1// Copyright 2018 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
14package procfs
15
16import (
17	"bytes"
18	"io/ioutil"
19	"os"
20	"strconv"
21	"strings"
22)
23
24// ProcStat provides status information about the process,
25// read from /proc/[pid]/stat.
26type ProcStatus struct {
27	// The process ID.
28	PID int
29	// The process name.
30	Name string
31
32	// Peak virtual memory size.
33	VmPeak uint64
34	// Virtual memory size.
35	VmSize uint64
36	// Locked memory size.
37	VmLck uint64
38	// Pinned memory size.
39	VmPin uint64
40	// Peak resident set size.
41	VmHWM uint64
42	// Resident set size (sum of RssAnnon RssFile and RssShmem).
43	VmRSS uint64
44	// Size of resident anonymous memory.
45	RssAnon uint64
46	// Size of resident file mappings.
47	RssFile uint64
48	// Size of resident shared memory.
49	RssShmem uint64
50	// Size of data segments.
51	VmData uint64
52	// Size of stack segments.
53	VmStk uint64
54	// Size of text segments.
55	VmExe uint64
56	// Shared library code size.
57	VmLib uint64
58	// Page table entries size.
59	VmPTE uint64
60	// Size of second-level page tables.
61	VmPMD uint64
62	// Swapped-out virtual memory size by anonymous private.
63	VmSwap uint64
64	// Size of hugetlb memory portions
65	HugetlbPages uint64
66
67	// Number of voluntary context switches.
68	VoluntaryCtxtSwitches uint64
69	// Number of involuntary context switches.
70	NonVoluntaryCtxtSwitches uint64
71}
72
73// NewStatus returns the current status information of the process.
74func (p Proc) NewStatus() (ProcStatus, error) {
75	f, err := os.Open(p.path("status"))
76	if err != nil {
77		return ProcStatus{}, err
78	}
79	defer f.Close()
80
81	data, err := ioutil.ReadAll(f)
82	if err != nil {
83		return ProcStatus{}, err
84	}
85
86	s := ProcStatus{PID: p.PID}
87
88	lines := strings.Split(string(data), "\n")
89	for _, line := range lines {
90		if !bytes.Contains([]byte(line), []byte(":")) {
91			continue
92		}
93
94		kv := strings.SplitN(line, ":", 2)
95
96		// removes spaces
97		k := string(strings.TrimSpace(kv[0]))
98		v := string(strings.TrimSpace(kv[1]))
99		// removes "kB"
100		v = string(bytes.Trim([]byte(v), " kB"))
101
102		// value to int when possible
103		// we can skip error check here, 'cause vKBytes is not used when value is a string
104		vKBytes, _ := strconv.ParseUint(v, 10, 64)
105		// convert kB to B
106		vBytes := vKBytes * 1024
107
108		s.fillStatus(k, v, vKBytes, vBytes)
109	}
110
111	return s, nil
112}
113
114func (s *ProcStatus) fillStatus(k string, vString string, vUint uint64, vUintBytes uint64) {
115	switch k {
116	case "Name":
117		s.Name = vString
118	case "VmPeak":
119		s.VmPeak = vUintBytes
120	case "VmSize":
121		s.VmSize = vUintBytes
122	case "VmLck":
123		s.VmLck = vUintBytes
124	case "VmPin":
125		s.VmPin = vUintBytes
126	case "VmHWM":
127		s.VmHWM = vUintBytes
128	case "VmRSS":
129		s.VmRSS = vUintBytes
130	case "RssAnon":
131		s.RssAnon = vUintBytes
132	case "RssFile":
133		s.RssFile = vUintBytes
134	case "RssShmem":
135		s.RssShmem = vUintBytes
136	case "VmData":
137		s.VmData = vUintBytes
138	case "VmStk":
139		s.VmStk = vUintBytes
140	case "VmExe":
141		s.VmExe = vUintBytes
142	case "VmLib":
143		s.VmLib = vUintBytes
144	case "VmPTE":
145		s.VmPTE = vUintBytes
146	case "VmPMD":
147		s.VmPMD = vUintBytes
148	case "VmSwap":
149		s.VmSwap = vUintBytes
150	case "HugetlbPages":
151		s.HugetlbPages = vUintBytes
152	case "voluntary_ctxt_switches":
153		s.VoluntaryCtxtSwitches = vUint
154	case "nonvoluntary_ctxt_switches":
155		s.NonVoluntaryCtxtSwitches = vUint
156	}
157}
158
159// TotalCtxtSwitches returns the total context switch.
160func (s ProcStatus) TotalCtxtSwitches() uint64 {
161	return s.VoluntaryCtxtSwitches + s.NonVoluntaryCtxtSwitches
162}
163