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/*
* Copyright 2003-2018 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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 "OggSerial.hxx"
#include "util/Compiler.h"
#include <atomic>
#include <chrono>
static std::atomic_uint next_ogg_serial;
int
GenerateOggSerial() noexcept
{
unsigned serial = ++next_ogg_serial;
if (gcc_unlikely(serial < 16)) {
/* first-time initialization: seed with a clock value,
which is random enough for our use */
/* this code is not race-free, but good enough */
using namespace std::chrono;
const auto now = steady_clock::now().time_since_epoch();
const auto now_ms = duration_cast<milliseconds>(now);
const unsigned seed = now_ms.count();
next_ogg_serial = serial = seed;
}
return serial;
}
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