How to check if the JIT compiler is off in Java

Question

I would like to know how to check if the JIT compiler is turned off. I have the following code which is meant to turn the JIT compiler off.The problem is, I am not sure if it is actually doing that. So I was wondering if there is a way of checking if the JIT is off. I looked at the Compiler class but there isn't any method like isDisabled/enabled().

Code:

Compiler.disable();  

Any help or direction will be highly appreciated.

Answer 1

You can printout methods when they get compiled, with `-XX:+PrintCompilation if your method isn't printed out or suddenly gets faster after it is print out, you can see the likely cause.

Answer 2

In the article Performance Features and Tools.

The JIT compiler was first made available as a performance update in the Java Development Kit (JDK) 1.1.6 software release and is now a standard tool invoked whenever you use the java interpreter command in the Java 2 platform release.

You can disable the JIT compiler using the -Djava.compiler=NONE option to the Java VM.

So, you can deduce that when the variable is not set, or set to something other than NONE, then the JIT is enabled.