folk_core/
runtime.rs

1//! Abstraction over how PHP workers are spawned.
2//!
3//! `WorkerPool` does not know what a PHP process is. It asks the
4//! `Runtime` to spawn a worker; the runtime returns a `WorkerHandle` which
5//! gives the pool a way to execute requests and to terminate the worker.
6//!
7//! In phase 23 (extension mode), the runtime spawns OS threads that run PHP
8//! inside the same process. Communication is via channels (zero IPC).
9
10use anyhow::Result;
11use async_trait::async_trait;
12
13/// A handle to a spawned worker.
14///
15/// The pool dispatches requests via `execute` and controls lifecycle via
16/// `ready` and `terminate`.
17#[async_trait]
18pub trait WorkerHandle: Send + 'static {
19    /// Worker identifier (thread ID, PID, or synthetic).
20    fn id(&self) -> u32;
21
22    /// Wait for the worker to signal readiness.
23    /// Returns once the worker has booted and is ready to accept requests.
24    async fn ready(&mut self) -> Result<()>;
25
26    /// Execute a single request: send structured data, receive result.
27    async fn execute(
28        &mut self,
29        method: &str,
30        payload: serde_json::Value,
31    ) -> Result<serde_json::Value>;
32
33    /// Terminate the worker. Implementations should signal shutdown and
34    /// wait for the worker to exit.
35    async fn terminate(&mut self) -> Result<()>;
36
37    /// Whether this worker can be recycled (terminated and respawned).
38    /// Returns `false` for the main thread worker which cannot be restarted.
39    fn is_recyclable(&self) -> bool {
40        true
41    }
42}
43
44/// Spawns workers per a runtime-specific strategy.
45#[async_trait]
46pub trait Runtime: Send + Sync + 'static {
47    /// Spawn a single worker and return a handle.
48    ///
49    /// The caller must call `ready()` before dispatching requests.
50    async fn spawn(&self) -> Result<Box<dyn WorkerHandle>>;
51}
52
53// --- MockRuntime: in-memory runtime for tests ---
54
55type MockResponder =
56    std::sync::Arc<dyn Fn(&str, &serde_json::Value) -> Result<serde_json::Value> + Send + Sync>;
57
58/// In-memory runtime used in tests. Each spawned worker echoes requests back.
59pub struct MockRuntime {
60    responder: MockResponder,
61    next_id: std::sync::atomic::AtomicU32,
62}
63
64impl MockRuntime {
65    /// Create a mock runtime that echoes the payload back as the result.
66    pub fn echo() -> Self {
67        Self {
68            responder: std::sync::Arc::new(|_method, payload| Ok(payload.clone())),
69            next_id: std::sync::atomic::AtomicU32::new(10000),
70        }
71    }
72}
73
74#[async_trait]
75impl Runtime for MockRuntime {
76    async fn spawn(&self) -> Result<Box<dyn WorkerHandle>> {
77        let id = self
78            .next_id
79            .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
80        Ok(Box::new(MockWorker {
81            id,
82            responder: self.responder.clone(),
83            terminated: false,
84        }))
85    }
86}
87
88/// In-memory worker used by `MockRuntime`.
89pub struct MockWorker {
90    id: u32,
91    responder: MockResponder,
92    terminated: bool,
93}
94
95#[async_trait]
96impl WorkerHandle for MockWorker {
97    fn id(&self) -> u32 {
98        self.id
99    }
100
101    async fn ready(&mut self) -> Result<()> {
102        Ok(())
103    }
104
105    async fn execute(
106        &mut self,
107        method: &str,
108        payload: serde_json::Value,
109    ) -> Result<serde_json::Value> {
110        if self.terminated {
111            anyhow::bail!("worker terminated");
112        }
113        (self.responder)(method, &payload)
114    }
115
116    async fn terminate(&mut self) -> Result<()> {
117        self.terminated = true;
118        Ok(())
119    }
120}
folk_core/runtime.rs

folk_core/
runtime.rs
