Differences between Dalvik and art

What is Dalvik:
Dalvik is a Java virtual machine designed by Google for the Android platform. Dalvik virtual machine is one of the core components of the Android mobile device platform developed by Google and other vendors. It supports conversion. dex (Dalvik executable) format Java application running ,. dex format is a compression format designed for Dalvik, suitable for systems with limited memory and processor speed. Dalvik is optimized to allow instances of multiple virtual machines to run simultaneously in limited memory, and each Dalvik application is executed as an independent Linux Process. Independent processes can prevent all programs from being shut down when the Virtual Machine crashes.

What is art:
The Android operating system has matured. Google's Android team began to focus on some underlying components, one of which was responsible for the Dalvik runtime of the application program. Google developers have spent two years developing a faster execution efficiency, higher power-saving alternative to art runtime. Art represents Android runtime, which processes application execution in a completely different way than Dalvik. Dalvik relies on a just-in-time (JIT) compiler to interpret bytecode. The application code compiled by the developer needs to run on the user's device through an interpreter. This mechanism is not efficient, but it makes it easier for applications to run on different hardware and architectures. Art has completely changed this practice. During application installation, bytecode is pre-compiled to the machine language. This mechanism is called ahead-of-time (AOT) compilation. After removing the interpreted code, the application execution will be more efficient and start faster.

 

Advantages of Art:
1. A significant improvement in system performance.
2. faster application startup, faster operation, smoother experience, and more timely touch feedback.
3. longer battery endurance.

4. Support lower hardware.

Disadvantages of Art:
1. A larger storage space may increase by 10%-20%.
2. Longer application installation time.

In general, the function of art is to change the space for time ".