internal_linux.cc 7.0 KB

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  1. // Copyright (c) 2012 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. #include "base/process/internal_linux.h"
  5. #include <limits.h>
  6. #include <unistd.h>
  7. #include <map>
  8. #include <string>
  9. #include <vector>
  10. #include "base/files/file_util.h"
  11. #include "base/logging.h"
  12. #include "base/notreached.h"
  13. #include "base/strings/string_number_conversions.h"
  14. #include "base/strings/string_split.h"
  15. #include "base/strings/string_util.h"
  16. #include "base/threading/thread_restrictions.h"
  17. #include "base/time/time.h"
  18. #include "build/build_config.h"
  19. // Not defined on AIX by default.
  20. #if BUILDFLAG(IS_AIX)
  21. #define NAME_MAX 255
  22. #endif
  23. namespace base {
  24. namespace internal {
  25. const char kProcDir[] = "/proc";
  26. const char kStatFile[] = "stat";
  27. FilePath GetProcPidDir(pid_t pid) {
  28. return FilePath(kProcDir).Append(NumberToString(pid));
  29. }
  30. pid_t ProcDirSlotToPid(const char* d_name) {
  31. int i;
  32. for (i = 0; i < NAME_MAX && d_name[i]; ++i) {
  33. if (!IsAsciiDigit(d_name[i])) {
  34. return 0;
  35. }
  36. }
  37. if (i == NAME_MAX)
  38. return 0;
  39. // Read the process's command line.
  40. pid_t pid;
  41. std::string pid_string(d_name);
  42. if (!StringToInt(pid_string, &pid)) {
  43. NOTREACHED();
  44. return 0;
  45. }
  46. return pid;
  47. }
  48. bool ReadProcFile(const FilePath& file, std::string* buffer) {
  49. DCHECK(FilePath(kProcDir).IsParent(file));
  50. buffer->clear();
  51. // Synchronously reading files in /proc is safe.
  52. ThreadRestrictions::ScopedAllowIO allow_io;
  53. if (!ReadFileToString(file, buffer)) {
  54. DLOG(WARNING) << "Failed to read " << file.MaybeAsASCII();
  55. return false;
  56. }
  57. return !buffer->empty();
  58. }
  59. bool ReadProcStats(pid_t pid, std::string* buffer) {
  60. FilePath stat_file = internal::GetProcPidDir(pid).Append(kStatFile);
  61. return ReadProcFile(stat_file, buffer);
  62. }
  63. bool ParseProcStats(const std::string& stats_data,
  64. std::vector<std::string>* proc_stats) {
  65. // |stats_data| may be empty if the process disappeared somehow.
  66. // e.g. http://crbug.com/145811
  67. if (stats_data.empty())
  68. return false;
  69. // The stat file is formatted as:
  70. // pid (process name) data1 data2 .... dataN
  71. // Look for the closing paren by scanning backwards, to avoid being fooled by
  72. // processes with ')' in the name.
  73. size_t open_parens_idx = stats_data.find(" (");
  74. size_t close_parens_idx = stats_data.rfind(") ");
  75. if (open_parens_idx == std::string::npos ||
  76. close_parens_idx == std::string::npos ||
  77. open_parens_idx > close_parens_idx) {
  78. DLOG(WARNING) << "Failed to find matched parens in '" << stats_data << "'";
  79. NOTREACHED();
  80. return false;
  81. }
  82. open_parens_idx++;
  83. proc_stats->clear();
  84. // PID.
  85. proc_stats->push_back(stats_data.substr(0, open_parens_idx));
  86. // Process name without parentheses.
  87. proc_stats->push_back(
  88. stats_data.substr(open_parens_idx + 1,
  89. close_parens_idx - (open_parens_idx + 1)));
  90. // Split the rest.
