1 /*

     2  * Copyright (c) 2017, 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 jdk.test.lib.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 }