Code Explainers

Code explainers tagged #concurrency

ruby 
class Debouncer
  def initialize(delay:)
    @delay = delay
    @mutex = Mutex.new

A thread-safe debouncer in Ruby

concurrency debouncing mutex
Advanced 5 steps
ruby 
require "net/http"
require "json"
 
class UrlFetcher

A thread-pool URL fetcher in Ruby

concurrency thread-pool queues
Intermediate 8 steps
rust 
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::thread;
 

A round-robin worker pool in Rust

concurrency thread-pool channels
Intermediate 7 steps
ruby 
class SyncContactsJob < ApplicationJob
  queue_as :external_api
 
  MAX_CONCURRENCY = 5

Rate-limited CRM sync in a Rails job

background-jobs rate-limiting redis
Advanced 9 steps
python 
import threading
from functools import wraps
 
 

A thread-safe debounce decorator in Python

decorators debounce threading
Advanced 6 steps
rust 
use axum::{
    extract::State,
    http::StatusCode,
    Json,

Idempotent webhook handling in Axum

deduplication idempotency shared-state
Intermediate 8 steps
go 
package middleware
 
import (
	"log"

Per-IP rate limiting middleware in Gin

rate-limiting middleware concurrency
Intermediate 8 steps
java 
@Component
public class InventoryReconciliationJob {
 
    private static final Logger log = LoggerFactory.getLogger(InventoryReconciliationJob.class);

Distributed scheduled jobs with Spring locks

distributed-locking scheduling concurrency
Advanced 8 steps
go 
package middleware
 
import (
	"net/http"

A per-IP rate limiter middleware in Gin

rate-limiting token-bucket middleware
Intermediate 8 steps
python 
import json
import hashlib
from datetime import timedelta
 

Idempotent payment endpoints in FastAPI

idempotency redis distributed-locking
Advanced 9 steps
java 
public class SlidingLogRateLimiter {
 
    private final int maxRequests;
    private final long windowMillis;

How a sliding-log rate limiter works

rate-limiting concurrency sliding-window
Advanced 8 steps
go 
package theme
 
import (
	"fmt"

Per-tenant HTML templates with Gin's renderer

multi-tenancy concurrency html-templates
Advanced 8 steps
python 
import time
import threading
from enum import Enum
from functools import wraps

Building a circuit breaker in Python

circuit-breaker resilience decorators
Advanced 7 steps
typescript 
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent, HttpErrorResponse } from '@angular/common/http';
import { BehaviorSubject, Observable, throwError } from 'rxjs';
import { catchError, filter, take, switchMap } from 'rxjs/operators';

Refreshing auth tokens in an Angular interceptor

http-interceptor token-refresh rxjs
Advanced 8 steps
php 
<?php
 
namespace App\Http\Middleware;
 

Idempotent requests with Laravel middleware

idempotency middleware caching
Advanced 8 steps
go 
package middleware
 
import (
	"net/http"

A maintenance-mode gate in Gin

middleware atomic-flag concurrency
Intermediate 8 steps
php 
<?php
 
namespace App\Services;
 

Optimistic locking on invoices in Laravel

optimistic-locking transactions concurrency
Advanced 6 steps
typescript 
export class Semaphore {
  private available: number;
  private readonly waiters: Array<() => void> = [];
 

Building an async Semaphore in TypeScript

concurrency async-await promises
Advanced 6 steps