AtomicBoolean: add compare_and_set API

Abierto
#540 7 comentarios 0 reacciones 0 asignados Ver en GitHub

Nadie ha tomado este issue todavía.

Evaluación

Dificultad
3/5
Tiempo estimado
1-2 días
Aptitud para principiantes
35/100
Tipo de issue
Nueva funcionalidad
Claridad
Bastante claro
Estado de actividad
Estancado
Stack tecnológico
ruby
Área
backend

Línea de trabajo

Start by locating the AtomicBoolean implementation and its current value API. Review how the existing atomic value behavior is tested, then determine where the compare_and_set entry point belongs. Done means the proposed API supports the false-to-true use case described in the issue and its behavior is covered by the project’s tests.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

enhancement looking-for-contributor medium-priority

Compare-and-set is a useful functionality (that's why it exists in the Java API). It can save one from race conditions, as explained below.

Use case
  • Assume an atomicboolean called LOCKED, set to false.
  • Multiple concurrent threads run the following code:
if !LOCKED.value
  LOCKED.value = true
  # do something ....
  LOCKED.value = false
end

In this scenario, concurrent threads can read a false in if !LOCKED.value, and enter the if block. That defeats the purpose of an atomicboolean-backed lock.

If there was a CAS API, the fixed code would look like this:

if LOCKED.compare_and_set(false, true)

Furthermore

Ruby has no "tryLock" either. So it's not immediately obvious how to create non-blocking synchronized code. Boolean CAS would offer a nice alternative which Java programmers (and others) already are familiar with.

What do you think?

Cheers - Victor

Lenguaje dominante
Ruby
Estrellas
5.8k
Forks
420
Merge medio
20 h 45 min
PR fusionados (30 d)
4

Guía de contribución

Abrir la guía de contribución

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de ruby-concurrency/concurrent-ruby

Todos los issues de ruby-concurrency/concurrent-ruby

Issues similares

Más issues de Ruby

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.