github.com/guyezi/gofrontend@v0.0.0-20200228202240-7a62a49e62c0/libgo/go/internal/syscall/unix/nonblocking.go (about)

     1  // Copyright 2018 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  // +build dragonfly freebsd hurd linux netbsd openbsd
     6  
     7  package unix
     8  
     9  import "syscall"
    10  
    11  //extern __go_fcntl_uintptr
    12  func fcntl(uintptr, uintptr, uintptr) (uintptr, uintptr)
    13  
    14  func IsNonblock(fd int) (nonblocking bool, err error) {
    15  	flag, e1 := fcntl(uintptr(fd), syscall.F_GETFL, 0)
    16  	if e1 != 0 {
    17  		return false, syscall.Errno(e1)
    18  	}
    19  	return flag&syscall.O_NONBLOCK != 0, nil
    20  }