topic Memory Corruption error of ArcObjects in multithreading environment in ArcObjects SDK Questions

Memory Corruption error of ArcObjects in multithreading environment

AnilDhiman — Wed, 21 Jul 2010 14:52:08 GMT

In our program, we are trying to indentify differences between two different versions of Geodatabases

Inorder to increase the performance, we are trying to run Arcobjects in a multithreaded environment. We have created IWorkspaceFactory per thread

We are facing below mentioned error
The thread 'Win32 Thread' (0x2058) has exited with code 0 (0x0).
HEAP[KernUpdater.exe]: Heap block at 1C6D87B8 modified at 1C6D899C past requested size of 1dc
Windows has triggered a breakpoint in KernUpdater.exe.

Even though this error is random, it generally occurs when we are trying to do a
ITable.opentable or ITable.search or differenceCursor.next functions

This error crops up when these functions are invoked by different threads at the same time. We have ensured that the workspaces instances are not shared across threads, even though they are connecting to the same databases.

Can any one please help?

Re: Memory Corruption error of ArcObjects in multithreading environment

KirkKuykendall — Wed, 21 Jul 2010 15:25:53 GMT

Try following the pattern in the raster subset example, but instead of creating a thread for each raster band, create a thread for each table.
http://resources.esri.com/help/9.3/arcgisengine/dotnet/ViewCodePages/a520994c-1b3b-4036-a2ca-89dc76333a16SubsetRasterTool.cs.htm

Re: Memory Corruption error of ArcObjects in multithreading environment

AnilDhiman — Wed, 21 Jul 2010 15:59:30 GMT

Thanks for the quick response

We may get functional errors if we create one thread per table. In our application we are serializing the propertyset and then creating workspace at the thread level, but since the connection parameters are same for the threads, the same reference of workspace would be used...

I read this from ESRI documentation

"Workspaces are not singleton objects, but requesting a workspace with the same properties as an existing instance returns a reference to it (referred to as unique instancing)."

Is the shared workspace causing access violation exception?