blob: 14c256a5901d8a115e5f36d9efa05fbe92ae41ba [file] [log] [blame]
/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "environment.h"
#include <stdlib.h>
#include <vector>
#include <base/logging.h>
#include "utils.h"
std::vector<int> GetOnlineCpus() {
std::vector<int> result;
FILE* fp = fopen("/sys/devices/system/cpu/online", "re");
if (fp == nullptr) {
PLOG(ERROR) << "can't open online cpu information";
return result;
}
LineReader reader(fp);
char* line;
if ((line = reader.ReadLine()) != nullptr) {
result = GetOnlineCpusFromString(line);
}
CHECK(!result.empty()) << "can't get online cpu information";
return result;
}
std::vector<int> GetOnlineCpusFromString(const std::string& s) {
std::vector<int> result;
bool have_dash = false;
const char* p = s.c_str();
char* endp;
long cpu;
// Parse line like: 0,1-3, 5, 7-8
while ((cpu = strtol(p, &endp, 10)) != 0 || endp != p) {
if (have_dash && result.size() > 0) {
for (int t = result.back() + 1; t < cpu; ++t) {
result.push_back(t);
}
}
have_dash = false;
result.push_back(cpu);
p = endp;
while (!isdigit(*p) && *p != '\0') {
if (*p == '-') {
have_dash = true;
}
++p;
}
}
return result;
}