You've already forked mariadb-columnstore-engine
mirror of
https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
synced 2025-11-03 17:13:17 +03:00
107 lines
2.6 KiB
C++
107 lines
2.6 KiB
C++
/* Copyright (C) 2014 InfiniDB, Inc.
|
|
|
|
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 Street, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
/** @file */
|
|
|
|
#pragma once
|
|
|
|
#include <unistd.h>
|
|
#include <stdint.h>
|
|
#include <sched.h>
|
|
#include <atomic>
|
|
|
|
/*
|
|
This is an attempt to wrap the differneces between Windows and Linux around atomic ops.
|
|
Boost has something in interprocess::ipcdetail, but it doesn't have 64-bit API's.
|
|
*/
|
|
|
|
namespace atomicops
|
|
{
|
|
// Atomic operations for atomic<int64_t> references
|
|
inline int64_t atomicAddRef(std::atomic<int64_t>& ref, int64_t val)
|
|
{
|
|
return ref.fetch_add(val, std::memory_order_relaxed);
|
|
}
|
|
|
|
inline int64_t atomicSubRef(std::atomic<int64_t>& ref, int64_t val)
|
|
{
|
|
return ref.fetch_sub(val, std::memory_order_relaxed);
|
|
}
|
|
// Returns the resulting, incremented value
|
|
template <typename T>
|
|
inline T atomicInc(volatile T* mem)
|
|
{
|
|
return __sync_add_and_fetch(mem, 1);
|
|
}
|
|
|
|
// decrements, but returns the pre-decrement value
|
|
template <typename T>
|
|
inline T atomicDec(volatile T* mem)
|
|
{
|
|
return __sync_fetch_and_add(mem, -1);
|
|
}
|
|
|
|
// Returns the resulting value (but doesn't need to yet)
|
|
template <typename T>
|
|
inline T atomicAdd(volatile T* mem, T val)
|
|
{
|
|
return __sync_add_and_fetch(mem, val);
|
|
}
|
|
|
|
// Returns the resulting value
|
|
template <typename T>
|
|
inline T atomicSub(volatile T* mem, T val)
|
|
{
|
|
return __sync_sub_and_fetch(mem, val);
|
|
}
|
|
|
|
// Implements a memory barrier
|
|
inline void atomicMb()
|
|
{
|
|
__sync_synchronize();
|
|
}
|
|
|
|
// Returns true iff the CAS took place, that is
|
|
// if (*mem == comp) {
|
|
// *mem = swap;
|
|
// return true;
|
|
// } else {
|
|
// return false;
|
|
// }
|
|
template <typename T>
|
|
inline bool atomicCAS(volatile T* mem, T comp, T swap)
|
|
{
|
|
// If the current value of *mem is comp, then write swap into *comp. Return true if the comparison is
|
|
// successful and swap was written.
|
|
return __sync_bool_compare_and_swap(mem, comp, swap);
|
|
}
|
|
|
|
// implements a zero out of a variable
|
|
template <typename T>
|
|
inline void atomicZero(volatile T* mem)
|
|
{
|
|
__sync_xor_and_fetch(mem, *mem);
|
|
}
|
|
|
|
// Implements a scheduler yield
|
|
inline void atomicYield()
|
|
{
|
|
sched_yield();
|
|
}
|
|
|
|
} // namespace atomicops
|