1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
// Copyright 2014 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 "extensions/browser/api/system_cpu/cpu_info_provider.h"
#include <stdint.h>
#include <cstdio>
#include <sstream>
#include "base/files/file_util.h"
#include "base/format_macros.h"
namespace extensions {
namespace {
const char kProcStat[] = "/proc/stat";
} // namespace
bool CpuInfoProvider::QueryCpuTimePerProcessor(
std::vector<api::system_cpu::ProcessorInfo>* infos) {
DCHECK(infos);
// WARNING: this method may return incomplete data because some processors may
// be brought offline at runtime. /proc/stat does not report statistics of
// offline processors. CPU usages of offline processors will be filled with
// zeros.
//
// An example of output of /proc/stat when processor 0 and 3 are online, but
// processor 1 and 2 are offline:
//
// cpu 145292 20018 83444 1485410 995 44 3578 0 0 0
// cpu0 138060 19947 78350 1479514 570 44 3576 0 0 0
// cpu3 2033 32 1075 1400 52 0 1 0 0 0
std::string contents;
if (!base::ReadFileToString(base::FilePath(kProcStat), &contents))
return false;
std::istringstream iss(contents);
std::string line;
// Skip the first line because it is just an aggregated number of
// all cpuN lines.
std::getline(iss, line);
while (std::getline(iss, line)) {
if (line.compare(0, 3, "cpu") != 0)
continue;
uint64_t user = 0, nice = 0, sys = 0, idle = 0;
uint32_t pindex = 0;
int vals =
sscanf(line.c_str(),
"cpu%" PRIu32 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64,
&pindex,
&user,
&nice,
&sys,
&idle);
if (vals != 5 || pindex >= infos->size()) {
NOTREACHED();
return false;
}
infos->at(pindex).usage.kernel = static_cast<double>(sys);
infos->at(pindex).usage.user = static_cast<double>(user + nice);
infos->at(pindex).usage.idle = static_cast<double>(idle);
infos->at(pindex).usage.total =
static_cast<double>(sys + user + nice + idle);
}
return true;
}
} // namespace extensions
|
