Passing a COM object as a parameter via Remoting

[Catherine Jones]

Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[Tom Carter]

Hi Catherine,

First off there is no color that I can see in this post so it's a
bit difficult to follow. However, a couple of ideas come to mind.. No
firewall issues right?, Can you go back to the single directional
channels and verify that the port is actually open and ready to
recieve/transmit data? netstat...

else try...

TcpChannel channel = new TcpChannel(9000);
ChannelServices.RegisterChannel(channel);

SampleWellKnown objectWellKnown = new SampleWellKnown();

// After the channel is registered, the object needs to be registered
// with the remoting infrastructure. So, Marshal is called.
ObjRef objrefWellKnown = RemotingServices.Marshal(objectWellKnown,
"objectWellKnownUri");
Console.WriteLine("An instance of SampleWellKnown type is published at
{0}.", objrefWellKnown.URI);

Console.WriteLine("Press enter to unregister SampleWellKnown, so that
it is no longer available on this channel.");
Console.ReadLine();
RemotingServices.Disconnect(objectWellKnown);

Console.WriteLine("Press enter to end the server process.");
Console.ReadLine();

~~~~~~~~~~~~~
Tommie Carter
www.premiertechnology.com
--

Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[enrico sabbadin @ infinito]

drop
ChannelServices.RegisterChannel (new TcpChannel(0));

on startup in the "process" throwing the exception.



about hanging .. you might be facing an STA thread lock due to reentrancy ..
have a look at this

http://www.dotnetremoting.cc/FAQs/Handling_Events_Hangs_Application.asp (the
link might be invalid, ingo site has moved if i rememebr well)


you can download from here
(http://www.codearchitects.com/casubscription/default.aspx) a message
brokering system implemented in .net remoting which shows how to handle
correctly the above mentioned issues.



p.s.: i think you should avoid passing com objects across machine and
process boundaries .. you are asking for troubles ..

there are security issues and marshaling implementatin bugs for some -
execution flow/object type passed - patterns

IMO

Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[Catherine Jones]

Hi Enrico

Thanks for your time.
Although I'm able to find the issue related to hanging problem

( it was due to reentrancy problem ),

I come up to two solutions for this problem to solve:

1. Is to span a new worker thread

2. to use Moniker ( using the api createObjRefMoniker )

I just want your input on, if using createObjRefMoniker is safe ?

Regards.

drop
ChannelServices.RegisterChannel (new TcpChannel(0));

on startup in the "process" throwing the exception.



about hanging .. you might be facing an STA thread lock due to reentrancy ...
have a look at this

http://www.dotnetremoting.cc/FAQs/Handling_Events_Hangs_Application.asp (the
link might be invalid, ingo site has moved if i rememebr well)


you can download from here
(http://www.codearchitects.com/casubscription/default.aspx) a message
brokering system implemented in .net remoting which shows how to handle
correctly the above mentioned issues.



p.s.: i think you should avoid passing com objects across machine and
process boundaries .. you are asking for troubles ..

there are security issues and marshaling implementatin bugs for some -
execution flow/object type passed - patterns

IMO

Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[enrico sabbadin @ infinito]

I've faced the problem in a message brokering system. In this case I put the
message in a .net queue , where another thread picks it up and deliver the
message. Using async delegate or the trhead pool is not an option if you
need to guarantee message / method call delivery order

I've never used createObjRefMoniker , will you elaborate on this option ?

Hi Enrico

Thanks for your time.
Although I'm able to find the issue related to hanging problem

( it was due to reentrancy problem ),

I come up to two solutions for this problem to solve:

1. Is to span a new worker thread

2. to use Moniker ( using the api createObjRefMoniker )

I just want your input on, if using createObjRefMoniker is safe ?

Regards.

drop
ChannelServices.RegisterChannel (new TcpChannel(0));

on startup in the "process" throwing the exception.



about hanging .. you might be facing an STA thread lock due to

reentrancy

..
have a look at this

http://www.dotnetremoting.cc/FAQs/Handling_Events_Hangs_Application.asp (the
