Added simple thread pool executor class

tests/test_thread_pool_executor.cc

@@ -0,0 +1,45 @@
+/**
+ * tests/test_thread_pool_executor.cc
+ *
+ * Copyright (c) 2021-2022 Bartek Kryza <bkryza@gmail.com>
+ *
+ * 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.
+ */
+#define CATCH_CONFIG_MAIN
+
+#include "catch.h"
+
+#include "util/thread_pool_executor.h"
+
+TEST_CASE("Test thread_pool_executor", "[unit-test]")
+{
+    using clanguml::util::thread_pool_executor;
+
+    thread_pool_executor pool{4};
+
+    std::atomic_int counter{0};
+
+    std::vector<std::future<void>> futs;
+
+    const unsigned int kTaskCount = 1000;
+
+    for (auto i = 0U; i < kTaskCount; i++) {
+        futs.emplace_back(pool.add([&counter]() { counter++; }));
+    }
+
+    for (auto &f : futs) {
+        f.get();
+    }
+
+    CHECK(counter == kTaskCount);
+}