gui: start the emulator in new thread

[ngoquang2708]

Fix Qt GUI not responding in Linux.

Fix: #882.

[ngoquang2708]

@DanielSvoboda Can you help with the Qt window crash when resizing.

[GHU7924]

@ngoquang2708 There is a moment when the active window overlaps the previous one, just like now, when a PR with a status column was added, an empty rectangle appears, which freezes when closed and you have to stop the emulator.
In addition, when installing *.pkg, the progress was not displayed, if I remember correctly.

I suppose you are aware of this.

[ngoquang2708]

I think those issues are not relevant to this PR though.

[EmptyVisual]

In testing this, it fixes the issue with the main window stuck in a loop of not responding while the game window is running. So now once I launch a game, I can tab to the main emulator window and change settings.

Two issues that still remain and are not resolved by this MR:

• Closing the game window also closes the entire emulator application.
• userfaultd still needs to be commented out; otherwise, there’s a persistent hang on the game window within seconds of launching any non-specific game and it does not recover (can hear audio, but the game itself is frozen). This is a blocker for me in testing mains precompiled binaries. I have to remove the userfaultd code every time from the source and compile.

For reference:
Arch
Linux 6.12.4
CPU: Ryzen 5800X
GPU: Radeon 6900 XT (mesa-git-25.0.0_devel.199185.f0797c60e50)

[kavika13]

I tested this fix, and it seems to be working well for me. Thanks for the work!

Edit: Yeah, userfaultfd is causing problems for me too when trying to A/B vs main. They just merged #1777 minutes ago, so that should no longer be a problem and is unrelated to this PR.

[raphaelthegreat]

Nice, this is quite useful