pa_simple_read() timing test

#include <libvisual/libvisual.h>
#include <pulse/simple.h>
#include <pulse/error.h>
#include <boost/format.hpp>
#include <iostream>
#include <vector>
#include <cmath>
#include <cstdlib>

typedef std::vector<LV::Time> TimingProfile;

unsigned int const frame_count = 200;

namespace {

  TimingProfile record_read_durations (unsigned int frame_count, unsigned int sample_rate, unsigned int samples_per_read, double wait_time)
  {
      uint64_t wait_time_usecs = wait_time * VISUAL_USEC_PER_SEC;

      int error;

      pa_sample_spec sample_spec { PA_SAMPLE_S16LE, sample_rate, 2 };

      pa_simple* snd = pa_simple_new (nullptr,
                                      "pa_blocking_read_test",
                                      PA_STREAM_RECORD,
                                      nullptr,
                                      "record",
                                      &sample_spec,
                                      nullptr,
                                      nullptr,
                                      &error);

      TimingProfile read_durations (frame_count);

      int16_t snd_buffer[samples_per_read*2];

      LV::Timer read_timer;

      for (unsigned int i = 0; i < frame_count; i++) {
          read_timer.start ();
          pa_simple_read (snd, snd_buffer, sizeof (snd_buffer), &error);
          read_durations[i] = read_timer.elapsed ();

          LV::Time::usleep (wait_time_usecs);
      }

      pa_simple_free (snd);

      return read_durations;
  }

}

int main (int argc, char** argv)
{
    LV::System::init (argc, argv);

    TimingProfile durations1 = record_read_durations (frame_count, 44100, 1024, 1/60.0);
    TimingProfile durations2 = record_read_durations (frame_count, 44100, 1024, 1/40.0);
    TimingProfile durations3 = record_read_durations (frame_count, 44100, 1024, 1/20.0);
    TimingProfile durations4 = record_read_durations (frame_count, 44100, 1024, 0);

    for (unsigned int i = 0; i < frame_count; i++) {
        std::cout << boost::format ("%d %.8f %.8f %.8f %.8f\n")
            % i
            % durations1[i].to_secs ()
            % durations2[i].to_secs ()
            % durations3[i].to_secs ()
            % durations4[i].to_secs ();
    }

    return EXIT_SUCCESS;
}