Add thread Barrier unit test

paddle/utils/tests/CMakeLists.txt

@@ -3,6 +3,7 @@ add_simple_unittest(test_Logging)
 add_simple_unittest(test_Thread)
 add_simple_unittest(test_StringUtils)
 add_simple_unittest(test_CustomStackTrace)
+add_simple_unittest(test_ThreadBarrier)
 
 add_executable(
     test_CustomStackTracePrint

paddle/utils/tests/test_ThreadBarrier.cpp

+/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.
+
+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 <set>
+#include <vector>
+#include "paddle/utils/Logging.h"
+#include "paddle/utils/CommandLineParser.h"
+#include "paddle/utils/Util.h"
+#include "paddle/utils/Locks.h"
+
+P_DEFINE_int32(test_thread_num, 100, "testing thread number");
+
+void testNormalImpl(size_t thread_num,
+                    const std::function<void(size_t,
+                    std::mutex&, std::set<std::thread::id>&,
+                    paddle::ThreadBarrier&)>& callback) {
+ std::mutex mutex;
+ std::set<std::thread::id> tids;
+ paddle::ThreadBarrier barrier(thread_num);
+
+ std::vector<std::thread> threads;
+ threads.reserve(thread_num);
+ for (int32_t i = 0; i < thread_num; ++i) {
+    threads.emplace_back([&thread_num, &mutex,
+                         &tids, &barrier, &callback]{
+        callback(thread_num, mutex, tids, barrier);
+    });
+ }
+
+ for (auto& thread : threads) {
+   thread.join();
+ }
+}
+
+TEST(ThreadBarrier, normalTest) {
+  for (auto &thread_num : {10, 30, 50 , 100 , 300, 1000}) {
+    testNormalImpl(thread_num,
+                  [](size_t thread_num, std::mutex& mutex,
+                  std::set<std::thread::id>& tids,
+                  paddle::ThreadBarrier& barrier){
+      {
+        std::lock_guard<std::mutex> guard(mutex);
+        tids.insert(std::this_thread::get_id());
+      }
+      barrier.wait();
+      // Check whether all threads reach this point or not
+      CHECK_EQ(tids.size(), thread_num);
+    });
+  }
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  paddle::initMain(argc, argv);
+  return RUN_ALL_TESTS();
+}