LDC optimized builds causing unexpected behaviour when sharing variable between threads

[Keivan Shah]

On Wednesday, 1 June 2022 at 16:46:51 UTC, kinke wrote:
> On Wednesday, 1 June 2022 at 13:35:45 UTC, Keivan Shah wrote:
>> probably will use 
>> [core.atomic.atomicFence](https://dlang.org/phobos/core_atomic.html#.atomicFence) to ensure the memoryOrdering.
>
> `core.atomic.atomic{Load,Store}` handle this:
>
> ```
> void main()
> {
>     import std.stdio : writeln;
>     import core.thread;
>     import core.atomic;
>
>     writeln("Starting...");
>     shared bool done = false;
>     new Thread({ atomicStore(done, true); }).start();
>     while (!atomicLoad(done))
>     {
>     } // Wait for done
>     writeln("Done!");
> }
> ``

Hey kinke,
Thanks for the snippet, I have some existing code that follows 
the pattern similar to the example I had given. There are a lot 
of variables that are shared between the 2 threads and so instead 
of changing the reads and writes for every variable to be 
`atomic{Store,Load}`, I was thinking if `atomicFence` might 
achieve the same effect with far lesser code change requirements. 
Would that be recommended or should I use `atomic{Store,Load}` 
instead?

Regards and Thanks,
Keivan Shah