Hi *
I'm implementing a provider using the MSSCCI. I need to call the callback function LPTEXTOUTPROC of the IDE (VS2005) in another thread. So evertime SccOpenProject ois called a new thead will be created and the function pointer is passed. Calling LPTEXTOUTPROC works great in any direct Scc* call, but somehow it's not working when called in the thread - I'm really clueless how I can make this work...
simplified, this is what I try in the scc dll:
in SccOpenProject:
...
if (lpTextOutProc != NULL){
lpTextOutProc("test",SCC_MSG_ERROR); //a test, works great
m_hCallbackDispatchThread = CreateThread( NULL, 0, callbackDispatchThreadFunc, lpTextOutProc, 0, NULL);

...
in the callbackDispatchThreadFunc:
DWORD WINAPI callbackDispatchThreadFunc( LPVOID lpParam ){
LPTEXTOUTPROC txtout = reinterpret_cast<LPTEXTOUTPROC>(lpParam);
txtout("test",SCC_MSG_ERROR); //a test, doesn't work
...

Is there any way to use the LPTEXTOUTPROC function pointer passed in SccOpenProject in another thread?
Florian

Sinceyou're getting an error, it looks like the callback function can't be used from another thread (at least in VisualStudio as IDE).

I think what's going on is that VS is trying to get the Output window service (SID_SVsOutputWindow) and use it to write the message in the output window. In VS services can't be obtained directly from background threads with a simple QueryService call - they have to be marshaled, and scci code does not do that.

Even more, in VS10 with the shell being implemented as WPF, accessing the UI elements (e.g. to display the message) can only be done on the thread that created them, which is the UI/main thread. Again, in VS the scci code does not expect this function to be called from background threads and won't marshal the call back to the UI thread.

You'll have to do the thread synchronization/call marshaling yourself in the MSSCCI provider code, and do the textout callback from the main thread.

Alin

Sinceyou're getting an error, it looks like the callback function can't be used from another thread (at least in VisualStudio as IDE).

I think what's going on is that VS is trying to get the Output window service (SID_SVsOutputWindow) and use it to write the message in the output window. In VS services can't be obtained directly from background threads with a simple QueryService call - they have to be marshaled, and scci code does not do that.

Even more, in VS10 with the shell being implemented as WPF, accessing the UI elements (e.g. to display the message) can only be done on the thread that created them, which is the UI/main thread. Again, in VS the scci code does not expect this function to be called from background threads and won't marshal the call back to the UI thread.

You'll have to do the thread synchronization/call marshaling yourself in the MSSCCI provider code, and do the textout callback from the main thread.

Alin

Hi Alin,

Many thanks for the information, I assumed the Marshalling would be the reason, but not sure. Now it's clear. :-)

Sincerely,
Wesley

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Hi Wesley, hi Alin,

as usual: many thank for the answer! I really appreciate your fast replies.
Regarding the function call: I already feared, it wouldn't be possible to solve this the easy way - I forward the MSSCCI calls to to a Java component, which is responsible for processing the call. This is done synchronously via JNI :/
So it seems, there is no way around the threading-game.

Thanks again

Sincerely,
Florian