Threading & Multi-Threading

Educate developers on safe threading patterns in FreePascal/Lazarus.

17|7|Updated Mar 26, 2026
One-click install
npx skills add https://github.com/delphicleancode/lazarus-spec-kit --skill threading-multi-threading
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: Threading & Multi-Threading
Source: https://github.com/delphicleancode/lazarus-spec-kit/tree/main/.gemini/skills/threading
Command: npx skills add https://github.com/delphicleancode/lazarus-spec-kit --skill threading-multi-threading

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Threading in FreePascal/Lazarus patterns for safe and efficient concurrent execution, enabling responsive UI and robust background processing.

Core Features & Use Cases

  • TThread-based workers and cancellation patterns
  • Synchronize and Queue for UI updates without blocking
  • Producer-Consumer coordination using thread-safe primitives

Quick Start

Start a background thread to perform long-running work and update the UI safely from the main thread.

Frequently Asked Questions about Threading & Multi-Threading

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I update the UI from a background thread in Lazarus without freezing the application?

Use Synchronize or Queue to execute UI updates on the main thread, preventing freezing and ensuring thread-safe access to GUI components from background workers.

What is the best way to implement worker thread cancellation in FreePascal?

Implement worker thread cancellation in FreePascal using TThread patterns combined with TEvent, allowing background tasks to terminate safely and cleanly when requested.

How do I share resources between threads in FreePascal without causing race conditions?

Share resources between threads in FreePascal using synchronization primitives like TCriticalSection to lock data, preventing concurrent access race conditions.

Can I use TThread for producer-consumer coordination in Lazarus applications?

Yes, you can use TThread for producer-consumer coordination in Lazarus by applying thread-safe primitives like TEvent and TCriticalSection to manage queue interactions safely.

Why does my Lazarus GUI crash when accessing components from a worker thread?

Your Lazarus GUI crashes because accessing UI components directly from worker threads violates thread safety; you must use Synchronize or Queue to route access to the main thread.