Merge branch 'master' of https://github.com/google/benchmark

appveyor.yml

 version: '{build}'
 
+image: Visual Studio 2017
+
 configuration:
   - Debug
   - Release
 
 environment:
   matrix:
-    - compiler: msvc-12-seh
-      generator: "Visual Studio 12 2013"
+    - compiler: msvc-15-seh
+      generator: "Visual Studio 15 2017"
 
-    - compiler: msvc-12-seh
-      generator: "Visual Studio 12 2013 Win64"
+    - compiler: msvc-15-seh
+      generator: "Visual Studio 15 2017 Win64"
 
     - compiler: msvc-14-seh
       generator: "Visual Studio 14 2015"
@@ -18,9 +20,16 @@ environment:
     - compiler: msvc-14-seh
       generator: "Visual Studio 14 2015 Win64"
 
+    - compiler: msvc-12-seh
+      generator: "Visual Studio 12 2013"
+
+    - compiler: msvc-12-seh
+      generator: "Visual Studio 12 2013 Win64"
+
     - compiler: gcc-5.3.0-posix
       generator: "MinGW Makefiles"
       cxx_path: 'C:\mingw-w64\i686-5.3.0-posix-dwarf-rt_v4-rev0\mingw32\bin'
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
 
 matrix:
   fast_finish: true
@@ -30,12 +39,6 @@ install:
   - if "%generator%"=="MinGW Makefiles" (set "PATH=%PATH:C:\Program Files\Git\usr\bin;=%")
   - if not "%cxx_path%"=="" (set "PATH=%PATH%;%cxx_path%")
 
-# TODO Remove this. This is a hack to work around bogus warning messages
-# See http://goo.gl/euguBI for more information.
-before_build:
-  - del "C:\Program Files (x86)\MSBuild\14.0\Microsoft.Common.targets\ImportAfter\Xamarin.Common.targets"
-  - del "C:\Program Files (x86)\MSBuild\12.0\Microsoft.Common.targets\ImportAfter\Xamarin.Common.targets"
-
 build_script:
   - md _build -Force
   - cd _build
@@ -51,4 +54,3 @@ artifacts:
     name: logs
   - path: '_build/Testing/**/*.xml'
     name: test_results
-

include/benchmark/benchmark_api.h

@@ -577,9 +577,17 @@ class Benchmark {
 
   // Set the minimum amount of time to use when running this benchmark. This
   // option overrides the `benchmark_min_time` flag.
-  // REQUIRES: `t > 0`
+  // REQUIRES: `t > 0` and `Iterations` has not been called on this benchmark.
   Benchmark* MinTime(double t);
 
+  // Specify the amount of iterations that should be run by this benchmark.
+  // REQUIRES: 'n > 0' and `MinTime` has not been called on this benchmark.
+  //
+  // NOTE: This function should only be used when *exact* iteration control is
+  //   needed and never to control or limit how long a benchmark runs, where
+  // `--benchmark_min_time=N` or `MinTime(...)` should be used instead.
+  Benchmark* Iterations(size_t n);
+
   // Specify the amount of times to repeat this benchmark. This option overrides
   // the `benchmark_repetitions` flag.
   // REQUIRES: `n > 0`
@@ -668,6 +676,7 @@ class Benchmark {
   TimeUnit time_unit_;
   int range_multiplier_;
   double min_time_;
+  size_t iterations_;
   int repetitions_;
   bool use_real_time_;
   bool use_manual_time_;

src/CMakeLists.txt

@@ -49,7 +49,7 @@ write_basic_package_version_file(
     "${version_config}" VERSION ${GIT_VERSION} COMPATIBILITY SameMajorVersion
 )
 
-configure_file("${CMAKE_SOURCE_DIR}/cmake/Config.cmake.in" "${project_config}" @ONLY)
+configure_file("${PROJECT_SOURCE_DIR}/cmake/Config.cmake.in" "${project_config}" @ONLY)
 
 # Install target (will install the library to specified CMAKE_INSTALL_PREFIX variable)
 install(

src/benchmark.cc

@@ -285,7 +285,8 @@ std::vector<BenchmarkReporter::Run> RunBenchmark(
     std::vector<BenchmarkReporter::Run>* complexity_reports) {
   std::vector<BenchmarkReporter::Run> reports;  // return value
 
