Every article tagged Concurrency, in one place.
Showing 8 articles
A goroutine is a lightweight thread managed by the Go runtime. You can run hundreds of thousands of them. Channels let goroutines pass data safely. Start goroutines and wait for them var wg sync.WaitGroup urls := []string{"https://go.dev", "https://pkg.go.dev"...
When several app instances run the same scheduled job, you often want exactly one of them to do the work. A Redis lock is a simple way to coordinate. Acquire with SET NX PX import { randomUUID } from 'node:crypto'; async function acquireLock(name, ttlMs) { con...
asyncio lets one thread wait on many network operations at once. It shines for I/O-heavy work: calling APIs, scraping, chat servers, database queries. The basics import asyncio import httpx async def fetch_status(client: httpx.AsyncClient, url: str) -> int: re...
Two users buy the last item at the same moment. Without the right transaction design, you sell it twice. These patterns prevent that. Transactions BEGIN; UPDATE accounts SET balance = balance - 500 WHERE id = 1; UPDATE accounts SET balance = balance + 500 WHER...
"Deadlock found when trying to get lock; try restarting transaction" is one of the most common MySQL errors in busy apps. It's not a bug in MySQL; it's two transactions waiting on each other. How a deadlock happens Transaction A Transaction B UPDATE accounts ....
Node.js runs your JavaScript on a single thread. That's fine for I/O, but a CPU-heavy task (resizing images, parsing a huge file, heavy maths) blocks the event loop, and every other request waits. Spot the problem app.get('/report', (req, res) => { const resul...
A context.Context carries a cancellation signal and an optional deadline through a chain of function calls. When a user closes the browser tab, every database query and HTTP call made for that request can stop. Every request already has one func handleSearch(w...
For decades, CPython's Global Interpreter Lock (GIL) allowed only one thread to run Python bytecode at a time. Threads helped with I/O, but not with CPU-heavy work. Free-threaded builds of Python remove the GIL. The timeline Python 3.13 introduced an experimen...
