I have a program that I run and in the middle I get this message:
Managed Debugging Assistant 'ContextSwitchDeadlock' has detected a problem in 'C:\Documents and Settings\Lena G\My Documents\SchoolStuff\IR Information\Home Work\FianlProject\finalProject\finalProject\bin\Debug\finalProject.vshost.exe'.
Additional Information: The CLR has been unable to transition from COM context 0x3407968 to COM context 0x3407ad8 for 60 seconds. The thread that owns the destination context/apartment is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages. This situation generally has a negative performance impact and may even lead to the application becoming non responsive or memory usage accumulating continually over time. To avoid this problem, all single threaded apartment (STA) threads should use pumping wait primitives (such as CoWaitForMultipleHandles) and routinely pump messages during long running operations.
I understand that it has something to do with the fact that it runs for 60 seconds without stopping or something like that? How is it a problem?
I also put [STAThread] before the main of my program because if I remove it then it shows me this message:
An unhandled exception of type 'System.Threading.ThreadStateException' occurred in System.Windows.Forms.dll
Additional information: Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it. This exception is only raised if a debugger is attached to the process.
Anyone know how I can solve this problem?
Thanks in advance,
Lena
You need to make sure that your thread that owns the COM component isn't being "locked up" via processing for >60 seconds.
What's probably happening is that you have a COM object in a form, and you're doing work on the UI thread. If your UI gets blocked by the processing for >60 seconds, the COM component can complain.
Consider using a BackgroundWorker instance to handle your long running process. This would push the work onto a background thread, and allow the COM component to process messages without complaints.
It is a warning that's generated when you make calls on an ActiveX object from a background thread and your main thread is blocked. Perhaps more likely: there was a bug in the retail version of Visual Studio 2005 that tripped this warning for no good reason. It got fixed in Service Pack 1, be sure you have that installed. Yet another workaround is to shut it up. Debug + Exceptions, Managed Debugging Assistants, untick the ContextSwitchDeadlock warning. But use SP1 if you don't have it.
Related
I'm getting a
ContextSwitchDeadlock
when adding a CustomXMLPart after performing a Documents.Add().
The same code was working fine last week..
I understand that ContextSwitchDeadlock is caused by a long running operation (this is not a duplicate question).
Why would the CustomXMLParts.Add() command result in a long running operation?
Anyone come across this? and any ideas how to troubleshoot?
ContextSwitchDeadlock occurred Message: Managed Debugging Assistant
'ContextSwitchDeadlock' has detected a problem in 'C:\Program Files
(x86)\Microsoft Office\root\Office16\WINWORD.EXE'. Additional
information: The CLR has been unable to transition from COM context
0xfdb520 to COM context 0xfdb468 for 60 seconds. The thread that owns
the destination context/apartment is most likely either doing a non
pumping wait or processing a very long running operation without
pumping Windows messages. This situation generally has a negative
performance impact and may even lead to the application becoming non
responsive or memory usage accumulating continually over time. To
avoid this problem, all single threaded apartment (STA) threads should
use pumping wait primitives (such as CoWaitForMultipleHandles) and
routinely pump messages during long running operations.
The context switch deadlock can show up when debugging a long running process. For the most part you can ignore it if the process is expected to be long running.
see previous stackoverflow answer
I'll start by saying I do not have a lot of experience in troubleshooting multi-threading problems. So a lot of what I've read about debugging race conditions, dead locks, live locks, etc. are strictly theoretical to me.
I have this .NET application that is making use of a dynamically loaded native win32 dll. If the dll is never loaded the application terminates without a problem. However, if the dll is loaded then when the user exits the application the UI disappears but the process never terminates.
I've turned on native code debugging in the project settings so I can see all the threads that are running. When the user closes the application window the main thread appears to terminate. I know this because if I perform a Break All in the Threads windows in Visual Studio the main thread is re-categorized as a worker thread and there is no call stack available for it. There are 20 other threads still active, all with call stacks. I've looked through the call stacks for all of these threads and nothing sticks out at me (there's no mention of the dll in any of the call stacks).
What steps can I take to narrow down the cause of this problem? Are there any additional tools I should be using to help pin point the problem?
This means that some of your Foreground Threads are still alive. Unlike Background Threads, Foreground Threads keeps the process alive.
You should either use Background Threads or Stop your Foregrounds Threads to be able to exit the process gracefully.
Windows application will automatically exit when all of its thread(s) are stopped.
As you said
If the dll is never loaded the application terminates without a
problem
I'm assuming all the running threads are unmanaged threads(not created by clr). There is no concept of background threads in native code. All threads must be terminated to terminate the process.
You must find a way to signal all threads to exit in that library. See if you have any api exposed for that.
If you don't find anything, you've got a "Sledge Hammer" approach. i.e Terminate the process with Environment.Exit which works almost always. Be sure you use this approach as a last resort as this can corrupt the process state.
A couple of days ago I began to get an error with a c# winform application I've been creating stating that
The CLR has been unable to transition from COM context 0x278f58 to COM context 0x2790c8 for 60 seconds. The thread that owns the destination context/apartment
is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages.
This is occuring when I am using a separate thread to run exe processes to avoid freezing up the ui. In a release version, this program runs fine and as expected but pretty much makes it impossible to consistently debug my program (sometimes works fine, others not so fine)..
