fix: Fix flycheck generations not being synced for multiple workspaces

crates/rust-analyzer/src/flycheck.rs

@@ -147,13 +147,13 @@ pub(crate) struct FlycheckHandle {
     sender: Sender<StateChange>,
     _thread: stdx::thread::JoinHandle,
     id: usize,
-    generation: AtomicUsize,
+    generation: Arc<AtomicUsize>,
 }
 
 impl FlycheckHandle {
     pub(crate) fn spawn(
         id: usize,
-        generation: DiagnosticsGeneration,
+        generation: Arc<AtomicUsize>,
         sender: Sender<FlycheckMessage>,
         config: FlycheckConfig,
         sysroot_root: Option<AbsPathBuf>,
@@ -163,7 +163,7 @@ impl FlycheckHandle {
     ) -> FlycheckHandle {
         let actor = FlycheckActor::new(
             id,
-            generation,
+            generation.load(Ordering::Relaxed),
             sender,
             config,
             sysroot_root,
@@ -176,7 +176,7 @@ impl FlycheckHandle {
             stdx::thread::Builder::new(stdx::thread::ThreadIntent::Worker, format!("Flycheck{id}"))
                 .spawn(move || actor.run(receiver))
                 .expect("failed to spawn thread");
-        FlycheckHandle { id, generation: generation.into(), sender, _thread: thread }
+        FlycheckHandle { id, generation, sender, _thread: thread }
     }
 
     /// Schedule a re-start of the cargo check worker to do a workspace wide check.

crates/rust-analyzer/src/reload.rs

@@ -13,7 +13,7 @@
 //! project is currently loading and we don't have a full project model, we
 //! still want to respond to various  requests.
 // FIXME: This is a mess that needs some untangling work
-use std::{iter, mem};
+use std::{iter, mem, sync::atomic::AtomicUsize};
 
 use hir::{ChangeWithProcMacros, ProcMacrosBuilder, db::DefDatabase};
 use ide_db::{
@@ -866,12 +866,13 @@ impl GlobalState {
         let invocation_strategy = config.invocation_strategy();
         let next_gen =
             self.flycheck.iter().map(FlycheckHandle::generation).max().unwrap_or_default() + 1;
+        let generation = Arc::new(AtomicUsize::new(next_gen));
 
         self.flycheck = match invocation_strategy {
             crate::flycheck::InvocationStrategy::Once => {
                 vec![FlycheckHandle::spawn(
                     0,
-                    next_gen,
+                    generation.clone(),
                     sender.clone(),
                     config,
                     None,
@@ -915,7 +916,7 @@ impl GlobalState {
                     .map(|(id, (root, manifest_path, target_dir), sysroot_root)| {
                         FlycheckHandle::spawn(
                             id,
-                            next_gen,
+                            generation.clone(),
                             sender.clone(),
                             config.clone(),
                             sysroot_root,