// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/process/internal_linux.h" #include <limits.h> #include <unistd.h> #include <map> #include <string> #include <vector> #include "base/files/file_util.h" #include "base/logging.h" #include "base/strings/string_number_conversions.h" #include "base/strings/string_split.h" #include "base/strings/string_util.h" #include "base/threading/thread_restrictions.h" #include "base/time/time.h" namespace base { namespace internal { const char kProcDir[] = "/proc"; const char kStatFile[] = "stat"; FilePath GetProcPidDir(pid_t pid) { return FilePath(kProcDir).Append(IntToString(pid)); } pid_t ProcDirSlotToPid(const char* d_name) { int i; for (i = 0; i < NAME_MAX && d_name[i]; ++i) { if (!IsAsciiDigit(d_name[i])) { return 0; } } if (i == NAME_MAX) return 0; // Read the process's command line. pid_t pid; std::string pid_string(d_name); if (!StringToInt(pid_string, &pid)) { NOTREACHED(); return 0; } return pid; } bool ReadProcFile(const FilePath& file, std::string* buffer) { buffer->clear(); // Synchronously reading files in /proc is safe. ThreadRestrictions::ScopedAllowIO allow_io; if (!ReadFileToString(file, buffer)) { DLOG(WARNING) << "Failed to read " << file.MaybeAsASCII(); return false; } return !buffer->empty(); } bool ReadProcStats(pid_t pid, std::string* buffer) { FilePath stat_file = internal::GetProcPidDir(pid).Append(kStatFile); return ReadProcFile(stat_file, buffer); } bool ParseProcStats(const std::string& stats_data, std::vector<std::string>* proc_stats) { // |stats_data| may be empty if the process disappeared somehow. // e.g. http://crbug.com/145811 if (stats_data.empty()) return false; // The stat file is formatted as: // pid (process name) data1 data2 .... dataN // Look for the closing paren by scanning backwards, to avoid being fooled by // processes with ')' in the name. size_t open_parens_idx = stats_data.find(" ("); size_t close_parens_idx = stats_data.rfind(") "); if (open_parens_idx == std::string::npos || close_parens_idx == std::string::npos || open_parens_idx > close_parens_idx) { DLOG(WARNING) << "Failed to find matched parens in '" << stats_data << "'"; NOTREACHED(); return false; } open_parens_idx++; proc_stats->clear(); // PID. proc_stats->push_back(stats_data.substr(0, open_parens_idx)); // Process name without parentheses. proc_stats->push_back( stats_data.substr(open_parens_idx + 1, close_parens_idx - (open_parens_idx + 1))); // Split the rest. std::vector<std::string> other_stats = SplitString( stats_data.substr(close_parens_idx + 2), " ", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL); for (size_t i = 0; i < other_stats.size(); ++i) proc_stats->push_back(other_stats[i]); return true; } typedef std::map<std::string, std::string> ProcStatMap; void ParseProcStat(const std::string& contents, ProcStatMap* output) { StringPairs key_value_pairs; SplitStringIntoKeyValuePairs(contents, ' ', '\n', &key_value_pairs); for (size_t i = 0; i < key_value_pairs.size(); ++i) { output->insert(key_value_pairs[i]); } } int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats, ProcStatsFields field_num) { DCHECK_GE(field_num, VM_PPID); CHECK_LT(static_cast<size_t>(field_num), proc_stats.size()); int64_t value; return StringToInt64(proc_stats[field_num], &value) ? value : 0; } size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats, ProcStatsFields field_num) { DCHECK_GE(field_num, VM_PPID); CHECK_LT(static_cast<size_t>(field_num), proc_stats.size()); size_t value; return StringToSizeT(proc_stats[field_num], &value) ? value : 0; } int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num) { std::string stats_data; if (!ReadProcStats(pid, &stats_data)) return 0; std::vector<std::string> proc_stats; if (!ParseProcStats(stats_data, &proc_stats)) return 0; return GetProcStatsFieldAsInt64(proc_stats, field_num); } size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid, ProcStatsFields field_num) { std::string stats_data; if (!ReadProcStats(pid, &stats_data)) return 0; std::vector<std::string> proc_stats; if (!ParseProcStats(stats_data, &proc_stats)) return 0; return GetProcStatsFieldAsSizeT(proc_stats, field_num); } Time GetBootTime() { FilePath path("/proc/stat"); std::string contents; if (!ReadProcFile(path, &contents)) return Time(); ProcStatMap proc_stat; ParseProcStat(contents, &proc_stat); ProcStatMap::const_iterator btime_it = proc_stat.find("btime"); if (btime_it == proc_stat.end()) return Time(); int btime; if (!StringToInt(btime_it->second, &btime)) return Time(); return Time::FromTimeT(btime); } TimeDelta ClockTicksToTimeDelta(int clock_ticks) { // This queries the /proc-specific scaling factor which is // conceptually the system hertz. To dump this value on another // system, try // od -t dL /proc/self/auxv // and look for the number after 17 in the output; mine is // 0000040 17 100 3 134512692 // which means the answer is 100. // It may be the case that this value is always 100. static const int kHertz = sysconf(_SC_CLK_TCK); return TimeDelta::FromMicroseconds( Time::kMicrosecondsPerSecond * clock_ticks / kHertz); } } // namespace internal } // namespace base