Source file src/pkg/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 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	}