folly/test/SingletonThreadLocalTest.cpp

   1 /*
   2  * Copyright 2016 Facebook, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <thread>
  18 #include <unordered_set>
  19 #include <vector>
  20
  21 #include <folly/SingletonThreadLocal.h>
  22 #include <folly/Synchronized.h>
  23
  24 #include <gtest/gtest.h>
  25
  26 using namespace folly;
  27
  28 namespace {
  29 static std::atomic<std::size_t> fooCreatedCount{0};
  30 static std::atomic<std::size_t> fooDeletedCount{0};
  31 struct Foo {
  32   Foo() {
  33     ++fooCreatedCount;
  34   }
  35   ~Foo() {
  36     ++fooDeletedCount;
  37   }
  38 };
  39 using FooSingletonTL = SingletonThreadLocal<Foo>;
  40 FooSingletonTL theFooSingleton;
  41 }
  42
  43 TEST(SingletonThreadLocalTest, OneSingletonPerThread) {
  44   const std::size_t targetThreadCount{64};
  45   std::atomic<std::size_t> completedThreadCount{0};
  46   Synchronized<std::unordered_set<Foo*>> fooAddresses{};
  47   std::vector<std::thread> threads{};
  48   auto threadFunction =
  49       [&fooAddresses, targetThreadCount, &completedThreadCount] {
  50         fooAddresses.wlock()->emplace(&FooSingletonTL::get());
  51         ++completedThreadCount;
  52         while (completedThreadCount < targetThreadCount) {
  53           std::this_thread::yield();
  54         }
  55       };
  56   {
  57     for (std::size_t threadCount{0}; threadCount < targetThreadCount;
  58          ++threadCount) {
  59       threads.emplace_back(threadFunction);
  60     }
  61   }
  62   for (auto& thread : threads) {
  63     thread.join();
  64   }
  65   EXPECT_EQ(threads.size(), fooAddresses.rlock()->size());
  66   EXPECT_EQ(threads.size(), fooCreatedCount);
  67   EXPECT_EQ(threads.size(), fooDeletedCount);
  68 }