Thread- PostUIMessage throws com_error Exceptions

Question

We have developed a TestStand (4.2) OI including a tracelogger function. Code moduls (dll's coded in C++) used in sequences can send trace messages to the OI using the PostUIMessage function (see following code):
  try
    // Get the thread that is
executing from the Sequence Context  
    thread =
seqContext->GetThread();
    thread->PostUIMessage(
static_cast<enum
UIMessageCodes>(UIMsg_UserMessageBase+4)
,Level
                          ,_bstr_t(Msg)
,TRUE);
  catch( _com_error &com_error ) /* TestStand API only
throws this kind of exception */
It happens that every 10ms a message is send. In general this works well both when running the sequence in the sequence editor and in our OI. But after a time spawn of about 10 min to a few hours (depends on the frequency of the messages) the PostUIMessage throws a com_error Exception.
Remark: The code is declared as critical section to ensure it works in multi threaded environments too.
Does someone has an idea what might be the reason for these exceptions and how to avoid them?
Thanks in advance
Peter
Solved!
Go to Solution.

Answer 1

Mr.Doug,
              Thanks for the Valuable reply. I am sorry for my late reply.
I have applied the thread priorities to all threads and there is no change in CPU time ( No effect using multi threading concept). I would like to know in detail Mr.Doug..
My Problem :
                   1) Collecting data (which is a flaw location from plate) with the help of ultrasonic waves and its real time data, I am displaying the flaw location which is collected (using PCL 1751 cards) in the Graphical format. Here i am not getting the actual position of the flaw. Due to the time delay.
Solution implemented :
                   1) Implemeted multi thread concept but still facing the same issues.
Example:
Actual flaw position say : 120 MM (from plate)
First time when i execute my application it shows : 110 MM
Next time when i execute it shows as                    : 113 MM
Like this it varying every time.
Could you please help me out to sort this issue.
Thanks and Expecting the Solution....