src/java.base/linux/classes/jdk/internal/platform/cgroupv1/SubSystem.java
changeset 50545 292a4a87c321
child 50989 3bc865cc2122
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/linux/classes/jdk/internal/platform/cgroupv1/SubSystem.java	Tue Jun 12 18:51:45 2018 -0400
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.platform.cgroupv1;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.Optional;
+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 (root.indexOf(cgroupPath) == 0) {
+                        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.
+     *
+     * @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(BufferedReader bufferedReader = Files.newBufferedReader(Paths.get(subsystem.path(), parm))) {
+            String line = bufferedReader.readLine();
+            return line;
+        }
+        catch (IOException e) {
+            return null;
+        }
+
+    }
+
+    public static long getLongValue(SubSystem subsystem, String parm) {
+        String strval = getStringValue(subsystem, parm);
+
+        if (strval == null) return 0L;
+
+        long retval = Long.parseLong(strval);
+
+        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.
+     *
+     * @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 = Files.lines(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.
+     *
+     * @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;
+    }
+}