chore: import upstream snapshot with attribution

test/cpp/fluid/framework/threadpool_test.cc

@@ -0,0 +1,64 @@
+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+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 "paddle/fluid/framework/threadpool.h"
+
+#include <gtest/gtest.h>
+
+#include <atomic>
+
+namespace framework = paddle::framework;
+
+void do_sum(std::vector<std::future<void>>* fs,
+            std::mutex* mu,
+            std::atomic<int>* sum,
+            int cnt) {
+  for (int i = 0; i < cnt; ++i) {
+    std::lock_guard<std::mutex> l(*mu);
+    fs->push_back(phi::Async([sum]() { sum->fetch_add(1); }));
+  }
+}
+
+TEST(ThreadPool, ConcurrentInit) {
+  phi::ThreadPool* pool;
+  int n = 50;
+  std::vector<std::thread> threads;
+  for (int i = 0; i < n; ++i) {
+    std::thread t([&pool]() { pool = phi::ThreadPool::GetInstance(); });
+    threads.push_back(std::move(t));
+  }
+  for (auto& t : threads) {
+    t.join();
+  }
+}
+
+TEST(ThreadPool, ConcurrentRun) {
+  std::atomic<int> sum(0);
+  std::vector<std::thread> threads;
+  std::vector<std::future<void>> fs;
+  std::mutex fs_mu;
+  int n = 50;
+  // sum = (n * (n + 1)) / 2
+  for (int i = 1; i <= n; ++i) {
+    std::thread t(do_sum, &fs, &fs_mu, &sum, i);
+    threads.push_back(std::move(t));
+  }
+  for (auto& t : threads) {
+    t.join();
+  }
+  for (auto& t : fs) {
+    t.wait();
+  }
+  EXPECT_EQ(sum, ((n + 1) * n) / 2);
+}