C1 -> Lua -> C2 -> C1

[CHU Run-min <churunmin@...>]

There is a C function named Foo in host program.
There is a Lua function named bar in a script.
There is a lua_CFunction named Goo.

Foo calls bar, bar maybe calls Goo, but Goo calls Foo, is it OK?

(Suppose the Lua function bar is a window message handling center.)