From e0d3b8ebdc7eea01c979cb2af0dd876b58de0ff5 Mon Sep 17 00:00:00 2001
From: John Spray <john@neon.tech>
Date: Thu, 19 Oct 2023 18:42:03 +0100
Subject: [PATCH] noisy completion

---
 libs/utils/src/completion.rs     | 38 ++++++++++++++++++++++++++++----
 pageserver/src/bin/pageserver.rs |  4 ++++
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/libs/utils/src/completion.rs b/libs/utils/src/completion.rs
index e2e84dd0ee..d6797e5fe3 100644
--- a/libs/utils/src/completion.rs
+++ b/libs/utils/src/completion.rs
@@ -1,12 +1,36 @@
-use std::sync::Arc;
+use std::sync::{atomic::AtomicI32, Arc};
 
 use tokio::sync::{mpsc, Mutex};
 
 /// While a reference is kept around, the associated [`Barrier::wait`] will wait.
 ///
 /// Can be cloned, moved and kept around in futures as "guard objects".
-#[derive(Clone)]
-pub struct Completion(mpsc::Sender<()>);
+pub struct Completion {
+    sender: mpsc::Sender<()>,
+    refcount: Arc<AtomicI32>,
+}
+
+impl Clone for Completion {
+    fn clone(&self) -> Self {
+        let i = self
+            .refcount
+            .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+        tracing::info!("Completion::clone[{:p}]: {i}", &(*self.refcount));
+        Self {
+            sender: self.sender.clone(),
+            refcount: self.refcount.clone(),
+        }
+    }
+}
+
+impl Drop for Completion {
+    fn drop(&mut self) {
+        let i = self
+            .refcount
+            .fetch_sub(1, std::sync::atomic::Ordering::SeqCst);
+        tracing::info!("Completion::drop[{:p}]: {i}", &(*self.refcount));
+    }
+}
 
 /// Barrier will wait until all clones of [`Completion`] have been dropped.
 #[derive(Clone)]
@@ -45,5 +69,11 @@ pub fn channel() -> (Completion, Barrier) {
     let (tx, rx) = mpsc::channel::<()>(1);
     let rx = Mutex::new(rx);
     let rx = Arc::new(rx);
-    (Completion(tx), Barrier(rx))
+    (
+        Completion {
+            sender: tx,
+            refcount: Arc::new(AtomicI32::new(1)),
+        },
+        Barrier(rx),
+    )
 }
diff --git a/pageserver/src/bin/pageserver.rs b/pageserver/src/bin/pageserver.rs
index 9518266467..c1304b8707 100644
--- a/pageserver/src/bin/pageserver.rs
+++ b/pageserver/src/bin/pageserver.rs
@@ -363,6 +363,10 @@ fn start_pageserver(
     let (background_jobs_can_start, background_jobs_barrier) = utils::completion::channel();
     let (tenants_can_start, tenants_can_start_barrier) = utils::completion::channel();
 
+    tracing::info!("init_remote_done_tx:");
+    let c = init_remote_done_tx.clone();
+    drop(c);
+
     let order = pageserver::InitializationOrder {
         initial_tenant_load_remote: Some(init_done_tx),
         initial_tenant_load: Some(init_remote_done_tx),