Hi there! I think I just found a concurrency issue...

# koin

[sloydev]

Hi there! I think I just found a concurrency issue in Koin. After a few weeks hunting a crash we were having in production, I found out that Koin was sometimes creating more than one instance of a dependency declared as single.
I've isolated the issue to a concurrency bug in SingleInstanceFactory. I have an (ugly) test reproducing it, and a possible solution. It's tricky because the probability of happening is very low, but it happens ^^'
@arnaud.giuliani would you like me to open a PR? Or do you prefer to discuss it here before?

[arnaud.giuliani]

open PR & propose test to reproduce it, sure 👍

[arnaud.giuliani]

let’s continue to talk also here

[sloydev]

ok, great! I'll try to do that tomorrow morning 🙂

[arnaud.giuliani]

sure, thanks

[sloydev]

Here you go! I tried to explain everything the best I could
https://github.com/InsertKoinIO/koin/pull/914

[arnaud.giuliani]

yep, when you talked about that yesteray, I was looking at the double check and the get part effectively

[arnaud.giuliani]

answered, we can remove synchronized from create part then

[sloydev]

cool! I wasn't sure if create is used for anything else. I'll remove it 🙂

[arnaud.giuliani]

yes, create is just used by get 🙂

[arnaud.giuliani]

thanks

[sloydev]

glad I could help!