Adaptive Hot Reload for Low-Latency Class Structure Changes

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Solution Overview

Problem

Existing hot reload mechanisms for software applications result in excessive latency and computational resource usage due to unnecessary redeployment and regeneration of class loaders, and existing bytecode update tools are limited in scope and reliability.

Innovation Solution

A method that determines whether updates to a software application change the class structure, and if not, updates the runtime executable unit using an instrumentation API without redeployment, while regenerating only necessary bytecode; if changes are structural, the unit is redeployed with minimized bytecode regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hot reload tools drop and re-create class loader for class changes, then changes to classes are reflected in runtime environment, but latency increases to one second or more

Engineering Contradiction:
Improveclass updates reflected in runtimeVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the class loader into a runtime executable unit that can be selectively updated. Instead of replacing the entire class loader, only the necessary portions are regenerated and merged back, reducing the impact time and latency while maintaining the reliability of class updates in the runtime environment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic updates to the class loader by allowing partial regeneration of bytecode and selective merging of changes. This dynamic approach enables the system to adapt to different update scenarios, reducing latency when possible while maintaining reliability when necessary, thus resolving the contradiction between update speed and correctness.

Inventive Principle:
Principle #15Dynamics

2Reliability

If software application is redeployed for class structure changes, then changes are applied, but initialization tasks are repeated consuming excessive computational resources

Engineering Contradiction:
Improveclass structure changes appliedVSAvoidcomputational resources
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by regenerating only the necessary bytecode for affected classes rather than the entire application. The system identifies and updates only the minimal required portions, avoiding unnecessary initialization tasks and computational resources while ensuring class structure changes are properly applied.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs preliminary analysis to determine which classes and bytecode need regeneration before actually updating. By pre-identifying the scope of changes and preparing only the necessary components, the system avoids redundant initialization tasks and reduces computational resource consumption while maintaining reliable application of class structure changes.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If bytecode is completely regenerated for class changes, then all changes are reflected, but computational resources and time are wasted on unchanged bytecode

Engineering Contradiction:
Improvechanges reflected accuratelyVSAvoidupdate speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts only the necessary bytecode regeneration operations from the complete regeneration process. By identifying and isolating only the affected classes and methods that need updating, the system eliminates wasted computational resources on unchanged bytecode while ensuring all necessary changes are accurately reflected.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by regenerating bytecode selectively only for the specific classes and methods that have changed, rather than regenerating the entire bytecode base. This localized approach maintains the accuracy of changes while significantly improving update speed by avoiding unnecessary regeneration of unchanged portions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3974965B1Adaptive hot reload for class changes
Publication Date: 2026.04.08 RED HAT LLC
  • EP3974965B1 patent drawingFigure 1
  • EP3974965B1 patent drawingFigure 2
  • EP3974965B1 patent drawingFigure 3

AI summary

Improved systems and methods for hot reloading software applications are provided. In one embodiment, a method is provide that includes detecting an update for a software application. It may be determined whether the update represents a change to a class structure of the software application. If the update does not represent a class change, framework metadata for a class corresponding to the update may be replaced. If the update represents a class change, a runtime executable unit of the software application may be removed and replaced. After replacing the framework metadata and/or the runtime executable unit, the software application may be executed according to the update.