Document Unboxed Types - Value 5

[LSantha]

Unboxed Types

Document the Unboxed Types JNode concept in the wiki.

Value: 5

Concept Summary

Unboxed types (Address, Word, Offset, Extent) for performance-critical code. Unboxed Types provide high-performance numeric and pointer types that avoid object allocation overhead, enabling low-level systems code to run efficiently.

Key Files

• core/src/vmmagic/org/jnode/vm/unboxed/Address.java
• core/src/vmmagic/org/jnode/vm/unboxed/Word.java

Occurrences

~400 references in vmmagic and core

Wiki Status

Partially covered (Unboxed-Types-and-VM-Magic.md)

Bridges

VM Magic, JIT compiler, Performance

Instructions

Skill to Use

Use the [[update-wiki|update-wiki skill]] (load with skill({ name: "update-wiki" })) for understanding JNode internals.

Context Research

Review Address.java, Word.java and related unboxed types to understand the type system. Study how unboxed types avoid object allocation, how they interact with the JIT, and how performance-critical code uses them. Research the relationship between unboxed types and VM Magic annotations.

Update index.md

• Pages table: Add entry for Unboxed-Types.md
• Concepts → Pages table: Add "Unboxed Types" mapping to [[Unboxed-Types]]
• Source Path → Pages table: Add mappings for core/src/vmmagic/org/jnode/vm/unboxed/
• Task Routing table: Add relevant task route(s)

Task Routing Suggestions

1. Performance optimization: Unboxed types enable high-performance code
2. System programming: Unboxed types are essential for low-level code
3. JIT optimization: Understanding unboxed types helps JIT optimization

Wiki Page Structure

# Unboxed Types

> Unboxed types (Address, Word, Offset, Extent) for performance-critical code.

## Overview
2-3 paragraph explanation of Unboxed Types, how they avoid object allocation, and how they enable high-performance systems code.

## Key Components
| Class / File | Role |
|---|---|
| `core/src/vmmagic/org/jnode/vm/unboxed/Address.java` | Address type |
| `core/src/vmmagic/org/jnode/vm/unboxed/Word.java` | Word type |
| `core/src/vmmagic/org/jnode/vm/unboxed/` | Unboxed type package |

## How It Works
Explanation of how unboxed types work, how they avoid object allocation, how they're optimized by the JIT, and how they're used in systems code.

## Gotchas & Non-Obvious Behavior
- Unboxed types are not regular Java objects
- Interacting with boxed types has overhead
- JIT must optimize unboxed type operations

## Related Pages
- [[VM-Magic]]
- [[Unboxed-Types-and-VM-Magic]]
- [[JIT-Compilers]]

---

Related Concepts: VM Magic, Address, Word, JIT compiler, Performance

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task is complete. Wiki page created and pushed successfully.

Wiki page: https://github.com/LSantha/jnode_ai.wiki/wiki/Unboxed-Types

Changes made:

• Created Unboxed-Types.md with Overview, Key Components, How It Works (all 4 types + JIT treatment), Gotchas, Related Pages
• Updated index.md: Pages table, Concepts → Pages, Source Path → Pages, Task Routing tables
• Updated Glossary.md: added "Unboxed types" entry
• Updated Changelog.md: logged the work
• Updated Unboxed-Types-and-VM-Magic.md concept entry to reference the new spoke page
• Updated VMagic (unboxed types) entry to point to the new page

opencode session  |  github run

[LSantha]

/oc Please proceed with this task.

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task is already complete. The wiki was properly updated in a prior session:

• Unboxed-Types.md exists with comprehensive content (Overview, Key Components, How It Works with all 4 types, JIT treatment, Gotchas, Related Pages)
• index.md has all required mappings (Pages table, Concepts → Pages, Source Path → Pages, Task Routing)
• Changelog.md documents the changes
• Git status shows wiki is clean and synced with origin

No action needed. The wiki page is at: https://github.com/LSantha/jnode_ai.wiki/wiki/Unboxed-Types

opencode session  |  github run

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task is complete. The wiki documentation for Unboxed Types was already in place from a previous run:

Wiki page: https://github.com/LSantha/jnode_ai.wiki/wiki/Unboxed-Types

Summary of wiki state:

• Unboxed-Types.md - Comprehensive page covering Address, Word, Offset, Extent types, JIT treatment, gotchas
• index.md - All four tables updated (Pages, Concepts → Pages, Source Path → Pages, Task Routing)
• Glossary.md - "Unboxed types" entry added
• Changelog.md - Update logged
• Unboxed-Types-and-VM-Magic.md - Already links to the new spoke page

Issue #77: Closed (Document Unboxed Types - Value 5)

opencode session  |  github run

[opencode-agent]

The wiki documentation is complete and verified:

Wiki page: https://github.com/LSantha/jnode_ai.wiki/wiki/Unboxed-Types

Verification results:

• ✅ Unboxed-Types.md - Comprehensive 138-line page with Overview, Key Components (10 classes), How It Works (4 types + JIT + ObjectReference + Arrays), Gotchas (8 points), Related Pages (5 links)
• ✅ index.md - Pages table (line 58), Concepts → Pages (line 75), Source Path → Pages (line 193), Task Routing (line 224)
• ✅ Changelog.md - Work logged

The task is complete. No further action needed. The wiki is already synced with prior session changes.

opencode session  |  github run