mirror of
https://github.com/ton-blockchain/ton
synced 2025-03-09 15:40:10 +00:00
72 lines
1.6 KiB
C++
72 lines
1.6 KiB
C++
/*
|
|
This file is part of TON Blockchain Library.
|
|
|
|
TON Blockchain Library is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation, either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
TON Blockchain Library 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 Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with TON Blockchain Library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
Copyright 2017-2020 Telegram Systems LLP
|
|
*/
|
|
#pragma once
|
|
|
|
#include "td/utils/port/thread.h"
|
|
|
|
#include <atomic>
|
|
#include <memory>
|
|
|
|
namespace td {
|
|
|
|
class SpinLock {
|
|
struct Unlock {
|
|
void operator()(SpinLock *ptr) {
|
|
ptr->unlock();
|
|
}
|
|
};
|
|
|
|
class InfBackoff {
|
|
int cnt = 0;
|
|
|
|
public:
|
|
bool next() {
|
|
cnt++;
|
|
if (cnt < 50) {
|
|
//TODO pause
|
|
return true;
|
|
} else {
|
|
td::this_thread::yield();
|
|
return true;
|
|
}
|
|
}
|
|
};
|
|
|
|
public:
|
|
using Lock = std::unique_ptr<SpinLock, Unlock>;
|
|
|
|
Lock lock() {
|
|
InfBackoff backoff;
|
|
while (!try_lock()) {
|
|
backoff.next();
|
|
}
|
|
return Lock(this);
|
|
}
|
|
bool try_lock() {
|
|
return !flag_.test_and_set(std::memory_order_acquire);
|
|
}
|
|
|
|
private:
|
|
std::atomic_flag flag_ = ATOMIC_FLAG_INIT;
|
|
void unlock() {
|
|
flag_.clear(std::memory_order_release);
|
|
}
|
|
};
|
|
|
|
} // namespace td
|