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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
package resource_pool
import (
"fmt"
"sync"
"errors"
)
// A resource pool implementation that manages multiple resource location
// entries. The handles to each resource location entry acts independently.
// For example "tcp localhost:11211" could act as memcache
// shard 0 and "tcp localhost:11212" could act as memcache shard 1.
type multiResourcePool struct {
options Options
createPool func(Options) ResourcePool
rwMutex sync.RWMutex
isLameDuck bool // guarded by rwMutex
// NOTE: the locationPools is guarded by rwMutex, but the pool entries
// are not.
locationPools map[string]ResourcePool
}
// This returns a MultiResourcePool, which manages multiple
// resource location entries. The handles to each resource location
// entry acts independently.
//
// When createPool is nil, NewSimpleResourcePool is used as default.
func NewMultiResourcePool(
options Options,
createPool func(Options) ResourcePool) ResourcePool {
if createPool == nil {
createPool = NewSimpleResourcePool
}
return &multiResourcePool{
options: options,
createPool: createPool,
rwMutex: sync.RWMutex{},
isLameDuck: false,
locationPools: make(map[string]ResourcePool),
}
}
// See ResourcePool for documentation.
func (p *multiResourcePool) NumActive() int32 {
total := int32(0)
p.rwMutex.RLock()
defer p.rwMutex.RUnlock()
for _, pool := range p.locationPools {
total += pool.NumActive()
}
return total
}
// See ResourcePool for documentation.
func (p *multiResourcePool) ActiveHighWaterMark() int32 {
high := int32(0)
p.rwMutex.RLock()
defer p.rwMutex.RUnlock()
for _, pool := range p.locationPools {
val := pool.ActiveHighWaterMark()
if val > high {
high = val
}
}
return high
}
// See ResourcePool for documentation.
func (p *multiResourcePool) NumIdle() int {
total := 0
p.rwMutex.RLock()
defer p.rwMutex.RUnlock()
for _, pool := range p.locationPools {
total += pool.NumIdle()
}
return total
}
// See ResourcePool for documentation.
func (p *multiResourcePool) Register(resourceLocation string) error {
if resourceLocation == "" {
return errors.New("Registering invalid resource location")
}
p.rwMutex.Lock()
defer p.rwMutex.Unlock()
if p.isLameDuck {
return fmt.Errorf(
"Cannot register %s to lame duck resource pool",
resourceLocation)
}
if _, inMap := p.locationPools[resourceLocation]; inMap {
return nil
}
pool := p.createPool(p.options)
if err := pool.Register(resourceLocation); err != nil {
return err
}
p.locationPools[resourceLocation] = pool
return nil
}
// See ResourcePool for documentation.
func (p *multiResourcePool) Unregister(resourceLocation string) error {
p.rwMutex.Lock()
defer p.rwMutex.Unlock()
if pool, inMap := p.locationPools[resourceLocation]; inMap {
_ = pool.Unregister("")
pool.EnterLameDuckMode()
delete(p.locationPools, resourceLocation)
}
return nil
}
func (p *multiResourcePool) ListRegistered() []string {
p.rwMutex.RLock()
defer p.rwMutex.RUnlock()
result := make([]string, 0, len(p.locationPools))
for key, _ := range p.locationPools {
result = append(result, key)
}
return result
}
// See ResourcePool for documentation.
func (p *multiResourcePool) Get(
resourceLocation string) (ManagedHandle, error) {
pool := p.getPool(resourceLocation)
if pool == nil {
return nil, fmt.Errorf(
"%s is not registered in the resource pool",
resourceLocation)
}
return pool.Get(resourceLocation)
}
// See ResourcePool for documentation.
func (p *multiResourcePool) Release(handle ManagedHandle) error {
pool := p.getPool(handle.ResourceLocation())
if pool == nil {
return errors.New(
"Resource pool cannot take control of a handle owned " +
"by another resource pool")
}
return pool.Release(handle)
}
// See ResourcePool for documentation.
func (p *multiResourcePool) Discard(handle ManagedHandle) error {
pool := p.getPool(handle.ResourceLocation())
if pool == nil {
return errors.New(
"Resource pool cannot take control of a handle owned " +
"by another resource pool")
}
return pool.Discard(handle)
}
// See ResourcePool for documentation.
func (p *multiResourcePool) EnterLameDuckMode() {
p.rwMutex.Lock()
defer p.rwMutex.Unlock()
p.isLameDuck = true
for _, pool := range p.locationPools {
pool.EnterLameDuckMode()
}
}
func (p *multiResourcePool) getPool(resourceLocation string) ResourcePool {
p.rwMutex.RLock()
defer p.rwMutex.RUnlock()
if pool, inMap := p.locationPools[resourceLocation]; inMap {
return pool
}
return nil
}
|
