fix kill main window in --server

src/ipc.rs

@@ -699,6 +699,9 @@ async fn check_pid(postfix: &str) {
             }
         }
     }
+    // if not remove old ipc file, the new ipc creation will fail
+    // if we remove a ipc file, but the old ipc process is still running, 
+    // new connection to the ipc will connect to new ipc, old connection to old ipc still keep alive
     std::fs::remove_file(&Config::ipc_path(postfix)).ok();
 }
 
@@ -985,31 +988,6 @@ pub async fn test_rendezvous_server() -> ResultType<()> {
     Ok(())
 }
 
-#[cfg(windows)]
-pub fn is_ipc_file_exist(suffix: &str) -> ResultType<bool> {
-    // Not change this to std::path::Path::exists, unless it can be ensured that it can find the ipc which occupied by a process that taskkill can't kill.
-    let prefix = "\\\\.\\pipe\\";
-    let file_name = Config::ipc_path(suffix).replace(prefix, "");
-    let mut err = None;
-    for entry in std::fs::read_dir(prefix)? {
-        match entry {
-            Ok(entry) => {
-                if entry.file_name().into_string().unwrap_or_default() == file_name {
-                    return Ok(true);
-                }
-            }
-            Err(e) => {
-                err = Some(e);
-            }
-        }
-    }
-    if let Some(e) = err {
-        Err(e.into())
-    } else {
-        Ok(false)
-    }
-}
-
 #[tokio::main(flavor = "current_thread")]
 pub async fn send_url_scheme(url: String) -> ResultType<()> {
     connect(1_000, "_url")

src/server.rs

@@ -467,12 +467,9 @@ pub async fn start_server(is_server: bool) {
         std::thread::spawn(move || {
             if let Err(err) = crate::ipc::start("") {
                 log::error!("Failed to start ipc: {}", err);
-                #[cfg(windows)]
-                if crate::is_server() && crate::ipc::is_ipc_file_exist("").unwrap_or(false) {
+                if crate::is_server() {
                     log::error!("ipc is occupied by another process, try kill it");
-                    if let Err(e) = crate::platform::try_kill_rustdesk_main_window_process() {
-                        log::error!("kill failed: {}", e);
-                    }
+                    std::thread::spawn(stop_main_window_process).join().ok();
                 }
                 std::process::exit(-1);
             }
@@ -636,3 +633,19 @@ async fn sync_and_watch_config_dir() {
     }
     log::warn!("skipped config sync");
 }
+
+#[tokio::main(flavor = "current_thread")]
+pub async fn stop_main_window_process() {
+    // this may also kill another --server process,
+    // but --server usually can be auto restarted by --service, so it is ok
+    if let Ok(mut conn) = crate::ipc::connect(1000, "").await {
+        conn.send(&crate::ipc::Data::Close).await.ok();
+    }
+    #[cfg(windows)]
+    {
+        // in case above failure, e.g. zombie process
+        if let Err(e) = crate::platform::try_kill_rustdesk_main_window_process() {
+            log::error!("kill failed: {}", e);
+        }
+    }
+}