【性能调优】CPU 排查：火焰图的采集与解读

local samples = {}
local function profile(label, fn)
    local t0 = os.clock()
    fn()
    local cost = os.clock() - t0
    samples[label] = (samples[label] or 0) + cost
end
setontimerex(198, 300)
function ontimer198()
    local worst, worstCost = "", 0
    for label, cost in pairs(samples) do
        if cost > worstCost then
            worst, worstCost = label, cost
        end
    end
    if worst ~= "" then
        sendcentermsg("CPU 热点：" .. worst .. "，5 分钟累计 " .. string.format("%.2f", worstCost) .. " 秒")
    end
    samples = {}
end

local rankDirty = false
local function markRankDirty()
    rankDirty = true
end
setontimerex(199, 5)
function ontimer199()
    if rankDirty then
        profile("rebuild_rank", rebuildRankCache)
        rankDirty = false
    end
end