On 01/24/2014 09:36 PM, Andrej Golovnin wrote: > Could you please explain it a little bit more? When is that > optimization applied, e.g. what conditions are required for this > optimization, since which version of JDK/Hotspot it is supported, > where it is implemented in JDK? > > When I take look at a product I'm working on, I see a lot instances > of ArrayList$Itr objects, which are created by for-each loops (we > use JDK 7u51).
Rather than asking these questions, you should have a look: Read the bytecode javac generates. Build a debug JVM and look at the assembly code HotSpot produces. Turn on GC tracing and have a look. Use a system profiling tool (e.g. oprofile) to measure the time taken. Don't believe what anyone tells you: find out for yourself. Then you'll know. Andrew.
