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
|
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"bufio"
"cmd/internal/browser"
"flag"
"fmt"
"html/template"
"internal/trace"
"io"
"log"
"net"
"net/http"
"os"
"sync"
)
const usageMessage = "" +
`Usage of 'go tool trace':
Given a trace file produced by 'go test':
go test -trace=trace.out pkg
Open a web browser displaying trace:
go tool trace [flags] [pkg.test] trace.out
Generate a pprof-like profile from the trace:
go tool trace -pprof=TYPE [pkg.test] trace.out
[pkg.test] argument is required for traces produced by Go 1.6 and below.
Go 1.7 does not require the binary argument.
Supported profile types are:
- net: network blocking profile
- sync: synchronization blocking profile
- syscall: syscall blocking profile
- sched: scheduler latency profile
Flags:
-http=addr: HTTP service address (e.g., ':6060')
-pprof=type: print a pprof-like profile instead
Note that while the various profiles available when launching
'go tool trace' work on every browser, the trace viewer itself
(the 'view trace' page) comes from the Chrome/Chromium project
and is only actively tested on that browser.
`
var (
httpFlag = flag.String("http", "localhost:0", "HTTP service address (e.g., ':6060')")
pprofFlag = flag.String("pprof", "", "print a pprof-like profile instead")
// The binary file name, left here for serveSVGProfile.
programBinary string
traceFile string
)
func main() {
flag.Usage = func() {
fmt.Fprintln(os.Stderr, usageMessage)
os.Exit(2)
}
flag.Parse()
// Go 1.7 traces embed symbol info and does not require the binary.
// But we optionally accept binary as first arg for Go 1.5 traces.
switch flag.NArg() {
case 1:
traceFile = flag.Arg(0)
case 2:
programBinary = flag.Arg(0)
traceFile = flag.Arg(1)
default:
flag.Usage()
}
var pprofFunc func(io.Writer) error
switch *pprofFlag {
case "net":
pprofFunc = pprofIO
case "sync":
pprofFunc = pprofBlock
case "syscall":
pprofFunc = pprofSyscall
case "sched":
pprofFunc = pprofSched
}
if pprofFunc != nil {
if err := pprofFunc(os.Stdout); err != nil {
dief("failed to generate pprof: %v\n", err)
}
os.Exit(0)
}
if *pprofFlag != "" {
dief("unknown pprof type %s\n", *pprofFlag)
}
ln, err := net.Listen("tcp", *httpFlag)
if err != nil {
dief("failed to create server socket: %v\n", err)
}
log.Printf("Parsing trace...")
events, err := parseEvents()
if err != nil {
dief("%v\n", err)
}
log.Printf("Serializing trace...")
params := &traceParams{
events: events,
endTime: int64(1<<63 - 1),
}
data, err := generateTrace(params)
if err != nil {
dief("%v\n", err)
}
log.Printf("Splitting trace...")
ranges = splitTrace(data)
log.Printf("Opening browser")
if !browser.Open("http://" + ln.Addr().String()) {
fmt.Fprintf(os.Stderr, "Trace viewer is listening on http://%s\n", ln.Addr().String())
}
// Start http server.
http.HandleFunc("/", httpMain)
err = http.Serve(ln, nil)
dief("failed to start http server: %v\n", err)
}
var ranges []Range
var loader struct {
once sync.Once
events []*trace.Event
err error
}
func parseEvents() ([]*trace.Event, error) {
loader.once.Do(func() {
tracef, err := os.Open(traceFile)
if err != nil {
loader.err = fmt.Errorf("failed to open trace file: %v", err)
return
}
defer tracef.Close()
// Parse and symbolize.
events, err := trace.Parse(bufio.NewReader(tracef), programBinary)
if err != nil {
loader.err = fmt.Errorf("failed to parse trace: %v", err)
return
}
loader.events = events
})
return loader.events, loader.err
}
// httpMain serves the starting page.
func httpMain(w http.ResponseWriter, r *http.Request) {
if err := templMain.Execute(w, ranges); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
}
var templMain = template.Must(template.New("").Parse(`
<html>
<body>
{{if $}}
{{range $e := $}}
<a href="/trace?start={{$e.Start}}&end={{$e.End}}">View trace ({{$e.Name}})</a><br>
{{end}}
<br>
{{else}}
<a href="/trace">View trace</a><br>
{{end}}
<a href="/goroutines">Goroutine analysis</a><br>
<a href="/io">Network blocking profile</a><br>
<a href="/block">Synchronization blocking profile</a><br>
<a href="/syscall">Syscall blocking profile</a><br>
<a href="/sched">Scheduler latency profile</a><br>
</body>
</html>
`))
func dief(msg string, args ...interface{}) {
fmt.Fprintf(os.Stderr, msg, args...)
os.Exit(1)
}
|
