Java Hotspot Compiler Brief

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1)      Other name: JIT Compiler, Dynamic Compiler
2)      How a java program runs in JVM?
-          javac: translate java code to byte code
-          JVM Interpreter runs instruction by instruction

-          In JVM, there is a lightweight profiler detects common block of instructions running (for example loop) and try to optimize the execution ON-FLY, immediate speed up. For example: we run 5*5*5 for 1000 time, it gets faster after some runs.



Why do I care? 
     You may run bench-marking test. The result will come out funny and you will wonder why.

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