From a0fa6e31d8141ab920176832bca205ef33a6072c Mon Sep 17 00:00:00 2001
From: Emerson Knapp <537409+emersonknapp@users.noreply.github.com>
Date: Wed, 6 Sep 2023 04:56:45 -0700
Subject: [PATCH] Add unique_lock implementation with clang thread safety
 annotations (#180)

* Add unique_lock implementation with clang thread safety annotations

Signed-off-by: Emerson Knapp <emerson.b.knapp@gmail.com>
Co-authored-by: Chris Lalancette <clalancette@gmail.com>
---
 CMakeLists.txt                    |  3 +++
 include/rcpputils/unique_lock.hpp | 43 +++++++++++++++++++++++++++++++
 test/test_unique_lock.cpp         | 26 +++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 include/rcpputils/unique_lock.hpp
 create mode 100644 test/test_unique_lock.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b2a6772..d2d51b5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -140,6 +140,9 @@ if(BUILD_TESTING)
 
   ament_add_gtest(test_accumulator test/test_accumulator.cpp)
   target_link_libraries(test_accumulator ${PROJECT_NAME})
+
+  ament_add_gtest(test_unique_lock test/test_unique_lock.cpp)
+  target_link_libraries(test_unique_lock ${PROJECT_NAME})
 endif()
 
 ament_package()
diff --git a/include/rcpputils/unique_lock.hpp b/include/rcpputils/unique_lock.hpp
new file mode 100644
index 0000000..121b8b6
--- /dev/null
+++ b/include/rcpputils/unique_lock.hpp
@@ -0,0 +1,43 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCPPUTILS__UNIQUE_LOCK_HPP_
+#define RCPPUTILS__UNIQUE_LOCK_HPP_
+
+#include <mutex>
+
+#include "rcpputils/thread_safety_annotations.hpp"
+
+namespace rcpputils
+{
+
+/**
+ * @brief Trivial std::unique_lock wrapper providing constructor that allows Clang's
+ * Thread Safety Analysis.
+ * The libc++ std::unique_lock does not have these annotations.
+ */
+template<typename MutexT>
+class RCPPUTILS_TSA_SCOPED_CAPABILITY unique_lock : public std::unique_lock<MutexT>
+{
+public:
+  explicit unique_lock(MutexT & mu) RCPPUTILS_TSA_ACQUIRE(mu)
+  : std::unique_lock<MutexT>(mu)
+  {}
+
+  ~unique_lock() RCPPUTILS_TSA_RELEASE() {}
+};
+
+}  // namespace rcpputils
+
+#endif  // RCPPUTILS__UNIQUE_LOCK_HPP_
diff --git a/test/test_unique_lock.cpp b/test/test_unique_lock.cpp
new file mode 100644
index 0000000..36c8c4d
--- /dev/null
+++ b/test/test_unique_lock.cpp
@@ -0,0 +1,26 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <gtest/gtest.h>
+
+#include <rcpputils/unique_lock.hpp>
+
+TEST(test_time, test_compile_multiple_mutex_types) {
+  // Very simple check that this compiles with different mutex types
+  std::mutex regular_mutex;
+  rcpputils::unique_lock<std::mutex> lock1(regular_mutex);
+
+  std::recursive_mutex recursive_mutex;
+  rcpputils::unique_lock<std::recursive_mutex> lock2(recursive_mutex);
+}