From 55401b1e53661a91f13269b2266c6429d2d7ff10 Mon Sep 17 00:00:00 2001
From: Ian Douglas Scott <idscott@system76.com>
Date: Tue, 17 Jun 2025 17:50:30 -0700
Subject: [PATCH] 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        |  1 +
 Cargo.toml        |  1 +
 src/dbus/mod.rs   | 37 +++++++++++++++----------------------
 src/dbus/power.rs | 10 +++++-----
 src/state.rs      |  6 ++++--
 5 files changed, 26 insertions(+), 29 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e5e28b32..46f9128a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -834,6 +834,7 @@ dependencies = [
  "egui",
  "egui_plot",
  "futures-executor",
+ "futures-util",
  "i18n-embed",
  "i18n-embed-fl",
  "iced_tiny_skia",
diff --git a/Cargo.toml b/Cargo.toml
index 394d19f8..409f3e32 100644
--- a/Cargo.toml
+++ b/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"
diff --git a/src/dbus/mod.rs b/src/dbus/mod.rs
index d66fa665..7f20c72b 100644
--- a/src/dbus/mod.rs
+++ b/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");
diff --git a/src/dbus/power.rs b/src/dbus/power.rs
index 9d9d37b6..346b8107 100644
--- a/src/dbus/power.rs
+++ b/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)
 }
diff --git a/src/state.rs b/src/state.rs
index 1dc7b6ef..3d755e4a 100644
--- a/src/state.rs
+++ b/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,