forked from scylladb/scylladb
-
Notifications
You must be signed in to change notification settings - Fork 0
/
clocks-impl.hh
36 lines (29 loc) · 972 Bytes
/
clocks-impl.hh
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
/*
* Copyright (C) 2017-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include <algorithm>
#include <atomic>
#include <chrono>
#include <cstdint>
extern std::atomic<int64_t> clocks_offset;
template<typename Duration>
inline void forward_jump_clocks(Duration delta)
{
auto d = std::chrono::duration_cast<std::chrono::seconds>(delta).count();
clocks_offset.fetch_add(d, std::memory_order_relaxed);
}
inline std::chrono::seconds get_clocks_offset()
{
auto off = clocks_offset.load(std::memory_order_relaxed);
return std::chrono::seconds(off);
}
// Returns a time point which is earlier from t by d, or minimum time point if it cannot be represented.
template<typename Clock, typename Duration, typename Rep, typename Period>
inline
auto saturating_subtract(std::chrono::time_point<Clock, Duration> t, std::chrono::duration<Rep, Period> d) -> decltype(t) {
return std::max(t, decltype(t)::min() + d) - d;
}