Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on November 23, 2012 1:41 pm wrote:
> Every switch causes recompilation of all functions in that class and all other functions which
> they were inlined into. Do you understand the problem with your "optimization" now?

Modern JITs do not aggressively recompile the code they find, especially in cold paths. They have multiple tiers of execution starting with interpretation and all the way to full global optimization and specialization. On top of that all employ caching of compiled code, once something has been compiled there's no need to recompile it again

In the light of long-running programs the overheads are peanuts, especially considering the amount of freedom they give you. That's the difference between telling your boss that you have to stop your production deployment to restart it with logging enabled (or debugging, mind you) and just turning logging on, looking at whatever you need to look at and then turning it off again without a single glitch visible to the program's users.