[libcxx-commits] [libcxx] [libc++] std::barrier uses native wait (PR #171041)

via libcxx-commits libcxx-commits at lists.llvm.org
Sun Dec 7 06:53:20 PST 2025


https://github.com/huixie90 updated https://github.com/llvm/llvm-project/pull/171041

>From cd942d4948077be4594d67ba650b8ee80644d166 Mon Sep 17 00:00:00 2001
From: Hui Xie <hui.xie1990 at gmail.com>
Date: Sun, 7 Dec 2025 14:49:00 +0000
Subject: [PATCH] [libc++] std::barrier uses native wait

---
 libcxx/include/barrier | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libcxx/include/barrier b/libcxx/include/barrier
index 5f9b471f01741..4eaa719e51610 100644
--- a/libcxx/include/barrier
+++ b/libcxx/include/barrier
@@ -54,6 +54,7 @@ namespace std
 
 #    include <__assert>
 #    include <__atomic/atomic.h>
+#    include <__atomic/atomic_sync.h>
 #    include <__atomic/memory_order.h>
 #    include <__cstddef/ptrdiff_t.h>
 #    include <__memory/unique_ptr.h>
@@ -142,8 +143,7 @@ public:
     return __old_phase;
   }
   _LIBCPP_HIDE_FROM_ABI void wait(arrival_token&& __old_phase) const {
-    auto const __test_fn = [this, __old_phase]() -> bool { return __phase_.load(memory_order_acquire) != __old_phase; };
-    std::__libcpp_thread_poll_with_backoff(__test_fn, __libcpp_timed_backoff_policy());
+    __phase_.wait(__old_phase, std::memory_order_acquire);
   }
   _LIBCPP_HIDE_FROM_ABI void arrive_and_drop() {
     __expected_adjustment_.fetch_sub(1, memory_order_relaxed);



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