github.com/insolar/x-crypto@v0.0.0-20191031140942-75fab8a325f6/rand/internal/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 darwin dragonfly freebsd linux netbsd openbsd solaris
     6  
     7  package unix
     8  
     9  import (
    10  	"syscall"
    11  	_ "unsafe" // for go:linkname
    12  )
    13  
    14  //go:linkname syscall_fcntl syscall.fcntl
    15  func syscall_fcntl(fd int, cmd int, arg int) (val int, err error)
    16  
    17  func IsNonblock(fd int) (nonblocking bool, err error) {
    18  	flag, err := syscall_fcntl(fd, syscall.F_GETFL, 0)
    19  	if err != nil {
    20  		return false, err
    21  	}
    22  	return flag&syscall.O_NONBLOCK != 0, nil
    23  }