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
e174696351
EM and PP are most resource-hungry runtimes.
The merge enables to control their cummulative
resource consumption, thread allocation + enables
zero-copy data exchange b/w local EM and PP facilities.
56 lines
1.2 KiB
C++
56 lines
1.2 KiB
C++
#pragma once
|
|
|
|
#include <atomic>
|
|
|
|
// To be refactored. There are two issues with this implentation.
|
|
// 1. It can be replaced with a lock despite the memory_order_acquire/release mem order. Needs
|
|
// std::atomic_flag instead.
|
|
// 2. https://www.realworldtech.com/forum/?threadid=189711&curpostid=189723
|
|
namespace utils
|
|
{
|
|
inline void getSpinlock(std::atomic<bool>& lock)
|
|
{
|
|
bool _false = false;
|
|
while (!lock.compare_exchange_weak(_false, true, std::memory_order_acquire))
|
|
_false = false;
|
|
}
|
|
|
|
inline bool trySpinlock(std::atomic<bool>& lock)
|
|
{
|
|
bool _false = false;
|
|
bool ret = lock.compare_exchange_weak(_false, true, std::memory_order_acquire);
|
|
return ret;
|
|
}
|
|
|
|
inline void releaseSpinlock(std::atomic<bool>& lock)
|
|
{
|
|
lock.store(false, std::memory_order_release);
|
|
}
|
|
|
|
// c++20 offers a combination of wait/notify methods but
|
|
// I prefer to use a simpler version of uspace spin lock.
|
|
class USpaceSpinLock
|
|
{
|
|
public:
|
|
USpaceSpinLock(std::atomic_flag& flag) : flag_(flag)
|
|
{
|
|
while (flag_.test_and_set(std::memory_order_acquire))
|
|
{
|
|
;
|
|
}
|
|
};
|
|
~USpaceSpinLock()
|
|
{
|
|
release();
|
|
};
|
|
inline void release()
|
|
{
|
|
flag_.clear(std::memory_order_release);
|
|
}
|
|
|
|
private:
|
|
std::atomic_flag& flag_;
|
|
};
|
|
|
|
} // namespace utils
|