Lua时间轮：批量定时器的分槽管理

-- 错误：每对象挂一个系统定时器，调度器超载
for _, obj in ipairs(allTimers) do
    scheduleOne(obj.sec, obj.fn)
end

local SLOTS = 60
local wheel, cur = {}, 0
local function addTimer(sec, fn)
    local slot = (cur + sec) % SLOTS
    wheel[slot] = wheel[slot] or {}
    table.insert(wheel[slot], fn)
end
local function onSecond()
    cur = (cur + 1) % SLOTS
    local list = wheel[cur]
    wheel[cur] = nil
    if list then
        for _, fn in ipairs(list) do
            fn()
        end
    end
end