diff --git a/quickwit/quickwit-actors/src/actor_state.rs b/quickwit/quickwit-actors/src/actor_state.rs
index 8b9e4190f60..0fb68156fa4 100644
--- a/quickwit/quickwit-actors/src/actor_state.rs
+++ b/quickwit/quickwit-actors/src/actor_state.rs
@@ -71,7 +71,7 @@ impl ActorState {
     }
 }
 
-pub struct AtomicState(AtomicU32);
+pub(crate) struct AtomicState(AtomicU32);
 
 impl Default for AtomicState {
     fn default() -> Self {
@@ -80,7 +80,7 @@ impl Default for AtomicState {
 }
 
 impl AtomicState {
-    pub fn process(&self) {
+    pub(crate) fn process(&self) {
         let _ = self.0.compare_exchange(
             ActorState::Idle as u32,
             ActorState::Processing as u32,
@@ -89,7 +89,7 @@ impl AtomicState {
         );
     }
 
-    pub fn idle(&self) {
+    pub(crate) fn idle(&self) {
         let _ = self.0.compare_exchange(
             ActorState::Processing as u32,
             ActorState::Idle as u32,
@@ -98,7 +98,7 @@ impl AtomicState {
         );
     }
 
-    pub fn pause(&self) {
+    pub(crate) fn pause(&self) {
         let _ = self
             .0
             .fetch_update(Ordering::SeqCst, Ordering::SeqCst, |state| {
@@ -109,7 +109,7 @@ impl AtomicState {
             });
     }
 
-    pub fn resume(&self) {
+    pub(crate) fn resume(&self) {
         let _ = self.0.compare_exchange(
             ActorState::Paused as u32,
             ActorState::Processing as u32,
diff --git a/quickwit/quickwit-actors/src/spawn_builder.rs b/quickwit/quickwit-actors/src/spawn_builder.rs
index 42d94f43ad4..c3f0b114b46 100644
--- a/quickwit/quickwit-actors/src/spawn_builder.rs
+++ b/quickwit/quickwit-actors/src/spawn_builder.rs
@@ -201,7 +201,13 @@ impl<A: Actor + Default> SpawnBuilder<A> {
     }
 }
 
-/// Returns `None` if no message is available at the moment.
+/// Receives an envelope from either the high priority queue or the low priority queue.
+///
+/// In the paused state, the actor will only attempt to receive high priority messages.
+///
+/// If no message is available, this function will yield until a message arrives.
+/// If a high priority message is arrives first it is guaranteed to be processed first.
+/// This other way around is however not guaranteed.
 async fn recv_envelope<A: Actor>(inbox: &mut Inbox<A>, ctx: &ActorContext<A>) -> Envelope<A> {
     if ctx.state().is_running() {
         ctx.protect_future(inbox.recv()).await.expect(