link might be invalid, ingo site has moved if i rememebr well)


you can download from here
(http://www.codearchitects.com/casubscription/default.aspx) a message
brokering system implemented in .net remoting which shows how to handle
correctly the above mentioned issues.



p.s.: i think you should avoid passing com objects across machine and
process boundaries .. you are asking for troubles ..

there are security issues and marshaling implementatin bugs for some -
execution flow/object type passed - patterns

IMO

Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does

not
come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[Catherine Jones]

Hello Enrico
Firstly thanks a lot for all your help and time.
I really appreciate that you are following up with me here.
Please help me resolve the issue.
We're making an MTA thread ( by default all the worker threads are MTA ) and there by we are marshalling our com object in this thread using
RuntimeServices.Marshal() and then unmarshal it in the worker thread using RuntimeServices.UnMarshal() and then call the method on server

passing this marshalled object.So what happens is that the Trasparent Proxy object lies with the main thread whereas the servercall goes on the child thread.

We prototyped it and it seems to work fine.

createObjRefMoniker :

Well in this case we create a named moniker of our com object and pass that name to server instead of the object itself, now using this name we get the com object reference on server and call the method on this.

Regards

Catherine

I've faced the problem in a message brokering system. In this case I put the
message in a .net queue , where another thread picks it up and deliver the
message. Using async delegate or the trhead pool is not an option if you
need to guarantee message / method call delivery order

I've never used createObjRefMoniker , will you elaborate on this option ?

Hi Enrico

Thanks for your time.
Although I'm able to find the issue related to hanging problem

( it was due to reentrancy problem ),

I come up to two solutions for this problem to solve:

1. Is to span a new worker thread

2. to use Moniker ( using the api createObjRefMoniker )

I just want your input on, if using createObjRefMoniker is safe ?

Regards.

drop
ChannelServices.RegisterChannel (new TcpChannel(0));

on startup in the "process" throwing the exception.



about hanging .. you might be facing an STA thread lock due to

reentrancy

..
have a look at this

http://www.dotnetremoting.cc/FAQs/Handling_Events_Hangs_Application.asp (the
link might be invalid, ingo site has moved if i rememebr well)


you can download from here
(http://www.codearchitects.com/casubscription/default.aspx) a message
brokering system implemented in .net remoting which shows how to handle
correctly the above mentioned issues.



p.s.: i think you should avoid passing com objects across machine and
process boundaries .. you are asking for troubles ..

there are security issues and marshaling implementatin bugs for some -
execution flow/object type passed - patterns

IMO



Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this application has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not
come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!

 

[enrico sabbadin @ infinito]

thanks about the info on createObjRefMoniker.

using :
RuntimeServices.Marshal() and then unmarshal it in the worker thread using
RuntimeServices.UnMarshal() and then call the method on server

sounds like the coorect equivalent of what you had to do on native code , so
i think you are in the correct path

however, another option i think of is to use the GIT (global interface
table) to (marshal once, get a token, unmarshal (many times) using the
token)

btw , did you solve
------
System.Runtime.Remoting.RemotingException: This remoting proxy has no
channel sink which means either the server has no registered server channels
that are listening, or this application has no suitable client channel to
talk to the server."
------

dropping
ChannelServices.RegisterChannel (new TcpChannel(0));
on the client side ?


Hello Enrico
Firstly thanks a lot for all your help and time.
I really appreciate that you are following up with me here.
Please help me resolve the issue.
We're making an MTA thread ( by default all the worker threads are MTA ) and
there by we are marshalling our com object in this thread using
RuntimeServices.Marshal() and then unmarshal it in the worker thread using
