|  | // Copyright 2011 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. | 
|  |  | 
|  | package time | 
|  |  | 
|  | import ( | 
|  | "errors" | 
|  | "syscall" | 
|  | ) | 
|  |  | 
|  | // for testing: whatever interrupts a sleep | 
|  | func interrupt() { | 
|  | } | 
|  |  | 
|  | func open(name string) (uintptr, error) { | 
|  | fd, err := syscall.Open(name, syscall.O_RDONLY, 0) | 
|  | if err != nil { | 
|  | return 0, err | 
|  | } | 
|  | return uintptr(fd), nil | 
|  | } | 
|  |  | 
|  | func read(fd uintptr, buf []byte) (int, error) { | 
|  | return syscall.Read(syscall.Handle(fd), buf) | 
|  | } | 
|  |  | 
|  | func closefd(fd uintptr) { | 
|  | syscall.Close(syscall.Handle(fd)) | 
|  | } | 
|  |  | 
|  | func preadn(fd uintptr, buf []byte, off int) error { | 
|  | whence := seekStart | 
|  | if off < 0 { | 
|  | whence = seekEnd | 
|  | } | 
|  | if _, err := syscall.Seek(syscall.Handle(fd), int64(off), whence); err != nil { | 
|  | return err | 
|  | } | 
|  | for len(buf) > 0 { | 
|  | m, err := syscall.Read(syscall.Handle(fd), buf) | 
|  | if m <= 0 { | 
|  | if err == nil { | 
|  | return errors.New("short read") | 
|  | } | 
|  | return err | 
|  | } | 
|  | buf = buf[m:] | 
|  | } | 
|  | return nil | 
|  | } |