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_INTERNAL_LINUX_H_
   9 #define BASE_PROCESS_INTERNAL_LINUX_H_
  10
  11 #include <unistd.h>
  12
  13 #include "base/files/file_path.h"
  14
  15 namespace base {
  16
  17 class Time;
  18 class TimeDelta;
  19
  20 namespace internal {
  21
  22 // "/proc"
  23 extern const char kProcDir[];
  24
  25 // "stat"
  26 extern const char kStatFile[];
  27
  28 // Returns a FilePath to "/proc/pid".
  29 base::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.
  35 pid_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.
  39 bool 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.
  44 bool 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.
  50 enum 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.
  66 int64 GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
  67                                ProcStatsFields field_num);
  68
  69 // Same as GetProcStatsFieldAsInt64(), but for size_t values.
  70 size_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.
  75 int64 ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);
  76
  77 // Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
  78 size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
  79                                        ProcStatsFields field_num);
  80
  81 // Returns the time that the OS started. Clock ticks are relative to this.
  82 Time GetBootTime();
  83
  84 // Converts Linux clock ticks to a wall time delta.
  85 TimeDelta ClockTicksToTimeDelta(int clock_ticks);
  86
  87 }  // namespace internal
  88 }  // namespace base
  89
  90 #endif  // BASE_PROCESS_INTERNAL_LINUX_H_