lua-snapshot

Make a snapshot for lua state to detect memory leaks.

See dump.lua for example.

Build

make linux

or

make mingw (in windows)

or

make macosx

tutorial

如下示例:

local lss = require "lsnapshot"

local sss = nil
lss.start_snapshot()

local tmp = {}
sss = {}
local function foo()
    return sss
end
local k = {}
k[1] = 1
k[2] = 2
local function test()
    sss[1] = 1
    return foo()
end

local function ff()
    k[3] = 3
end

local function dd()
    ff()
end

local function ee()
    return k[1]
end

local function bb()
    dd()
end

local function cc()
    ee()
end

local function aa(p)
    bb()
    cc()
    return p
end

local p = test()

aa(p)

lss.dstop_snapshot(40)

在需要做快照的地方调用start_snapshot, 结尾处调用dstop_snapshot([count]), 其中count为要打印的对象个数，不填的话会全部打印。 dstop_snapshot 会列出从start_snapshot开始到结束创建出来的仍然被持有的对象,结果会根据size按照从大到小排序.

执行输出结果:

$ lua dump.lua
------------------ diff snapshot ------------------
[1] type:(T) addr:0x5648cc8274f0 size:0.1171875KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->(T)k{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:19)ff{#dump.lua:0}->(T)k
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:27)ee{#dump.lua:0}->(T)k
[2] type:(T) addr:0x5648cc827450 size:0.0703125KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->(T)p{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:14)test{#dump.lua:0}->(T)sss
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:8)foo{#dump.lua:0}->(T)sss
[3] type:(T) addr:0x5648cc8273c0 size:0.0546875KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->(T)tmp{#dump.lua:0}
[4] type:([email protected]:39) addr:0x5648cc827600 size:0.046875KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:39)aa{#dump.lua:0}
[5] type:([email protected]:14) addr:0x5648cc827530 size:0.046875KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:14)test{#dump.lua:0}
[6] type:([email protected]:19) addr:0x5648cc814f30 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:19)ff{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:23)dd{#dump.lua:0}->([email protected]:19)ff
[7] type:([email protected]:31) addr:0x5648cc827760 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:31)bb{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:39)aa{#dump.lua:0}->([email protected]:31)bb
[8] type:([email protected]:35) addr:0x5648cc8150e0 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:35)cc{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:39)aa{#dump.lua:0}->([email protected]:35)cc
[9] type:([email protected]:8) addr:0x5648cc827280 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:8)foo{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:14)test{#dump.lua:0}->([email protected]:8)foo
[10] type:([email protected]:27) addr:0x5648cc8276b0 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:27)ee{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:35)cc{#dump.lua:0}->([email protected]:27)ee
[11] type:([email protected]:23) addr:0x5648cc827590 size:0.0390625KB
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:23)dd{#dump.lua:0}
        Root->(T)[registry]->(L@thread ./lsnapshot.lua:266 dump.lua:49 [C])[1]->([email protected]:31)bb{#dump.lua:0}->([email protected]:23)dd
--------------- all size:0.5703125Kb ---------------

其中[X]为索引, 第二个字段包含(T/U/L/C/S).

• (T)表示的为table 类型
• (U)表示userdata 类型
• (L)表示lua function类型,包含函数路径
• (C)表示cfunction 类型
• (S)表示thread 类型
• (A)表示string 类型

第三个为fullpath路径. size:0.0390625KB 表示的为改对象占用的大小