// Copyright 2020 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#ifndef ZIRCON_KERNEL_INCLUDE_KERNEL_TASK_RUNTIME_STATS_H_
#define ZIRCON_KERNEL_INCLUDE_KERNEL_TASK_RUNTIME_STATS_H_

#include <zircon/syscalls/object.h>
#include <zircon/time.h>

// Holds information about the runtime of a task.
struct TaskRuntimeStats {
  // The total duration spent running on a CPU.
  zx_duration_t cpu_time = 0;

  // The total duration spent ready to start running.
  zx_duration_t queue_time = 0;

  // The total duration (in ticks) spent handling page faults.
  zx_ticks_t page_fault_ticks = 0;

  // The total duration (in ticks) spent contented on kernel locks.
  zx_ticks_t lock_contention_ticks = 0;

  // Add another TaskRuntimeStats into this one.
  void Add(const TaskRuntimeStats& other) {
    cpu_time = zx_duration_add_duration(cpu_time, other.cpu_time);
    queue_time = zx_duration_add_duration(queue_time, other.queue_time);
    page_fault_ticks = zx_ticks_add_ticks(page_fault_ticks, other.page_fault_ticks);
    lock_contention_ticks = zx_ticks_add_ticks(lock_contention_ticks, other.lock_contention_ticks);
  }

  void AccumulateRuntimeTo(zx_info_task_runtime_t* info) const;
};

#endif  // ZIRCON_KERNEL_INCLUDE_KERNEL_TASK_RUNTIME_STATS_H_