gcUnmanagedToManaged MDA

The gcUnmanagedToManaged managed debugging assistant (MDA) causes a garbage collection whenever a thread transitions from unmanaged to managed code.

Symptoms

An application running unmanaged user components using COM and platform invoke is causing a nondeterministic access violation in the CLR.

Cause

If an application is running unmanaged user components, then those components might have corrupted the garbage-collected heap. This causes an access violation in the CLR when the garbage collector tries to walk the object graph.

Resolution

Enabling this assistant reduces the time between when the unmanaged component corrupts the garbage-collected heap and when the access violation happens by forcing a garbage collection to occur before every managed transition.

Effect on the Runtime

Causes a garbage collection whenever a thread transitions from unmanaged to managed code.

Output

This MDA produces no output.

Configuration

<mdaConfig>  
  <assistants>  
    <gcUnmanagedToManaged/>  
  </assistants>  
</mdaConfig>  

See Also

MarshalAsAttribute
Diagnosing Errors with Managed Debugging Assistants
gcManagedToUnmanaged
Interop Marshaling