1// Copyright 2019 The Prometheus Authors
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14// +build !windows
15
16package sysfs
17
18import (
19	"path/filepath"
20	"strings"
21
22	"github.com/prometheus/procfs/internal/util"
23)
24
25// ClockSource contains metrics related to the clock source
26type ClockSource struct {
27	Name      string
28	Available []string
29	Current   string
30}
31
32// ClockSources returns clocksource information including current and available clocksources
33// read from '/sys/devices/system/clocksource'
34func (fs FS) ClockSources() ([]ClockSource, error) {
35
36	clocksourcePaths, err := filepath.Glob(fs.sys.Path("devices/system/clocksource/clocksource[0-9]*"))
37	if err != nil {
38		return nil, err
39	}
40
41	clocksources := make([]ClockSource, len(clocksourcePaths))
42	for i, clocksourcePath := range clocksourcePaths {
43		clocksourceName := strings.TrimPrefix(filepath.Base(clocksourcePath), "clocksource")
44
45		clocksource, err := parseClocksource(clocksourcePath)
46		if err != nil {
47			return nil, err
48		}
49		clocksource.Name = clocksourceName
50		clocksources[i] = *clocksource
51	}
52
53	return clocksources, nil
54}
55
56func parseClocksource(clocksourcePath string) (*ClockSource, error) {
57
58	stringFiles := []string{
59		"available_clocksource",
60		"current_clocksource",
61	}
62	stringOut := make([]string, len(stringFiles))
63	var err error
64
65	for i, f := range stringFiles {
66		stringOut[i], err = util.SysReadFile(filepath.Join(clocksourcePath, f))
67		if err != nil {
68			return &ClockSource{}, err
69		}
70	}
71
72	return &ClockSource{
73		Available: strings.Fields(stringOut[0]),
74		Current:   stringOut[1],
75	}, nil
76}
77