chore: delete unused util/lock module (#27223)

This commit is contained in:
Kit Langton
2026-05-13 11:08:35 -04:00
committed by GitHub
parent 50dccac915
commit 650f67a05a
2 changed files with 0 additions and 170 deletions

View File

@@ -1,98 +0,0 @@
const locks = new Map<
string,
{
readers: number
writer: boolean
waitingReaders: (() => void)[]
waitingWriters: (() => void)[]
}
>()
function get(key: string) {
if (!locks.has(key)) {
locks.set(key, {
readers: 0,
writer: false,
waitingReaders: [],
waitingWriters: [],
})
}
return locks.get(key)!
}
function process(key: string) {
const lock = locks.get(key)
if (!lock || lock.writer || lock.readers > 0) return
// Prioritize writers to prevent starvation
if (lock.waitingWriters.length > 0) {
const nextWriter = lock.waitingWriters.shift()!
nextWriter()
return
}
// Wake up all waiting readers
while (lock.waitingReaders.length > 0) {
const nextReader = lock.waitingReaders.shift()!
nextReader()
}
// Clean up empty locks
if (lock.readers === 0 && !lock.writer && lock.waitingReaders.length === 0 && lock.waitingWriters.length === 0) {
locks.delete(key)
}
}
export async function read(key: string): Promise<Disposable> {
const lock = get(key)
return new Promise((resolve) => {
if (!lock.writer && lock.waitingWriters.length === 0) {
lock.readers++
resolve({
[Symbol.dispose]: () => {
lock.readers--
process(key)
},
})
} else {
lock.waitingReaders.push(() => {
lock.readers++
resolve({
[Symbol.dispose]: () => {
lock.readers--
process(key)
},
})
})
}
})
}
export async function write(key: string): Promise<Disposable> {
const lock = get(key)
return new Promise((resolve) => {
if (!lock.writer && lock.readers === 0) {
lock.writer = true
resolve({
[Symbol.dispose]: () => {
lock.writer = false
process(key)
},
})
} else {
lock.waitingWriters.push(() => {
lock.writer = true
resolve({
[Symbol.dispose]: () => {
lock.writer = false
process(key)
},
})
})
}
})
}
export * as Lock from "./lock"

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@@ -1,72 +0,0 @@
import { describe, expect, test } from "bun:test"
import { Lock } from "@/util/lock"
function tick() {
return new Promise<void>((r) => queueMicrotask(r))
}
async function flush(n = 5) {
for (let i = 0; i < n; i++) await tick()
}
describe("util.lock", () => {
test("writer exclusivity: blocks reads and other writes while held", async () => {
const key = "lock:" + Math.random().toString(36).slice(2)
const state = {
writer2: false,
reader: false,
writers: 0,
}
// Acquire writer1
using writer1 = await Lock.write(key)
state.writers++
expect(state.writers).toBe(1)
// Start writer2 candidate (should block)
const writer2Task = (async () => {
const w = await Lock.write(key)
state.writers++
expect(state.writers).toBe(1)
state.writer2 = true
// Hold for a tick so reader cannot slip in
await tick()
return w
})()
// Start reader candidate (should block)
const readerTask = (async () => {
const r = await Lock.read(key)
state.reader = true
return r
})()
// Flush microtasks and assert neither acquired
await flush()
expect(state.writer2).toBe(false)
expect(state.reader).toBe(false)
// Release writer1
writer1[Symbol.dispose]()
state.writers--
// writer2 should acquire next
const writer2 = await writer2Task
expect(state.writer2).toBe(true)
// Reader still blocked while writer2 held
await flush()
expect(state.reader).toBe(false)
// Release writer2
writer2[Symbol.dispose]()
state.writers--
// Reader should now acquire
const reader = await readerTask
expect(state.reader).toBe(true)
reader[Symbol.dispose]()
})
})