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base / profiler / periodic_sampling_scheduler.h [blame]
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_PROFILER_PERIODIC_SAMPLING_SCHEDULER_H_
#define BASE_PROFILER_PERIODIC_SAMPLING_SCHEDULER_H_
#include "base/time/time.h"
namespace base {
// The scheduler works by splitting execution time into repeated periods such
// that the time to take one collection represents
// |fraction_of_execution_time_to_sample| of the period, and the time not spent
// sampling represents 1 - |fraction_of_execution_time_to_sample| of the period.
// The collection start time is chosen randomly within each period such that the
// entire collection is contained within the period.
// It repeatedly schedules periodic sampling of the
// thread through calls to GetTimeToNextCollection().
class BASE_EXPORT PeriodicSamplingScheduler {
public:
PeriodicSamplingScheduler(TimeDelta sampling_duration,
double fraction_of_execution_time_to_sample,
TimeTicks start_time);
PeriodicSamplingScheduler(const PeriodicSamplingScheduler&) = delete;
PeriodicSamplingScheduler& operator=(const PeriodicSamplingScheduler&) =
delete;
virtual ~PeriodicSamplingScheduler();
// Returns the amount of time between now and the next collection.
TimeDelta GetTimeToNextCollection();
protected:
// Virtual to provide seams for test use.
virtual double RandDouble() const;
virtual TimeTicks Now() const;
private:
const TimeDelta period_duration_;
const TimeDelta sampling_duration_;
TimeTicks period_start_time_;
};
} // namespace base
#endif // BASE_PROFILER_PERIODIC_SAMPLING_SCHEDULER_H_