Extract folly/io/async/test/RequestContextTest.cpp (from Thrift).

Summary: [Folly] Extract folly/io/async/test/RequestContextTest.cpp (from Thrift).

Reviewed By: @haijunz

Differential Revision: D2350908

folly/io/async/test/RequestContextTest.cpp

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 <thread>
+
+#include <folly/io/async/EventBase.h>
+#include <folly/io/async/Request.h>
+
+using namespace folly;
+
+class TestData : public RequestData {
+ public:
+  explicit TestData(int data) : data_(data) {}
+  ~TestData() override {}
+  int data_;
+};
+
+TEST(RequestContext, SimpleTest) {
+  EventBase base;
+
+
+  // There should always be a default context with get()
+  EXPECT_TRUE(RequestContext::get() != nullptr);
+
+
+  // but not with saveContext()
+  EXPECT_EQ(RequestContext::saveContext(), nullptr);
+  RequestContext::create();
+  EXPECT_NE(RequestContext::saveContext(), nullptr);
+  RequestContext::create();
+  EXPECT_NE(RequestContext::saveContext(), nullptr);
+
+  EXPECT_EQ(nullptr, RequestContext::get()->getContextData("test"));
+
+  RequestContext::get()->setContextData(
+    "test",
+    std::unique_ptr<TestData>(new TestData(10)));
+  base.runInEventBaseThread([&](){
+      EXPECT_TRUE(RequestContext::get() != nullptr);
+      auto data = dynamic_cast<TestData*>(
+        RequestContext::get()->getContextData("test"))->data_;
+      EXPECT_EQ(10, data);
+      base.terminateLoopSoon();
+    });
+  auto th = std::thread([&](){
+      base.loopForever();
+  });
+  th.join();
+  EXPECT_TRUE(RequestContext::get() != nullptr);
+  auto a = dynamic_cast<TestData*>(
+    RequestContext::get()->getContextData("test"));
+  auto data = a->data_;
+  EXPECT_EQ(10, data);
+
+  RequestContext::setContext(std::shared_ptr<RequestContext>());
+  // There should always be a default context
+  EXPECT_TRUE(nullptr != RequestContext::get());
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  google::InitGoogleLogging(argv[0]);
+  google::ParseCommandLineFlags(&argc, &argv, true);
+
+  return RUN_ALL_TESTS();
+}