1 /* 2 * Copyright (c) 2020, Red Hat Inc. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.internal.platform; 27 28 import java.io.BufferedReader; 29 import java.io.IOException; 30 import java.io.UncheckedIOException; 31 import java.nio.file.Files; 32 import java.nio.file.Path; 33 import java.nio.file.Paths; 34 import java.security.AccessController; 35 import java.security.PrivilegedActionException; 36 import java.security.PrivilegedExceptionAction; 37 import java.util.List; 38 import java.util.stream.Stream; 39 40 public final class CgroupUtil { 41 readFilePrivileged(Path path)42 public static Stream<String> readFilePrivileged(Path path) throws IOException { 43 try { 44 PrivilegedExceptionAction<Stream<String>> pea = () -> Files.lines(path); 45 return AccessController.doPrivileged(pea); 46 } catch (PrivilegedActionException e) { 47 unwrapIOExceptionAndRethrow(e); 48 throw new InternalError(e.getCause()); 49 } catch (UncheckedIOException e) { 50 throw e.getCause(); 51 } 52 } 53 unwrapIOExceptionAndRethrow(PrivilegedActionException pae)54 static void unwrapIOExceptionAndRethrow(PrivilegedActionException pae) throws IOException { 55 Throwable x = pae.getCause(); 56 if (x instanceof IOException) 57 throw (IOException) x; 58 if (x instanceof RuntimeException) 59 throw (RuntimeException) x; 60 if (x instanceof Error) 61 throw (Error) x; 62 } 63 readStringValue(CgroupSubsystemController controller, String param)64 static String readStringValue(CgroupSubsystemController controller, String param) throws IOException { 65 PrivilegedExceptionAction<BufferedReader> pea = () -> 66 Files.newBufferedReader(Paths.get(controller.path(), param)); 67 try (BufferedReader bufferedReader = 68 AccessController.doPrivileged(pea)) { 69 String line = bufferedReader.readLine(); 70 return line; 71 } catch (PrivilegedActionException e) { 72 unwrapIOExceptionAndRethrow(e); 73 throw new InternalError(e.getCause()); 74 } catch (UncheckedIOException e) { 75 throw e.getCause(); 76 } 77 } 78 readAllLinesPrivileged(Path path)79 public static List<String> readAllLinesPrivileged(Path path) throws IOException { 80 try { 81 PrivilegedExceptionAction<List<String>> pea = () -> Files.readAllLines(path); 82 return AccessController.doPrivileged(pea); 83 } catch (PrivilegedActionException e) { 84 unwrapIOExceptionAndRethrow(e); 85 throw new InternalError(e.getCause()); 86 } catch (UncheckedIOException e) { 87 throw e.getCause(); 88 } 89 } 90 } 91