Add thread cached ints benchmark

Summary: Add thread cached ints benchmark

Reviewed By: yfeldblum

Differential Revision: D9212949

fbshipit-source-id: 552aab15e7421f74b5cec3ce4abd211ab3141153

folly/test/ThreadCachedIntsBenchmark.cpp

+/*
+ * Copyright 2018-present Facebook, Inc.
+ *
+ * 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 <folly/Benchmark.h>
+#include <folly/synchronization/detail/ThreadCachedInts.h>
+
+using namespace folly;
+
+void runTest(int iters) {
+  BenchmarkSuspender susp;
+
+  detail::ThreadCachedInts<void> counters;
+  counters.increment(0);
+
+  susp.dismiss();
+
+  // run the test loop
+  for (int i = 0; i < iters; i++) {
+    counters.increment(0);
+  }
+}
+
+BENCHMARK_DRAW_LINE();
+BENCHMARK(Increment, iters) {
+  runTest(iters);
+}
+BENCHMARK_DRAW_LINE();
+
+int main(int argc, char* argv[]) {
+  gflags::ParseCommandLineFlags(&argc, &argv, true);
+  folly::runBenchmarks();
+
+  return 0;
+}