Adding Google benchmarking library.

third_party/google_benchmark/src/timers.cc

Index: third_party/google_benchmark/src/timers.cc
diff --git a/third_party/google_benchmark/src/timers.cc b/third_party/google_benchmark/src/timers.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8d56e8adf8d4cceb538828ee3316294c081995d1
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+++ b/third_party/google_benchmark/src/timers.cc
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+// Copyright 2015 Google Inc. All rights reserved.
+//
+// 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 "timers.h"
+#include "internal_macros.h"
+
+#ifdef BENCHMARK_OS_WINDOWS
+#include <Shlwapi.h>
+#include <VersionHelpers.h>
+#include <Windows.h>
+#else
+#include <fcntl.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>  // this header must be included before 'sys/sysctl.h' to avoid compilation error on FreeBSD
+#include <unistd.h>
+#if defined BENCHMARK_OS_FREEBSD || defined BENCHMARK_OS_MACOSX
+#include <sys/sysctl.h>
+#endif
+#if defined(BENCHMARK_OS_MACOSX)
+#include <mach/mach_init.h>
+#include <mach/mach_port.h>
+#include <mach/thread_act.h>
+#endif
+#endif
+
+#ifdef BENCHMARK_OS_EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
+#include <cerrno>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
+#include <iostream>
+#include <limits>
+#include <mutex>
+
+#include "check.h"
+#include "log.h"
+#include "sleep.h"
+#include "string_util.h"
+
+namespace benchmark {
+
+// Suppress unused warnings on helper functions.
+#if defined(__GNUC__)
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+namespace {
+#if defined(BENCHMARK_OS_WINDOWS)
+double MakeTime(FILETIME const& kernel_time, FILETIME const& user_time) {
+  ULARGE_INTEGER kernel;
+  ULARGE_INTEGER user;
+  kernel.HighPart = kernel_time.dwHighDateTime;
+  kernel.LowPart = kernel_time.dwLowDateTime;
+  user.HighPart = user_time.dwHighDateTime;
+  user.LowPart = user_time.dwLowDateTime;
+  return (static_cast<double>(kernel.QuadPart) +
+          static_cast<double>(user.QuadPart)) *
+         1e-7;
+}
+#else
+double MakeTime(struct rusage const& ru) {
+  return (static_cast<double>(ru.ru_utime.tv_sec) +
+          static_cast<double>(ru.ru_utime.tv_usec) * 1e-6 +
+          static_cast<double>(ru.ru_stime.tv_sec) +
+          static_cast<double>(ru.ru_stime.tv_usec) * 1e-6);
+}
+#endif
+#if defined(BENCHMARK_OS_MACOSX)
+double MakeTime(thread_basic_info_data_t const& info) {
+  return (static_cast<double>(info.user_time.seconds) +
+          static_cast<double>(info.user_time.microseconds) * 1e-6 +
+          static_cast<double>(info.system_time.seconds) +
+          static_cast<double>(info.system_time.microseconds) * 1e-6);
+}
+#endif
+#if defined(CLOCK_PROCESS_CPUTIME_ID) || defined(CLOCK_THREAD_CPUTIME_ID)
+double MakeTime(struct timespec const& ts) {
+  return ts.tv_sec + (static_cast<double>(ts.tv_nsec) * 1e-9);
+}
+#endif
+
+BENCHMARK_NORETURN static void DiagnoseAndExit(const char* msg) {
+  std::cerr << "ERROR: " << msg << std::endl;
+  std::exit(EXIT_FAILURE);
+}
+
+}  // end namespace
+
+double ProcessCPUUsage() {
+#if defined(BENCHMARK_OS_WINDOWS)
+  HANDLE proc = GetCurrentProcess();
+  FILETIME creation_time;
+  FILETIME exit_time;
+  FILETIME kernel_time;
+  FILETIME user_time;
+  if (GetProcessTimes(proc, &creation_time, &exit_time, &kernel_time,
+                      &user_time))
+    return MakeTime(kernel_time, user_time);
+  DiagnoseAndExit("GetProccessTimes() failed");
+#elif defined(BENCHMARK_OS_EMSCRIPTEN)
+  // clock_gettime(CLOCK_PROCESS_CPUTIME_ID, ...) returns 0 on Emscripten.
