Re: coroutine.resume() crash

[Sean Conner <sean@...>]

It was thus said that the Great John Dunn once stated:
> I am using Lua 5.3.2 and have some Lua modules that implement asynchronous
> callbacks. I was trying to wrap them in coroutines to make them act a
> little more like async/await and when I do that I get a crash
> 
>   ldo:636
>       Exception thrown: read access violation
>       ci->u.l.base was 0xFFFFFFFFFFFFFFFF
> 
> Here's example code that shows the problem - it crashes when running
> 'bad_lua'. Am I just misunderstanding how coroutines can operate?

  I was unable to reproduce the issue with Lua 5.3.2.  I did, however, have
some issues with compiling your code using G++ 11.2.0 under Linux (with the
latest version of Ubuntu).

> #include <string>

  Ths needs to be <cstring>.

> struct timer_t
> {
	...
> };

  The compiler complained that timer_t was already defined in a system
header.  I changed it from 'struct timer_t' to 'struct mytimer'.

> void timer_init(lua_State* L)
> {
>   luaL_register(L, "Timer", timer_lib_methods);
> }

  The function luaL_register() isn't defined for Lua 5.3.2 (although you
might have headers that include some compatability macros for it).  This was
an easy change:

	void timer_init(lua_State* L)
	{
	  luaL_newlib(L,timer_lib_methods);
	  lua_setglobal(L,"Timer");
	}

  With those changes, the code compled and when run, I got:

[spc]matrix:/tmp>./co 
running good code
init good
timer_call_after
init good
trigger
tick
running bad code
trigger
tick

  I won't claim a compiler bug just yet---it might be caused by issues I
outlined here.  It might also help with knowing the operating system and
compiler you saw the error with.

  -spc