Home | History | Annotate | Download | only in process
      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/file_path.h"
     16 
     17 namespace base {
     18 
     19 class Time;
     20 class TimeDelta;
     21 
     22 namespace internal {
     23 
     24 // "/proc"
     25 extern const char kProcDir[];
     26 
     27 // "stat"
     28 extern const char kStatFile[];
     29 
     30 // Returns a FilePath to "/proc/pid".
     31 base::FilePath GetProcPidDir(pid_t pid);
     32 
     33 // Take a /proc directory entry named |d_name|, and if it is the directory for
     34 // a process, convert it to a pid_t.
     35 // Returns 0 on failure.
     36 // e.g. /proc/self/ will return 0, whereas /proc/1234 will return 1234.
     37 pid_t ProcDirSlotToPid(const char* d_name);
     38 
     39 // Reads /proc/<pid>/stat into |buffer|. Returns true if the file can be read
     40 // and is non-empty.
     41 bool ReadProcStats(pid_t pid, std::string* buffer);
     42 
     43 // Takes |stats_data| and populates |proc_stats| with the values split by
     44 // spaces. Taking into account the 2nd field may, in itself, contain spaces.
     45 // Returns true if successful.
     46 bool ParseProcStats(const std::string& stats_data,
     47                     std::vector<std::string>* proc_stats);
     48 
     49 // Fields from /proc/<pid>/stat, 0-based. See man 5 proc.
     50 // If the ordering ever changes, carefully review functions that use these
     51 // values.
     52 enum ProcStatsFields {
     53   VM_COMM           = 1,   // Filename of executable, without parentheses.
     54   VM_STATE          = 2,   // Letter indicating the state of the process.
     55   VM_PPID           = 3,   // PID of the parent.
     56   VM_PGRP           = 4,   // Process group id.
     57   VM_UTIME          = 13,  // Time scheduled in user mode in clock ticks.
     58   VM_STIME          = 14,  // Time scheduled in kernel mode in clock ticks.
     59   VM_NUMTHREADS     = 19,  // Number of threads.
     60   VM_STARTTIME      = 21,  // The time the process started in clock ticks.
     61   VM_VSIZE          = 22,  // Virtual memory size in bytes.
     62   VM_RSS            = 23,  // Resident Set Size in pages.
     63 };
     64 
     65 // Reads the |field_num|th field from |proc_stats|. Returns 0 on failure.
     66 // This version does not handle the first 3 values, since the first value is
     67 // simply |pid|, and the next two values are strings.
     68 int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
     69                                  ProcStatsFields field_num);
     70 
     71 // Same as GetProcStatsFieldAsInt64(), but for size_t values.
     72 size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
     73                                 ProcStatsFields field_num);
     74 
     75 // Convenience wrapper around GetProcStatsFieldAsInt64(), ParseProcStats() and
     76 // ReadProcStats(). See GetProcStatsFieldAsInt64() for details.
     77 int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);
     78 
     79 // Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
     80 size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
     81                                        ProcStatsFields field_num);
     82 
     83 // Returns the time that the OS started. Clock ticks are relative to this.
     84 Time GetBootTime();
     85 
     86 // Converts Linux clock ticks to a wall time delta.
     87 TimeDelta ClockTicksToTimeDelta(int clock_ticks);
     88 
     89 }  // namespace internal
     90 }  // namespace base
     91 
     92 #endif  // BASE_PROCESS_INTERNAL_LINUX_H_
     93