Re: Does Lua need a JIT?

[Marc Balmer <marc@...>]

Am 22.02.17 um 04:40 schrieb 云风 Cloud Wu:
> Dibyendu Majumdar <mobile@majumdar.org.uk
> <mailto:mobile@majumdar.org.uk>>于2017年2月22日周三 上午5:12写道：
> 
>     I am not a games programmer and do not know whether interpreted Lua is
>     good enough in this case.
> 
> 
> I have been a game programmer for 20 years, and use lua since 4.0 . I
> think lua is good enough for game project because it's easy to embed to
> game engine. We need a flexible dynamic language for  gameplay  and GUI
> , and the performance only exists in game engine, which is written by C
> or C++.   I remember that I have tried to embed lua, python, javascript
> to my game engine for my first MMORPG project in 2001. lua is the best
> choice, because its less memory overhead, and we can easily manipulate
> the memory usage (We should run the game client in 64M Ram).
>  
> 
>     In my opinion, having worked on Ravi and in my usage of it, Lua is not
>     a general purpose language that you would use to build a large scale
>     application. This is not because of any deficiency in Lua, it is more
>     that large scale development is better done in statically typed
>     languages like Java, C#, Go, Swift etc. The cost of developing complex
>     applications in a dynamic language is just too high. I know that many
>     folks on this list will probably disagree with this view, but leaving
>     aside your love for Lua and your wish to use Lua everywhere, would you
>     still use Lua as a general purpose application development platform?
> 
> 
> We now use lua both in game client and server. For our game server,
> there are about 10K C loc (https://github.com/cloudwu/skynet) for the
> framework , and more than 100K lua loc for gameplay. 
> 
> For mmo game server, Lua is still the best choice rather than go,erlang,
> python or nodejs because we choose the actor model for the game server
> framework like erlang. We can run thousands lua vm in one process that
> python can't (because of GIL). LuaJIT is not suitable too because of 2G
> memory limit. I think our framework (skynet) has better performance than
> nodejs even nodejs use v8 JIT, because skynet can use all the cpu cores.
> I have tried luaJIT for my framework , only 10%~15% performance
> improvements.
> 
> And coroutine in lua can be a better solution for asynchronous
> programming than callback model in nodejs.
> 
> I agree lua is not suitable for large program, but a large scale
> application can be build with many small parts. We can run many lua vm
> in one process like skynet does.

Why should Lua not be suitable for large programs?  It absolutely is.