Global Variable Strategy Tester Question

 

Is there a variable of any kind that I can access from an expert which persists across strategy tester optimization runs?

I have tried GlobalVariable functions however they don't appear to persist across optimization tests.

I don't want to resort to using files as that seems like a hack and potentially problematic with multithreaded access. (Again with no global variable available for the expert in the strategy tester, I can't lock across expert instances) 

Documentation on MQL5: File Functions / FileSize
  • www.mql5.com
File Functions / FileSize - Documentation on MQL5