libgo/go/time/sys_unix.go

   1 // Copyright 2011 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
   6
   7 package time
   8
   9 import (
  10         "errors"
  11         "syscall"
  12 )
  13
  14 // for testing: whatever interrupts a sleep
  15 func interrupt() {
  16         syscall.Kill(syscall.Getpid(), syscall.SIGCHLD)
  17 }
  18
  19 // readFile reads and returns the content of the named file.
  20 // It is a trivial implementation of ioutil.ReadFile, reimplemented
  21 // here to avoid depending on io/ioutil or os.
  22 func readFile(name string) ([]byte, error) {
  23         f, err := syscall.Open(name, syscall.O_RDONLY, 0)
  24         if err != nil {
  25                 return nil, err
  26         }
  27         defer syscall.Close(f)
  28         var (
  29                 buf [4096]byte
  30                 ret []byte
  31                 n   int
  32         )
  33         for {
  34                 n, err = syscall.Read(f, buf[:])
  35                 if n > 0 {
  36                         ret = append(ret, buf[:n]...)
  37                 }
  38                 if n == 0 || err != nil {
  39                         break
  40                 }
  41         }
  42         return ret, err
  43 }
  44
  45 func open(name string) (uintptr, error) {
  46         fd, err := syscall.Open(name, syscall.O_RDONLY, 0)
  47         if err != nil {
  48                 return 0, err
  49         }
  50         return uintptr(fd), nil
  51 }
  52
  53 func closefd(fd uintptr) {
  54         syscall.Close(int(fd))
  55 }
  56
  57 func preadn(fd uintptr, buf []byte, off int) error {
  58         whence := 0
  59         if off < 0 {
  60                 whence = 2
  61         }
  62         if _, err := syscall.Seek(int(fd), int64(off), whence); err != nil {
  63                 return err
  64         }
  65         for len(buf) > 0 {
  66                 m, err := syscall.Read(int(fd), buf)
  67                 if m <= 0 {
  68                         if err == nil {
  69                                 return errors.New("short read")
  70                         }
  71                         return err
  72                 }
  73                 buf = buf[m:]
  74         }
  75         return nil
  76 }