Use single-threaded runtime when launching service

mullvad-daemon/src/main.rs

@@ -1,9 +1,7 @@
 use mullvad_daemon::{
     logging,
     management_interface::{ManagementInterfaceEventBroadcaster, ManagementInterfaceServer},
-    rpc_uniqueness_check,
-    runtime::new_runtime_builder,
-    version, Daemon, DaemonCommandChannel, DaemonCommandSender,
+    rpc_uniqueness_check, runtime, version, Daemon, DaemonCommandChannel, DaemonCommandSender,
 };
 use std::{path::PathBuf, thread, time::Duration};
 use talpid_types::ErrorExt;
@@ -22,11 +20,7 @@ const DAEMON_LOG_FILENAME: &str = "daemon.log";
 const EARLY_BOOT_LOG_FILENAME: &str = "early-boot-fw.log";
 
 fn main() {
-    let runtime = new_runtime_builder().build().unwrap_or_else(|e| {
-        eprintln!("{}", e.display_chain());
-        std::process::exit(1);
-    });
-
+    let runtime = new_runtime();
     let exit_code = match runtime.block_on(run()) {
         Ok(_) => 0,
         Err(error) => {
@@ -44,6 +38,19 @@ fn main() {
     std::process::exit(exit_code);
 }
 
+fn new_runtime() -> tokio::runtime::Runtime {
+    let mut builder = match cli::get_config().command {
+        #[cfg(target_os = "windows")]
+        cli::Command::RunAsService | cli::Command::RegisterService => runtime::new_current_thread(),
+        _ => runtime::new_multi_thread(),
+    };
+
+    builder.build().unwrap_or_else(|e| {
+        eprintln!("{}", e.display_chain());
+        std::process::exit(1);
+    })
+}
+
 async fn run() -> Result<(), String> {
     let config = cli::get_config();
 

mullvad-daemon/src/runtime.rs

@@ -1,7 +1,13 @@
 use tokio::runtime;
 
-pub fn new_runtime_builder() -> runtime::Builder {
+pub fn new_multi_thread() -> runtime::Builder {
     let mut builder = runtime::Builder::new_multi_thread();
     builder.worker_threads(4).enable_all();
     builder
 }
+
+pub fn new_current_thread() -> runtime::Builder {
+    let mut builder = runtime::Builder::new_current_thread();
+    builder.enable_all();
+    builder
+}

mullvad-daemon/src/system_service.rs

@@ -1,5 +1,5 @@
 use crate::cli;
-use mullvad_daemon::{runtime::new_runtime_builder, DaemonShutdownHandle};
+use mullvad_daemon::{runtime::new_multi_thread, DaemonShutdownHandle};
 use once_cell::sync::Lazy;
 use std::{
     env,
@@ -98,7 +98,7 @@ pub fn handle_service_main(_arguments: Vec<OsString>) {
 
     let log_dir = crate::get_log_dir(cli::get_config()).expect("Log dir should be available here");
 
-    let runtime = new_runtime_builder().build();
+    let runtime = new_multi_thread().build();
     let runtime = match runtime {
         Err(error) => {
             log::error!("{}", error.display_chain());

mullvad-jni/src/lib.rs

@@ -19,7 +19,7 @@ use jnix::{
 };
 use mullvad_api::{rest::Error as RestError, StatusCode};
 use mullvad_daemon::{
-    device, exception_logging, logging, runtime::new_runtime_builder,
+    device, exception_logging, logging, runtime::new_multi_thread,
     settings::patch::Error as PatchError, version, Daemon, DaemonCommandChannel,
 };
 use mullvad_types::{
@@ -551,7 +551,7 @@ fn spawn_daemon(
         .map_err(Error::CreateGlobalReference)?;
     let (tx, rx) = mpsc::channel();
 
-    let runtime = new_runtime_builder()
+    let runtime = new_multi_thread()
         .build()
         .map_err(Error::InitializeTokioRuntime)?;