JVM Architecture, Class Loading & Bytecode Execution
Peel back the Java Virtual Machine. Understand the ClassLoader subsystem, bytecode structure, JIT tiered compilation, and JVM execution mechanics.
Basic understanding of programming syntax and compilation concepts
Deep mastery of HotSpot JVM subsystems, classloaders, bytecode execution, and Project Loom virtual threads.
Read in order, or jump to what you need.
Every lesson builds on the one before it. Open any lesson to read the explanation, run the examples, and try the practice challenges.
- 01.01The JVM Architecture & Three-Phase ClassLoader Subsystem4 min
Examine the inner architecture of the Java Virtual Machine. Trace class loading across Loading, Linking, and Initialization phases.
- 01.02Bytecode Disassembly, The Constant Pool & Stack Machine Execution4 min
Disassemble class files using javap. Master the constant pool, operand stack instructions, local variable arrays, and bytecode verification.
- 01.03JIT Tiered Compilation: C1 Compiler, C2 Optimizations & GraalVM4 min
Explore the JIT compiler pipeline. Master Tiered Compilation (Interpreter, C1 Client, C2 Server), Escape Analysis, Loop Unrolling, and Inlining.
- 01.04Java 21 Concurrency Revolution: Virtual Threads & Project Loom4 min
Master modern Java 21 concurrency. Contrast heavy OS Platform Threads with lightweight M:N Virtual Threads, carrier thread mounting, and unpinned blocking.
Ready to move on?
Inspect compiled bytecode using javap and benchmark virtual thread throughput against platform threads.
Open the module self-check