...
Run Format

Source file src/internal/poll/sock_cloexec.go

Documentation: internal/poll

  // 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
  
  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 {
  		syscall.CloseOnExec(ns)
  	}
  	if err != nil {
  		return -1, nil, "accept", err
  	}
  	if err = syscall.SetNonblock(ns, true); err != nil {
  		CloseFunc(ns)
  		return -1, nil, "setnonblock", err
  	}
  	return ns, sa, "", nil
  }
  

View as plain text