Mode d’emploi
- Copiez la commande et examinez le paquet avant de l’installer dans votre environnement agent.
- Consultez le document original pour les outils, identifiants et environnements requis.
- Décrivez les entrées et le livrable souhaité ; comparez la sortie aux sources.
npx skills add https://github.com/actionbook/rust-skills --skill m12-lifecycleAvant de commencer
- L’installation n’inclut ni abonnement au modèle, ni quota API, ni accès aux fichiers.
- Étoiles et installations reflètent l’activité, pas un test indépendant de qualité ou de sécurité.
Document Skill original
Rendu depuis le dépôt source en conservant titres, exemples, code, tableaux, liens et images.
Resource Lifecycle
Layer 2: Design Choices
Core Question
When should this resource be created, used, and cleaned up?
Before implementing lifecycle:
- What's the resource's scope?
- Who owns the cleanup responsibility?
- What happens on error?
Lifecycle Pattern → Implementation
| Pattern | When | Implementation |
|---|---|---|
| RAII | Auto cleanup | Drop trait |
| Lazy init | Deferred creation | OnceLock, LazyLock |
| Pool | Reuse expensive resources | r2d2, deadpool |
| Guard | Scoped access | MutexGuard pattern |
| Scope | Transaction boundary | Custom struct + Drop |
Thinking Prompt
Before designing lifecycle:
- What's the resource cost?
- Cheap → create per use
- Expensive → pool or cache
- Global → lazy singleton
- What's the scope?
- Function-local → stack allocation
- Request-scoped → passed or extracted
- Application-wide → static or Arc
- What about errors?
- Cleanup must happen → Drop
- Cleanup is optional → explicit close
- Cleanup can fail → Result from close
Trace Up ↑
To domain constraints (Layer 3):
"How should I manage database connections?"
↑ Ask: What's the connection cost?
↑ Check: domain-* (latency requirements)
↑ Check: Infrastructure (connection limits)| Question | Trace To | Ask |
|---|---|---|
| Connection pooling | domain-* | What's acceptable latency? |
| Resource limits | domain-* | What are infra constraints? |
| Transaction scope | domain-* | What must be atomic? |
Trace Down ↓
To implementation (Layer 1):
"Need automatic cleanup"
↓ m02-resource: Implement Drop
↓ m01-ownership: Clear owner for cleanup
"Need lazy initialization"
↓ m03-mutability: OnceLock for thread-safe
↓ m07-concurrency: LazyLock for sync
"Need connection pool"
↓ m07-concurrency: Thread-safe pool
↓ m02-resource: Arc for sharingQuick Reference
| Pattern | Type | Use Case |
|---|---|---|
| RAII | Drop trait | Auto cleanup on scope exit |
| Lazy Init | OnceLock, LazyLock | Deferred initialization |
| Pool | r2d2, deadpool | Connection reuse |
| Guard | MutexGuard | Scoped lock release |
| Scope | Custom struct | Transaction boundaries |
Lifecycle Events
| Event | Rust Mechanism |
|---|---|
| Creation | new(), Default |
| Lazy Init | OnceLock::get_or_init |
| Usage | &self, &mut self |
| Cleanup | Drop::drop() |
Pattern Templates
RAII Guard
rust
struct FileGuard {
path: PathBuf,
_handle: File,
}
impl Drop for FileGuard {
fn drop(&mut self) {
// Cleanup: remove temp file
let _ = std::fs::remove_file(&self.path);
}
}Lazy Singleton
rust
use std::sync::OnceLock;
static CONFIG: OnceLock<Config> = OnceLock::new();
fn get_config() -> &'static Config {
CONFIG.get_or_init(|| {
Config::load().expect("config required")
})
}Common Errors
| Error | Cause | Fix |
|---|---|---|
| Resource leak | Forgot Drop | Implement Drop or RAII wrapper |
| Double free | Manual memory | Let Rust handle |
| Use after drop | Dangling reference | Check lifetimes |
| E0509 move out of Drop | Moving owned field | Option::take() |
| Pool exhaustion | Not returned | Ensure Drop returns |
Anti-Patterns
| Anti-Pattern | Why Bad | Better |
|---|---|---|
| Manual cleanup | Easy to forget | RAII/Drop |
lazy_static! | External dep | std::sync::OnceLock |
| Global mutable state | Thread unsafety | OnceLock or proper sync |
| Forget to close | Resource leak | Drop impl |
Related Skills
| When | See |
|---|---|
| Smart pointers | m02-resource |
| Thread-safe init | m07-concurrency |
| Domain scopes | m09-domain |
| Error in cleanup | m06-error-handling |
