Reuse Lua's Coroutine

[jiang yu <yu.jiang.163@...>]

Hi !

  In my game server there are so many lua's coroutine to make thing easy -- such as instead of state machine. when profile it I find it cost too much memory and cause gc more often. So I want reuse Lua's Coroutine, according to lua gems http://www.lua.org/gems/sample.pdf: I write a file in 200 line(140 for test) to do it.(hope not brother you).

  the question is, the test can not pass the test_error_oldnew(), the situation is: test1 create a coroutine and run it, the pool find it end and give the coroutine to test2, but the test1 not realise it end and resume it again. 

  I know it is a bug that should not happen,but may be happen. in the normal lua case, it is not dangerous just get a error and easily detect, but under coroutine pool it is very dangerous and can not detect. how to deal with it?

--coroutine pool

local freelist={};

function get_freelist()

return freelist;

end

function find_free()

if #freelist > 0 then

local free = freelist[#freelist]

table.remove(freelist)

return free

end

end

CO_TAG = "CO" --for safe use CO_TAG

function create_co()

local co = coroutine.create(

function (...)

local arg = {...}

while true do

if arg[1] ~= CO_TAG then

--do nothing, but can not error(...) because the co is in freelist. but how to let caller know it?

print("error! arg[1] ~= CO_TAG",arg[1])

else

assert(type(arg[2]) == "function",arg[2])

arg[2](unpack(arg,3))

table.insert(freelist,coroutine.running())

end

arg = {coroutine.yield("co_end")}

end

end)

return co

end

function get_free_co()

return find_free() or create_co()

end

function wrap(f)

local free = get_free_co()

return function(...)

local isok, msg = coroutine.resume(free,CO_TAG,f,...)

if not isok then

print("CO.wrap error: ", msg)

end

return isok, msg

end

end

function run(f,...)

local free = get_free_co()

return coroutine.resume(free,CO_TAG,f,...)

end

function run_rt_co(f,...)

local free = get_free_co()

return free,coroutine.resume(free,CO_TAG,f,...)

end

--test

local test_co1

function t1(p1)

test_co1 = coroutine.running()

print("inco t1 1",p1)

local rt = coroutine.yield("t1 y1")

assert(rt == "r1")

print("inco t1 end",rt)

end

local test_co2

function t2(p1,p2)

test_co2 = coroutine.running()

print("inco t2 1",p1,p2)

local rt = coroutine.yield("t2 y2")

assert(rt == "r2")

print("inco t2 2",rt)

rt = coroutine.yield("t2 y2")

assert(rt == "r2")

print("inco t2 end",rt)

end

local test_co3

function t3(p1,p2)

test_co3 = coroutine.running()

print("inco t3 1",p1,p2)

local rt = coroutine.yield("t3 y3")

assert(rt == "r3")

error("inco t3")

rt = coroutine.yield("t3 y3")

assert(rt == "r3")

print("inco t3 end",rt)

end

function test()

print("#freelist",#freelist)

assert(#freelist == 0)

local ok,rt = run(t1,"p1")

print('run(t1,"p1")',ok,rt)

ok,rt = coroutine.resume(test_co1,"r1")

print('coroutine.resume(test_co1,"r1")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

ok,rt = run(t2,"p1","p2")

assert(test_co1 == test_co2)

--print("freelist",#freelist)

print('run(t2,"p1","p2")',ok,rt)

ok,rt = coroutine.resume(test_co2,"r2")

print('coroutine.resume(test_co2,"r2")',ok,rt)

ok,rt = coroutine.resume(test_co2,"r2")

print('coroutine.resume(test_co2,"r2")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

end

function test_wrap()

print("#freelist",#freelist)

assert(#freelist == 0)

local f1 = wrap(t1)

local ok,rt = f1("p1")

print('f1("p1")',ok,rt)

ok,rt = coroutine.resume(test_co1,"r1")

print('coroutine.resume(test_co1,"r1")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

local f2 = wrap(t2)

ok,rt = f2("p1","p2")

assert(test_co1 == test_co2)

--print("freelist",#freelist)

print('f2("p1","p2")',ok,rt)

ok,rt = coroutine.resume(test_co2,"r2")

print('coroutine.resume(test_co2,"r2")',ok,rt)

ok,rt = coroutine.resume(test_co2,"r2")

print('coroutine.resume(test_co2,"r2")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

end

function test_error()

print("#freelist",#freelist)

assert(#freelist == 0)

local f3 = wrap(t3)

print("local f3 = wrap(t3)")

ok,rt = f3("p1","p2")

print('f3("p1","p2")',ok,rt)

ok,rt = coroutine.resume(test_co3,"r3")

print('coroutine.resume(test_co3,"r3")',ok,rt)

ok,rt = coroutine.resume(test_co3,"r3")

print('coroutine.resume(test_co3,"r3")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 0)

end

function test_error_tag()

print("#freelist",#freelist)

assert(#freelist == 0)

local f1 = wrap(t1)

local ok,rt = f1("p1")

print('f1("p1")',ok,rt)

ok,rt = coroutine.resume(test_co1,"r1")

print('coroutine.resume(test_co1,"r1")',ok,rt)

assert(#freelist == 1)

ok,rt = coroutine.resume(test_co1,"r1") --CO_TAG will used here!

print('coroutine.resume(test_co1,"r1")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

end

function test_error_oldnew()

print("#freelist",#freelist)

assert(#freelist == 0)

local f1 = wrap(t1)

local ok,rt = f1("p1")

print('f1("p1")',ok,rt)

ok,rt = coroutine.resume(test_co1,"r1")

print('coroutine.resume(test_co1,"r1")',ok,rt)

print("#freelist",#freelist)

assert(#freelist == 1)

local f2 = wrap(t2)

print("local f2 = wrap(t2)")

ok,rt = f2("p1","p2")

assert(test_co1 == test_co2)

print("freelist",#freelist)

assert(#freelist == 0)

print('f2("p1","p2")',ok,rt)

ok,rt = coroutine.resume(test_co2,"r2")

print('coroutine.resume(test_co2,"r2")',ok,rt)

ok,rt = coroutine.resume(test_co1,"r1")

print('coroutine.resume(test_co1,"r1")',ok,rt)

print("#freelist",#freelist)

end

test_error_oldnew()