-
Notifications
You must be signed in to change notification settings - Fork 44
/
mclock.go
129 lines (109 loc) · 3.51 KB
/
mclock.go
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
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
// Copyright 2016 The CortexTheseus Authors
// This file is part of the CortexTheseus library.
//
// The CortexTheseus 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 3 of the License, or
// (at your option) any later version.
//
// The CortexTheseus 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 the CortexTheseus library. If not, see <http://www.gnu.org/licenses/>.
// Package mclock is a wrapper for a monotonic clock source
package mclock
import (
"time"
"github.com/aristanetworks/goarista/monotime"
)
// AbsTime represents absolute monotonic time.
type AbsTime time.Duration
// Now returns the current absolute monotonic time.
func Now() AbsTime {
return AbsTime(monotime.Now())
}
// Add returns t + d as absolute time.
func (t AbsTime) Add(d time.Duration) AbsTime {
return t + AbsTime(d)
}
// Sub returns t - t2 as a duration.
func (t AbsTime) Sub(t2 AbsTime) time.Duration {
return time.Duration(t - t2)
}
// The Clock interface makes it possible to replace the monotonic system clock with
// a simulated clock.
type Clock interface {
Now() AbsTime
Sleep(time.Duration)
NewTimer(time.Duration) ChanTimer
After(time.Duration) <-chan AbsTime
AfterFunc(d time.Duration, f func()) Timer
}
// Timer is a cancellable event created by AfterFunc.
type Timer interface {
// Stop cancels the timer. It returns false if the timer has already
// expired or been stopped.
Stop() bool
}
// ChanTimer is a cancellable event created by NewTimer.
type ChanTimer interface {
Timer
// The channel returned by C receives a value when the timer expires.
C() <-chan AbsTime
// Reset reschedules the timer with a new timeout.
// It should be invoked only on stopped or expired timers with drained channels.
Reset(time.Duration)
}
// System implements Clock using the system clock.
type System struct {
offset AbsTime
}
// Now returns the current monotonic time.
func (c System) Now() AbsTime {
//return AbsTime(monotime.Now())
return AbsTime(monotime.Now()) + c.offset
}
func (c *System) SetAbsTime(now AbsTime) {
c.offset = now - AbsTime(monotime.Now())
}
// Sleep blocks for the given duration.
func (c System) Sleep(d time.Duration) {
time.Sleep(d)
}
// NewTimer creates a timer which can be rescheduled.
func (c System) NewTimer(d time.Duration) ChanTimer {
ch := make(chan AbsTime, 1)
t := time.AfterFunc(d, func() {
// This send is non-blocking because that's how time.Timer
// behaves. It doesn't matter in the happy case, but does
// when Reset is misused.
select {
case ch <- c.Now():
default:
}
})
return &systemTimer{t, ch}
}
// After returns a channel which receives the current time after d has elapsed.
func (c System) After(d time.Duration) <-chan AbsTime {
ch := make(chan AbsTime, 1)
time.AfterFunc(d, func() { ch <- c.Now() })
return ch
}
// AfterFunc runs f on a new goroutine after the duration has elapsed.
func (c System) AfterFunc(d time.Duration, f func()) Timer {
return time.AfterFunc(d, f)
}
type systemTimer struct {
*time.Timer
ch <-chan AbsTime
}
func (st *systemTimer) Reset(d time.Duration) {
st.Timer.Reset(d)
}
func (st *systemTimer) C() <-chan AbsTime {
return st.ch
}