codesnips

mutex

rust 
use std::collections::HashMap;
use std::sync::{Arc, Mutex, PoisonError};

#[derive(Default)]
struct Metrics {
    per_endpoint: HashMap<String, u64>,

Thread-Safe Request Metrics with Arc, Mutex, and a Poison-Recovery Guard

rust concurrency arc
by codesnips 3 tabs
typescript 
import { Pool } from "pg";

async function keyFor(pool: Pool, name: string): Promise<string> {
  const { rows } = await pool.query<{ key: string }>(
    "SELECT hashtextextended($1, 0) AS key",
    [name]

Postgres advisory lock for one-at-a-time work

postgres concurrency reliability
by codesnips 3 tabs
rust 
use std::collections::HashMap;
use std::sync::Mutex;

pub type AccountId = u64;
pub type Cents = i64;

Atomic Double-Entry Ledger Transfers With Rust Locking and Poison Recovery

ledger concurrency double-entry
by codesnips 3 tabs
ruby 
require "securerandom"

class RedisMutex
  class LockError < StandardError; end

  UNLOCK_SCRIPT = <<~LUA.freeze

Redis-Based Distributed Mutex (with TTL)

rails redis concurrency
by codesnips 2 tabs