From: Max Kellermann <max.kellermann@ionos.com>
Date: Tue, 8 Oct 2024 12:50:02 +0000 (+0200)
Subject: msg/async/AsyncConnection: do not wrap writeCallback in `std::optional`
X-Git-Tag: v20.0.0~792^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=c72dae9b6e4b37c508a3ebb1410172fb7c434e8a;p=ceph.git

msg/async/AsyncConnection: do not wrap writeCallback in `std::optional`

Since `std::function` is nullable and as an `operator bool()`, we can
easily eliminate the `std::optional` overhead.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---

diff --git a/src/msg/async/AsyncConnection.cc b/src/msg/async/AsyncConnection.cc
index 683be086efad..649977e5b969 100644
--- a/src/msg/async/AsyncConnection.cc
+++ b/src/msg/async/AsyncConnection.cc
@@ -621,7 +621,7 @@ void AsyncConnection::fault()
 }
 
 void AsyncConnection::_stop() {
-  writeCallback.reset();
+  writeCallback = {};
   dispatch_queue->discard_queue(conn_id);
   async_msgr->unregister_conn(this);
   worker->release_worker();
@@ -737,8 +737,7 @@ void AsyncConnection::handle_write_callback() {
   recv_start_time = ceph::mono_clock::now();
   write_lock.lock();
   if (writeCallback) {
-    auto callback = *writeCallback;
-    writeCallback.reset();
+    auto callback = std::move(writeCallback);
     write_lock.unlock();
     callback(0);
     return;
diff --git a/src/msg/async/AsyncConnection.h b/src/msg/async/AsyncConnection.h
index 78a590f8ca39..a4f18e2c4fb5 100644
--- a/src/msg/async/AsyncConnection.h
+++ b/src/msg/async/AsyncConnection.h
@@ -223,7 +223,7 @@ private:
 
   std::unique_ptr<Protocol> protocol;
 
-  std::optional<std::function<void(ssize_t)>> writeCallback;
+  std::function<void(ssize_t)> writeCallback;
   std::function<void(char *, ssize_t)> readCallback;
   std::optional<unsigned> pendingReadLen;
   char *read_buffer;
diff --git a/src/msg/async/ProtocolV1.cc b/src/msg/async/ProtocolV1.cc
index cecf81498c70..a53f6389c310 100644
--- a/src/msg/async/ProtocolV1.cc
+++ b/src/msg/async/ProtocolV1.cc
@@ -1294,7 +1294,7 @@ void ProtocolV1::reset_recv_state()
 
   // clean read and write callbacks
   connection->pendingReadLen.reset();
-  connection->writeCallback.reset();
+  connection->writeCallback = {};
 
   if (state > THROTTLE_MESSAGE && state <= READ_FOOTER_AND_DISPATCH &&
       connection->policy.throttler_messages) {
diff --git a/src/msg/async/ProtocolV2.cc b/src/msg/async/ProtocolV2.cc
index 11b3885a2240..79fdf6c30a36 100644
--- a/src/msg/async/ProtocolV2.cc
+++ b/src/msg/async/ProtocolV2.cc
@@ -266,7 +266,7 @@ void ProtocolV2::reset_recv_state() {
 
   // clean read and write callbacks
   connection->pendingReadLen.reset();
-  connection->writeCallback.reset();
+  connection->writeCallback = {};
 
   next_tag = static_cast<Tag>(0);