100 ; x++)
int y= 0;
_bstr_t bstChk = _T("");
for (int i=0;i<10;i++)
{
bstChk += (_bstr_t)(long) a + _T("\n");
}
bstMain += (_bstr_t)(long) a + _T("\n");
//LogToFile(bstChk +_T("\t in Process ... ")+(_bstr_t) (long) this =
+_T("\n"),_T("C:\\Chk.Log"));
}
}
catch(...)
{
bstMain += (_bstr_t)(long)GetLastError();
}
Result->vt = VT_BSTR;
_bstr_t bstVal = (_bstr_t) bsInput;
Result->bstrVal = bstVal.copy();
LogToFile(_T("Ending ... ")+(_bstr_t) (long) this + _T(" with" ) + =
bstMain +_T("\n"),_T("C:\\Chk.Log"));
return S_OK;
}
and i used following code in .NET exe to call my com server in multiple =
threads
static int x = 0;
void chk()
{
Type Typ = Type.GetTypeFromProgID("Test.Main");
Object Obj = Activator.CreateInstance(Typ);
object[] ObjArr = new object[1];
ObjArr[0] = x.ToString() ;
x++;
object Result="";
try{
Result = Typ.InvokeMember("Check", BindingFlags.InvokeMethod, null, =
Obj, ObjArr);
}
catch(Exception e)
{
Exception ex = e.InnerException;
if (ex == null)
ex = e;
MessageBox.Show(ex.Message + " "+ ex.Source);
}
MessageBox.Show(Result.ToString());
}
private void button1_Click(object sender, EventArgs e)
{
Thread ChkThread = new Thread(new ThreadStart(chk));
ChkThread.Priority = ThreadPriority.Lowest;
ChkThread.IsBackground = true;
ChkThread.Start();
Thread ChkThread1 = new Thread(new ThreadStart(chk));
ChkThread1.Priority = ThreadPriority.Lowest;
ChkThread1.IsBackground = true;
ChkThread1.Start();
Thread ChkThrea2 = new Thread(new ThreadStart(chk));
ChkThrea2.Priority = ThreadPriority.Lowest;
ChkThrea2.IsBackground = true;
ChkThrea2.Start();
}
and when i run this test .net exe i am getting following error
Error HRESULT E_FAIL has been returned from a call to a COM component. =
mscorlib
The server threw an exception. (Exception from HRESULT: 0x80010105 =
(RPC_E_SERVERFAULT))
Please help inform me if i am missing any specific info to explain the =
problem.
Virat
"Igor Tandetnik" <itandetnik@mvps.org> wrote in message =
news:OHNjHDzbIHA.4196@TK2MSFTNGP04.phx.gbl...
Andy Larter <AndyLarter@discussions.microsoft.com> wrote:
Please can you confirm that my understanding of COM out-of-process
servers is correct.
1) The threading model of all objects in a COM EXE is determined by
the _ATL_FREE_THREADED or _ATL_APARTMENT_THREADED macro.
Not directly. The threading model is determined by whether the thread
that registers the class factory for the object has entered STA or =
MTA.
I'm talking about the thread that calls CoRegisterClassObject =
(possibly
indirectly via CAtlExeModuleT::RegisterClassObjects). Typically, but =
not
necessarily, that's the application's main thread.
Now, if you use CAtlExeModule in your application (as you would in a
default wizard-generated project), it initializes COM in its =
constructor
based on those macros, and registers class factories in its Run()
method. So if you want to play funny games with apartments, you can't
use CAtlExeModule and will have to roll equivalent functionality
yourself.
_ATL_FREE_THREADED and _ATL_APARTMENT_THREADED also determine whether
CComObjectRoot uses thread-safe reference counting. For your own
objects, you can derive from CComObjectRootEx instead and specify
explicitly whether or not you want it to be thread-safe. But you can't =
do this for class factories (unless you are willing to write a custom
one), so their thread-safety is controled by those macros. Naturally, =
if
you want the object to live in MTA, it has to be thread-safe. If the
object lives in STA, you can still make it thread-safe, it'll just add =
slight performance overhead.
2) You can't mix the threading model of objects in a COM EXE, they =
are
either all apartment or all free threaded, depending on the macro.
In principle, you can. You just register class factories for different =
CLSIDs from different apartments. But default ATL project setup is not =
designed for this, so it will take some work to suppress default
behavior and put in custom one.
In addition, it is possible to write a fancy class factory that, while =
itself registered on one apartment, actually creates objects in other
apartments. CComClassFactoryAutoThread does this.
