State Isolation

Kind: principle

Layer: Atomic Boundary

Record: architecture:state-isolation

Severity: mandatory

Scope: function, component, service

Canonical: Ontology

A design rule that each piece of mutable state belongs to one unit of concurrent execution, so no two units that run at the same time can write it.

Listed in Architecture principles, after Pessimistic Locking and before Controlled Side Effects.

Requires

• Encapsulation
• Ownership

Reinforces

• Predictability
• Concurrency Correctness

Enables

• Testability

Conflicts with

• Shared Mutable State

In tension with

• Data Sharing

Tensions

• State Isolation / Data Sharing

Contracts

• Resource Core

Violated by

• Global Mutable State

Refactored by

• Encapsulate State
• Pass Context Explicitly
• Make Immutable

Severity

• mandatory

Category

• Transactions / State / Concurrency

Enforced by

• rules/eslint/closure-no-module-singleton.eslint.rule.ts

Linked from

• Phase binding
• Seven controls, seven classes
• Anti-patterns
• Correctness / Determinism / Verification
• Core Modular Design
• Core Modular Design
• Core Vocabulary
• Correctness / Determinism / Verification
• Creational Patterns
• Transactions / State / Concurrency
• Architectural Clusters
• Severity levels
• The resolutions