Clone a lua state

Recently, I have encountered many difficulties when I was developing using C++ and Lua. My situation is: for some reason, there开发者_如何转开发 can be thousands of Lua-states in my C++ program. But these states should be same just after initialization. Of course, I can do luaL_loadlibs() and lua_loadfile() for each state, but that is pretty heavy(in fact, it takes a rather long time for me even just initial one state). So, I am wondering the following schema: What about keeping a separate Lua-state(the only state that has to be initialized) which is then cloned for other Lua-states, is that possible?

When I started with Lua, like you I once wrote a program with thousands of states, had the same problem and thoughts, until I realized I was doing it totally wrong :)

Lua has coroutines and threads, you need to use these features to do what you need. They can be a bit tricky at first but you should be able to understand them in a few days, it'll be well worth your time.

Unfortunately, no.

You could try Pluto to serialize the whole state. It does work pretty well, but in most cases it costs roughly the same time as normal initialization.

take a look to the following lua API call I think it is what you exactly need.

lua_State *lua_newthread (lua_State *L);

This creates a new thread, pushes it on the stack, and returns a pointer to a lua_State that represents this new thread. The new thread returned by this function shares with the original thread its global environment, but has an independent execution stack.

There is no explicit function to close or to destroy a thread. Threads are subject to garbage collection, like any Lua object.

I think it will be hard to do exactly what you're requesting here given that just copying the state would have internal references as well as potentially pointers to external data. One would need to reconstruct those internal references in order to not just have multiple states pointing to the clone source.

You could serialize out the state after one starts up and then load that into subsequent states. If initialization is really expensive, this might be worth it.

I think the closest thing to doing what you want that would be relatively easy would be to put the states in different processes by initializing one state and then forking, however your operating system supports it: http://en.wikipedia.org/wiki/Fork_(operating_system)

If you want something available from within Lua, you could try something like this: How do you construct a read-write pipe with lua?