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livetrax/libs/pbd/microseconds.cc

105 lines
2.7 KiB
C++

/*
* Copyright (C) 2021 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2013-2015 Tim Mayberry <mojofunk@gmail.com>
* Copyright (C) 2014-2015 John Emmas <john@creativepost.co.uk>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <time.h>
#ifdef PLATFORM_WINDOWS
#include <windows.h>
#endif
#include "pbd/error.h"
#include "pbd/microseconds.h"
#include "pbd/i18n.h"
#ifdef PLATFORM_WINDOWS
static double timer_rate_usecs = 0.0;
#endif
#ifdef __MACH__
#include <mach/mach_time.h>
#ifndef CLOCK_REALTIME
#define MACH_NEED_MICROSECONDS_TIMEBASE
static mach_timebase_info_data_t timebase;
/* Thanks Apple for not implementing this basic SUSv2, POSIX.1-2001 function
*/
#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC 0
int
clock_gettime (int /*clk_id*/, struct timespec* t)
{
uint64_t time;
time = mach_absolute_time ();
double nseconds = ((double)time * (double)timebase.numer) / ((double)timebase.denom);
double seconds = ((double)time * (double)timebase.numer) / ((double)timebase.denom * 1e9);
t->tv_sec = seconds;
t->tv_nsec = nseconds;
return 0;
}
#endif /* CLOCK_REALTIME */
#endif /* __MACH__ */
void
PBD::microsecond_timer_init ()
{
#ifdef PLATFORM_WINDOWS
LARGE_INTEGER freq;
if (!QueryPerformanceFrequency(&freq) || freq.QuadPart < 1) {
info << X_("Failed to determine frequency of QPC\n") << endmsg;
timer_rate_usecs = 0;
} else {
timer_rate_usecs = 1000000.0 / freq.QuadPart;
}
#endif
#ifdef MACH_NEED_MICROSECONDS_TIMEBASE
mach_timebase_info (&timebase);
#endif
}
/** Return a monotonic value for the number of microseconds that have elapsed
* since an arbitrary zero origin.
*/
PBD::microseconds_t
PBD::get_microseconds ()
{
#ifdef PLATFORM_WINDOWS
LARGE_INTEGER time;
if (timer_rate_usecs) {
if (QueryPerformanceCounter (&time)) {
return (microseconds_t) (time.QuadPart * timer_rate_usecs);
}
}
return (microseconds_t) 0;
#else
struct timespec ts;
if (clock_gettime (CLOCK_MONOTONIC, &ts) != 0) {
/* EEEK! */
return 0;
}
return (microseconds_t)ts.tv_sec * 1000000 + (ts.tv_nsec / 1000);
#endif
}