From b5c4553a66e710ea53aa7045fce328c0681fda65 Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@scylladb.com>
Date: Thu, 30 Jun 2022 16:02:26 +0300
Subject: [PATCH] storage_service: Sanitize stop_transport()

It generates ignored future that can be avoided if using forwarding to
shared_future<>'s promise

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
---
 service/storage_service.cc | 15 +++++----------
 service/storage_service.hh |  2 +-
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/service/storage_service.cc b/service/storage_service.cc
index c74257e70f..36313670a2 100644
--- a/service/storage_service.cc
+++ b/service/storage_service.cc
@@ -1282,9 +1282,10 @@ future<> endpoint_lifecycle_notifier::unregister_subscriber(endpoint_lifecycle_s
 
 future<> storage_service::stop_transport() {
     if (!_transport_stopped.has_value()) {
-        _transport_stopped.emplace();
+        promise<> stopped;
+        _transport_stopped = stopped.get_future();
 
-        (void) seastar::async([this] {
+        seastar::async([this] {
             slogger.info("Stop transport: starts");
 
             slogger.debug("shutting down migration manager");
@@ -1301,18 +1302,12 @@ future<> storage_service::stop_transport() {
 
             _stream_manager.invoke_on_all(&streaming::stream_manager::shutdown).get();
             slogger.info("Stop transport: shutdown stream_manager done");
-        }).then_wrapped([this] (future<> f) {
-            if (f.failed()) {
-                _transport_stopped->set_exception(f.get_exception());
-            } else {
-                _transport_stopped->set_value();
-            }
 
             slogger.info("Stop transport: done");
-        });
+        }).forward_to(std::move(stopped));
     }
 
-    return _transport_stopped->get_shared_future();
+    return _transport_stopped.value();
 }
 
 future<> storage_service::drain_on_shutdown() {
diff --git a/service/storage_service.hh b/service/storage_service.hh
index b9f23b4e5b..309538159e 100644
--- a/service/storage_service.hh
+++ b/service/storage_service.hh
@@ -734,7 +734,7 @@ public:
 
 private:
     promise<> _drain_finished;
-    std::optional<shared_promise<>> _transport_stopped;
+    std::optional<shared_future<>> _transport_stopped;
     future<> do_drain();
     /**
      * Seed data to the endpoints that will be responsible for it at the future