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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package jdk.internal.platform.cgroupv1;

import java.io.BufferedReader;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Stream;

public class SubSystem {
    String root;
    String mountPoint;
    String path;

    public SubSystem(String root, String mountPoint) {
        this.root = root;
        this.mountPoint = mountPoint;
    }

    public void setPath(String cgroupPath) {
        if (root != null && cgroupPath != null) {
            if (root.equals("/")) {
                if (!cgroupPath.equals("/")) {
                    path = mountPoint + cgroupPath;
                }
                else {
                    path = mountPoint;
                }
            }
            else {
                if (root.equals(cgroupPath)) {
                    path = mountPoint;
                }
                else {
                    if (cgroupPath.startsWith(root)) {
                        if (cgroupPath.length() > root.length()) {
                            String cgroupSubstr = cgroupPath.substring(root.length());
                            path = mountPoint + cgroupSubstr;
                        }
                    }
                }
            }
        }
    }

    public String path() {
        return path;
    }

    
getSubSystemStringValue Return the first line of the file "parm" argument from the subsystem. TODO: Consider using weak references for caching BufferedReader object.
Params:
  • subsystem –
  • parm –
Returns:Returns the contents of the file specified by param.
/** * getSubSystemStringValue * * Return the first line of the file "parm" argument from the subsystem. * * TODO: Consider using weak references for caching BufferedReader object. * * @param subsystem * @param parm * @return Returns the contents of the file specified by param. */
public static String getStringValue(SubSystem subsystem, String parm) { if (subsystem == null) return null; try { return subsystem.readStringValue(parm); } catch (IOException e) { return null; } } private String readStringValue(String param) throws IOException { PrivilegedExceptionAction<BufferedReader> pea = () -> Files.newBufferedReader(Paths.get(path(), param)); try (BufferedReader bufferedReader = AccessController.doPrivileged(pea)) { String line = bufferedReader.readLine(); return line; } catch (PrivilegedActionException e) { Metrics.unwrapIOExceptionAndRethrow(e); throw new InternalError(e.getCause()); } } public static long getLongValueMatchingLine(SubSystem subsystem, String param, String match, Function<String, Long> conversion) { long retval = Metrics.unlimited_minimum + 1; // default unlimited try { List<String> lines = subsystem.readMatchingLines(param); for (String line : lines) { if (line.startsWith(match)) { retval = conversion.apply(line); break; } } } catch (IOException e) { // Ignore. Default is unlimited. } return retval; } private List<String> readMatchingLines(String param) throws IOException { try { PrivilegedExceptionAction<List<String>> pea = () -> Files.readAllLines(Paths.get(path(), param)); return AccessController.doPrivileged(pea); } catch (PrivilegedActionException e) { Metrics.unwrapIOExceptionAndRethrow(e); throw new InternalError(e.getCause()); } } public static long getLongValue(SubSystem subsystem, String parm) { String strval = getStringValue(subsystem, parm); return convertStringToLong(strval); } public static long convertStringToLong(String strval) { long retval = 0; if (strval == null) return 0L; try { retval = Long.parseLong(strval); } catch (NumberFormatException e) { // For some properties (e.g. memory.limit_in_bytes) we may overflow the range of signed long. // In this case, return Long.MAX_VALUE BigInteger b = new BigInteger(strval); if (b.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) > 0) { return Long.MAX_VALUE; } } return retval; } public static double getDoubleValue(SubSystem subsystem, String parm) { String strval = getStringValue(subsystem, parm); if (strval == null) return 0L; double retval = Double.parseDouble(strval); return retval; }
getSubSystemlongEntry Return the long value from the line containing the string "entryname" within file "parm" in the "subsystem". TODO: Consider using weak references for caching BufferedReader object.
Params:
  • subsystem –
  • parm –
  • entryname –
Returns:long value
/** * getSubSystemlongEntry * * Return the long value from the line containing the string "entryname" * within file "parm" in the "subsystem". * * TODO: Consider using weak references for caching BufferedReader object. * * @param subsystem * @param parm * @param entryname * @return long value */
public static long getLongEntry(SubSystem subsystem, String parm, String entryname) { String val = null; if (subsystem == null) return 0L; try (Stream<String> lines = Metrics.readFilePrivileged(Paths.get(subsystem.path(), parm))) { Optional<String> result = lines.map(line -> line.split(" ")) .filter(line -> (line.length == 2 && line[0].equals(entryname))) .map(line -> line[1]) .findFirst(); return result.isPresent() ? Long.parseLong(result.get()) : 0L; } catch (IOException e) { return 0L; } } public static int getIntValue(SubSystem subsystem, String parm) { String val = getStringValue(subsystem, parm); if (val == null) return 0; return Integer.parseInt(val); }
StringRangeToIntArray Convert a string in the form of 1,3-4,6 to an array of integers containing all the numbers in the range.
Params:
  • range –
Returns:int[] containing a sorted list of processors or memory nodes
/** * StringRangeToIntArray * * Convert a string in the form of 1,3-4,6 to an array of * integers containing all the numbers in the range. * * @param range * @return int[] containing a sorted list of processors or memory nodes */
public static int[] StringRangeToIntArray(String range) { int[] ints = new int[0]; if (range == null) return ints; ArrayList<Integer> results = new ArrayList<>(); String strs[] = range.split(","); for (String str : strs) { if (str.contains("-")) { String lohi[] = str.split("-"); // validate format if (lohi.length != 2) { continue; } int lo = Integer.parseInt(lohi[0]); int hi = Integer.parseInt(lohi[1]); for (int i = lo; i <= hi; i++) { results.add(i); } } else { results.add(Integer.parseInt(str)); } } // sort results results.sort(null); // convert ArrayList to primitive int array ints = new int[results.size()]; int i = 0; for (Integer n : results) { ints[i++] = n; } return ints; } public static class MemorySubSystem extends SubSystem { private boolean hierarchical; public MemorySubSystem(String root, String mountPoint) { super(root, mountPoint); } boolean isHierarchical() { return hierarchical; } void setHierarchical(boolean hierarchical) { this.hierarchical = hierarchical; } } }