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
|
// +build linux
package tcplisten
import (
"fmt"
"io/ioutil"
"os"
"strconv"
"strings"
"syscall"
)
const (
soReusePort = 0x0F
tcpFastOpen = 0x17
)
func enableDeferAccept(fd int) error {
if err := syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_DEFER_ACCEPT, 1); err != nil {
return fmt.Errorf("cannot enable TCP_DEFER_ACCEPT: %s", err)
}
return nil
}
func enableFastOpen(fd int) error {
if err := syscall.SetsockoptInt(fd, syscall.SOL_TCP, tcpFastOpen, fastOpenQlen); err != nil {
return fmt.Errorf("cannot enable TCP_FASTOPEN(qlen=%d): %s", fastOpenQlen, err)
}
return nil
}
const fastOpenQlen = 16 * 1024
func soMaxConn() (int, error) {
data, err := ioutil.ReadFile(soMaxConnFilePath)
if err != nil {
// This error may trigger on travis build. Just use SOMAXCONN
if os.IsNotExist(err) {
return syscall.SOMAXCONN, nil
}
return -1, err
}
s := strings.TrimSpace(string(data))
n, err := strconv.Atoi(s)
if err != nil || n <= 0 {
return -1, fmt.Errorf("cannot parse somaxconn %q read from %s: %s", s, soMaxConnFilePath, err)
}
// Linux stores the backlog in a uint16.
// Truncate number to avoid wrapping.
// See https://github.com/golang/go/issues/5030 .
if n > 1<<16-1 {
n = 1<<16 - 1
}
return n, nil
}
const soMaxConnFilePath = "/proc/sys/net/core/somaxconn"
|
