Introduction To Dart VM

The Dart Virtual Machine (Dart VM) is a component of the Dart platform that executes Dart bytecode. It is responsible for efficiently running Dart programs and providing a runtime environment for various Dart applications.

Kernel service, which handles compilation of Dart source into Kernel binary. VM then will run resulting Kernel binary.

The Dart Virtual Machine is a critical component of the Dart platform, providing a high-performance runtime environment for Dart programs. It offers a range of features, including garbage collection, concurrency support, native extensions, and profiling tools, enabling developers to build powerful and efficient applications. With its cross-platform support and seamless integration with popular IDEs, the Dart VM empowers developers to create performant Dart applications for a wide range of platforms and use cases.

The Dart VM is designed to be fast, efficient, and portable. It provides a just-in-time (JIT) compiler and an ahead-of-time (AOT) compiler for optimizing and executing Dart code. The JIT compiler allows for rapid development cycles by quickly compiling and executing code during the development process. On the other hand, the AOT compiler generates highly optimized machine code in advance, resulting in faster startup times and better performance for standalone Dart applications.

Does Flutter use Dart Virtual Machine (VM)?

Flutter uses Dart as its primary language and takes full advantage of Dart’s features, including running the Dart code in the Dart Virtual Machine (VM).

Flutter completely separates compilation to Kernel and execution from Kernel by putting them onto different devices: compilation happens on the developer machine (host) and execution is handled on the target mobile device, which receives Kernel binaries send to it by flutter tool.

Dart provides a flexible runtime through its VM that makes it possible to run both JIT (Just-In-Time) compiled code and AOT (Ahead-Of-Time) compiled code, which Flutter uses during different app life-cycle stages.

During the development phase, Dart VM runs with JIT compilation. This enables developers to make changes in the code and see them reflected in the app in real-time — a feature known as hot-reloading. The Dart VM keeps the compiled code in memory and updates it as the developer modifies the source code.

When you’re ready to release your Flutter app , the Dart VM compiles the Dart code using AOT compilation. AOT compilation converts the Dart code into machine code in advance, which results in faster app startup times and smoother execution. It’s important to note that in this phase, there’s no actual Dart VM included in the final app – the Dart code is compiled directly into native machine code for the respective platform (like ARM or x86 for mobile devices).

It’s also worth mentioning that the Dart VM provides other features to Flutter, such as garbage collection for memory management, and a rich set of core libraries for functionalities like collections, async programming, string manipulation, and more.

In summary, Flutter uses Dart VM for running Dart code efficiently with flexibility during the development and debugging stages, and it uses AOT compilation for creating a highly optimised final app binary for distribution.

When is the Dart VM Created?

The Dart Virtual Machine (Dart VM) is created when a Dart program starts running. Essentially, the Dart VM is an engine that executes Dart code in a managed runtime environment, bridging the gap between high-level Dart code and lower-level machine code.

However, in the case of Flutter, the Dart VM works bit differently. When a Flutter application is executed in development mode, the Dart VM is created and is used for JIT (Just-In-Time) compilation, enabling features like hot reload. The Dart VM is active throughout your session as you test and develop your Flutter application.

For building and releasing Flutter apps, Dart uses AOT (Ahead-Of-Time) compilation, which compiles Dart code directly into native machine code for each platform (Android, iOS, etc). So when a Flutter app is running on a device, it’s not actually using the Dart VM. Instead, it’s executing the compiled machine code directly.