3) The only way to use say a apartment threaded object in a free
threaded server is to host the object in a COM DLL.
Are you talking about objects the server itself implements? In =
addition
to techniques described in my response to question #2, you can create
your own object on an STA thread (which presumably you create
specifically for this purpose) with CComObject::CreateInstance,
completely bypassing COM registration and class factory mechanism. =
Don't
forget to marshal the object's interface pointer to your MTA thread, =
and
don't forget to run a message pump on your STA thread.
--
With best wishes,
Igor Tandetnik
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to =
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925
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<DIV><FONT face=Arial size=2>Hi it's virat here. and i was trying to =
create a
MTA out-process server. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>i took help from the =
article<BR></FONT><A
href="http://support.microsoft.com/kb/244495"><FONT face=Arial
size=2>http://support.microsoft.com/kb/244495</FONT></A></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>and created my Exe Com server as MTA =
and then tried
to call my exe from .NET using multiple threads at same time. i have
following function in my COM Exe Server which i am calling from
..NET.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>STDMETHODIMP CMain::Check(BSTR bsInput, =
VARIANT
*Result)<BR>{<BR> LogToFile(_T("Entered ... ")+(_bstr_t) (long) =
this
+_T("\n"),_T("C:\\Chk.Log"));<BR> _bstr_t bstMain =
_T("");<BR> try{<BR> for (unsigned long a =0; a < =
80000 ; a
++)<BR> {<BR> for (int x=0;x <100 ;
x++)<BR> int y= 0;<BR> _bstr_t =
bstChk
= _T("");<BR> for (int
i=0;i<10;i++)<BR> {<BR> bstC=
hk +=
(_bstr_t)(long) a +
_T("\n");<BR> }<BR> bstMain += =
(_bstr_t)(long)
a + _T("\n");<BR> //LogToFile(bstChk +_T("\t in Process =
....
")+(_bstr_t) (long) this
+_T("\n"),_T("C:\\Chk.Log"));<BR> }<BR> }<BR> catch(=
....)<BR> {<BR> bstMain
+= (_bstr_t)(long)GetLastError();<BR> }<BR> Result->vt =
=
VT_BSTR;<BR> _bstr_t bstVal = (_bstr_t)
bsInput;<BR> Result->bstrVal =
bstVal.copy();<BR> LogToFile(_T("Ending ... ")+(_bstr_t) (long) =
this + _T("
with" ) + bstMain +_T("\n"),_T("C:\\Chk.Log"));<BR> return
S_OK;<BR>}</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>and i used following code in .NET exe =
to call my
com server in multiple threads</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>
<P><FONT face=Arial size=2>static int x = 0;<BR>void =
chk()<BR>{<BR>Type Typ =
Type.GetTypeFromProgID("Test.Main");<BR>Object Obj =
Activator.CreateInstance(Typ);<BR>object[] ObjArr = new =
object[1];<BR>ObjArr[0]
= x.ToString() ;<BR>x++;<BR>object Result="";<BR>try{<BR>Result =
Typ.InvokeMember("Check", BindingFlags.InvokeMethod, null, Obj,
ObjArr);<BR>}<BR>catch(Exception e)<BR>{<BR>Exception ex =
e.InnerException;<BR>if (ex == null)<BR>ex = =
e;<BR>MessageBox.Show(ex.Message +
" "+ =
ex.Source);<BR>}<BR>MessageBox.Show(Result.ToString());<BR>}</FONT></P>
<P><FONT face=Arial size=2>private void button1_Click(object sender, =
EventArgs
e)<BR>{<BR>Thread ChkThread = new Thread(new
ThreadStart(chk));<BR>ChkThread.Priority =
ThreadPriority.Lowest;<BR>ChkThread.IsBackground =
true;<BR>ChkThread.Start();<BR>Thread ChkThread1 = new Thread(new
ThreadStart(chk));<BR>ChkThread1.Priority =
ThreadPriority.Lowest;<BR>ChkThread1.IsBackground =
true;<BR>ChkThread1.Start();<BR>Thread ChkThrea2 = new Thread(new
ThreadStart(chk));<BR>ChkThrea2.Priority =
ThreadPriority.Lowest;<BR>ChkThrea2.IsBackground =
true;<BR>ChkThrea2.Start();<BR>}</FONT></P>
<P><FONT face=Arial size=2>and when i run this test .net exe i am =
getting
following error</FONT></P></DIV>
<DIV><FONT face=Arial size=2>Error HRESULT E_FAIL has been returned =
from a call
to a COM component. mscorlib<BR></FONT><FONT face=Arial =
size=2>The server
threw an exception. (Exception from HRESULT: 0x80010105
(RPC_E_SERVERFAULT)) </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Please help inform me if i am missing =
any specific
