libgo/go/os/pipe_linux.go

   1 // Copyright 2013 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 package os
   6
   7 import "syscall"
   8
   9 // Pipe returns a connected pair of Files; reads from r return bytes written to w.
  10 // It returns the files and an error, if any.
  11 func Pipe() (r *File, w *File, err error) {
  12         var p [2]int
  13
  14         e := syscall.Pipe2(p[0:], syscall.O_CLOEXEC)
  15         // pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
  16         // might not be implemented.
  17         if e == syscall.ENOSYS {
  18                 // See ../syscall/exec.go for description of lock.
  19                 syscall.ForkLock.RLock()
  20                 e = syscall.Pipe(p[0:])
  21                 if e != nil {
  22                         syscall.ForkLock.RUnlock()
  23                         return nil, nil, NewSyscallError("pipe", e)
  24                 }
  25                 syscall.CloseOnExec(p[0])
  26                 syscall.CloseOnExec(p[1])
  27                 syscall.ForkLock.RUnlock()
  28         } else if e != nil {
  29                 return nil, nil, NewSyscallError("pipe2", e)
  30         }
  31
  32         return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil
  33 }