Art for Art’s Sake
Earlier we said that the DVM interprets the bytecode, but we weren’t being 100 percent accurate. The DVM uses a Just in Time (JIT) compiler rather than a simple interpreter, which has the benefit of many years of the JVM compiler theory and thus gives much better performance than a basic interpreter. JIT compilers are a lot faster than straightforward interpreters. JIT doesn’t have any effect either way on security because the classes.dex is not modified by the compiler.
In KitKat, Google introduced a new VM called the Android Runtime (ART). This new type of VM, called an Ahead-Of-Time (AOT) compiler, optimizes the classes.dex file when it is installed on the phone or device. Currently you can use either the DVM or ART on your ...
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