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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/390223051): Remove C-library calls to fix the errors.
#pragma allow_unsafe_libc_calls
#endif
#include "extensions/browser/api/system_cpu/cpu_info_provider.h"
#include <inttypes.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%" SCNu32 " %" SCNu64 " %" SCNu64 " %" SCNu64 " %" SCNu64,
&pindex, &user, &nice, &sys, &idle);
if (vals != 5 || pindex >= infos->size()) {
// TODO(b/326303922): This fires in internal integration tests, reevaluate
// whether this should be (and can be made) unreachable or handle it.
DUMP_WILL_BE_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
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