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_INTERNAL_LINUX_H_
9 #define BASE_PROCESS_INTERNAL_LINUX_H_
10
11 #include <stddef.h>
12 #include <stdint.h>
13 #include <unistd.h>
14
15 #include "base/files/dir_reader_posix.h"
16 #include "base/files/file_path.h"
17 #include "base/process/process_handle.h"
18 #include "base/strings/string_number_conversions.h"
19 #include "base/threading/platform_thread.h"
20
21 #include <unistd.h> /* pid_t */
22
23 namespace base {
24
25 class Time;
26 class TimeDelta;
27
28 namespace internal {
29
30 // "/proc"
31 extern const char kProcDir[];
32
33 // "stat"
34 extern const char kStatFile[];
35
36 // Returns a FilePath to "/proc/pid".
37 base::FilePath GetProcPidDir(pid_t pid);
38
39 // Reads a file from /proc into a string. This is allowed on any thread as
40 // reading from /proc does not hit the disk. Returns true if the file can be
41 // read and is non-empty.
42 bool ReadProcFile(const FilePath& file, std::string* buffer);
43
44 // Take a /proc directory entry named |d_name|, and if it is the directory for
45 // a process, convert it to a pid_t.
46 // Returns 0 on failure.
47 // e.g. /proc/self/ will return 0, whereas /proc/1234 will return 1234.
48 pid_t ProcDirSlotToPid(const char* d_name);
49
50 // Reads /proc/<pid>/stat into |buffer|. Returns true if the file can be read
51 // and is non-empty.
52 bool ReadProcStats(pid_t pid, std::string* buffer);
53
54 // Takes |stats_data| and populates |proc_stats| with the values split by
55 // spaces. Taking into account the 2nd field may, in itself, contain spaces.
56 // Returns true if successful.
57 bool ParseProcStats(const std::string& stats_data,
58 std::vector<std::string>* proc_stats);
59
60 // Fields from /proc/<pid>/stat, 0-based. See man 5 proc.
61 // If the ordering ever changes, carefully review functions that use these
62 // values.
63 enum ProcStatsFields {
64 #if defined(OS_BSD)
65 VM_COMM = 0, // Command name.
66 VM_PPID = 2, // Parent process id.
67 VM_PGRP = 3, // Process group id.
68 VM_STARTTIME = 7, // The process start time.
69 VM_UTIME = 8, // The user time.
70 VM_STIME = 9, // The system time
71 #else
72 VM_COMM = 1, // Filename of executable, without parentheses.
73 VM_STATE = 2, // Letter indicating the state of the process.
74 VM_PPID = 3, // PID of the parent.
75 VM_PGRP = 4, // Process group id.
76 VM_MINFLT = 9, // Minor page fault count excluding children.
77 VM_MAJFLT = 11, // Major page fault count excluding children.
78 VM_UTIME = 13, // Time scheduled in user mode in clock ticks.
79 VM_STIME = 14, // Time scheduled in kernel mode in clock ticks.
80 VM_NUMTHREADS = 19, // Number of threads.
81 VM_STARTTIME = 21, // The time the process started in clock ticks.
82 VM_VSIZE = 22, // Virtual memory size in bytes.
83 VM_RSS = 23, // Resident Set Size in pages.
84 #endif
85 };
86
87 // Reads the |field_num|th field from |proc_stats|. Returns 0 on failure.
88 // This version does not handle the first 3 values, since the first value is
89 // simply |pid|, and the next two values are strings.
90 int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
91 ProcStatsFields field_num);
92
93 // Same as GetProcStatsFieldAsInt64(), but for size_t values.
94 size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
95 ProcStatsFields field_num);
96
97 // Convenience wrappers around GetProcStatsFieldAsInt64(), ParseProcStats() and
98 // ReadProcStats(). See GetProcStatsFieldAsInt64() for details.
99 int64_t ReadStatsFilendGetFieldAsInt64(const FilePath& stat_file,
100 ProcStatsFields field_num);
101 int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);
102 int64_t ReadProcSelfStatsAndGetFieldAsInt64(ProcStatsFields field_num);
103
104 // Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
105 size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
106 ProcStatsFields field_num);
107
108 // Returns the time that the OS started. Clock ticks are relative to this.
109 Time GetBootTime();
110
111 // Returns the amount of time spent in user space since boot across all CPUs.
112 TimeDelta GetUserCpuTimeSinceBoot();
113
114 // Converts Linux clock ticks to a wall time delta.
115 TimeDelta ClockTicksToTimeDelta(int clock_ticks);
116
117 // Executes the lambda for every task in the process's /proc/<pid>/task
118 // directory. The thread id and file path of the task directory are provided as
119 // arguments to the lambda.
120 template <typename Lambda>
ForEachProcessTask(base::ProcessHandle process,Lambda && lambda)121 void ForEachProcessTask(base::ProcessHandle process, Lambda&& lambda) {
122 // Iterate through the different threads tracked in /proc/<pid>/task.
123 FilePath fd_path = GetProcPidDir(process).Append("task");
124
125 DirReaderPosix dir_reader(fd_path.value().c_str());
126 if (!dir_reader.IsValid())
127 return;
128
129 for (; dir_reader.Next();) {
130 const char* tid_str = dir_reader.name();
131 if (strcmp(tid_str, ".") == 0 || strcmp(tid_str, "..") == 0)
132 continue;
133
134 PlatformThreadId tid;
135 if (!StringToInt(tid_str, &tid))
136 continue;
137
138 FilePath task_path = fd_path.Append(tid_str);
139 lambda(tid, task_path);
140 }
141 }
142
143 } // namespace internal
144 } // namespace base
145
146 #endif // BASE_PROCESS_INTERNAL_LINUX_H_
147