-
Notifications
You must be signed in to change notification settings - Fork 81
/
relay_timer_pool.go
158 lines (135 loc) · 4.46 KB
/
relay_timer_pool.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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
// Copyright (c) 2017 Uber Technologies, Inc.
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package tchannel
import (
"math"
"sync"
"time"
)
type relayTimerTrigger func(items *relayItems, id uint32, isOriginator bool)
type relayTimerPool struct {
pool sync.Pool
trigger relayTimerTrigger
verify bool
}
type relayTimer struct {
pool *relayTimerPool // const
timer *time.Timer // const
active bool // mutated on Start/Stop
stopped bool // mutated on Stop
released bool // mutated on Get/Release.
// Per-timer parameters passed back when the timer is triggered.
items *relayItems
id uint32
isOriginator bool
}
func (rt *relayTimer) OnTimer() {
rt.verifyNotReleased()
items, id, isOriginator := rt.items, rt.id, rt.isOriginator
rt.markTimerInactive()
rt.pool.trigger(items, id, isOriginator)
}
func newRelayTimerPool(trigger relayTimerTrigger, verify bool) *relayTimerPool {
return &relayTimerPool{
trigger: trigger,
verify: verify,
}
}
// Get returns a relay timer that has not started. Timers must be started explicitly
// using the Start function.
func (tp *relayTimerPool) Get() *relayTimer {
timer, ok := tp.pool.Get().(*relayTimer)
if ok {
timer.released = false
return timer
}
rt := &relayTimer{
pool: tp,
}
// Go timers are started by default. However, we need to separate creating
// the timer and starting the timer for use in the relay code paths.
// To make this work without more locks in the relayTimer, we create a Go timer
// with a huge timeout so it doesn't run, then stop it so we can start it later.
rt.timer = time.AfterFunc(time.Duration(math.MaxInt64), rt.OnTimer)
if !rt.timer.Stop() {
panic("relayTimer requires timers in stopped state, but failed to stop underlying timer")
}
return rt
}
// Put returns a relayTimer back to the pool.
func (tp *relayTimerPool) Put(rt *relayTimer) {
if tp.verify {
// If we are trying to verify correct pool behavior, then we don't release
// the timer, and instead ensure no methods are called after being released.
return
}
tp.pool.Put(rt)
}
// Start starts a timer with the given duration for the specified ID.
func (rt *relayTimer) Start(d time.Duration, items *relayItems, id uint32, isOriginator bool) {
rt.verifyNotReleased()
if rt.active {
panic("Tried to start an already-active timer")
}
rt.active = true
rt.stopped = false
rt.items = items
rt.id = id
rt.isOriginator = isOriginator
if wasActive := rt.timer.Reset(d); wasActive {
panic("relayTimer's underlying timer was Started multiple times without Stop")
}
}
func (rt *relayTimer) markTimerInactive() {
rt.active = false
rt.items = nil
rt.id = 0
rt.items = nil
rt.isOriginator = false
}
// Stop stops the timer and returns whether the timer was stopped.
// If the timer has been executed, it returns false, but in all other
// cases, it returns true (even if the timer was stopped previously).
func (rt *relayTimer) Stop() bool {
rt.verifyNotReleased()
if rt.stopped {
return true
}
stopped := rt.timer.Stop()
if stopped {
rt.stopped = true
rt.markTimerInactive()
}
return stopped
}
// Release releases a timer back to the timer pool. The timer MUST have run or be
// stopped before Release is called.
func (rt *relayTimer) Release() {
rt.verifyNotReleased()
if rt.active {
panic("only stopped or completed timers can be released")
}
rt.released = true
rt.pool.Put(rt)
}
func (rt *relayTimer) verifyNotReleased() {
if rt.released {
panic("Released timer cannot be used")
}
}