What is the main function of the JIT mechanism and why is it used in the program execution process?

JIT (Just-In-Time) is a compilation mechanism that converts bytecode or intermediate code into machine code at runtime. The main function of JIT is to improve performance by combining the advantages of interpreted and compiled languages.

During program execution, JIT analyzes frequently used code sections and compiles them into native code, allowing them to run faster than interpretation. This is especially useful for dynamic languages and environments where pre-compiling all code is impossible or inefficient.

In Flutter, JIT is used during development for quick app launch and updates (hot reload), speeding up the development cycle. In the release version, AOT (Ahead-Of-Time) compilation is typically used for maximum performance.

Example: when running a Flutter app in debug mode, JIT compiles Dart code into machine code on the fly, allowing quick changes without a full rebuild.