Thread overview
Fixing race issues the right way
Apr 05, 2020
solidstate1991
Apr 05, 2020
Stefan Koch
Apr 20, 2020
solidstate1991
Apr 06, 2020
Mathias LANG
April 05, 2020
My game engine is currently broken due to some race issue I don't really know how to resolve.

It seems that the compiler tries to skip instructions that are not locked with a `writeln()` or something similar. Usually I can safely remove the writeln after compiling it once with that way. However I've once ran into an issue when a previously working code just started to emit random junk data depending on CPU usage, and in that case the aforementioned workaround only partially worked (delaying crashes, etc).

I've heard something about Mutex, however I lack the experience with multithreading.
April 05, 2020
On Sunday, 5 April 2020 at 22:24:27 UTC, solidstate1991 wrote:
> My game engine is currently broken due to some race issue I don't really know how to resolve.
>
> It seems that the compiler tries to skip instructions that are not locked with a `writeln()` or something similar. Usually I can safely remove the writeln after compiling it once with that way. However I've once ran into an issue when a previously working code just started to emit random junk data depending on CPU usage, and in that case the aforementioned workaround only partially worked (delaying crashes, etc).
>
> I've heard something about Mutex, however I lack the experience with multithreading.

Look at your program in a debugger and see if it does spawn threads.
If it does find out where and why they are spawned.
April 06, 2020
On Sunday, 5 April 2020 at 22:24:27 UTC, solidstate1991 wrote:
> My game engine is currently broken due to some race issue I don't really know how to resolve.
>
> It seems that the compiler tries to skip instructions that are not locked with a `writeln()` or something similar. Usually I can safely remove the writeln after compiling it once with that way. However I've once ran into an issue when a previously working code just started to emit random junk data depending on CPU usage, and in that case the aforementioned workaround only partially worked (delaying crashes, etc).
>
> I've heard something about Mutex, however I lack the experience with multithreading.

Is there public code you can link to ?
Look for any usage of `__gshared`. Are you using `shared` as well ? Turn on `-preview=nosharedaccess` to get better diagnostic. Are you using any `extern` code ? How do you communicate between threads ? Message passing, or simple shared memory ?
April 20, 2020
On Sunday, 5 April 2020 at 22:33:50 UTC, Stefan Koch wrote:
>
> Look at your program in a debugger and see if it does spawn threads.
> If it does find out where and why they are spawned.

Thanks for the answer, but it seems the issue was the lack of the ability of unittesting such a large package. So I broke out collections-d similarly to other projects.