LÖVE

I have a "it works fine in Linux, but fails in Windows" error that I think is really a "it happens to work in Linux, but never in Windows" issue.

Namely, I have library code for our game built into a .so/.dll using gcc (for both Linux and Windows.) Unfortunately, when I run in Windows I get a segfault when I attempt to register my C functions. Here is the first line in my main.lua: In my .so/.dll I have:
Naturally lslib is setup with the correct table of functions. The debugger tells me that the seg fault occurs on 'luaL_register'. I put printf in there to confirm. If I print out lua_State (the L), I get a non-null pointer. Again Linux works without issue...

From what I researched on the internet, I've noticed that if threads are used (which gdb reports Love2d is using) then the passed in lua_State may have a race condition with the garbage collection. A solution listed is to use only the global lua state when Lua was instantiated. Unfortunately, I don't know how to get it. Although, I don't know how this would happen as the thread should still be open...

Is there a love2d C function to get the global lua state? Maybe in a Love2d .dll? I noticed in lua 5.2 that there is a function call to get this, but we have 5.1.

Also, is there a way to run love2d in a single thread? It is annoying running a debugger and/or Valgrind on love2d...

This function have been removed from Lua 5.2, try using updated API.

Which function are you referring to? If I try to call any regular lua function on the passed in lua_State *L, I get a seg fault. Is there a different function beside the luaopen_* to use for interfacing with C? If so, what is it?

I'm referring to the function that crashes your dll - luaL_register. There's a new method of registering C functions in 5.2. Consult the manual. https://www.lua.org/pil/26.html https://www.lua.org/manual/5.2/manual.html#4

Also I don't believe single-threaded LOVE is possible, because the audio module has hard-coded multithreading in it, and so does the entire OpenAL and SDL's input module I believe (I could be wrong) which is hard-coded to hook to the window module. You can try disabling audio, sound, window, joystick, keyboard, mouse, touch and thread modules - then it might run in a single threaded mode. At that point you should just use bare LuaJIT, which is single threaded by design.

I have tried the ones in (https://www.lua.org/pil/26.1.html) namely lua_pushcfunction, and lua_setglobal. I get the same seg fault. Happens on the first lua_* function I call. I've even tried lua_createtable just for the fun of it.

You are mentioning lua5.2. I was under the impression we are using lua 5.1. Has there been a change I missed? If so, I bet that is the issue.
https://love2d.org/forums/viewtopic.php?t=83356

I just redownloaded the Window's Love 11.3 zip file: it contain a lua51.dll. Is there a different dll I should use?

LuaJIT is based on 5.1 specs with some 5.2 features backported, with little implementation details available; it's a special case. Then again it might be simply the case of building your DLL against Lua binaries and not LuaJIT ones.

Do you know what compiler love2d is compiled with? I use mingw, maybe it is a compiler mismatch of some sort.

For compiling, I use the same headers for both Linux and Windows. As for the .dll I use the one supplied with love2d .zip file. I'll have to look at regular lua dll.

Official builds of LÖVE 11.x for Windows have been compiled with VS2013.

That's being said, mixing DLLs between different (MSVC) compiler can cause problems.

At first, I'd look at "lslib" variables. The luaL_reg should be terminated with {NULL, NULL} to indicate the end of functions to register, so.

AuahDark, Thank you, but my lslib does have the sentinel.

My tests show that yes, you are correct, mixing the 64-bit mingw with 64-bit msvc causes issues. I found out on LuaJIT's site: http://luajit.org/install.html that LuaJit is NOT compatible with 64-bit mingw! Although, LuaJIT is compatible with with 32-bit mingw.

Once I switched to 32-bit (using the -m32 flag) the code compiled and ran as expected. So love2d 32-bit works with my setup when I switch to 32-bit binaries. Anyone reading this, keep in mind that it looks like you will need to use mscv if you want 64-bit C dll on Windows to work with love2d. (Although, I did not test this.)

I'm glad it isn't a threading issue...

Thank you everyone!