-  size_t iters = 1;
+  const bool has_explicit_iteration_count = b.iterations != 0;
+  size_t iters = has_explicit_iteration_count ? b.iterations : 1;
   std::unique_ptr<internal::ThreadManager> manager;
   std::vector<std::thread> pool(b.threads - 1);
   const int repeats =
@@ -295,7 +296,7 @@ std::vector<BenchmarkReporter::Run> RunBenchmark(
       (b.report_mode == internal::RM_Unspecified
            ? FLAGS_benchmark_report_aggregates_only
            : b.report_mode == internal::RM_ReportAggregatesOnly);
-  for (int i = 0; i < repeats; i++) {
+  for (int repetition_num = 0; repetition_num < repeats; repetition_num++) {
     for (;;) {
       // Try benchmark
       VLOG(2) << "Running " << b.name << " for " << iters << "\n";
@@ -331,10 +332,20 @@ std::vector<BenchmarkReporter::Run> RunBenchmark(
 
       const double min_time =
           !IsZero(b.min_time) ? b.min_time : FLAGS_benchmark_min_time;
-      // If this was the first run, was elapsed time or cpu time large enough?
-      // If this is not the first run, go with the current value of iter.
-      if ((i > 0) || results.has_error_ || (iters >= kMaxIterations) ||
-          (seconds >= min_time) || (results.real_time_used >= 5 * min_time)) {
+
+      // Determine if this run should be reported; Either it has
+      // run for a sufficient amount of time or because an error was reported.
+      const bool should_report =  repetition_num > 0
+        || has_explicit_iteration_count // An exact iteration count was requested
+        || results.has_error_
+        || iters >= kMaxIterations
+        || seconds >= min_time // the elapsed time is large enough
+        // CPU time is specified but the elapsed real time greatly exceeds the
+        // minimum time. Note that user provided timers are except from this
+        // sanity check.
+        || ((results.real_time_used >= 5 * min_time) && !b.use_manual_time);
+
+      if (should_report) {
         BenchmarkReporter::Run report =
             CreateRunReport(b, results, iters, seconds);
         if (!report.error_occurred && b.complexity != oNone)

src/benchmark_api_internal.h

@@ -28,6 +28,7 @@ struct Benchmark::Instance {
   bool last_benchmark_instance;
   int repetitions;
   double min_time;
+  size_t iterations;
   int threads;  // Number of concurrent threads to us
 };
 

src/benchmark_register.cc

@@ -31,6 +31,7 @@
 #include <fstream>
 #include <iostream>
 #include <memory>
+#include <sstream>
 #include <thread>
 
 #include "check.h"
@@ -143,6 +144,7 @@ bool BenchmarkFamilies::FindBenchmarks(
         instance.time_unit = family->time_unit_;
         instance.range_multiplier = family->range_multiplier_;
         instance.min_time = family->min_time_;
+        instance.iterations = family->iterations_;
         instance.repetitions = family->repetitions_;
         instance.use_real_time = family->use_real_time_;
         instance.use_manual_time = family->use_manual_time_;
@@ -163,16 +165,17 @@ bool BenchmarkFamilies::FindBenchmarks(
             }
           }
           
-          instance.name += std::to_string(arg);
+          instance.name += StringPrintF("%d", arg);
           ++arg_i;
         }
 
-        if (!IsZero(family->min_time_)) {
+        if (!IsZero(family->min_time_))
           instance.name += StringPrintF("/min_time:%0.3f", family->min_time_);
-        }
-        if (family->repetitions_ != 0) {
+        if (family->iterations_ != 0)
+          instance.name += StringPrintF("/iterations:%d", family->iterations_);
+        if (family->repetitions_ != 0)
           instance.name += StringPrintF("/repeats:%d", family->repetitions_);
-        }
+
         if (family->use_manual_time_) {
           instance.name += "/manual_time";
         } else if (family->use_real_time_) {
@@ -219,6 +222,7 @@ Benchmark::Benchmark(const char* name)
       time_unit_(kNanosecond),
       range_multiplier_(kRangeMultiplier),
       min_time_(0),
+      iterations_(0),
       repetitions_(0),
       use_real_time_(false),
       use_manual_time_(false),
@@ -344,6 +348,22 @@ Benchmark* Benchmark::RangeMultiplier(int multiplier) {
   return this;
 }
 
+
+Benchmark* Benchmark::MinTime(double t) {
+  CHECK(t > 0.0);
+  CHECK(iterations_ == 0);
+  min_time_ = t;
+  return this;
+}
+
+
+Benchmark* Benchmark::Iterations(size_t n) {
+  CHECK(n > 0);
+  CHECK(IsZero(min_time_));
+  iterations_ = n;
+  return this;
+}
+
 Benchmark* Benchmark::Repetitions(int n) {
   CHECK(n > 0);
   repetitions_ = n;
@@ -355,12 +375,6 @@ Benchmark* Benchmark::ReportAggregatesOnly(bool value) {
   return this;
 }
 
-Benchmark* Benchmark::MinTime(double t) {
-  CHECK(t > 0.0);
-  min_time_ = t;
-  return this;
-}
-
 Benchmark* Benchmark::UseRealTime() {
   CHECK(!use_manual_time_)
       << "Cannot set UseRealTime and UseManualTime simultaneously.";

src/colorprint.cc

@@ -89,7 +89,7 @@ std::string FormatString(const char* msg, va_list args) {
 
   std::size_t size = 256;
   char local_buff[256];
-  auto ret = std::vsnprintf(local_buff, size, msg, args_cp);
+  auto ret = vsnprintf(local_buff, size, msg, args_cp);
 
   va_end(args_cp);
 
