From c290e60af1f4e94f1b83aa3539a6dca09169e2c5 Mon Sep 17 00:00:00 2001
From: Logan McNaughton <848146+loganmc10@users.noreply.github.com>
Date: Tue, 16 Jun 2026 11:33:27 +0200
Subject: [PATCH] put tokio runtime in dedicated thread (#1086)

* put tokio runtime in dedicated thread

* more

* more

* more

* more
---
 Cargo.toml               |  2 +-
 src/lib.rs               | 24 +++++++++++++++++++-----
 src/main.rs              | 10 +++++++---
 src/retroachievements.rs |  5 ++---
 src/ui/android.rs        |  9 +++++++--
 5 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 4d6a18e5..1a752bd1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde-big-array = "0.5"
 sha2 = "0.11"
-tokio = {version = "1.46", features = ["rt-multi-thread", "macros", "fs", "process"] }
+tokio = {version = "1.46", features = ["rt-multi-thread", "fs", "process"] }
 spin_sleep = "1.3"
 encoding_rs = "0.8"
 mimalloc = "0.1"
diff --git a/src/lib.rs b/src/lib.rs
index a3612624..93056efe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -104,6 +104,19 @@ fn set_app_id() {
     }
 }
 
+pub fn create_runtime() -> (tokio::sync::oneshot::Sender<()>, tokio::runtime::Handle) {
+    let (tx, rx) = std::sync::mpsc::channel();
+    let (close_tx, close_rx) = tokio::sync::oneshot::channel::<()>();
+
+    std::thread::spawn(move || {
+        let rt = tokio::runtime::Runtime::new().expect("Failed to build runtime");
+        tx.send(rt.handle().clone()).unwrap();
+        rt.block_on(close_rx).unwrap();
+    });
+
+    (close_tx, rx.recv().unwrap())
+}
+
 pub fn run(args: Args, arg_count: usize) -> std::io::Result<()> {
     let dirs = ui::get_dirs();
 
@@ -213,9 +226,7 @@ pub fn run(args: Args, arg_count: usize) -> std::io::Result<()> {
                 tx.send(false).unwrap();
             }
 
-            tokio::task::block_in_place(move || {
-                rx.blocking_recv().unwrap();
-            });
+            rx.blocking_recv().unwrap();
 
             ra_config
         } else {
@@ -334,8 +345,10 @@ pub fn run(args: Args, arg_count: usize) -> std::io::Result<()> {
 
 #[cfg(target_os = "android")]
 #[unsafe(no_mangle)]
-#[tokio::main]
-async fn android_main(app: slint::android::AndroidApp) {
+fn android_main(app: slint::android::AndroidApp) {
+    let (close_tx, handle) = create_runtime();
+    let _guard = handle.enter();
+
     slint::android::init_with_event_listener(app.clone(), move |event| match event {
         slint::android::android_activity::PollEvent::Main(main_event) => match main_event {
             slint::android::android_activity::MainEvent::TerminateWindow { .. } => {
@@ -368,6 +381,7 @@ async fn android_main(app: slint::android::AndroidApp) {
     std::fs::create_dir_all(dirs.data_dir.join("states")).unwrap();
 
     ui::gui::app_window(&app_window, true);
+    close_tx.send(()).unwrap();
     *android::WEAK_SLINT_WINDOW.lock().unwrap() = None;
     *android::ANDROID_APP.lock().unwrap() = None;
 }
diff --git a/src/main.rs b/src/main.rs
index 3a3e5222..42f400d7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,8 +5,12 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
 
 use clap::Parser;
 
-#[tokio::main]
-async fn main() -> std::io::Result<()> {
+fn main() -> std::io::Result<()> {
+    let (close_tx, handle) = gopher64::create_runtime();
+    let _guard = handle.enter();
+
     let args = gopher64::Args::parse();
-    gopher64::run(args, std::env::args().count())
+    let result = gopher64::run(args, std::env::args().count());
+    close_tx.send(()).unwrap();
+    result
 }
diff --git a/src/retroachievements.rs b/src/retroachievements.rs
index ee81cbf6..5186b284 100644
--- a/src/retroachievements.rs
+++ b/src/retroachievements.rs
@@ -150,9 +150,8 @@ pub fn load_game(
         let tx_ptr = Box::into_raw(Box::new(tx)) as *mut std::ffi::c_void;
         ra_load_game(rom.as_ptr(), rom_size, tx_ptr);
     };
-    tokio::task::block_in_place(move || {
-        rx.blocking_recv().unwrap();
-    });
+
+    rx.blocking_recv().unwrap();
 
     let mut c_title = std::ptr::null();
     let mut c_image_url = std::ptr::null();
diff --git a/src/ui/android.rs b/src/ui/android.rs
index e16803ed..d0efa29a 100644
--- a/src/ui/android.rs
+++ b/src/ui/android.rs
@@ -1,4 +1,5 @@
 use crate::Args;
+use crate::create_runtime;
 use crate::run;
 use crate::ui;
 use clap::Parser;
@@ -158,17 +159,21 @@ fn argv_to_strings(argc: std::ffi::c_int, argv: *mut *mut std::ffi::c_char) -> V
 }
 
 #[unsafe(no_mangle)]
-#[tokio::main]
-pub async extern "C" fn gopher64_sdl_main(
+pub extern "C" fn gopher64_sdl_main(
     argc: std::ffi::c_int,
     argv: *mut *mut std::ffi::c_char,
 ) -> std::ffi::c_int {
+    let (close_tx, handle) = create_runtime();
+    let _guard = handle.enter();
+
     let raw = argv_to_strings(argc, argv);
     let args = Args::try_parse_from(raw).unwrap();
     if let Err(err) = run(args, argc as usize) {
+        close_tx.send(()).unwrap();
         eprintln!("Error running game: {err:?}");
         return 1;
     }
+    close_tx.send(()).unwrap();
     0
 }