Fix OOM error

[uyjulian]

Out of memory error occurs, preventing large assets from being loaded and "The Question" from being run in album override.

[uyjulian]

OOM error can still occur, but data aborts are no longer thrown.

[baconwaifu]

Applet mode RAM restrictions are well known, and impossible to bypass without a patch in atmosphere or other CFW. The best you can do is make it throw a "this won't work, launch in game mode" error instead of crashing.

[uyjulian]

OOM in "The Question" did not occur before I made an update to libnx.

Even if not using album override, the application can still run out of memory when large assets are loaded over a period of time.

[baconwaifu]

sounds like a memory leak then. Given that python is garbage-collected, a core dump should be able to piece together what filled the RAM. I'll take a look with twili when I have the time.

[uyjulian]

The following warning appears in the log:

romfs:/Contents/renpy/display/pgrender.py:118: UserWarning: Memory leak via Surface in pygame_sdl2.
  surf = Surface((width + 4, height + 4), 0, sample)

A couple of OOM tracebacks:

...
  File "romfs:/Contents/renpy/display/core.py", line 2314, in event_peek
    self.check_background_screenshot()
  File "romfs:/Contents/renpy/display/core.py", line 2162, in check_background_screenshot
    self.bgscreenshot_surface = renpy.display.draw.screenshot(self.surftree, self.fullscreen_video)
  File "gldraw.pyx", line 1382, in renpy.gl.gldraw.GLDraw.screenshot
  File "romfs:/Contents/renpy/display/pgrender.py", line 118, in surface
    surf = Surface((width + 4, height + 4), 0, sample)
  File "src/pygame_sdl2/surface.pyx", line 164, in pygame_sdl2.surface.Surface.__init__
error: Out of memory

...
  File "render.pyx", line 166, in renpy.display.render.render
  File "render.pyx", line 259, in renpy.display.render.render
  File "romfs:/Contents/renpy/text/text.py", line 2008, in render
    layout = Layout(self, width, height, renders, splits_from=virtual_layout)
  File "romfs:/Contents/renpy/text/text.py", line 821, in __init__
    tex = renpy.display.draw.load_texture(surf)
  File "gldraw.pyx", line 747, in renpy.gl.gldraw.GLDraw.load_texture
  File "gltexture.pyx", line 883, in renpy.gl.gltexture.texture_grid_from_surface
  File "gltexture.pyx", line 319, in renpy.gl.gltexture.TextureCore.load_surface
  File "gltexture.pyx", line 1174, in renpy.gl.gltexture.premultiply
MemoryError

...
    if self.event_peek():
  File "romfs:/Contents/renpy/display/core.py", line 2314, in event_peek
    self.check_background_screenshot()
  File "romfs:/Contents/renpy/display/core.py", line 2162, in check_background_screenshot
    self.bgscreenshot_surface = renpy.display.draw.screenshot(self.surftree, self.fullscreen_video)
  File "gldraw.pyx", line 1382, in renpy.gl.gldraw.GLDraw.screenshot
  File "romfs:/Contents/renpy/display/pgrender.py", line 118, in surface
    surf = Surface((width + 4, height + 4), 0, sample)
  File "src/pygame_sdl2/surface.pyx", line 164, in pygame_sdl2.surface.Surface.__init__
error: Out of memory

The following could be possible:

1. Memory leak in renpy.display.pgrender.Surface
2. Memory allocation/deallocation in threads is not working correctly

[uyjulian]

On Linux, I used a test project with various large images, audio, and music, and looped it for five minutes. Memory usage started at 529688 (title screen, before start) then ended at 1906304 (title screen, after start).
That is not even close to hitting the Switch's memory amount of 4GB.

It may be possible to get the amount of available memory by using

size_t mem_available;
svcGetInfo(&mem_available, InfoType_TotalMemorySize, CUR_PROCESS_HANDLE, 0);

,

size_t mem_used;
svcGetInfo(&mem_used, InfoType_UsedMemorySize, CUR_PROCESS_HANDLE, 0);

,

struct mallinfo mi = mallinfo();
size_t heap_available = mi.uordblks;

and

struct mallinfo mi = mallinfo();
size_t heap_used = mi.fordblks;

, but I haven't tried it out yet.

I may just do the following:

1. Decreasing heap size using __nx_heap_size variable
2. Allocating memory to the Python object allocator using svcMapPhysicalMemory and virtmemReserve

Python object allocator obmalloc.c uses mmap to decrease heap fragmentation.

[uyjulian]

For some reason, the heap size is randomized... Check out https://gist.github.com/uyjulian/df5e5c44a8304ba17536609f0358ac0a for how I determined this

[uyjulian]

I may try to use virtmemFindAslr / virtmemAddReservation / virtmemRemoveReservation to assist in heap fragmentation…

[uyjulian]

Need more confirmation that virtmemFindAslr will fix the issue…

[uyjulian]

Nope… In fact, virtmemFindAslr has a worse issue.

[uyjulian]

It looks like heap is limited to 384 MiB, so there's not much I can do right now until PhysicalMemory SVCs are implemented…