chore: improve client health checking (windows)

crates/els/Cargo.toml

@@ -30,7 +30,11 @@ molc = { version = "0.3" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.85"
 lsp-types = { version = "0.93.2", features = ["proposed"] }
+
+[target.'cfg(unix)'.dependencies]
 libc = "0.2"
+[target.'cfg(windows)'.dependencies]
+windows = { version = "0.58", features = ["Win32_System_Threading"] }
 
 [dev-dependencies]
 erg_proc_macros = { workspace = true }

crates/els/diagnostics.rs

@@ -34,13 +34,37 @@ use crate::server::{DefaultFeatures, ELSResult, RedirectableStdout, Server};
 use crate::server::{ASK_AUTO_SAVE_ID, HEALTH_CHECKER_ID};
 use crate::util::{self, NormalizedUrl};
 
-pub fn is_parent_alive(parent_pid: i32) -> bool {
+#[cfg(unix)]
+pub fn is_process_alive(pid: i32) -> bool {
     unsafe {
         // sig 0: check if the process exists
-        let alive = libc::kill(parent_pid, 0);
+        let alive = libc::kill(pid, 0);
         alive == 0
     }
 }
+#[cfg(windows)]
+pub fn is_process_alive(pid: i32) -> bool {
+    unsafe {
+        use windows::Win32::System::Threading::{
+            GetExitCodeProcess, OpenProcess, PROCESS_QUERY_INFORMATION,
+        };
+
+        const STILL_ACTIVE: u32 = 0x103u32;
+
+        let Ok(handle) = OpenProcess(PROCESS_QUERY_INFORMATION, false, pid as u32) else {
+            return false;
+        };
+        let mut code = 0;
+        let Ok(_) = GetExitCodeProcess(handle, &mut code) else {
+            return false;
+        };
+        code == STILL_ACTIVE
+    }
+}
+#[cfg(all(not(windows), not(unix)))]
+pub fn is_process_alive(_pid: i32) -> bool {
+    false
+}
 
 #[derive(Debug)]
 pub enum BuildASTError {
@@ -531,6 +555,9 @@ impl<Checker: BuildRunnable, Parser: Parsable> Server<Checker, Parser> {
         if self.stdout_redirect.is_some() {
             return;
         }
+        let Some(client_pid) = self.init_params.process_id.map(|x| x as i32) else {
+            return;
+        };
         let _self = self.clone();
         // FIXME: close this thread when the server is restarted
         spawn_new_thread(
@@ -554,11 +581,6 @@ impl<Checker: BuildRunnable, Parser: Parsable> Server<Checker, Parser> {
             },
             "start_client_health_checker_sender",
         );
-        let parent_pid = self
-            .init_params
-            .process_id
-            .map(|x| x as i32)
-            .unwrap_or_else(|| unsafe { libc::getppid() });
         spawn_new_thread(
             move || {
                 loop {
@@ -575,7 +597,7 @@ impl<Checker: BuildRunnable, Parser: Parsable> Server<Checker, Parser> {
                             // _log!(self, "Restart the server");
                             // send_error_info("Something went wrong, ELS has been restarted").unwrap();
                             // self_.restart();
-                            if !is_parent_alive(parent_pid) {
+                            if !is_process_alive(client_pid) {
                                 lsp_log!("Client seems to be dead");
                                 panic!("Client seems to be dead");
                             }