[cinvoke-dev] Re: Problem using tables in Lua callback

[Bradley Smith]

Thanks for the dll. After confirming that your dll also works on my 
setup, I figured out what the problem is. If I link to the 
lua5_1_2_Win32_vc8_lib.zip binaries instead of the ...dll8_lib.zip 
binaries, the crash occurs. Any idea why that would happen?

Thanks,
 Bradley

Will Weisser wrote:
> Hmm...
>
> $ lua5.1 bad.lua
> 1
> 2
> value 3
> crashes at next line
> value[1] = 4
>
>   
> > :o
> >     
>
> Clearly something is different with my setup.  I tried compiling
> cinvoke_lua.dll with VS.NET 2K5 instead of 2K3, but it still worked.
> I've attached the 2K3 version of the .dll anyway if that will
> help...it's statically linked with a 2K3-compiled cinvoke 1.0.
> Incidentally, I'm using the include files in lua5_1_2_Win32_dll8_lib.zip
> and the binaries in lua5_1_2_Win32_bin.zip off of luabinaries.  
>
> I'm stuck for now but let me know if you have any more info.
>
>         -W.W.
>
> -----Original Message-----
> From: Bradley Smith [mailto:address@hidden 
> Sent: Wednesday, May 23, 2007 10:24 PM
> To: address@hidden
> Subject: Problem using tables in Lua callback
>
> On Windows, when I try to use table.insert in a Lua callback, C/Invoke 
> crashes. Below is an example which is a variation on an example in the 
> C/Invoke Lua documentation. What is going wrong?
>
> Thanks,
>   Bradley
>
>
> ----- myfunc.c -----
> // Compiled with Visual Studio 2005 command: cl /LD myfunc.c
> #ifdef _WIN32
> __declspec(dllexport) void myfunc(void (*cb)(int), int);
> #endif
>
>
> void myfunc(void (*cb)(int), int i) {
>     cb(i);
> }
>
>
> ----- useMyfunc.lua -----
> require("cinvoke_lua")
>
> mylib = clibrary.new("myfunc.dll")
>
> function lua_cb(i)
>   if i == 3 then
>     t = {}
>     t.value = i
>     print("value " .. t.value)
>   elseif i == 4 then
>     t = {}
>     print("crashes at next line")
>     table.insert(t, i)
>     print("value[1] = " .. t[1])
>   else
>       print(i)
>     end
> end
>
> myfunc = mylib:get_function(Cvoid, "myfunc", Ccallback, Cint);
> cbobj = mylib:new_callback(Cvoid, lua_cb, Cint);
>
> myfunc(cbobj, 1) -- prints "1"
> myfunc(cbobj, 2) -- prints "2"
> myfunc(cbobj, 3) -- prints "3"
> myfunc(cbobj, 4) -- crashes
>
>
>