libgo/go/net/sys_cloexec.go

   1 // Copyright 2013 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 // This file implements sysSocket and accept for platforms that do not
   6 // provide a fast path for setting SetNonblock and CloseOnExec.
   7
   8 // +build darwin dragonfly nacl netbsd openbsd solaris
   9
  10 package net
  11
  12 import (
  13         "os"
  14         "syscall"
  15 )
  16
  17 // Wrapper around the socket system call that marks the returned file
  18 // descriptor as nonblocking and close-on-exec.
  19 func sysSocket(family, sotype, proto int) (int, error) {
  20         // See ../syscall/exec_unix.go for description of ForkLock.
  21         syscall.ForkLock.RLock()
  22         s, err := socketFunc(family, sotype, proto)
  23         if err == nil {
  24                 syscall.CloseOnExec(s)
  25         }
  26         syscall.ForkLock.RUnlock()
  27         if err != nil {
  28                 return -1, os.NewSyscallError("socket", err)
  29         }
  30         if err = syscall.SetNonblock(s, true); err != nil {
  31                 closeFunc(s)
  32                 return -1, os.NewSyscallError("setnonblock", err)
  33         }
  34         return s, nil
  35 }
  36
  37 // Wrapper around the accept system call that marks the returned file
  38 // descriptor as nonblocking and close-on-exec.
  39 func accept(s int) (int, syscall.Sockaddr, error) {
  40         // See ../syscall/exec_unix.go for description of ForkLock.
  41         // It is probably okay to hold the lock across syscall.Accept
  42         // because we have put fd.sysfd into non-blocking mode.
  43         // However, a call to the File method will put it back into
  44         // blocking mode. We can't take that risk, so no use of ForkLock here.
  45         ns, sa, err := acceptFunc(s)
  46         if err == nil {
  47                 syscall.CloseOnExec(ns)
  48         }
  49         if err != nil {
  50                 return -1, nil, os.NewSyscallError("accept", err)
  51         }
  52         if err = syscall.SetNonblock(ns, true); err != nil {
  53                 closeFunc(ns)
  54                 return -1, nil, os.NewSyscallError("setnonblock", err)
  55         }
  56         return ns, sa, nil
  57 }