Function tryAcquireComputerUseLock

src/utils/computerUse/computerUseLock.ts:148–195

()

 * same stale lock, only one create succeeds (the other reads the winner).
 */
export async function tryAcquireComputerUseLock(): Promise<AcquireResult> {
  const sessionId = getSessionId()
  const lock: ComputerUseLock = {
    sessionId,
    pid: process.pid,
    acquiredAt: Date.now(),
  }

  await mkdir(getClaudeConfigHomeDir(), { recursive: true })

  // Fresh acquisition.
  if (await tryCreateExclusive(lock)) {
    registerLockCleanup()
    return FRESH
  }

  const existing = await readLock()

  // Corrupt/unparseable — treat as stale (can't extract a blocking ID).
  if (!existing) {
    await unlink(getLockPath()).catch(() => {})
    if (await tryCreateExclusive(lock)) {
      registerLockCleanup()
      return FRESH
    }
    return { kind: 'blocked', by: (await readLock())?.sessionId ?? 'unknown' }
  }

  // Already held by this session.
  if (existing.sessionId === sessionId) return REENTRANT

  // Another live session holds it — blocked.
  if (isProcessRunning(existing.pid)) {
    return { kind: 'blocked', by: existing.sessionId }
  }

  // Stale lock — recover. Unlink then retry the exclusive create.
  // If another session is also recovering, one EEXISTs and reads the winner.
  logForDebugging(
    `Recovering stale computer-use lock from session ${existing.sessionId} (PID ${existing.pid})`,
  )
  await unlink(getLockPath()).catch(() => {})
  if (await tryCreateExclusive(lock)) {
    registerLockCleanup()
    return FRESH
  }
  return { kind: 'blocked', by: (await readLock())?.sessionId ?? 'unknown' }
}

/**
 * Release the computer-use lock if the current session owns it. Returns