bianhaifeng789-hue/skills-experimental/combined-abort-signal-pattern

Combined Abort Signal Pattern Skill

Combined Abort Signal Pattern - createCombinedAbortSignal + signal + signalB + timeoutMs + cleanup function + setTimeout + clearTimeout cleanup + removeEventListener cleanup + unref timer + Bun AbortSignal.timeout memory leak avoid + multi-source abort。

功能概述

从Claude Code的utils/combinedAbortSignal.ts提取的Combined abort signal模式，用于OpenClaw的多源Abort组合。

核心机制

createCombinedAbortSignal

export function createCombinedAbortSignal(
  signal: AbortSignal | undefined,
  opts?: { signalB?: AbortSignal; timeoutMs?: number },
): { signal: AbortSignal; cleanup: () => void } {
  const { signalB, timeoutMs } = opts ?? {}
  const combined = createAbortController()

  // Fast path: already aborted
  if (signal?.aborted || signalB?.aborted) {
    combined.abort()
    return { signal: combined.signal, cleanup: () => {} }
  }

  // Setup listeners and timer
  // ...

  return { signal: combined.signal, cleanup }
}
// Combined abort signal
# Aborts on: signal abort, signalB abort, timeout
# Returns cleanup function

signal + signalB + timeoutMs

signal: AbortSignal | undefined  // Primary signal
signalB?: AbortSignal            // Secondary signal
timeoutMs?: number               // Timeout in milliseconds
// Three abort sources
# Primary signal
# Secondary signal
# Timeout

cleanup Function

return { signal: combined.signal, cleanup }
// cleanup: () => void
// Removes event listeners
// Clears timeout timer
# Cleanup on completion

setTimeout + clearTimeout cleanup

let timer: ReturnType<typeof setTimeout> | undefined
const abortCombined = () => {
  if (timer !== undefined) clearTimeout(timer)
  combined.abort()
}

if (timeoutMs !== undefined) {
  timer = setTimeout(abortCombined, timeoutMs)
  timer.unref?.()
}

const cleanup = () => {
  if (timer !== undefined) clearTimeout(timer)
  signal?.removeEventListener('abort', abortCombined)
  signalB?.removeEventListener('abort', abortCombined)
}
// Timer + cleanup
# setTimeout for timeout
# clearTimeout in cleanup

removeEventListener cleanup

const cleanup = () => {
  if (timer !== undefined) clearTimeout(timer)
  signal?.removeEventListener('abort', abortCombined)
  signalB?.removeEventListener('abort', abortCombined)
}
// Remove listeners in cleanup
# Prevent memory leak
# Cleanup on completion

unref Timer

timer = setTimeout(abortCombined, timeoutMs)
timer.unref?.()
// unref: don't block process exit
# Timer doesn't keep Node alive

Bun AbortSignal.timeout memory leak avoid

// Use `timeoutMs` instead of passing `AbortSignal.timeout(ms)` as a signal —
// under Bun, `AbortSignal.timeout` timers are finalized lazily and accumulate
// in native memory until they fire (measured ~2.4KB/call held for the full
// timeout duration). This implementation uses `setTimeout` + `clearTimeout`
// so the timer is freed immediately on cleanup.
// Bun AbortSignal.timeout memory leak
# ~2.4KB/call held for full timeout
# setTimeout + clearTimeout freed immediately

multi-source abort

signal?.addEventListener('abort', abortCombined)
signalB?.addEventListener('abort', abortCombined)
if (timeoutMs !== undefined) timer = setTimeout(abortCombined, timeoutMs)
// Three abort sources
# Any source → combined.abort()
# Multi-source abort

实现建议

OpenClaw适配

1. combinedAbort: createCombinedAbortSignal pattern
2. cleanupFunction: cleanup function pattern
3. timerCleanup: setTimeout + clearTimeout pattern
4. bunMemoryLeak: Bun AbortSignal.timeout memory leak avoid pattern
5. multiSource: multi-source abort pattern

状态文件示例

{
  "signal": "AbortSignal",
  "signalB": "AbortSignal",
  "timeoutMs": 30000,
  "aborted": false,
  "cleanup": "() => void"
}

关键模式

cleanup Function Return

return {signal: combined.signal, cleanup: () => {...}} → cleanup removes listeners + clears timer → cleanup on completion
# cleanup function返回
# removes listeners + clears timer
# completion时cleanup

setTimeout + clearTimeout Pattern

setTimeout → abortCombined | clearTimeout(timer) → cleanup → immediate free → no native memory accumulation
# setTimeout + clearTimeout pattern
# 立即free timer
# 无native memory accumulation

Bun AbortSignal.timeout Memory Leak

AbortSignal.timeout(ms) → ~2.4KB/call native memory → lazy finalize → setTimeout/clearTimeout → immediate free
# Bun AbortSignal.timeout memory leak
# ~2.4KB/call native memory
# lazy finalize
# setTimeout/clearTimeout立即free

unref Timer Don't Block Exit

timer.unref() → don't block process exit → allow Node exit while timer pending
# unref不阻塞exit
# Node可以在timer pending时exit

Multi-Source Abort Any Triggers

signal abort | signalB abort | timeout → combined.abort() → any source → abort
# multi-source abort
# 任一source触发abort

借用价值

• ⭐⭐⭐⭐⭐ cleanup function return pattern
• ⭐⭐⭐⭐⭐ setTimeout + clearTimeout pattern
• ⭐⭐⭐⭐⭐ Bun AbortSignal.timeout memory leak avoid pattern
• ⭐⭐⭐⭐⭐ unref timer pattern
• ⭐⭐⭐⭐⭐ Multi-source abort pattern

来源

• Claude Code: utils/combinedAbortSignal.ts (64 lines)
• 分析报告: P56-4