Tokio

Setup

In most projects this part is unnecessary because you only need the capabilities from Tokio that Tauri re-exports in tauri::async_runtime. However, if you need more advanced functionalities from the broader Tokio ecosystem there’s absolutely nothing wrong with adding it directly.

cargo add tokio

Async Main Function

Caution

Don’t use tokio::main to create an async fn main for your Tauri app. The reason is very simple. You don’t need it, Tauri already provides you with a Tokio Runtime, and all the macro does is generate a new main function for you that sets up a runtime before running the main function. Whatever you have that you think needs to run specifically in the main function I promise can run in the .setup function instead.

async fn setup(app: AppHandle) {
  // Do your async setup here instead
}

fn main() {
  Builder()
  .setup(|app| {
    tauri::async_runtime::block_on(setup(app.handle()));
  })
}

Background Threads

In order to spawn a background thread in Tauri all you have to do is use tauri::async_runtime::spawn(). This will schedule an async function to be executed by one of the Tokio runtimes worker threads.

Caution

If your background thread isn’t going to run cooperatively yielding somewhat frequently it might be better to use std::thread::spawn or Rayon for that task.

async fn my_daemon() {
  loop {
    println!("I run in the background!");
    tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
  }
}

fn main() {
  Builder()
  .setup(|app| {
    tauri::async_runtime::spawn(my_daemon());
  })
}