[bug] App hangs on creating a new window, with window-state and single-instance installed

[hut36]

Description

With window-state and single-instance installed, app hangs when creating a new window from single-instance's init() function.

Steps to reproduce

This is the repo to reproduce: https://github.com/hut36/tauri-window-hang

Steps to reproduce with the provided repo:

1. pnpm i && pnpm tauri build --debug. This produces tauri-window-hang.exe;
2. Launch the app by double-clicking tauri-window-hang.exe. This opens Window 1;
3. Double-click tauri-window-hang.exe, this opens Main Window;
4. Close Main Window;
5. Double-click tauri-window-hang.exe again, this is to open Main Window. App hangs here.

Alternative steps to reproduce the problem with the provided repo:

1. pnpm i && pnpm tauri build --debug. This produces tauri-window-hang.exe;
2. Launch the app by double-clicking tauri-window-hang.exe. This opens Window 1;
3. Double-click tauri-window-hang.exe, this opens Main Window;
4. Quit the app by closing all windows. This is to ensure windows' states are saved to disk;
5. Repeat steps 2 and 3, now app hangs on step 3.

If plugin window-state is removed(comment out line .plugin(tauri_plugin_window_state::Builder::new().build())), then it'll be successful to create Main Window.

Expected behaviour

Window is created without any problem.

tauri info

[✔] Environment
    - OS: Windows 10.0.22631 x86_64 (X64)
    ✔ WebView2: 130.0.2849.56
    ✔ MSVC: Visual Studio 生成工具 2022
    ✔ rustc: 1.82.0 (f6e511eec 2024-10-15)
    ✔ cargo: 1.82.0 (8f40fc59f 2024-08-21)
    ✔ rustup: 1.27.1 (54dd3d00f 2024-04-24)
    ✔ Rust toolchain: stable-x86_64-pc-windows-msvc (default)
    - node: 20.12.0
    - pnpm: 9.10.0
    - yarn: 1.22.22
    - npm: 9.6.3

[-] Packages
    - tauri 🦀: 2.1.1
    - tauri-build 🦀: 2.0.3
    - wry 🦀: 0.47.2
    - tao 🦀: 0.30.8
    - @tauri-apps/api : 2.1.1
    - @tauri-apps/cli : 2.1.0

[-] Plugins
    - tauri-plugin-shell 🦀: 2.0.2
    - @tauri-apps/plugin-shell : 2.0.1
    - tauri-plugin-window-state 🦀: 2.0.2
    - @tauri-apps/plugin-window-state : not installed!
    - tauri-plugin-single-instance 🦀: 2.0.1
    - @tauri-apps/plugin-single-instance : not installed!

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ../build
    - devUrl: http://localhost:1420/
    - framework: Svelte
    - bundler: Vite

[FabianLars]

I don't know why but it's this line

plugins-workspace/plugins/window-state/src/lib.rs

Line 199 in 5070476

self.set_position(PhysicalPosition {

[Legend-Master]

This is probably another dead lock caused by us locking plugins and then having events send to the event loop on the same thread in one of the callbacks

Noticed this when I write about this in tauri-apps/tauri#12032

[Legend-Master]

Yeah, from testing, this is indeed because of it

First lock here:

https://github.com/tauri-apps/tauri/blob/8f282c6305d9648e3ee99da3e27255cb5d09a01e/crates/tauri/src/manager/window.rs#L109-L115

And then in my case, set_size triggered a SetWindowPos call which made a WM_WINDOWPOSCHANGED message synchronously and this message got sent from tao to us and we're trying to lock plugins for the event handlers this time, and now we have a dead lock

https://github.com/tauri-apps/tauri/blob/8f282c6305d9648e3ee99da3e27255cb5d09a01e/crates/tauri/src/app.rs#L2292-L2296

I'm not quite sure why this is only the case when this is called from single instance plugin's callback though, maybe because itself is inside of a window procedure?