I've tried implementing this process by forcing a BackgroundWorker to be synchronous using multiple googled answers which solves the issue of this error but makes my program work in unexpected ways (textboxes populated before exe finished resulting in erroneous data).
I have read that this error will only occur in production and not in a release.. so my question is should I just try to live with this annoyance or is their a non backgroundworker solution? If any code example is needed I can provide but I don't believe it is necessary
The Managed Debugging Assistant (MDA) is telling you that a single-threaded apartment (STA) COM thread hasn't responded to a message in 60 seconds. STA COM is done through message passing. This exception occurs if MDA is switched on, which it is by default when running under a debugger. The MDA works to detect deadlock with a pre-defined timeout, and it's only effective when you're running the program under the VS debugger.
Since many COM components are STA and the main thread in Windows Forms is also STA, this is a warning that you’re blocking. This is probably occurring because you are stalling the message loop by spending time stepping through code.
To switch this off for a single project, add the following content to your application configuration file:
<mdaConfig>
<assistants>
<contextSwitchDeadlock enable="false" />
</assistants>
</mdaConfig>
To switch this off globally:
Click on the Debug menu in Visual Studio.
Choose the Exceptions option (Debug -> Exceptions).
The Exceptions window will open.
Expand the "Managed Debugging Assistants" node.
Uncheck the ContextSwitchDeadlock option under the Thrown column.
Click OK and close the Exceptions window.
The implication of disabling this MDA is that you lose a useful tool for discovering bugs before you release the application. Of course if you see this deadlock when not running under the debugger then you need to do a normal deadlock analysis.
While debugging an application i am getting the following error.
The CLR has been unable to transition from COM context 0x3b2d70 to COM
context 0x3b2ee0 for 60 seconds. The thread that owns the destination
context/apartment is most likely either doing a non pumping wait or
processing a very long running operation without pumping Windows
messages. This situation generally has a negative performance impact
and may even lead to the application becoming non responsive or memory
usage accumulating continually over time. To avoid this problem, all
single threaded apartment (STA) threads should use pumping wait
primitives (such as CoWaitForMultipleHandles) and routinely pump
messages during long running operations.
Why system throws this error.
I got the solution
Need to uncheck ContextSwitchDeadlock under Debug->Exceptions->Managed Debugging Assistants.
After unchecking ContextSwitchDeadlock its not throwing the error.
I have this simple code:
public void Run()
{
var invokerThread = new Thread(new ThreadStart(RunOnBackground));
invokerThread.Start();
}
private void RunOnBackground()
{
Trace.WriteLine("hi");
...
}
Unfortunately when running this code (from third party process) the thread doesn't really run.
Either in process explorer and in VS debugger I see that the thread is created and its state is "Running".
The main thread's apartment is STA and I've tried both STA and MTA on internal thread.
When I add to the Run() method at the end invokerThread.Join(); then the thread does run. But then again it doesn't really help.
What am I missing?
Edit: Here is some more information regarding the code hosting -
Run() method is called via COM interop from a process which is also managed executable assembly (the reason COM interop is used is because all other components in the system are native).
The method RunOnBackground() includes some more code after the tracing and generally its execution lasts between 10 - 20 seconds, including starting another process and waiting for its termination. Also I have some other areas in the code where I write some debug information to the Trace. While debugging the code, Run() runs as usual and after invokerThread.Start(); invokerThread's state is "Running" (though breakpoints inside the RunOnBackground() method don't stop).
When I add invokerThread.Join() at the end of the Run() method the debugger goes to RunOnBackground() after the Join().
There's some crucial information missing about what RunOnBackground() really does. This is otherwise a good match for what happens when you use apartment threaded COM objects on a worker thread. COM automatically marshals any method call on such an object from the worker thread to the STA thread on which it was created.
That can only work well when the STA thread observes STA threading requirements. It must pump a message loop and cannot block. Breaking those rules makes deadlock very likely, the worker thread call cannot complete until the STA thread dispatches the marshaled call. A sure sign that this is what is going on is seeing Thread.Join() solve the problem. It pumps a message loop internally in the CLR when it is called on an STA thread.
To diagnose this, you'll need Debug + Windows + Threads to see what that worker thread is blocking on. If my guess is right, it will be buried deep inside of the COM plumbing code, waiting for the marshaled call to complete. You can only see this by enabling unmanaged code debugging and setting up the Microsoft Symbol Server so you get debugging symbols for the plumbing code and get a reliable stack trace.
Fixing this is going to be difficult. You cannot magically flip a switch and make code run on a thread when it has explicitly stated that it doesn't support multi-threading. It is imperative that you create the instance of the COM object on the same thread that calls its methods. And that thread has to be an STA thread. Check this sample code for the approach. If you don't control the creation of the COM object then you're stuck.
I may say something stupid, but here is what I saw in MSDN Threads.
Look at the examples section at the end.
The output of the example is interesting, you can see there that the Thread created and started only starts executing when the main thread does a Sleep(0) or a Thread.Join().
It seems to be what exactly happens to you, doesn't it ?
Maybe try with a Sleep(0) on your main thread to really launch your working Thread.
Another workaround would be to use the BackGroundWorker.
As its name says it, it works on the Background and is really easy to use. It may be of much use to you.