[lldb] Add a basic unit test for the SharedCluster class

lldb/unittests/Utility/CMakeLists.txt

@@ -24,6 +24,7 @@ add_lldb_unittest(UtilityTests
   ReproducerInstrumentationTest.cpp
   ReproducerTest.cpp
   ScalarTest.cpp
+  SharedClusterTest.cpp
   StateTest.cpp
   StatusTest.cpp
   StreamTeeTest.cpp

lldb/unittests/Utility/SharedClusterTest.cpp

@@ -0,0 +1,55 @@
+//===-- SharedClusterTest.cpp ---------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/SharedCluster.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using namespace lldb_private;
+
+namespace {
+class DestructNotifier {
+public:
+  DestructNotifier(std::vector<int> &Queue, int Key) : Queue(Queue), Key(Key) {}
+  ~DestructNotifier() { Queue.push_back(Key); }
+
+  std::vector<int> &Queue;
+  const int Key;
+};
+} // namespace
+
+TEST(SharedCluster, ClusterManager) {
+  std::vector<int> Queue;
+  auto *CM = new ClusterManager<DestructNotifier>();
+  auto *One = new DestructNotifier(Queue, 1);
+  auto *Two = new DestructNotifier(Queue, 2);
+  CM->ManageObject(One);
+  CM->ManageObject(Two);
+
+  ASSERT_THAT(Queue, testing::IsEmpty());
+  {
+    SharingPtr<DestructNotifier> OnePtr = CM->GetSharedPointer(One);
+    ASSERT_EQ(OnePtr->Key, 1);
+    ASSERT_THAT(Queue, testing::IsEmpty());
+
+    {
+      SharingPtr<DestructNotifier> OnePtrCopy = OnePtr;
+      ASSERT_EQ(OnePtrCopy->Key, 1);
+      ASSERT_THAT(Queue, testing::IsEmpty());
+    }
+
+    {
+      SharingPtr<DestructNotifier> TwoPtr = CM->GetSharedPointer(Two);
+      ASSERT_EQ(TwoPtr->Key, 2);
+      ASSERT_THAT(Queue, testing::IsEmpty());
+    }
+
+    ASSERT_THAT(Queue, testing::IsEmpty());
+  }
+  ASSERT_THAT(Queue, testing::ElementsAre(1, 2));
+}