Q 08 - JIT

[HARSHITH-MV]

What is JIT ⁉️🙂

[AmjustGettingStarted]

⚙️ Just-In-Time (JIT) Compiler in Java

JIT stands for Just-in-Time compiler. It is a part of the Java Runtime Environment (JRE) and is used to improve the performance of Java applications during runtime.

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🔁 Step-by-Step Working of JIT:

1. Compilation Phase:

   • The Java source code is compiled by the javac compiler to generate bytecode (.class files).

2. Execution via JVM:

   • The generated bytecode is passed on to the Java Virtual Machine (JVM) for execution.

3. JIT Integration:

   • The JIT compiler, which is a component of the JVM, converts bytecode into native machine code at runtime.

4. Activation Condition:

   • Although JIT is enabled by default, it becomes active only when a method is invoked frequently enough.

5. Direct Native Execution:

   • Once compiled, the method’s native code is cached, and JVM directly calls this compiled version instead of interpreting the bytecode again.

6. Performance Boost:

   • Since the JVM skips interpretation and runs native machine code, the application's execution becomes faster and more efficient.

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💡 Summary: JIT compiles hot code paths at runtime, enabling faster execution by avoiding repeated interpretation.

[AmjustGettingStarted]