libgo/go/net/sock_linux.go

   1 // Copyright 2009 The Go Authors.  All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package net
   6
   7 import "syscall"
   8
   9 func maxListenerBacklog() int {
  10         fd, err := open("/proc/sys/net/core/somaxconn")
  11         if err != nil {
  12                 return syscall.SOMAXCONN
  13         }
  14         defer fd.close()
  15         l, ok := fd.readLine()
  16         if !ok {
  17                 return syscall.SOMAXCONN
  18         }
  19         f := getFields(l)
  20         n, _, ok := dtoi(f[0], 0)
  21         if n == 0 || !ok {
  22                 return syscall.SOMAXCONN
  23         }
  24         // Linux stores the backlog in a uint16.
  25         // Truncate number to avoid wrapping.
  26         // See issue 5030.
  27         if n > 1<<16-1 {
  28                 n = 1<<16 - 1
  29         }
  30         return n
  31 }