1 files changed, 92 insertions, 0 deletions
diff --git a/test/perf_counters_test.cc b/test/perf_counters_test.cc
new file mode 100644
index 0000000..b0a3ab0
--- /dev/null
+++ b/test/perf_counters_test.cc
@@ -0,0 +1,92 @@
+#include <cstdarg>
+#undef NDEBUG
+
+#include "../src/commandlineflags.h"
+#include "../src/perf_counters.h"
+#include "benchmark/benchmark.h"
+#include "output_test.h"
+
+namespace benchmark {
+
+BM_DECLARE_string(benchmark_perf_counters);
+
+}  // namespace benchmark
+
+static void BM_Simple(benchmark::State& state) {
+  for (auto _ : state) {
+    auto iterations = state.iterations();
+    benchmark::DoNotOptimize(iterations);
+  }
+}
+BENCHMARK(BM_Simple);
+ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_Simple\",$"}});
+
+const int kIters = 1000000;
+
+void BM_WithoutPauseResume(benchmark::State& state) {
+  int n = 0;
+
+  for (auto _ : state) {
+    for (auto i = 0; i < kIters; ++i) {
+      n = 1 - n;
+      benchmark::DoNotOptimize(n);
+    }
+  }
+}
+
+BENCHMARK(BM_WithoutPauseResume);
+ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_WithoutPauseResume\",$"}});
+
+void BM_WithPauseResume(benchmark::State& state) {
+  int m = 0, n = 0;
+
+  for (auto _ : state) {
+    for (auto i = 0; i < kIters; ++i) {
+      n = 1 - n;
+      benchmark::DoNotOptimize(n);
+    }
+
+    state.PauseTiming();
+    for (auto j = 0; j < kIters; ++j) {
+      m = 1 - m;
+      benchmark::DoNotOptimize(m);
+    }
+    state.ResumeTiming();
+  }
+}
+
+BENCHMARK(BM_WithPauseResume);
+
+ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_WithPauseResume\",$"}});
+
+static void CheckSimple(Results const& e) {
+  CHECK_COUNTER_VALUE(e, double, "CYCLES", GT, 0);
+}
+
+double withoutPauseResumeInstrCount = 0.0;
+double withPauseResumeInstrCount = 0.0;
+
+static void SaveInstrCountWithoutResume(Results const& e) {
+  withoutPauseResumeInstrCount = e.GetAs<double>("INSTRUCTIONS");
+}
+
+static void SaveInstrCountWithResume(Results const& e) {
+  withPauseResumeInstrCount = e.GetAs<double>("INSTRUCTIONS");
+}
+
+CHECK_BENCHMARK_RESULTS("BM_Simple", &CheckSimple);
+CHECK_BENCHMARK_RESULTS("BM_WithoutPauseResume", &SaveInstrCountWithoutResume);
+CHECK_BENCHMARK_RESULTS("BM_WithPauseResume", &SaveInstrCountWithResume);
+
+int main(int argc, char* argv[]) {
+  if (!benchmark::internal::PerfCounters::kSupported) {
+    return 0;
+  }
+  benchmark::FLAGS_benchmark_perf_counters = "CYCLES,INSTRUCTIONS";
+  benchmark::internal::PerfCounters::Initialize();
+  RunOutputTests(argc, argv);
+
+  BM_CHECK_GT(withPauseResumeInstrCount, kIters);
+  BM_CHECK_GT(withoutPauseResumeInstrCount, kIters);
+  BM_CHECK_LT(withPauseResumeInstrCount, 1.5 * withoutPauseResumeInstrCount);
+}