The default FEX preset (Performance + TSO) is fine for Unity. But when
the Default profile is switched to a preset
that turns TSO off (Performance, Extreme, Extreme-gn, Denuvo), Unity
players break. DroidDeck already keeps full TSO
for .NET games (`coreclr.dll`) whatever the preset; this gives Unity
players the same safety net for TSO.
Tested on a Pixel 10 Pro Fold (PowerVR DXT-48-1536), shared preset
Performance (TSO off):
| Game | Build | TSO off | TSO on |
| --- | --- | --- | --- |
| Megabonk | Unity 2023.2 IL2CPP, native Linux, "Linux x86 (FEX)" |
froze on about half of launches (every thread parked on a futex) | 5 of
5 starts, played run stayed responsive |
| Crab Game | Unity IL2CPP, Windows, Proton arm64 | 9 of 10 starts; 1
access violation in `UnityPlayer.dll` (read of a garbage pointer) | 10
of 10 starts |
Measured cost of TSO on Megabonk: none (+2% fps with TSO on, within
noise).
What changes:
- `droiddeck-game-env`: `unity_memory_ordering` sets `FEX_TSOENABLED=1`
when `UnityPlayer.dll`, `UnityPlayer.so` or
`GameAssembly.so` sits next to the executable (or one folder below). A
FEX preset chosen for the game still wins
(fixes sit between the shared preset and the per-game entry, as for
.NET).
- `droiddeck-fex`: the FEX tool now applies the environment half of
these game-file fixes, so native Linux Unity builds
get it too. Launch arguments some fixes add stay Proton-only.
- Docs paragraph in `docs/development/game-environment.md`; tests in
`test_game_environment.py` and
`test_droiddeck_fex.py`.
Device check of the change itself: with the session's
`droiddeck-game-env` patched, shared TSO off and no per-game
entry, Crab Game started with `FEX_TSOENABLED=1`.
Related to #1386, but not a fix for its Risk of Rain 2 crash: that game
is Unity Mono, which with the default preset
already has TSO on; the report points at multiblock instead (as the .NET
fix turns off). Both games tested here are
IL2CPP, so this PR doesn't change multiblock. #1386's other points
(`steam_appid.txt`, `device.txt`) aren't covered.
Tests (WSL, on main `16bedf36` with the patch): `test_game_environment`
+ `test_droiddeck_fex` 119 OK. Full `tools/tests`: 1114 tests, one
failure,
`test_appimage_run…test_a_failed_program_shows_the_log_it_wrote`, which
fails the same way without the patch.
MaxsTechReview
0c26a829ec