is there a better way to handle RPC_E_CALL_REJECTED exceptions when doing visual studio automation?

Question

this is what I'm currently doing:

    protected void setupProject()
    {
        bool lbDone = false;
        int liCount = 0;
        while (!lbDone && liCount < pMaxRetries)
        {
            try
            {
                pProject.ProjectItems.Item("Class1.cs").Delete();
                lbDone = true;
            }
            catch (System.Runtime.InteropServices.COMException loE)
            {
                liCount++;
                if ((uint)loE.ErrorCode == 0x80010001)
                {
                    // RPC_E_CALL_REJECTED - sleep half sec then try again
                    System.Threading.Thread.Sleep(pDelayBetweenRetry);
                }
            }
        }
    }

now I have that try catch block around most calls to the EnvDTE stuff, and it works well enough. The problem I have is when I to loop through a collection and do something to each item once.

foreach(ProjectItem pi in pProject.ProjectItems)
{
    // do something to pi
}

Sometimes I get the exception in the foreach(ProjectItem pi in pProject.ProjectItems) line. Since I don't want to start the foreach loop over if I get the RPC_E_CALL_REJECTED exception I'm not sure what I can do.

Edit to answer comment: Yes I'm automating VS from another program and yes I usually am using VS for something else at the same time. We have an application that reads an xml file then generates around 50 VS solutions based on the xml file. This usually takes a couple of hours so I try to do other work while this is happening.

Answer 1

There is a solution on this MSDN page: How to: Fix 'Application is Busy' and 'Call was Rejected By Callee' Errors. It shows how to implement a COM IOleMessageFilter interface so that it will automatically retry the call.

Answer 2

First, Hans doesn't want to say so but the best answer to "how to do this" is "don't do this". Just use separate instances of visual studio for your automation and your other work, if at all possible.

You need to take your problem statement out somewhere you can handle the error. You can do this by using in integer index instead of foreach.

// You might also need try/catch for this!
int cProjectItems = pProject.ProjectItems.Length;
for(iProjectItem = 0; iProjectItem < cProjectItems; iProjectItem++)
{
   bool bSucceeded = false;
   while(!bSucceeded)
   {
        try{
            ProjectItem pi = pProject.ProjectItems[iProjectItem];
            // do something with pi
            bSucceeded = true;
        }catch (System.Runtime.InteropServices.COMException loE)
        {
            liCount++;
            if ((uint)loE.ErrorCode == 0x80010001)                      {
                // RPC_E_CALL_REJECTED - sleep half sec then try again
                System.Threading.Thread.Sleep(pDelayBetweenRetry);
            }
        }  
   }

}