[libc++] Implementation of C++20's P1135R6 for libcxx
Differential Revision: https://reviews.llvm.org/D68480
diff --git a/libcxx/test/std/thread/thread.semaphore/acquire.pass.cpp b/libcxx/test/std/thread/thread.semaphore/acquire.pass.cpp
new file mode 100644
index 0000000..bb5f7fb
--- /dev/null
+++ b/libcxx/test/std/thread/thread.semaphore/acquire.pass.cpp
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
+// UNSUPPORTED: c++98, c++03, c++11
+
+// <semaphore>
+
+#include <semaphore>
+#include <thread>
+
+#include "test_macros.h"
+
+int main(int, char**)
+{
+ std::counting_semaphore<> s(2);
+
+ std::thread t([&](){
+ s.acquire();
+ });
+ t.join();
+
+ s.acquire();
+
+ return 0;
+}