concurrency

class NotifyFollowersJob
  include Sidekiq::Job

  sidekiq_options queue: :notifications, retry: 5

  def perform(post_id, actor_id)

use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::thread;

fn main() {
    let counter = Arc::new(AtomicUsize::new(0));

class AddUniqueIndexToInventorySnapshots < ActiveRecord::Migration[7.1]
  disable_ddl_transaction!

  def change
    add_index :inventory_snapshots,
              [:warehouse_id, :sku],

package cache

import (
  "context"
  "sync"
  "time"

import Redis from "ioredis";

export const redis = new Redis(process.env.REDIS_URL ?? "redis://localhost:6379");

export interface Codec<T> {
  encode(value: T): string;

ALTER TABLE documents ADD COLUMN version BIGINT NOT NULL DEFAULT 0;

class Document < ApplicationRecord
  belongs_to :account

  validates :source_url, presence: true

  before_save :normalize_checksum

module ConditionalGet
  extend ActiveSupport::Concern

  private

  def render_conditional(resource, extra: nil)

package com.example.demo.service;

import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

import java.util.List;

use std::collections::HashMap;
use std::hash::Hash;
use std::sync::{Arc, RwLock};

pub struct Memoizer<K, V> {
    store: RwLock<HashMap<K, Arc<V>>>,

package workpool

import (
	"context"
	"sync"
)

class CreateStripeEvents < ActiveRecord::Migration[7.1]
  def change
    create_table :stripe_events do |t|
      t.string :stripe_event_id, null: false
      t.string :event_type, null: false
      t.string :status, null: false, default: "received"