I'm using the Ruby C API to execute Ruby scripts, and I need each script to be in a separate environment. Each environment would have its own global variables and classes, and they wouldn't be accessible from the other environments. I imagine it being something like the Binding class but with more protection. I've read some things around here about multiple VMs in a single process. This sounds perfect, but I haven't seen anything concrete. I'd rather not use multiple processes, as that might not even work for this application. Have there been any new developments on this topic?
on 2013-03-18 22:27
on 2013-03-19 18:17
I believe this can be done. We can enclose all the VM state variables into a structure, then pass that structure into the functions that need it. Each function would then perform its task inside the specified VM. Since we're not working with multiple processes, each VM context can work with variables from other VMs. It might look like this in C: VM* vm_a = rb_vm_context_new(); VM* vm_b = rb_vm_context_new(); rb_define_global_const(vm_a, "hello", rb_str_new2("Hello!")); rb_define_global_const(vm_b, "hi", rb_str_new2("Hi!")); rb_eval_string(vm_a, "$hello"); // "Hello!" rb_eval_string(vm_a, "$hi"); // Qnil rb_eval_string(vm_b, "$hello"); // Qnil rb_eval_string(vm_b, "$hi"); // "Hi!" We can use it within Ruby somewhat like this: https://gist.github.com/timahoney/5197905 Is it a possibility?
on 2013-03-19 18:26
Might want to read this thread. It provides a bit of a post mortem on MVM. There were big plans to do this in like 2008 but they all fizzled out: http://www.ruby-forum.com/topic/1450200
on 2013-03-20 16:03
Tony Arcieri wrote in post #1102324: > Might want to read this thread. It provides a bit of a post mortem on > MVM. > There were big plans to do this in like 2008 but they all fizzled out: > > http://www.ruby-forum.com/topic/1450200 Thanks for the link. I see how the extensions would be a problem. How difficult would it be to rewrite the core extensions to work with MVM? It seems like finishing MVM would help us use native threads. Is that an important problem to solve?