Question

I have some experience in lua, but now I faced the challenge to which i could have simplest solution, if only statement in topic was possible.

The problem

In short, the program (set of programs) are to be connected through lua, forming some sort of IPC. Now, i can create Lua state on each one of them, but then i would still need to use Lua-Lua IPC. I can do it, but i thought that if I could just create one instance, and have access to it from all of these apps, i could simplify the process severely.

Now i am aware of the fact that the central lua app would need to be written in thread-safe way. As first, naive approach I wanted to queue data from all the applications and then use coroutines to resolve the events.

The question (broke into parts):

1. Is accesing one Lua state using native API calls possible from more than one ‘host’
2. If it is, how can it be done and what i must ensure I do, to be sure it will run correctly.
3. If not, that pretty much conludes the question, because I will try to use Lua IPC, which is pretty google’able.

Edit 1:
I’m now digging through different lua “communication” libraries, but really can’t find any. Point 3 of the question is now much more valuable, since I’m now stuck on localhost TCP + JSON.

Answer 1

Lua is not thread-safe within a lua_State (it’s safe to use multiple separate lua_States across threads, but not to access the same one in different threads). So even if the API had some inter-process communication stuff, it wouldn’t work with more than one process accessing it.