Code Explainers

Code explainers tagged #concurrency

rust 
use axum::{
    body::Body,
    extract::State,
    http::{Request, StatusCode},

A sliding-window rate limiter in Axum

rate-limiting middleware sliding-window
Intermediate 10 steps
rust 
use std::collections::HashMap;
use std::future::Future;
use std::hash::Hash;
use std::sync::{Arc, Mutex};

Deduplicating concurrent work in Rust

concurrency deduplication async
Advanced 7 steps
java 
public class AccountRepository {
 
    private final DataSource dataSource;
 

Optimistic locking with a version column in JDBC

optimistic-locking jdbc concurrency
Intermediate 8 steps
go 
package logsample
 
import (
	"sync"

A per-key rate limiter for log sampling

rate-limiting concurrency time-windows
Intermediate 7 steps
rust 
use std::sync::Arc;
use std::collections::HashMap;
use axum::{
    extract::State,

Hot-reloadable config with shared state in Axum

shared-state concurrency rwlock
Intermediate 7 steps
ruby 
require "thread"
 
class ConnectionPool
  class TimeoutError < StandardError; end

Building a thread-safe connection pool in Ruby

concurrency resource-pooling mutex
Advanced 8 steps
go 
package dedup
 
import (
	"hash/fnv"

A rolling Bloom filter deduper in Go

bloom-filter deduplication concurrency
Advanced 7 steps
java 
@Service
@RequiredArgsConstructor
public class ExchangeRateService {
 

Request-scoped rate caching in Spring

request-scope caching memoization
Advanced 6 steps
go 
package server
 
import (
	"net/http"

Rate limiting HTTP handlers with a token bucket

rate-limiting token-bucket middleware
Advanced 7 steps
java 
public final class CircuitBreaker {
 
    private enum State { CLOSED, OPEN, HALF_OPEN }
 

How a circuit breaker guards failing calls

state-machine resilience concurrency
Advanced 7 steps
php 
<?php
 
namespace App\Jobs;
 

Debouncing a Laravel shipping-rate job

queues debouncing atomic-locks
Advanced 9 steps
go 
package hashring
 
import (
	"hash/crc32"

How consistent hashing works in Go

consistent-hashing load-balancing concurrency
Intermediate 8 steps
go 
package metrics
 
import (
	"sync"

A thread-safe sliding-window average in Go

concurrency sliding-window running-average
Intermediate 8 steps
java 
public class RequestThrottler {
 
    private final Semaphore permits;
    private final long acquireTimeoutMillis;

Bounding concurrency with a Semaphore in Java

concurrency semaphore rate-limiting
Intermediate 6 steps
python 
import time
import threading
from flask import Flask, request, jsonify, g
 

A token-bucket rate limiter in Flask

rate-limiting token-bucket middleware
Intermediate 7 steps
ruby 
class Document < ApplicationRecord
  class StaleObjectError < StandardError
    def initialize(id)
      super("Document ##{id} was modified by another process")

Optimistic locking with retries in Rails

optimistic-locking concurrency transactions
Advanced 8 steps
go 
package handler
 
type flightResult struct {
	status int

Deduping in-flight requests in Gin

middleware concurrency deduplication
Advanced 9 steps
go 
package middleware
 
import (
	"net/http"

Per-IP write rate limiting in Gin

rate-limiting middleware concurrency
Intermediate 8 steps