1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 import java.io.BufferedReader;
  24 import java.io.File;
  25 import java.io.IOException;
  26 import java.nio.file.Files;
  27 import java.nio.file.Paths;
  28 import java.io.FileReader;
  29 import java.util.ArrayList;
  30 import java.util.Optional;
  31 import java.util.List;
  32 import java.util.stream.Collectors;
  33 import java.util.stream.Stream;
  34 import com.oracle.java.testlibrary.Asserts;
  35 
  36 
  37 // A simple CPU sets reader and parser
  38 public class CPUSetsReader {
  39     public static String PROC_SELF_STATUS_PATH="/proc/self/status";
  40 
  41     // Test the parser
  42     public static void test() {
  43         assertParse("0-7", "0,1,2,3,4,5,6,7");
  44         assertParse("1,3,6", "1,3,6");
  45         assertParse("0,2-4,6,10-11", "0,2,3,4,6,10,11");
  46         assertParse("0", "0");
  47     }
  48 
  49 
  50     private static void assertParse(String cpuSet, String expectedResult) {
  51         Asserts.assertEquals(listToString(parseCpuSet(cpuSet)), expectedResult);
  52     }
  53 
  54 
  55     public static String readFromProcStatus(String setType) {
  56         String path = PROC_SELF_STATUS_PATH;
  57         Optional<String> o = Optional.empty();
  58 
  59         System.out.println("readFromProcStatus() entering for: " + setType);
  60 
  61         try (Stream<String> stream = Files.lines(Paths.get(path))) {
  62             o = stream
  63                 .filter(line -> line.contains(setType))
  64                 .findFirst();
  65         } catch (IOException e) {
  66             return null;
  67         }
  68 
  69         if (!o.isPresent()) {
  70             return null;    // entry not found
  71         }
  72 
  73         String[] parts = o.get().replaceAll("\\s","").split(":");
  74 
  75         // Should be 2 parts, before and after ":"
  76         Asserts.assertEquals(parts.length, 2);
  77 
  78         String result = parts[1];
  79         System.out.println("readFromProcStatus() returning: " + result);
  80         return result;
  81     }
  82 
  83 
  84     public static List<Integer> parseCpuSet(String value) {
  85         ArrayList<Integer> result = new ArrayList<Integer>();
  86 
  87         try {
  88             String[] commaSeparated = value.split(",");
  89 
  90             for (String item : commaSeparated) {
  91                 if (item.contains("-")) {
  92                     addRange(result, item);
  93                 } else {
  94                     result.add(Integer.parseInt(item));
  95                 }
  96             }
  97         } catch (Exception e) {
  98             System.err.println("Exception in getMaxCpuSets(): " + e);
  99             return null;
 100         }
 101 
 102         return result;
 103     }
 104 
 105 
 106     private static void addRange(ArrayList<Integer> list, String s) {
 107         String[] range = s.split("-");
 108         if ( range.length != 2 ) {
 109             throw new RuntimeException("Range should only contain two items, but contains "
 110                                        + range.length + " items");
 111         }
 112 
 113         int min = Integer.parseInt(range[0]);
 114         int max = Integer.parseInt(range[1]);
 115 
 116         if (min >= max) {
 117             String msg = String.format("min is greater or equals to max, min = %d, max = %d",
 118                                        min, max);
 119             throw new RuntimeException(msg);
 120         }
 121 
 122         for (int i = min; i <= max; i++) {
 123             list.add(i);
 124         }
 125     }
 126 
 127 
 128     // Convert list of integers to string with comma-separated values
 129     public static String listToString(List<Integer> list) {
 130         return listToString(list, Integer.MAX_VALUE);
 131     }
 132 
 133     // Convert list of integers to a string with comma-separated values;
 134     // include up to maxCount.
 135     public static String listToString(List<Integer> list, int maxCount) {
 136         return list.stream()
 137             .limit(maxCount)
 138             .map(Object::toString)
 139             .collect(Collectors.joining(","));
 140     }
 141 }