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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:
typedef T base_t;
typedef std::atomic<base_t> atomic_t;
stat_t_trait() : stat_t_trait(base_t(0)) {
}
stat_t_trait(const base_t x) {
new(&counter) atomic_t(x);
}
~stat_t_trait() {
reinterpret_cast<atomic_t *>(&counter)->~atomic_t();
}
stat_t_trait(const stat_t_trait&) = delete;
base_t operator++(int) {
return (*reinterpret_cast<atomic_t *>(&counter))++;
}
base_t operator++() {
return ++(*reinterpret_cast<atomic_t *>(&counter));
}
base_t operator--(int) {
return (*reinterpret_cast<atomic_t *>(&counter))--;
}
base_t operator--() {
return --(*reinterpret_cast<atomic_t *>(&counter));
}
base_t operator+=(const stat_t_trait& v) {
return *reinterpret_cast<atomic_t *>(&counter) += *reinterpret_cast<const atomic_t *>(&v.counter);
}
base_t operator-=(const stat_t_trait& v) {
return *reinterpret_cast<atomic_t *>(&counter) -= *reinterpret_cast<const atomic_t *>(&v.counter);
}
base_t load() const {
return reinterpret_cast<const atomic_t *>(&counter)->load();
}
void store(base_t v) {
reinterpret_cast<atomic_t *>(&counter)->store(v);
}
operator base_t() const {
return reinterpret_cast<const atomic_t *>(&counter)->load();
}
private:
typename std::aligned_storage<sizeof(base_t), CPU_LEVEL1_DCACHE_LINESIZE>::type counter;
};
typedef stat_t_trait<uint64_t> stat_t;
typedef stat_t_trait<uint32_t> stat32_t;
typedef stat_t_trait<uint16_t> stat16_t;
}
#else
namespace pdns {
using stat_t = std::atomic<uint64_t>;
using stat32_t = std::atomic<uint32_t>;
using stat16_t = std::atomic<uint16_t>;
template <class T>
using stat_t_trait = std::atomic<T>;
}
#endif
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