Memory leaks on master with simple app not doing anything

[WSSDude]

This simple sample with latest master from git is causing 5 allocations to keep hanging.
Am I missing some free I should have done? I think I did not left anything for simple sample 🤔

I am on Windows 11, using Visual Studio 22 if it makes any difference.
Just this sample is causing mentioned issue, no other code is anywhere inbetween in the main itself.

SDLMAIN_DECLSPEC int SDL_main(int argc, char* argv[])
{
  const auto init_allocations = SDL_GetNumAllocations(); // NOTE: always seems to be 0 at this point, but leaving it for good measure...

  // Setup SDL
  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
  {
    printf("Error: %s\n", SDL_GetError());
    return -1;
  }

  // Setup window
  SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
  SDL_Window* window = SDL_CreateWindow("SDL2 Example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);

  // Main loop
  bool done = false;
  while (!done)
  {
    SDL_Event event;
    while (SDL_PollEvent(&event))
    {
      if (event.type == SDL_QUIT)
        done = true;
      if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
        done = true;
    }
  }

  SDL_DestroyWindow(window);
  SDL_Quit();

  SDL_assert(init_allocations == SDL_GetNumAllocations()); // ERROR: assertion fails, as there seem to be 5 allocations performed inside some of these functions that do not get freed
  return 0;
}

[WSSDude]

Ok, somehow I can't get the 5 allocations mentioned now after trying to replace memory functions to be able to monitor what allocations are not freed...
Am getting 3 after replacement.

With replacement, those 3 places seem to be:

• thread local storage allocation inside src\thread\SDL_thread.c in function int SDL_TLSSet(SDL_TLSID id, const void *value, void (SDLCALL *destructor)(void *)) (culprit seems to be SDL_realloc)
• error buffer allocation in src\thread\SDL_thread.c inside function SDL_error* SDL_GetErrBuf(void) (there is only one SDL_malloc)
• IME composition allocation in src\video\windows\SDL_windowskeyboard.c inside function void WIN_InitKeyboard(_THIS) (assignment of data->ime_composition, SDL_malloc call)

Every single one of these come from inital call to SDL_Init function, looking at the stack trace.

[huth]

I'm seeing a similar problem - using this even more simple C program:

#include <SDL2/SDL.h>

int main()
{
  SDL_Init(SDL_INIT_VIDEO);
  SDL_Quit();
  return 0;
}

Compiling it with gcc -fsanitize=address sdltest.c -o sdltest -lSDL2 and running the test program, I can see a lot of leaks reported. For some reason, some of the leaks seem to go away if I also add SDL_INIT_AUDIO to the SDL_Init() call.

[icculus]

The error state and tls allocation (which is related to error state) is intentional, as far as I know (and I think we added a function you can call to clean this up manually).

The Windows IME thing is probably a legit leak to fix though. I'll take a look tomorrow.

[slouken]

The TLS cleanup function is SDL_TLSCleanup()

The memory leak is fixed in 15bcf58

Thanks!