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TMessagesProj/jni/voip/webrtc/base/process/internal_linux.h

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+// Copyright (c) 2013 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.
+
+// This file contains internal routines that are called by other files in
+// base/process/.
+
+#ifndef BASE_PROCESS_INTERNAL_LINUX_H_
+#define BASE_PROCESS_INTERNAL_LINUX_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#include "base/files/file_path.h"
+
+namespace base {
+
+class Time;
+class TimeDelta;
+
+namespace internal {
+
+// "/proc"
+extern const char kProcDir[];
+
+// "stat"
+extern const char kStatFile[];
+
+// Returns a FilePath to "/proc/pid".
+base::FilePath GetProcPidDir(pid_t pid);
+
+// Take a /proc directory entry named |d_name|, and if it is the directory for
+// a process, convert it to a pid_t.
+// Returns 0 on failure.
+// e.g. /proc/self/ will return 0, whereas /proc/1234 will return 1234.
+pid_t ProcDirSlotToPid(const char* d_name);
+
+// Reads /proc/<pid>/stat into |buffer|. Returns true if the file can be read
+// and is non-empty.
+bool ReadProcStats(pid_t pid, std::string* buffer);
+
+// Takes |stats_data| and populates |proc_stats| with the values split by
+// spaces. Taking into account the 2nd field may, in itself, contain spaces.
+// Returns true if successful.
+bool ParseProcStats(const std::string& stats_data,
+                    std::vector<std::string>* proc_stats);
+
+// Fields from /proc/<pid>/stat, 0-based. See man 5 proc.
+// If the ordering ever changes, carefully review functions that use these
+// values.
+enum ProcStatsFields {
+  VM_COMM = 1,         // Filename of executable, without parentheses.
+  VM_STATE = 2,        // Letter indicating the state of the process.
+  VM_PPID = 3,         // PID of the parent.
+  VM_PGRP = 4,         // Process group id.
+  VM_MINFLT = 9,       // Minor page fault count excluding children.
+  VM_MAJFLT = 11,      // Major page fault count excluding children.
+  VM_UTIME = 13,       // Time scheduled in user mode in clock ticks.
+  VM_STIME = 14,       // Time scheduled in kernel mode in clock ticks.
+  VM_NUMTHREADS = 19,  // Number of threads.
+  VM_STARTTIME = 21,   // The time the process started in clock ticks.
+  VM_VSIZE = 22,       // Virtual memory size in bytes.
+  VM_RSS = 23,         // Resident Set Size in pages.
+};
+
+// Reads the |field_num|th field from |proc_stats|. Returns 0 on failure.
+// This version does not handle the first 3 values, since the first value is
+// simply |pid|, and the next two values are strings.
+int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
+                                 ProcStatsFields field_num);
+
+// Same as GetProcStatsFieldAsInt64(), but for size_t values.
+size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
+                                ProcStatsFields field_num);
+
+// Convenience wrappers around GetProcStatsFieldAsInt64(), ParseProcStats() and
+// ReadProcStats(). See GetProcStatsFieldAsInt64() for details.
+int64_t ReadStatsFilendGetFieldAsInt64(const FilePath& stat_file,
+                                       ProcStatsFields field_num);
+int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);
+int64_t ReadProcSelfStatsAndGetFieldAsInt64(ProcStatsFields field_num);
+
+// Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
+size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid,
+                                       ProcStatsFields field_num);
+
+// Returns the time that the OS started. Clock ticks are relative to this.
+Time GetBootTime();
+
+// Returns the amount of time spent in user space since boot across all CPUs.
+TimeDelta GetUserCpuTimeSinceBoot();
+
+// Converts Linux clock ticks to a wall time delta.
+TimeDelta ClockTicksToTimeDelta(int clock_ticks);
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // BASE_PROCESS_INTERNAL_LINUX_H_