@@ -104,7 +104,7 @@ std::string FormatString(const char* msg, va_list args) {
     // we did not provide a long enough buffer on our first attempt.
     size = (size_t)ret + 1;  // + 1 for the null byte
     std::unique_ptr<char[]> buff(new char[size]);
-    ret = std::vsnprintf(buff.get(), size, msg, args);
+    ret = vsnprintf(buff.get(), size, msg, args);
     CHECK(ret > 0 && ((size_t)ret) < size);
     return buff.get();
   }

src/complexity.cc

@@ -35,9 +35,9 @@ BigOFunc* FittingCurve(BigO complexity) {
     case oNCubed:
       return [](int n) -> double { return std::pow(n, 3); };
     case oLogN:
-      return [](int n) { return std::log2(n); };
+      return [](int n) { return log2(n); };
     case oNLogN:
-      return [](int n) { return n * std::log2(n); };
+      return [](int n) { return n * log2(n); };
     case o1:
     default:
       return [](int) { return 1.0; };

test/CMakeLists.txt

@@ -2,6 +2,25 @@
 
 find_package(Threads REQUIRED)
 
+# NOTE: Some tests use `<cassert>` to perform the test. Therefore we must
+# strip -DNDEBUG from the default CMake flags in DEBUG mode.
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+  add_definitions( -UNDEBUG )
+  add_definitions(-DTEST_BENCHMARK_LIBRARY_HAS_NO_ASSERTIONS)
+  # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
+  foreach (flags_var_to_scrub
+      CMAKE_CXX_FLAGS_RELEASE
+      CMAKE_CXX_FLAGS_RELWITHDEBINFO
+      CMAKE_CXX_FLAGS_MINSIZEREL
+      CMAKE_C_FLAGS_RELEASE
+      CMAKE_C_FLAGS_RELWITHDEBINFO
+      CMAKE_C_FLAGS_MINSIZEREL)
+    string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
+      "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
+  endforeach()
+endif()
+
 # NOTE: These flags must be added after find_package(Threads REQUIRED) otherwise
 # they will break the configuration check.
 if (DEFINED BENCHMARK_CXX_LINKER_FLAGS)

test/complexity_test.cc

@@ -141,7 +141,7 @@ BENCHMARK(BM_Complexity_O_N_log_N)
 BENCHMARK(BM_Complexity_O_N_log_N)
     ->RangeMultiplier(2)
     ->Range(1 << 10, 1 << 16)
-    ->Complexity([](int n) { return n * std::log2(n); });
+    ->Complexity([](int n) { return n * log2(n); });
 BENCHMARK(BM_Complexity_O_N_log_N)
     ->RangeMultiplier(2)
     ->Range(1 << 10, 1 << 16)

test/diagnostics_test.cc

@@ -26,7 +26,7 @@ void TestHandler() {
 }
 
 void try_invalid_pause_resume(benchmark::State& state) {
-#if !defined(NDEBUG) && !defined(TEST_HAS_NO_EXCEPTIONS)
+#if !defined(TEST_BENCHMARK_LIBRARY_HAS_NO_ASSERTIONS) && !defined(TEST_HAS_NO_EXCEPTIONS)
   try {
     state.PauseTiming();
     std::abort();

test/options_test.cc

 #include "benchmark/benchmark_api.h"
-
 #include <chrono>
 #include <thread>
 
+#if defined(NDEBUG)
+#undef NDEBUG
+#endif
+#include <cassert>
+
 void BM_basic(benchmark::State& state) {
   while (state.KeepRunning()) {
   }
@@ -40,4 +44,22 @@ void CustomArgs(benchmark::internal::Benchmark* b) {
 
 BENCHMARK(BM_basic)->Apply(CustomArgs);
 
+void BM_explicit_iteration_count(benchmark::State& st) {
+  // Test that benchmarks specified with an explicit iteration count are
+  // only run once.
+  static bool invoked_before = false;
+  assert(!invoked_before);
+  invoked_before = true;
+
+  // Test that the requested iteration count is respected.
+  assert(st.max_iterations == 42);
+  size_t actual_iterations = 0;
+  while (st.KeepRunning())
+    ++actual_iterations;
+  assert(st.iterations() == st.max_iterations);
+  assert(st.iterations() == 42);
+
+}
+BENCHMARK(BM_explicit_iteration_count)->Iterations(42);
+
 BENCHMARK_MAIN()

test/register_benchmark_test.cc

@@ -114,14 +114,14 @@ void TestRegistrationAtRuntime() {
 #endif
 #ifndef BENCHMARK_HAS_NO_VARIADIC_REGISTER_BENCHMARK
   {
-    int x = 42;
+    const char* x = "42";
     auto capturing_lam = [=](benchmark::State& st) {
       while (st.KeepRunning()) {
       }
-      st.SetLabel(std::to_string(x));
+      st.SetLabel(x);
     };
     benchmark::RegisterBenchmark("lambda_benchmark", capturing_lam);
-    AddCases({{"lambda_benchmark", "42"}});
+    AddCases({{"lambda_benchmark", x}});
   }
 #endif
 }