info to explain the problem.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Virat</DIV>
<DIV><BR></DIV></FONT>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>"Igor Tandetnik" <</FONT><A
href="mailto:itandetnik@mvps.org"><FONT face=Arial
size=2>itandetnik@mvps.org</FONT></A><FONT face=Arial size=2>> =
wrote in
message </FONT><A =
href="news:OHNjHDzbIHA.4196@TK2MSFTNGP04.phx.gbl"><FONT
face=Arial =
size=2>news:OHNjHDzbIHA.4196@TK2MSFTNGP04.phx.gbl</FONT></A><FONT
face=Arial size=2>...</FONT></DIV><FONT face=Arial size=2>> =
Andy Larter
<</FONT><A href="mailto:AndyLarter@discussions.microsoft.com"><FONT =
face=Arial =
size=2>AndyLarter@discussions.microsoft.com</FONT></A><FONT
face=Arial size=2>> wrote:<BR>>> Please can you confirm =
that my
understanding of COM out-of-process<BR>>> servers is
correct.<BR>>><BR>>> 1) The threading model of all objects =
in a COM
EXE is determined by<BR>>> the _ATL_FREE_THREADED or
_ATL_APARTMENT_THREADED macro.<BR>> <BR>> Not directly. The =
threading
model is determined by whether the thread <BR>> that registers the =
class
factory for the object has entered STA or MTA. <BR>> I'm talking =
about the
thread that calls CoRegisterClassObject (possibly <BR>> indirectly =
via
CAtlExeModuleT::RegisterClassObjects). Typically, but not <BR>> =
necessarily,
that's the application's main thread.<BR>> <BR>> Now, if you use
CAtlExeModule in your application (as you would in a <BR>> default
wizard-generated project), it initializes COM in its constructor =
<BR>> based
on those macros, and registers class factories in its Run() <BR>> =
method. So
if you want to play funny games with apartments, you can't <BR>> use
CAtlExeModule and will have to roll equivalent functionality <BR>>
yourself.<BR>> <BR>> _ATL_FREE_THREADED and =
_ATL_APARTMENT_THREADED also
determine whether <BR>> CComObjectRoot uses thread-safe reference =
counting.
For your own <BR>> objects, you can derive from CComObjectRootEx =
instead and
specify <BR>> explicitly whether or not you want it to be =
thread-safe. But
you can't <BR>> do this for class factories (unless you are willing =
to write
a custom <BR>> one), so their thread-safety is controled by those =
macros.
Naturally, if <BR>> you want the object to live in MTA, it has to be
thread-safe. If the <BR>> object lives in STA, you can still make it
thread-safe, it'll just add <BR>> slight performance =
overhead.<BR>>
<BR>>> 2) You can't mix the threading model of objects in a COM =
EXE, they
are<BR>>> either all apartment or all free threaded, depending on =
the
macro.<BR>> <BR>> In principle, you can. You just register class =
factories
for different <BR>> CLSIDs from different apartments. But default ATL =
project
setup is not <BR>> designed for this, so it will take some work to =
suppress
default <BR>> behavior and put in custom one.<BR>> <BR>> In =
addition,
it is possible to write a fancy class factory that, while <BR>> =
itself
registered on one apartment, actually creates objects in other <BR>>
apartments. CComClassFactoryAutoThread does this.<BR>> <BR>>> =
3) The
only way to use say a apartment threaded object in a free<BR>>> =
threaded
server is to host the object in a COM DLL.<BR>> <BR>> Are you =
talking
about objects the server itself implements? In addition <BR>> to =
techniques
described in my response to question #2, you can create <BR>> your =
own object
on an STA thread (which presumably you create <BR>> specifically for =
this
purpose) with CComObject::CreateInstance, <BR>> completely bypassing =
COM
registration and class factory mechanism. Don't <BR>> forget to =
marshal the
object's interface pointer to your MTA thread, and <BR>> don't forget =
to run
a message pump on your STA thread.<BR>> -- <BR>> With best
wishes,<BR>> Igor Tandetnik<BR>> <BR>> With
sufficient thrust, pigs fly just fine. However, this is not <BR>> =
necessarily
a good idea. It is hard to be sure where they are going to <BR>> =
land, and it
could be dangerous sitting under them as they fly <BR>> overhead. -- =
RFC
1925<BR>> <BR>></FONT></BODY></HTML>
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