how do embed fiber for c/c++?

[monadbobo]

I notice that matz have added fiber in mruby, and I want to known how do embed fiber for c/c++?

Thanks!

[matz]

Could you tell me what you mean by 'embed fiber fo C/C++'?
Currently generation and context switching of fibers can only be done via Ruby.

[monadbobo]

Hi， I mean like lua_newthread/lua_yield/lua_resume in lua.

Thank you.

[matz]

That's what I imagined. Those functions are little bit weird, and unnatural (for me):

• lua_newthread creates empty coroutine
• lua_yield/lua_resume cannot cross C function boundaries, so that they switch context after returning from C functions

It's much easier to build libraries in Ruby in mruby than in Lua, so I thought we don't need those unnatural API functions. Maybe you can persuade me to provide those functions.

[monadbobo]

Hi, I want to embed mruby into Nginx , it like ngx_lua, and so I need create and control fiber(because everything is nonblock and asynchronous in Nginx) in Nginx.

Thanks!

[matz]

write part of your program in mruby and compile it (using mrbc) and link it with your C code.

[monadbobo]

ok, I will try it.

Thanks!

[carsonmcdonald]

@monadbobo In case you haven't seen it, there is already a Nginx module: https://github.com/matsumoto-r/ngx_mruby

[monadbobo]

Hi matz.

I tried what you said, but i think it can't solve my problem. Because I need to repeatedly enter the fiber. For example , I need to send or read (It is the send/read function of the nginx encapsulation) several times in mruby. At this time I may need to yield current fiber In Nginx when anyone function of send or read isn't finish (Receiving and sending it is asynchronous in Nginx), And after everything is complete, I need to resume fiber In Nginx.

Thanks.

[matz]

I am not sure whether I understand what you want to do.
Show us the code, if possible.

And tell me what you think about ngx_mruby.

[beoran]

Actually, the latest version of Lua (5.2) has the functions lua_yieldk, lua_callk, and lua_pcallk that do allow one to yield across c boundares, but they take an extra continuation function pointer argument to achieve this. More on this here: http://www.lua.org/manual/5.2/manual.html#4.7

I agree that lua_yield itself isn't too useful, but something like lua_yieldk / lua_callk would be handy indeed.

[matz]

I will check lua_yieldk / lua_callk.

[beoran]

In case it helps, I found an example of their use here:
http://stackoverflow.com/questions/16416711/how-to-yield-lua-script-in-c-function

[matz]

I still don't understand why you want to implement your code in C. Unlike Lua, you don't have to load explicitly to use mruby methods. As far as I understand, lua_yield and others are only to write yielding functions in Lua.