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/*
* This file is part of PowerDNS or dnsdist.
* Copyright -- PowerDNS.COM B.V. and its contributors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* In addition, for the avoidance of any doubt, permission is granted to
* link this program with OpenSSL and to (re)distribute the binaries
* produced as the result of such linking.
*
* 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.
*/
#pragma once
#include <atomic>
#ifndef DISABLE_FALSE_SHARING_PADDING
#define CPU_LEVEL1_DCACHE_LINESIZE 64 // Until we know better via configure/getconf
namespace pdns {
template <typename T>
class stat_t_trait {
public:
using base_t = T;
using atomic_t = std::atomic<base_t>;
stat_t_trait() : stat_t_trait(base_t(0)) {
}
stat_t_trait(const base_t value)
{
new(&counter) atomic_t(value);
}
stat_t_trait& operator=(const base_t& value) {
ref().store(value);
return *this;
}
~stat_t_trait() {
ref().~atomic_t();
}
stat_t_trait(stat_t_trait&&) = delete;
stat_t_trait& operator=(const stat_t_trait&) = delete;
stat_t_trait& operator=(stat_t_trait&&) = delete;
stat_t_trait(const stat_t_trait&) = delete;
base_t operator++(int) {
return ref()++;
}
base_t operator++() {
return ++(ref());
}
base_t operator--(int) {
return ref()--;
}
base_t operator--() {
return --(ref());
}
base_t operator+=(base_t arg) {
return ref() += arg;
}
base_t operator-=(base_t arg) {
return ref() -= arg;
}
base_t load() const {
return ref().load();
}
void store(base_t value) {
ref().store(value);
}
operator base_t() const {
return ref().load();
}
private:
atomic_t& ref() {
return *reinterpret_cast<atomic_t *>(&counter); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
}
const atomic_t& ref() const {
return *reinterpret_cast<const atomic_t *>(&counter); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
}
typename std::aligned_storage_t<sizeof(atomic_t), CPU_LEVEL1_DCACHE_LINESIZE> counter;
};
}
#else
namespace pdns {
template <class T>
using stat_t_trait = std::atomic<T>;
}
#endif
namespace pdns {
using stat_t = stat_t_trait<uint64_t>;
using stat32_t = stat_t_trait<uint32_t>;
using stat16_t = stat_t_trait<uint16_t>;
using stat_double_t = stat_t_trait<double>;
}
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