From: Max Kellermann <max.kellermann@ionos.com>
Date: Mon, 7 Oct 2024 19:13:22 +0000 (+0200)
Subject: common/Finisher: use `std::lock_guard` instead of `std::unique_lock`
X-Git-Tag: v20.0.0~789^2~12
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=5b97c09b6f02dc91f98d4ce70e7bb50ab2d26840;p=ceph.git

common/Finisher: use `std::lock_guard` instead of `std::unique_lock`

`std::lock_guard` is all we need here, and the added complexity of
`std::unique_lock` is not used and is usually optimized away by the
compiler.  Using `std::lock_guard` directly will reduce the amount of
work that the optimizer needs to do and saves some build CPU cycles.

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

diff --git a/src/common/Finisher.cc b/src/common/Finisher.cc
index ff931faffc1..20b8829d7ec 100644
--- a/src/common/Finisher.cc
+++ b/src/common/Finisher.cc
@@ -40,7 +40,7 @@ void Finisher::wait_for_empty()
 
 bool Finisher::is_empty()
 {
-  std::unique_lock ul(finisher_lock);
+  const std::lock_guard l{finisher_lock};
   return finisher_queue.empty();
 }
 
diff --git a/src/common/Finisher.h b/src/common/Finisher.h
index baf02bd26a4..46a4599b8d0 100644
--- a/src/common/Finisher.h
+++ b/src/common/Finisher.h
@@ -65,7 +65,7 @@ class Finisher {
  public:
   /// Add a context to complete, optionally specifying a parameter for the complete function.
   void queue(Context *c, int r = 0) {
-    std::unique_lock ul(finisher_lock);
+    const std::lock_guard l{finisher_lock};
     bool was_empty = finisher_queue.empty();
     finisher_queue.push_back(std::make_pair(c, r));
     if (was_empty) {
@@ -79,7 +79,7 @@ class Finisher {
   template<typename T>
   auto queue(T &ls) -> decltype(std::distance(ls.begin(), ls.end()), void()) {
     {
-      std::unique_lock ul(finisher_lock);
+      const std::lock_guard l{finisher_lock};
       if (finisher_queue.empty()) {
 	finisher_cond.notify_all();
       }