blob: 54e825b28652d9b0827dfda00c730a47a8b642e9 (
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
65
66
67
|
// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package pool provides a trivial integer pool.
package pool
import (
"gvisor.dev/gvisor/pkg/sync"
)
// Pool is a simple allocator.
type Pool struct {
mu sync.Mutex
// cache is the set of returned values.
cache []uint64
// Start is the starting value (if needed).
Start uint64
// max is the current maximum issued.
max uint64
// Limit is the upper limit.
Limit uint64
}
// Get gets a value from the pool.
func (p *Pool) Get() (uint64, bool) {
p.mu.Lock()
defer p.mu.Unlock()
// Anything cached?
if len(p.cache) > 0 {
v := p.cache[len(p.cache)-1]
p.cache = p.cache[:len(p.cache)-1]
return v, true
}
// Over the limit?
if p.Start == p.Limit {
return 0, false
}
// Generate a new value.
v := p.Start
p.Start++
return v, true
}
// Put returns a value to the pool.
func (p *Pool) Put(v uint64) {
p.mu.Lock()
p.cache = append(p.cache, v)
p.mu.Unlock()
}
|
