mariadb/include/my_counter.h
Vicențiu Ciorbaru 08c852026d Apply clang-tidy to remove empty constructors / destructors
This patch is the result of running
run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' .

Code style changes have been done on top. The result of this change
leads to the following improvements:

1. Binary size reduction.
* For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by
  ~400kb.
* A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb.

2. Compiler can better understand the intent of the code, thus it leads
   to more optimization possibilities. Additionally it enabled detecting
   unused variables that had an empty default constructor but not marked
   so explicitly.

   Particular change required following this patch in sql/opt_range.cc

   result_keys, an unused template class Bitmap now correctly issues
   unused variable warnings.

   Setting Bitmap template class constructor to default allows the compiler
   to identify that there are no side-effects when instantiating the class.
   Previously the compiler could not issue the warning as it assumed Bitmap
   class (being a template) would not be performing a NO-OP for its default
   constructor. This prevented the "unused variable warning".
2023-02-09 16:09:08 +02:00

49 lines
1.7 KiB
C++

#ifndef MY_COUNTER_H_INCLUDED
#define MY_COUNTER_H_INCLUDED
/*
Copyright (C) 2018 MariaDB Foundation
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; version 2 of the License.
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
*/
#include <atomic>
template <typename Type> class Atomic_counter
{
std::atomic<Type> m_counter;
Type add(Type i) { return m_counter.fetch_add(i, std::memory_order_relaxed); }
Type sub(Type i) { return m_counter.fetch_sub(i, std::memory_order_relaxed); }
public:
Atomic_counter(const Atomic_counter<Type> &rhs)
{ m_counter.store(rhs, std::memory_order_relaxed); }
Atomic_counter(Type val): m_counter(val) {}
Atomic_counter() = default;
Type operator++(int) { return add(1); }
Type operator--(int) { return sub(1); }
Type operator++() { return add(1) + 1; }
Type operator--() { return sub(1) - 1; }
Type operator+=(const Type i) { return add(i) + i; }
Type operator-=(const Type i) { return sub(i) - i; }
operator Type() const { return m_counter.load(std::memory_order_relaxed); }
Type operator=(const Type val)
{ m_counter.store(val, std::memory_order_relaxed); return val; }
};
#endif /* MY_COUNTER_H_INCLUDED */