I have a C callback that must call some functions declared in D. I can't call them off the C thread because it will result in a violation. What is a good way to dispatch the call to the main D program?

I'm thinking that I might have to create an extra thread that monitors for when a call needs to occur and does so. Doesn't seem very effective though? Does anyone know how C# does it?

On Wednesday, 6 September 2017 at 05:57:18 UTC, Psychological Cleanup wrote:
> I'm thinking that I might have to create an extra thread that monitors for when a call needs to occur and does so.

Would work.
If your code doesn't conflict with GC, it's fine to work in an unregistered thread.

On Wednesday, 6 September 2017 at 05:57:18 UTC, Psychological Cleanup wrote:
> I have a C callback that must call some functions declared in D. I can't call them off the C thread because it will result in a violation. What is a good way to dispatch the call to the main D program?
>
> I'm thinking that I might have to create an extra thread that monitors for when a call needs to occur and does so. Doesn't seem very effective though? Does anyone know how C# does it?

1/ mark the D function as "extern(C)".
2/ take care to how things are passed to the D functions, especially arrays.
3/ take care not to mutate memory created from the D side...i.e copy after the call.

On Wednesday, 6 September 2017 at 09:47:34 UTC, user1234 wrote:
> On Wednesday, 6 September 2017 at 05:57:18 UTC, Psychological Cleanup wrote:
>> I have a C callback that must call some functions declared in D. I can't call them off the C thread because it will result in a violation. What is a good way to dispatch the call to the main D program?
>>
>> I'm thinking that I might have to create an extra thread that monitors for when a call needs to occur and does so. Doesn't seem very effective though? Does anyone know how C# does it?
>
> 1/ mark the D function as "extern(C)".
> 2/ take care to how things are passed to the D functions, especially arrays.
> 3/ take care not to mutate memory created from the D side...i.e copy after the call.

This wont work. The callback must be relatively performant and must access the D code on the D side normally.