  91. std::vector<std::string> other_stats = SplitString(
  92. stats_data.substr(close_parens_idx + 2), " ",
  93. base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
  94. for (const auto& i : other_stats)
  95. proc_stats->push_back(i);
  96. return true;
  97. }
  98. typedef std::map<std::string, std::string> ProcStatMap;
  99. void ParseProcStat(const std::string& contents, ProcStatMap* output) {
  100. StringPairs key_value_pairs;
  101. SplitStringIntoKeyValuePairs(contents, ' ', '\n', &key_value_pairs);
  102. for (auto& i : key_value_pairs) {
  103. output->insert(std::move(i));
  104. }
  105. }
  106. int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
  107. ProcStatsFields field_num) {
  108. DCHECK_GE(field_num, VM_PPID);
  109. CHECK_LT(static_cast<size_t>(field_num), proc_stats.size());
  110. int64_t value;
  111. return StringToInt64(proc_stats[field_num], &value) ? value : 0;
  112. }
  113. size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
  114. ProcStatsFields field_num) {
  115. DCHECK_GE(field_num, VM_PPID);
  116. CHECK_LT(static_cast<size_t>(field_num), proc_stats.size());
  117. size_t value;
  118. return StringToSizeT(proc_stats[field_num], &value) ? value : 0;
  119. }
  120. int64_t ReadStatFileAndGetFieldAsInt64(const FilePath& stat_file,
  121. ProcStatsFields field_num) {
  122. std::string stats_data;
  123. if (!ReadProcFile(stat_file, &stats_data))
  124. return 0;
  125. std::vector<std::string> proc_stats;
  126. if (!ParseProcStats(stats_data, &proc_stats))
  127. return 0;
  128. return GetProcStatsFieldAsInt64(proc_stats, field_num);
  129. }
  130. int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num) {
  131. FilePath stat_file = internal::GetProcPidDir(pid).Append(kStatFile);
  132. return ReadStatFileAndGetFieldAsInt64(stat_file, field_num);
  133. }
  134. int64_t ReadProcSelfStatsAndGetFieldAsInt64(ProcStatsFields field_num) {
  135. FilePath stat_file = FilePath(kProcDir).Append("self").Append(kStatFile);
  136. return ReadStatFileAndGetFieldAsInt64(stat_file, field_num);
  137. }
  138. size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
  139. ProcStatsFields field_num) {
  140. std::string stats_data;
  141. if (!ReadProcStats(pid, &stats_data))
  142. return 0;
  143. std::vector<std::string> proc_stats;
  144. if (!ParseProcStats(stats_data, &proc_stats))
  145. return 0;
  146. return GetProcStatsFieldAsSizeT(proc_stats, field_num);
  147. }
  148. Time GetBootTime() {
  149. FilePath path("/proc/stat");
  150. std::string contents;
  151. if (!ReadProcFile(path, &contents))
  152. return Time();
  153. ProcStatMap proc_stat;
  154. ParseProcStat(contents, &proc_stat);
  155. ProcStatMap::const_iterator btime_it = proc_stat.find("btime");
  156. if (btime_it == proc_stat.end())
  157. return Time();
  158. int btime;
  159. if (!StringToInt(btime_it->second, &btime))
  160. return Time();
  161. return Time::FromTimeT(btime);
  162. }
  163. TimeDelta GetUserCpuTimeSinceBoot() {
  164. FilePath path("/proc/stat");
  165. std::string contents;
  166. if (!ReadProcFile(path, &contents))
  167. return TimeDelta();
  168. ProcStatMap proc_stat;
  169. ParseProcStat(contents, &proc_stat);
  170. ProcStatMap::const_iterator cpu_it = proc_stat.find("cpu");
  171. if (cpu_it == proc_stat.end())
  172. return TimeDelta();
  173. std::vector<std::string> cpu = SplitString(
  174. cpu_it->second, kWhitespaceASCII, TRIM_WHITESPACE, SPLIT_WANT_NONEMPTY);
  175. if (cpu.size() < 2 || cpu[0] != "cpu")
  176. return TimeDelta();
  177. uint64_t user;
  178. uint64_t nice;
  179. if (!StringToUint64(cpu[0], &user) || !StringToUint64(cpu[1], &nice))
  180. return TimeDelta();
  181. return ClockTicksToTimeDelta(checked_cast<int64_t>(user + nice));
  182. }
  183. TimeDelta ClockTicksToTimeDelta(int64_t clock_ticks) {
  184. // This queries the /proc-specific scaling factor which is
  185. // conceptually the system hertz. To dump this value on another
  186. // system, try
  187. // od -t dL /proc/self/auxv
  188. // and look for the number after 17 in the output; mine is
  189. // 0000040 17 100 3 134512692
  190. // which means the answer is 100.
  191. // It may be the case that this value is always 100.
  192. static const long kHertz = sysconf(_SC_CLK_TCK);
  193. return Microseconds(Time::kMicrosecondsPerSecond * clock_ticks / kHertz);
  194. }
  195. } // namespace internal
  196. } // namespace base