RuntimeServices.UnMarshal() and then call the method on server

passing this marshalled object.So what happens is that the Trasparent Proxy
object lies with the main thread whereas the servercall goes on the child
thread.

We prototyped it and it seems to work fine.

createObjRefMoniker :

Well in this case we create a named moniker of our com object and pass that
name to server instead of the object itself, now using this name we get the
com object reference on server and call the method on this.

Regards

Catherine

I've faced the problem in a message brokering system. In this case I put the
message in a .net queue , where another thread picks it up and deliver the
message. Using async delegate or the trhead pool is not an option if you
need to guarantee message / method call delivery order

I've never used createObjRefMoniker , will you elaborate on this option ?

Hi Enrico

Thanks for your time.
Although I'm able to find the issue related to hanging problem

( it was due to reentrancy problem ),

I come up to two solutions for this problem to solve:

1. Is to span a new worker thread

2. to use Moniker ( using the api createObjRefMoniker )

I just want your input on, if using createObjRefMoniker is safe ?

Regards.

drop
ChannelServices.RegisterChannel (new TcpChannel(0));

on startup in the "process" throwing the exception.



about hanging .. you might be facing an STA thread lock due to

reentrancy

..
have a look at this

http://www.dotnetremoting.cc/FAQs/Handling_Events_Hangs_Application.asp
(the

link might be invalid, ingo site has moved if i rememebr well)


you can download from here
(http://www.codearchitects.com/casubscription/default.aspx) a message
brokering system implemented in .net remoting which shows how to handle
correctly the above mentioned issues.



p.s.: i think you should avoid passing com objects across machine and
process boundaries .. you are asking for troubles ..

there are security issues and marshaling implementatin bugs for some -
execution flow/object type passed - patterns

IMO



Hi all, we need urgent help in a matter.

We are trying to pass a COM object from the client to server and are

facing some problems in the same.

We've our client in C# as well as the Server in C# and we're using

remoting for client to server communication.

Out client first creates an object of type System.__ComObject and

then passes it to our server using remoting, the

scenario can be visualized as :-



Com Server

Component A Exposing Interface IA and IB

C# Client

Type comType = Type.GetTypeFromCLSID( CLSID_A )

object objDisp = Activator.CreateInstance( comType );

TcpChannel chnl = new TcpChannel( 8086 );

ChannelServices.RegisterChannel( chnl );

//Through Reflection now we call a method on this IA which returns

Dispatch of IB ( in C# we get this as System.__ComObject )

Now we're creating a CAO for our component CSA and call the method

which expects as parameter the System.__ComObject Created earlier

RemotingConfiguration.RegisterActivatedClientType( typeof( CSA ),

"tcp://8085" );

CSA objCSA = new CSA.CSA();

objCSA.getSomething( objDisp );









C# Assembly

Component CSA





protected object m_objSess;

CSA::getSomething( objDisp )

{

m_objSess = objDisp;

//Now using reflection we call a method of this

System.__ComObject passed as parameter


}







C# Server

BinaryServerFormatterSinkProvider prov = new

BinaryServerFormatterSinkProvider();

prov.TypeFilterLevel = TypeFilterLevel.Full;


IDictionary prop = new HashTable();


prop["port"] = 8085;

TcpChannel chnl = new TcpChannel( prop, null, prov );

ChannelServices.RegisterChannel( chnl );

RemotingConfiguration.RegisterActivatedServiceType( typeof( CSA ) );



System.Console.Readline();






Now on executing the code ,at line marked in red it throws an

exception telling that "System.Runtime.Remoting.RemotingException: This

remoting proxy has no channel sink which means either the server has

no registered server channels that are listening, or this

application
has

no suitable client channel to talk to the server."

To remove this we opened a bi-directional ( as shown in the code

with blue color ) channel but when we do this the call hangs ( does not
come

out ) from the line marked in red ( while invoking the method using

reflection ).



Could you please throw some light on the missing snippets of code if

any and provide us some guideline as to how to proceed to make the calls

successful.

Thanks a lot for your time!