Dalvik (software)

Dalvik
Original author(s)Dan Bornstein
Repository
Operating systemLinux kernel
PlatformAndroid
SuccessorAndroid Runtime
TypeVirtual machine
LicenseApache License 2.0
Websitesource.android.com/devices/tech/dalvik/index.html

Dalvik is a discontinued process virtual machine (VM) in the Android operating system that executes applications written for Android.[1] (Dalvik bytecode format is still used as a distribution format, but no longer at runtime in newer Android versions.) Dalvik was an integral part of the Android software stack in the (now unsupported) Android versions 4.4 "KitKat" and earlier, which were commonly used on mobile devices such as mobile phones and tablet computers, and more in some devices such as smart TVs and wearables. Dalvik is open-source software, originally written by Dan Bornstein, who named it after the fishing village of Dalvík in Eyjafjörður, Iceland.[2][3]

Programs for Android are commonly written in Java and compiled to bytecode for the Java Virtual Machine, which is then translated to Dalvik bytecode and stored in .dex (Dalvik EXecutable) and .odex (Optimized Dalvik EXecutable) files; related terms odex and de-odex are associated with respective bytecode conversions. The compact Dalvik Executable format is designed for systems that are constrained in terms of memory and processor speed.

The successor of Dalvik is Android Runtime (ART), which uses the same bytecode and .dex files (but not .odex files), with the succession aiming at performance improvements. The new runtime environment was included for the first time in Android 4.4 "KitKat" as a technology preview,[4][5] and replaced Dalvik entirely in later versions; Android 5.0 "Lollipop" is the first version in which ART is the only included runtime.

  1. ^ "Debugging ART Garbage Collection". Retrieved 6 October 2015. The Dalvik runtime is no longer maintained or available [in current versions of Android] and its byte-code format is now used by ART.
  2. ^ Journal entry referencing the source of the name
  3. ^ "Google Calling: Inside Android, the gPhone SDK". onlamp.com. Archived from the original on 2017-01-10. Retrieved 2008-02-05.
  4. ^ Sean Buckley (2013-11-06). "'ART' experiment in Android KitKat improves battery life and speeds up apps". Engadget. Retrieved 2014-07-05.
  5. ^ Daniel P. (2013-11-07). "Experimental Google ART runtime in Android KitKat can bring twice faster app executions". phonearena.com. Retrieved 2014-07-05.