1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// This file contains internal routines that are called by other files in
6// base/process/.
7
8#ifndef BASE_PROCESS_LINUX_INTERNAL_H_
9#define BASE_PROCESS_LINUX_INTERNAL_H_
10
11#include <unistd.h>
12
13#include "base/files/file_path.h"
14
15namespace base {
16
17class Time;
18class TimeDelta;
19
20namespace internal {
21
22// "/proc"
23extern const char kProcDir[];
24
25// "stat"
26extern const char kStatFile[];
27
28// Returns a FilePath to "/proc/pid".
29base::FilePath GetProcPidDir(pid_t pid);
30
31// Take a /proc directory entry named |d_name|, and if it is the directory for
32// a process, convert it to a pid_t.
33// Returns 0 on failure.
34// e.g. /proc/self/ will return 0, whereas /proc/1234 will return 1234.
35pid_t ProcDirSlotToPid(const char* d_name);
36
37// Reads /proc/<pid>/stat into |buffer|. Returns true if the file can be read
38// and is non-empty.
39bool ReadProcStats(pid_t pid, std::string* buffer);
40
41// Takes |stats_data| and populates |proc_stats| with the values split by
42// spaces. Taking into account the 2nd field may, in itself, contain spaces.
43// Returns true if successful.
44bool ParseProcStats(const std::string& stats_data,
45                    std::vector<std::string>* proc_stats);
46
47// Fields from /proc/<pid>/stat, 0-based. See man 5 proc.
48// If the ordering ever changes, carefully review functions that use these
49// values.
50enum ProcStatsFields {
51  VM_COMM           = 1,   // Filename of executable, without parentheses.
52  VM_STATE          = 2,   // Letter indicating the state of the process.
53  VM_PPID           = 3,   // PID of the parent.
54  VM_PGRP           = 4,   // Process group id.
55  VM_UTIME          = 13,  // Time scheduled in user mode in clock ticks.
56  VM_STIME          = 14,  // Time scheduled in kernel mode in clock ticks.
57  VM_NUMTHREADS     = 19,  // Number of threads.
58  VM_STARTTIME      = 21,  // The time the process started in clock ticks.
59  VM_VSIZE          = 22,  // Virtual memory size in bytes.
60  VM_RSS            = 23,  // Resident Set Size in pages.
61};
62
63// Reads the |field_num|th field from |proc_stats|. Returns 0 on failure.
64// This version does not handle the first 3 values, since the first value is
65// simply |pid|, and the next two values are strings.
66int64 GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
67                               ProcStatsFields field_num);
68
69// Same as GetProcStatsFieldAsInt64(), but for size_t values.
70size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
71                                ProcStatsFields field_num);
72
73// Convenience wrapper around GetProcStatsFieldAsInt64(), ParseProcStats() and
74// ReadProcStats(). See GetProcStatsFieldAsInt64() for details.
75int64 ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);
76
77// Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
78size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
79                                       ProcStatsFields field_num);
80
81// Returns the time that the OS started. Clock ticks are relative to this.
82Time GetBootTime();
83
84// Converts Linux clock ticks to a wall time delta.
85TimeDelta ClockTicksToTimeDelta(int clock_ticks);
86
87}  // namespace internal
88}  // namespace base
89
90#endif  // BASE_PROCESS_LINUX_INTERNAL_H_
91