blob: 691cb8e36fe6f84672aa5d0073ad59fa14d7a270 [file] [log] [blame]
// Copyright 2013 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.
// This file implements sysSocket and accept for platforms that
// provide a fast path for setting SetNonblock and CloseOnExec.
// +build dragonfly freebsd linux netbsd openbsd
package poll
import "syscall"
// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(s int) (int, syscall.Sockaddr, string, error) {
ns, sa, err := Accept4Func(s, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
// On Linux the accept4 system call was introduced in 2.6.28
// kernel and on FreeBSD it was introduced in 10 kernel. If we
// get an ENOSYS error on both Linux and FreeBSD, or EINVAL
// error on Linux, fall back to using accept.
switch err {
case nil:
return ns, sa, "", nil
default: // errors other than the ones listed
return -1, sa, "accept4", err
case syscall.ENOSYS: // syscall missing
case syscall.EINVAL: // some Linux use this instead of ENOSYS
case syscall.EACCES: // some Linux use this instead of ENOSYS
case syscall.EFAULT: // some Linux use this instead of ENOSYS
// See ../syscall/exec_unix.go for description of ForkLock.
// It is probably okay to hold the lock across syscall.Accept
// because we have put fd.sysfd into non-blocking mode.
// However, a call to the File method will put it back into
// blocking mode. We can't take that risk, so no use of ForkLock here.
ns, sa, err = AcceptFunc(s)
if err == nil {
if err != nil {
return -1, nil, "accept", err
if err = syscall.SetNonblock(ns, true); err != nil {
return -1, nil, "setnonblock", err
return ns, sa, "", nil