Code Explainers

Code explainers tagged #concurrency

rust 
use axum::{extract::{Path, State}, http::StatusCode, Json};
use dashmap::DashMap;
use serde::Serialize;
use std::sync::Arc;

Request coalescing in an Axum handler

caching concurrency request-coalescing
Advanced 8 steps
go 
package config
 
import (
	"fmt"

A thread-safe config singleton in Go

singleton concurrency environment-variables
Intermediate 7 steps
rust 
use std::sync::mpsc;
use std::thread;
use std::time::Duration;
 

Running work with a timeout in Rust

concurrency channels timeout
Intermediate 7 steps
go 
package cache
 
import (
	"sync"

A thread-safe TTL cache in Go

concurrency mutex caching
Intermediate 9 steps
python 
import signal
import time
import logging
 

Graceful shutdown in a queue worker

signals graceful-shutdown message-queue
Intermediate 7 steps
php 
<?php
 
namespace App\Storage;
 

A race-free file counter in PHP

file-locking concurrency atomicity
Intermediate 7 steps
go 
package sse
 
import (
	"encoding/json"

Server-Sent Events streaming in Go

server-sent-events channels http-streaming
Intermediate 8 steps
go 
package middleware
 
import (
	"bytes"

Idempotent requests in Gin with Redis

idempotency caching middleware
Advanced 10 steps
go 
package middleware
 
import (
	"context"

A deadline-enforcing HTTP middleware in Go

middleware context goroutines
Advanced 7 steps
go 
package logbuffer
 
import (
	"bufio"

A buffered logger with background flushing in Go

concurrency buffering context
Intermediate 8 steps
ruby 
class ThumbnailPool
  def initialize(worker_count: 4, capacity: 100)
    @queue = SizedQueue.new(capacity)
    @running = true

A thread pool for thumbnail jobs in Ruby

concurrency thread-pool bounded-queue
Advanced 7 steps
java 
public class RequestCoalescer<K, V> {
 
    private final ConcurrentHashMap<K, CompletableFuture<V>> inFlight = new ConcurrentHashMap<>();
    private final Function<K, V> loader;

Coalescing duplicate requests in Java

concurrency caching completablefuture
Advanced 6 steps
javascript 
async function uploadInBatches(records, uploadFn, { batchSize = 100, concurrency = 3 } = {}) {
  const batches = [];
  for (let i = 0; i < records.length; i += batchSize) {
    batches.push(records.slice(i, i + batchSize));

Uploading records with bounded concurrency

concurrency worker-pool async-await
Advanced 8 steps
ruby 
class CircuitBreaker
  class OpenCircuitError < StandardError; end
 
  def initialize(failure_threshold: 5, reset_timeout: 30, half_open_max: 1)

How a circuit breaker guards failing calls

state-machine fault-tolerance concurrency
Advanced 9 steps
go 
package middleware
 
import (
	"crypto/sha256"

Deduplicating concurrent requests in Gin

singleflight request-coalescing middleware
Advanced 8 steps
rust 
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::thread;
use std::time::Duration;

Graceful thread shutdown with an atomic flag

concurrency atomics memory-ordering
Advanced 7 steps
php 
<?php
 
namespace App\Http\Middleware;
 

Idempotency keys in Laravel middleware

idempotency middleware caching
Advanced 8 steps
rust 
use std::sync::Arc;
use std::time::Duration;
 
use axum::{

Long-polling with Axum and Tokio Notify

long-polling concurrency shared-state
Advanced 8 steps