ObjectARX, threads problem??

[suparhigh12345]

If I have a function called 'linedraw' whose purpose is to create an 'acdb' object, and that function runs on a different thread using std::thread, I encounter an error with an 'Unhandled Access Violation Reading' message. The primary goal of running this function on a separate thread is to prevent it from blocking the main AutoCAD application. However, when I attempt to call this function inside the ARX entry point as follows:

....

case AcRx::kInitAppMsg:

std::thread(linedraw).detach(); // !!!!!!!

break;

etc...

I encounter the mentioned error. My intention is to avoid blocking the main AutoCAD app, especially when dealing with functions that may run indefinitely, such as calculations. Is there a solution for this scenario? Additionally, if I have the 'linedraw' function that should be triggered automatically (not from the command window) and can be initiated from another void() function or an external UI, is there a way to achieve this without causing the AutoCAD application to become unresponsive?

[daniel_cadext · Accepted solution]

ObjectARX is not thread-safe and multithreading is not supported...

https://help.autodesk.com/view/OARX/2023/ENU/?guid=GUID-85F9B4B9-1949-4BA2-AE95-8FB85CC5CE47

[suparhigh12345]

Does this mean that there is no way to utilize ObjectARX from a different thread, and is it impossible to include an infinite loop calculation as a function inside 'kInitAppMsg' without blocking the AutoCAD application?

[moogalm · Accepted solution]

Yes, you can't call any AcDb* API from different thread other than main thread. 

[daniel_cadext]

Maybe you can use an event, a command event, AcedWatchWinMsgFn or on idle

[Alexander.Rivilis · Accepted solution]

How to use threads in ObjectARX?