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
|
/*
Copyright 2013 Google Inc.
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 groupcache
import (
"errors"
"flag"
"log"
"net"
"net/http"
"os"
"os/exec"
"strconv"
"strings"
"sync"
"testing"
"time"
)
var (
peerAddrs = flag.String("test_peer_addrs", "", "Comma-separated list of peer addresses; used by TestHTTPPool")
peerIndex = flag.Int("test_peer_index", -1, "Index of which peer this child is; used by TestHTTPPool")
peerChild = flag.Bool("test_peer_child", false, "True if running as a child process; used by TestHTTPPool")
)
func TestHTTPPool(t *testing.T) {
if *peerChild {
beChildForTestHTTPPool()
os.Exit(0)
}
const (
nChild = 4
nGets = 100
)
var childAddr []string
for i := 0; i < nChild; i++ {
childAddr = append(childAddr, pickFreeAddr(t))
}
var cmds []*exec.Cmd
var wg sync.WaitGroup
for i := 0; i < nChild; i++ {
cmd := exec.Command(os.Args[0],
"--test.run=TestHTTPPool",
"--test_peer_child",
"--test_peer_addrs="+strings.Join(childAddr, ","),
"--test_peer_index="+strconv.Itoa(i),
)
cmds = append(cmds, cmd)
wg.Add(1)
if err := cmd.Start(); err != nil {
t.Fatal("failed to start child process: ", err)
}
go awaitAddrReady(t, childAddr[i], &wg)
}
defer func() {
for i := 0; i < nChild; i++ {
if cmds[i].Process != nil {
cmds[i].Process.Kill()
}
}
}()
wg.Wait()
// Use a dummy self address so that we don't handle gets in-process.
p := NewHTTPPool("should-be-ignored")
p.Set(addrToURL(childAddr)...)
// Dummy getter function. Gets should go to children only.
// The only time this process will handle a get is when the
// children can't be contacted for some reason.
getter := GetterFunc(func(ctx Context, key string, dest Sink) error {
return errors.New("parent getter called; something's wrong")
})
g := NewGroup("httpPoolTest", 1<<20, getter)
for _, key := range testKeys(nGets) {
var value string
if err := g.Get(nil, key, StringSink(&value)); err != nil {
t.Fatal(err)
}
if suffix := ":" + key; !strings.HasSuffix(value, suffix) {
t.Errorf("Get(%q) = %q, want value ending in %q", key, value, suffix)
}
t.Logf("Get key=%q, value=%q (peer:key)", key, value)
}
}
func testKeys(n int) (keys []string) {
keys = make([]string, n)
for i := range keys {
keys[i] = strconv.Itoa(i)
}
return
}
func beChildForTestHTTPPool() {
addrs := strings.Split(*peerAddrs, ",")
p := NewHTTPPool("http://" + addrs[*peerIndex])
p.Set(addrToURL(addrs)...)
getter := GetterFunc(func(ctx Context, key string, dest Sink) error {
dest.SetString(strconv.Itoa(*peerIndex) + ":" + key)
return nil
})
NewGroup("httpPoolTest", 1<<20, getter)
log.Fatal(http.ListenAndServe(addrs[*peerIndex], p))
}
// This is racy. Another process could swoop in and steal the port between the
// call to this function and the next listen call. Should be okay though.
// The proper way would be to pass the l.File() as ExtraFiles to the child
// process, and then close your copy once the child starts.
func pickFreeAddr(t *testing.T) string {
l, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
t.Fatal(err)
}
defer l.Close()
return l.Addr().String()
}
func addrToURL(addr []string) []string {
url := make([]string, len(addr))
for i := range addr {
url[i] = "http://" + addr[i]
}
return url
}
func awaitAddrReady(t *testing.T, addr string, wg *sync.WaitGroup) {
defer wg.Done()
const max = 1 * time.Second
tries := 0
for {
tries++
c, err := net.Dial("tcp", addr)
if err == nil {
c.Close()
return
}
delay := time.Duration(tries) * 25 * time.Millisecond
if delay > max {
delay = max
}
time.Sleep(delay)
}
}
|
