dbus: Use ThreadPool instead of zbus blocking API

The `zbus` blocking API just wraps the async API with `block_on`, so we
may as well use our own executor.

Cargo.lock

@@ -834,6 +834,7 @@ dependencies = [
  "egui",
  "egui_plot",
  "futures-executor",
+ "futures-util",
  "i18n-embed",
  "i18n-embed-fl",
  "iced_tiny_skia",

Cargo.toml

@@ -88,6 +88,7 @@ clap_lex = "0.7"
 parking_lot = "0.12.5"
 logind-zbus = { version = "5.3.2", optional = true }
 futures-executor = { version = "0.3.31", features = ["thread-pool"] }
+futures-util = "0.3.31"
 
 [dependencies.id_tree]
 branch = "feature/copy_clone"

src/dbus/mod.rs

@@ -5,6 +5,8 @@ use crate::{
 use anyhow::{Context, Result};
 use calloop::{InsertError, LoopHandle, RegistrationToken};
 use cosmic_comp_config::output::comp::OutputState;
+use futures_executor::{ThreadPool, block_on};
+use futures_util::stream::StreamExt;
 use std::collections::HashMap;
 use tracing::{error, warn};
 use zbus::blocking::{Connection, fdo::DBusProxy};
@@ -13,10 +15,13 @@ use zbus::blocking::{Connection, fdo::DBusProxy};
 pub mod logind;
 mod power;
 
-pub fn init(evlh: &LoopHandle<'static, State>) -> Result<Vec<RegistrationToken>> {
+pub fn init(
+    evlh: &LoopHandle<'static, State>,
+    executor: &ThreadPool,
+) -> Result<Vec<RegistrationToken>> {
     let mut tokens = Vec::new();
 
-    match power::init() {
+    match block_on(power::init()) {
         Ok(power_daemon) => {
             let (tx, rx) = calloop::channel::channel();
 
@@ -56,29 +61,17 @@ pub fn init(evlh: &LoopHandle<'static, State>) -> Result<Vec<RegistrationToken>>
                 .with_context(|| "Failed to add channel to event_loop")?;
 
             // start helper thread
-            let result = std::thread::Builder::new()
-                .name("system76-power-hotplug".to_string())
-                .spawn(move || {
-                    if let Ok(msg_iter) = power_daemon.receive_hot_plug_detect() {
-                        for msg in msg_iter {
-                            if tx.send(msg).is_err() {
-                                break;
-                            }
+            executor.spawn_ok(async move {
+                if let Ok(mut msg_iter) = power_daemon.receive_hot_plug_detect().await {
+                    while let Some(msg) = msg_iter.next().await {
+                        if tx.send(msg).is_err() {
+                            break;
                         }
                     }
-                })
-                .with_context(|| "Failed to start helper thread");
+                }
+            });
 
-            match result {
-                Ok(_handle) => {
-                    tokens.push(token);
-                    // detach thread
-                }
-                Err(err) => {
-                    evlh.remove(token);
-                    return Err(err);
-                }
-            }
+            tokens.push(token);
         }
         Err(err) => {
             tracing::info!(?err, "Failed to connect to com.system76.PowerDaemon");

src/dbus/power.rs

@@ -18,7 +18,7 @@
 //!
 //! …consequently `zbus-xmlgen` did not generate code for the above interfaces.
 
-use zbus::blocking::Connection;
+use zbus::Connection;
 
 #[zbus::proxy(
     interface = "com.system76.PowerDaemon",
@@ -79,9 +79,9 @@ pub trait PowerDaemon {
     fn power_profile_switch(&self, profile: &str) -> zbus::Result<()>;
 }
 
-pub fn init() -> anyhow::Result<PowerDaemonProxyBlocking<'static>> {
-    let conn = Connection::system()?;
-    let proxy = PowerDaemonProxyBlocking::new(&conn)?;
-    proxy.0.introspect()?;
+pub async fn init() -> anyhow::Result<PowerDaemonProxy<'static>> {
+    let conn = Connection::system().await?;
+    let proxy = PowerDaemonProxy::new(&conn).await?;
+    proxy.0.introspect().await?;
     Ok(proxy)
 }

src/state.rs

@@ -696,7 +696,9 @@ impl State {
         );
         let workspace_state = WorkspaceState::new(dh, client_not_sandboxed);
 
-        if let Err(err) = crate::dbus::init(&handle) {
+        let async_executor = ThreadPool::builder().pool_size(1).create().unwrap();
+
+        if let Err(err) = crate::dbus::init(&handle, &async_executor) {
             tracing::warn!(?err, "Failed to initialize dbus handlers");
         }
 
@@ -712,7 +714,7 @@ impl State {
                 display_handle: dh.clone(),
                 event_loop_handle: handle,
                 event_loop_signal: signal,
-                async_executor: ThreadPool::builder().pool_size(1).create().unwrap(),
+                async_executor,
 
                 popups: PopupManager::default(),
                 shell,