// 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 illumos linux netbsd openbsd

package net

import (
	
	
	
)

// Wrapper around the socket system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func sysSocket(, ,  int) (int, error) {
	,  := socketFunc(, |syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, )
	// On Linux the SOCK_NONBLOCK and SOCK_CLOEXEC flags were
	// introduced in 2.6.27 kernel and on FreeBSD both flags were
	// introduced in 10 kernel. If we get an EINVAL error on Linux
	// or EPROTONOSUPPORT error on FreeBSD, fall back to using
	// socket without them.
	switch  {
	case nil:
		return , nil
	default:
		return -1, os.NewSyscallError("socket", )
	case syscall.EPROTONOSUPPORT, syscall.EINVAL:
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	syscall.ForkLock.RLock()
	,  = socketFunc(, , )
	if  == nil {
		syscall.CloseOnExec()
	}
	syscall.ForkLock.RUnlock()
	if  != nil {
		return -1, os.NewSyscallError("socket", )
	}
	if  = syscall.SetNonblock(, true);  != nil {
		poll.CloseFunc()
		return -1, os.NewSyscallError("setnonblock", )
	}
	return , nil
}