/** @file realtime.h
* @brief Functions for handling a time or time interval in a double.
*/
/* Copyright (C) 2010,2013 Olly Betts
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef XAPIAN_INCLUDED_REALTIME_H
#define XAPIAN_INCLUDED_REALTIME_H
#include <cmath>
#include <ctime>
#include "safeerrno.h"
#include "safeunistd.h"
#ifndef __WIN32__
# ifdef HAVE_FTIME
# include <sys/timeb.h>
# endif
# ifdef HAVE_GETTIMEOFDAY
# include <sys/time.h>
# endif
#else
# include <sys/types.h>
# include <sys/timeb.h>
extern void xapian_sleep_milliseconds(unsigned int millisecs);
#endif
namespace RealTime {
/// Return the current time.
inline double now() {
#ifndef __WIN32__
// POSIX.1-2008 stopped specifying ftime(), so prefer gettimeofday().
# ifdef HAVE_GETTIMEOFDAY
struct timeval tv;
if (usual(gettimeofday(&tv, NULL) == 0))
return tv.tv_sec + (tv.tv_usec * 1e-6);
return double(std::time(NULL));
# elif defined HAVE_FTIME
struct timeb tp;
# ifdef FTIME_RETURNS_VOID
ftime(&tp);
# else
if (rare(ftime(&tp) != 0))
return double(std::time(NULL));
# endif
return tp.time + (tp.millitm * 1e-3);
# else
return double(std::time(NULL));
# endif
#else
struct __timeb64 tp;
_ftime64(&tp);
return tp.time + tp.millitm * 1e-3;
#endif
}
/** Return the end time for a timeout in @a timeout seconds.
*
* If @a timeout is 0, that means "no timeout", so 0 is returned. Otherwise
* the current time plus @a timeout seconds is returned.
*/
inline double end_time(double timeout) {
return (timeout == 0.0 ? timeout : timeout + now());
}
/// Sleep until the time represented by this object.
inline void sleep(double t) {
#ifndef __WIN32__
double delta;
struct timeval tv;
do {
delta = t - RealTime::now();
if (delta <= 0.0)
return;
tv.tv_sec = long(delta);
tv.tv_usec = long(std::fmod(delta, 1.0) * 1e6);
} while (select(0, NULL, NULL, NULL, &tv) < 0 && errno == EINTR);
#else
double delta = t - RealTime::now();
if (delta <= 0.0)
return;
while (rare(delta > 4294967.0)) {
xapian_sleep_milliseconds(4294967000u);
delta -= 4294967.0;
}
xapian_sleep_milliseconds(unsigned(delta * 1000.0));
#endif
}
}
#endif // XAPIAN_INCLUDED_REALTIME_H