cycle_timer.cc

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/*
    Copyright (C) 2002 Andrew Morton

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <cstdio>
#include <fstream>
#include "pbd/error.h"
#include "ardour/cycle_timer.h"

#include "ardour/libardour_visibility.h"

#include "i18n.h"

using namespace std;
using namespace PBD;

float CycleTimer::cycles_per_usec = 0;

float
get_mhz()
{
        FILE *f;

        if ((f = fopen("/proc/cpuinfo", "r")) == 0) {
                fatal << _("CycleTimer::get_mhz(): can't open /proc/cpuinfo") << endmsg;
                abort(); /*NOTREACHED*/
                return 0.0f;
        }

        while (true) {

                float mhz;
                int ret;
                char buf[1000];

                if (fgets (buf, sizeof(buf), f) == 0) {
                        fatal << _("CycleTimer::get_mhz(): cannot locate cpu MHz in /proc/cpuinfo") << endmsg;
                        abort(); /*NOTREACHED*/
                        return 0.0f;
                }

#ifdef __powerpc__

                int   imhz;

                /* why can't the PPC crew standardize their /proc/cpuinfo format ? */
                ret = sscanf (buf, "clock\t: %dMHz", &imhz);
                mhz = (float) imhz;

#else /* XXX don't assume its x86 just because its not power pc */
                ret = sscanf (buf, "cpu MHz         : %f", &mhz);

#endif
                if (ret == 1) {
                        fclose(f);
                        return mhz;
                }
        }

        fatal << _("cannot locate cpu MHz in /proc/cpuinfo") << endmsg;
        abort(); /*NOTREACHED*/
        return 0.0f;
}

StoringTimer::StoringTimer (int N)
{
        _point = new int[N];
        _value = new cycles_t[N];
        _ref = new cycles_t[N];
        _max_points = N;
        _points = 0;
}
        

void
StoringTimer::dump (string const & file)
{
        ofstream f (file.c_str ());

        f << min (_points, _max_points) << "\n";
        f << get_mhz () << "\n";
        for (int i = 0; i < min (_points, _max_points); ++i) {
                f << _point[i] << " " << _ref[i] << " " << _value[i] << "\n";
        }
}

void
StoringTimer::ref ()
{
        _current_ref = get_cycles ();
}

void
StoringTimer::check (int p)
{
        if (_points == _max_points) {
                ++_points;
                return;
        } else if (_points > _max_points) {
                return;
        }
        
        _point[_points] = p;
        _value[_points] = get_cycles ();
        _ref[_points] = _current_ref;
        
        ++_points;
}

#ifdef PT_TIMING
StoringTimer ST (64 * 1024);
#endif