third-party/benchmark/test/benchmark_min_time_flag_time_test.cc

   1 #include <cassert>
   2 #include <climits>
   3 #include <cmath>
   4 #include <cstdlib>
   5 #include <cstring>
   6 #include <iostream>
   7 #include <string>
   8 #include <vector>
   9
  10 #include "benchmark/benchmark.h"
  11
  12 // Tests that we can specify the min time with
  13 // --benchmark_min_time=<NUM> (no suffix needed) OR
  14 // --benchmark_min_time=<NUM>s
  15 namespace {
  16
  17 // This is from benchmark.h
  18 typedef int64_t IterationCount;
  19
  20 class TestReporter : public benchmark::ConsoleReporter {
  21  public:
  22   virtual bool ReportContext(const Context& context) BENCHMARK_OVERRIDE {
  23     return ConsoleReporter::ReportContext(context);
  24   };
  25
  26   virtual void ReportRuns(const std::vector<Run>& report) BENCHMARK_OVERRIDE {
  27     assert(report.size() == 1);
  28     ConsoleReporter::ReportRuns(report);
  29   };
  30
  31   virtual void ReportRunsConfig(double min_time, bool /* has_explicit_iters */,
  32                                 IterationCount /* iters */) BENCHMARK_OVERRIDE {
  33     min_times_.push_back(min_time);
  34   }
  35
  36   TestReporter() {}
  37
  38   virtual ~TestReporter() {}
  39
  40   const std::vector<double>& GetMinTimes() const { return min_times_; }
  41
  42  private:
  43   std::vector<double> min_times_;
  44 };
  45
  46 bool AlmostEqual(double a, double b) {
  47   return std::fabs(a - b) < std::numeric_limits<double>::epsilon();
  48 }
  49
  50 void DoTestHelper(int* argc, const char** argv, double expected) {
  51   benchmark::Initialize(argc, const_cast<char**>(argv));
  52
  53   TestReporter test_reporter;
  54   const size_t returned_count =
  55       benchmark::RunSpecifiedBenchmarks(&test_reporter, "BM_MyBench");
  56   assert(returned_count == 1);
  57
  58   // Check the min_time
  59   const std::vector<double>& min_times = test_reporter.GetMinTimes();
  60   assert(!min_times.empty() && AlmostEqual(min_times[0], expected));
  61 }
  62
  63 }  // end namespace
  64
  65 static void BM_MyBench(benchmark::State& state) {
  66   for (auto s : state) {
  67   }
  68 }
  69 BENCHMARK(BM_MyBench);
  70
  71 int main(int argc, char** argv) {
  72   // Make a fake argv and append the new --benchmark_min_time=<foo> to it.
  73   int fake_argc = argc + 1;
  74   const char** fake_argv = new const char*[static_cast<size_t>(fake_argc)];
  75
  76   for (int i = 0; i < argc; ++i) fake_argv[i] = argv[i];
  77
  78   const char* no_suffix = "--benchmark_min_time=4";
  79   const char* with_suffix = "--benchmark_min_time=4.0s";
  80   double expected = 4.0;
  81
  82   fake_argv[argc] = no_suffix;
  83   DoTestHelper(&fake_argc, fake_argv, expected);
  84
  85   fake_argv[argc] = with_suffix;
  86   DoTestHelper(&fake_argc, fake_argv, expected);
  87
  88   delete[] fake_argv;
  89   return 0;
  90 }