blob: 88d1859f32f586e912cbf96daef96944758bfd10 (
plain)
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:nil -*-
// vim: ts=8 sw=2 smarttab
#include "throttle.h"
namespace crimson::common {
int64_t Throttle::take(int64_t c)
{
if (max == 0u) {
return 0;
}
count += c;
return count;
}
int64_t Throttle::put(int64_t c)
{
if (max == 0u) {
return 0;
}
if (!c) {
return count;
}
on_free_slots.signal();
count -= c;
return count;
}
seastar::future<> Throttle::get(size_t c)
{
if (max == 0u) {
return seastar::make_ready_future<>();
}
pending++;
return on_free_slots.wait([this, c] {
return !_should_wait(c);
}).then([this, c] {
pending--;
count += c;
return seastar::make_ready_future<>();
});
}
void Throttle::reset_max(size_t m) {
if (max == m) {
return;
}
if (m > max) {
on_free_slots.signal();
}
max = m;
}
bool Throttle::_should_wait(size_t c) const {
if (!max) {
return false;
}
return ((c <= max && count + c > max) || // normally stay under max
(c >= max && count > max)); // except for large c
}
} // namespace crimson::common
|
