BandwidthLimit.cc

/*
 * SPDX-License-Identifier: GPL-2.0
 *
 * Copyright (c) 2018 Intel Corporation
 *
 * Authors: Yao Yuan <yuan.yao@intel.com>
 */

#include <unistd.h>
#include <string.h>
#include <vector>
#include <thread>
#include <iostream>

#include "BandwidthLimit.h"
#include "lib/stats.h"

const float BandwidthLimit::MAX_TIME_HISTORY = 3;

void BandwidthLimit::add_and_sleep(unsigned long bytes)
{
  float time_delta;
  timeval cur_time;

  if (0 == bwlimit_byteps)
    return;

  if (!last_time.tv_sec && !last_time.tv_usec) {
    allow_bytes = 0;
    gettimeofday(&last_time, NULL);
    return;
  }

  std::unique_lock<std::mutex> lock(mlock);

  gettimeofday(&cur_time, NULL);
  time_delta = tv_secs(last_time, cur_time);
  if (time_delta > MAX_TIME_HISTORY)
    time_delta = MAX_TIME_HISTORY;

  last_time = cur_time;

  allow_bytes += time_delta * bwlimit_byteps;
  allow_bytes -= bytes;

  if (allow_bytes < 0) {
    float sleep_time;
    sleep_time = ((-allow_bytes) / bwlimit_byteps) * 1000000;
    //printf("thread will sleep %f microseconds\n", sleep_time);
    usleep(sleep_time);
  }
}