base/process/internal_linux.h

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