Squashed 'third_party/google-benchmark/' content from commit 785e2c3
Change-Id: Iaaca5eca89f717081452e643a233e86425b03e89
git-subtree-dir: third_party/google-benchmark
git-subtree-split: 785e2c3158589e8ef48c59ba80e48d76bdbd8902
diff --git a/src/thread_timer.h b/src/thread_timer.h
new file mode 100644
index 0000000..eaf108e
--- /dev/null
+++ b/src/thread_timer.h
@@ -0,0 +1,69 @@
+#ifndef BENCHMARK_THREAD_TIMER_H
+#define BENCHMARK_THREAD_TIMER_H
+
+#include "check.h"
+#include "timers.h"
+
+namespace benchmark {
+namespace internal {
+
+class ThreadTimer {
+ public:
+ ThreadTimer() = default;
+
+ // Called by each thread
+ void StartTimer() {
+ running_ = true;
+ start_real_time_ = ChronoClockNow();
+ start_cpu_time_ = ThreadCPUUsage();
+ }
+
+ // Called by each thread
+ void StopTimer() {
+ CHECK(running_);
+ running_ = false;
+ real_time_used_ += ChronoClockNow() - start_real_time_;
+ // Floating point error can result in the subtraction producing a negative
+ // time. Guard against that.
+ cpu_time_used_ += std::max<double>(ThreadCPUUsage() - start_cpu_time_, 0);
+ }
+
+ // Called by each thread
+ void SetIterationTime(double seconds) { manual_time_used_ += seconds; }
+
+ bool running() const { return running_; }
+
+ // REQUIRES: timer is not running
+ double real_time_used() {
+ CHECK(!running_);
+ return real_time_used_;
+ }
+
+ // REQUIRES: timer is not running
+ double cpu_time_used() {
+ CHECK(!running_);
+ return cpu_time_used_;
+ }
+
+ // REQUIRES: timer is not running
+ double manual_time_used() {
+ CHECK(!running_);
+ return manual_time_used_;
+ }
+
+ private:
+ bool running_ = false; // Is the timer running
+ double start_real_time_ = 0; // If running_
+ double start_cpu_time_ = 0; // If running_
+
+ // Accumulated time so far (does not contain current slice if running_)
+ double real_time_used_ = 0;
+ double cpu_time_used_ = 0;
+ // Manually set iteration time. User sets this with SetIterationTime(seconds).
+ double manual_time_used_ = 0;
+};
+
+} // namespace internal
+} // namespace benchmark
+
+#endif // BENCHMARK_THREAD_TIMER_H