blob: 3b73fa0bdd9d8a9728794e39f3daaccad3e13476 (
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
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
|
// Copyright 2016 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
// Run a slow C function saving a CPU profile.
/*
#include <stdint.h>
int salt1;
int salt2;
void cpuHog() {
int foo = salt1;
int i;
for (i = 0; i < 100000; i++) {
if (foo > 0) {
foo *= foo;
} else {
foo *= foo + 1;
}
}
salt2 = foo;
}
void cpuHog2() {
}
static int cpuHogCount;
struct cgoTracebackArg {
uintptr_t context;
uintptr_t sigContext;
uintptr_t* buf;
uintptr_t max;
};
// pprofCgoTraceback is passed to runtime.SetCgoTraceback.
// For testing purposes it pretends that all CPU hits in C code are in cpuHog.
// Issue #29034: At least 2 frames are required to verify all frames are captured
// since runtime/pprof ignores the runtime.goexit base frame if it exists.
void pprofCgoTraceback(void* parg) {
struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
arg->buf[0] = (uintptr_t)(cpuHog) + 0x10;
arg->buf[1] = (uintptr_t)(cpuHog2) + 0x4;
arg->buf[2] = 0;
++cpuHogCount;
}
// getCpuHogCount fetches the number of times we've seen cpuHog in the
// traceback.
int getCpuHogCount() {
return cpuHogCount;
}
*/
import "C"
import (
"fmt"
"os"
"runtime"
"runtime/pprof"
"time"
"unsafe"
)
func init() {
register("CgoPprof", CgoPprof)
}
func CgoPprof() {
runtime.SetCgoTraceback(0, unsafe.Pointer(C.pprofCgoTraceback), nil, nil)
f, err := os.CreateTemp("", "prof")
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(2)
}
if err := pprof.StartCPUProfile(f); err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(2)
}
t0 := time.Now()
for C.getCpuHogCount() < 2 && time.Since(t0) < time.Second {
C.cpuHog()
}
pprof.StopCPUProfile()
name := f.Name()
if err := f.Close(); err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(2)
}
fmt.Println(name)
}
|
