Embedded Lua - timing out rogue scripts (e.g. infinite loop) - an example anyone?

Question

I have embedded Lua in a C++ application. I need to be able to kill rogue (i.e. badly written scripts) from hogging resources.

I know I will not be able to cater for

Answer 1

Snippet is not a proper use of terminology for what an implementation of this functionality would entail, and that is why you have not seen one. You could use debug hooks to provide callbacks during execution of Lua code. However, interrupting that process after a timeout is non-trivial and dependent upon your specific architecture.

You could consider using a longjmp to a jump buffer set just prior to the lua_call or lua_pcall after catching a time out in a luaHook. Then close that Lua context and handle the exception. The timeout could be implemented numerous ways and you likely already have something in mind that is used elsewhere in your project.

The best way to accomplish this task is to run the interpreter in a separate process. Then use the provided operating system facilities to control the child process. Please refer to RBerteig's excellent answer for more information on that approach.