+  // Use Emscripten-specific API. Reported CPU time would be exactly the
+  // same as total time, but this is ok because there aren't long-latency
+  // syncronous system calls in Emscripten.
+  return emscripten_get_now() * 1e-3;
+#elif defined(CLOCK_PROCESS_CPUTIME_ID) && !defined(BENCHMARK_OS_MACOSX)
+  // FIXME We want to use clock_gettime, but its not available in MacOS 10.11. See
+  // https://github.com/google/benchmark/pull/292
+  struct timespec spec;
+  if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &spec) == 0)
+    return MakeTime(spec);
+  DiagnoseAndExit("clock_gettime(CLOCK_PROCESS_CPUTIME_ID, ...) failed");
+#else
+  struct rusage ru;
+  if (getrusage(RUSAGE_SELF, &ru) == 0) return MakeTime(ru);
+  DiagnoseAndExit("getrusage(RUSAGE_SELF, ...) failed");
+#endif
+}
+
+double ThreadCPUUsage() {
+#if defined(BENCHMARK_OS_WINDOWS)
+  HANDLE this_thread = GetCurrentThread();
+  FILETIME creation_time;
+  FILETIME exit_time;
+  FILETIME kernel_time;
+  FILETIME user_time;
+  GetThreadTimes(this_thread, &creation_time, &exit_time, &kernel_time,
+                 &user_time);
+  return MakeTime(kernel_time, user_time);
+#elif defined(BENCHMARK_OS_MACOSX)
+  // FIXME We want to use clock_gettime, but its not available in MacOS 10.11. See
+  // https://github.com/google/benchmark/pull/292
+  mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
+  thread_basic_info_data_t info;
+  mach_port_t thread = pthread_mach_thread_np(pthread_self());
+  if (thread_info(thread, THREAD_BASIC_INFO, (thread_info_t)&info, &count) ==
+      KERN_SUCCESS) {
+    return MakeTime(info);
+  }
+  DiagnoseAndExit("ThreadCPUUsage() failed when evaluating thread_info");
+#elif defined(BENCHMARK_OS_EMSCRIPTEN)
+  // Emscripten doesn't support traditional threads
+  return ProcessCPUUsage();
+#elif defined(CLOCK_THREAD_CPUTIME_ID)
+  struct timespec ts;
+  if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) == 0) return MakeTime(ts);
+  DiagnoseAndExit("clock_gettime(CLOCK_THREAD_CPUTIME_ID, ...) failed");
+#else
+#error Per-thread timing is not available on your system.
+#endif
+}
+
+namespace {
+
+std::string DateTimeString(bool local) {
+  typedef std::chrono::system_clock Clock;
+  std::time_t now = Clock::to_time_t(Clock::now());
+  const std::size_t kStorageSize = 128;
+  char storage[kStorageSize];
+  std::size_t written;
+
+  if (local) {
+#if defined(BENCHMARK_OS_WINDOWS)
+    written =
+        std::strftime(storage, sizeof(storage), "%x %X", ::localtime(&now));
+#else
+    std::tm timeinfo;
+    std::memset(&timeinfo, 0, sizeof(std::tm));
+    ::localtime_r(&now, &timeinfo);
+    written = std::strftime(storage, sizeof(storage), "%F %T", &timeinfo);
+#endif
+  } else {
+#if defined(BENCHMARK_OS_WINDOWS)
+    written = std::strftime(storage, sizeof(storage), "%x %X", ::gmtime(&now));
+#else
+    std::tm timeinfo;
+    std::memset(&timeinfo, 0, sizeof(std::tm));
+    ::gmtime_r(&now, &timeinfo);
+    written = std::strftime(storage, sizeof(storage), "%F %T", &timeinfo);
+#endif
+  }
+  CHECK(written < kStorageSize);
+  ((void)written);  // prevent unused variable in optimized mode.
+  return std::string(storage);
+}
+
+}  // end namespace
+
+std::string LocalDateTimeString() { return DateTimeString(true); }
+
+}  // end namespace benchmark