jdk

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/*
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 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 */
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import static java.lang.Character.isDigit;
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import static java.lang.Long.parseLong;
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import static java.lang.System.getProperty;
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import static java.nio.file.Files.readAllBytes;
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import static java.util.Arrays.stream;
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import static java.util.stream.Collectors.joining;
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import static java.util.stream.Collectors.toList;
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import static jdk.test.lib.process.ProcessTools.createLimitedTestJavaProcessBuilder;
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import static jdk.test.lib.Platform.isWindows;
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import jdk.test.lib.Utils;
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import jdk.test.lib.Platform;
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import jtreg.SkippedException;
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import java.io.BufferedReader;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.io.FileOutputStream;
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import java.io.IOException;
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import java.io.InputStreamReader;
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import java.util.Collection;
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import java.util.concurrent.TimeoutException;
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import java.util.concurrent.CompletionException;
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import java.util.concurrent.TimeUnit;
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import java.util.Optional;
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import java.util.stream.Stream;
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/*
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 * @test TestInheritFD
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 * @bug 8176717 8176809 8222500
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 * @summary a new process should not inherit open file descriptors
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 * @comment On Aix lsof requires root privileges.
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 * @requires os.family != "aix"
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 * @library /test/lib
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 * @modules java.base/jdk.internal.misc
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 *          java.management
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 * @run driver TestInheritFD
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 */
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/**
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 * Test that HotSpot does not leak logging file descriptors.
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 *
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 * This test is performed in three steps. The first VM starts a second VM with
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 * gc logging enabled. The second VM starts a third VM and redirects the third
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 * VMs output to the first VM. The second VM then exits and hopefully closes
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 * its log file.
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 *
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 * The third VM waits for the second to exit and close its log file.
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 * On Windows, the third VM tries to rename the log file of the second VM.
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 * If it succeeds in doing so it means that the third VM did not inherit
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 * the open log file (windows cannot rename opened files easily).
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 * On unix like systems, the third VM uses "lsof" for verification.
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 *
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 * The third VM communicates success by printing "RETAINS FD". The first VM
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 * waits for the third VM to exit and checks that the string was printed by
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 * the third VM.
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 */
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public class TestInheritFD {
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    public static final String LEAKS_FD = "VM RESULT => LEAKS FD";
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    public static final String RETAINS_FD = "VM RESULT => RETAINS FD";
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    public static final String EXIT = "VM RESULT => VM EXIT";
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    public static final String LOG_SUFFIX = ".strangelogsuffixthatcanbecheckedfor";
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    public static final String USER_DIR = System.getProperty("user.dir");
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    public static final String LSOF_PID_PREFIX = " VM lsof pid=";
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    public static final String SECOND_VM_PID_PREFIX = "Second VM pid=";
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    public static final String THIRD_VM_PID_PREFIX = "Third VM pid=";
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    public static final String THIRD_VM_WAITING_PREFIX = "Third VM waiting for second VM pid=";
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    public static float timeoutFactor = Float.parseFloat(System.getProperty("test.timeout.factor", "1.0"));
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    public static long subProcessTimeout = (long)(15L * timeoutFactor);
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    // Extract a pid from the specified String at the specified start offset.
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    private static long extractPidFromStringOffset(String str, int start) {
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        int end;
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        for (end = start; end < str.length(); end++) {
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            if (!isDigit(str.charAt(end))) {
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                break;
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            }
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        }
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        if (start == end) {  // no digits at all
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            return -1;
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        }
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        return parseLong(str.substring(start, end));
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    }
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    // Wait for the sub-process pids identified in commFile to finish executing.
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    // Returns true if RETAINS_FD was found in the commFile and false otherwise.
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    enum Result {
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        FOUND_LEAKS_FD,
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        FOUND_RETAINS_FD,
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        FOUND_NONE // Unexpected.
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    };
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    private static Result waitForSubPids(File commFile) throws Exception {
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        String out = "";
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        int sleepCnt = 0;
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        long secondVMPID = -1;
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        long secondVMlsofPID = -1;
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        long thirdVMPID = -1;
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        long thirdVMlsofPID = -1;
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        // Only have to gather info until the doneWithPattern shows up in the output:
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        String doneWithPattern;
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        if (isWindows()) {
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            doneWithPattern = THIRD_VM_PID_PREFIX;
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        } else {
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            doneWithPattern = "Third" + LSOF_PID_PREFIX;
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        }
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        do {
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            out = new String(readAllBytes(commFile.toPath()));
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            if (secondVMPID == -1) {
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                int ind = out.indexOf(SECOND_VM_PID_PREFIX);
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                if (ind != -1) {
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                    int startPid = ind + SECOND_VM_PID_PREFIX.length();
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                    secondVMPID = extractPidFromStringOffset(out, startPid);
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                    System.out.println("secondVMPID=" + secondVMPID);
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                }
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            }
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            if (!isWindows() && secondVMlsofPID == -1) {
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                String prefix = "Second" + LSOF_PID_PREFIX;
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                int ind = out.indexOf(prefix);
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                if (ind != -1) {
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                    int startPid = ind + prefix.length();
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                    secondVMlsofPID = extractPidFromStringOffset(out, startPid);
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                    System.out.println("secondVMlsofPID=" + secondVMlsofPID);
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                }
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            }
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            if (thirdVMPID == -1) {
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                int ind = out.indexOf(THIRD_VM_PID_PREFIX);
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                if (ind != -1) {
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                    int startPid = ind + THIRD_VM_PID_PREFIX.length();
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                    thirdVMPID = extractPidFromStringOffset(out, startPid);
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                    System.out.println("thirdVMPID=" + thirdVMPID);
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                }
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            }
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            if (!isWindows() && thirdVMlsofPID == -1) {
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                String prefix = "Third" + LSOF_PID_PREFIX;
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                int ind = out.indexOf(prefix);
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                if (ind != -1) {
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                    int startPid = ind + prefix.length();
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                    thirdVMlsofPID = extractPidFromStringOffset(out, startPid);
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                    System.out.println("thirdVMlsofPID=" + thirdVMlsofPID);
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                }
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            }
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            Thread.sleep(100);
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            sleepCnt++;
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        } while (!out.contains(doneWithPattern) && !out.contains(EXIT));
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        System.out.println("Called Thread.sleep(100) " + sleepCnt + " times.");
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        long subPids[] = new long[4];       // At most 4 pids to check.
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        String subNames[] = new String[4];  // At most 4 names for those pids.
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        int ind = 0;
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        if (!isWindows() && secondVMlsofPID != -1) {
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            // The second VM's lsof cmd should be the first non-windows sub-process to finish:
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            subPids[ind] = secondVMlsofPID;
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            subNames[ind] = "second VM lsof";
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            ind++;
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        }
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        // The second VM should the second non-windows or first windows sub-process to finish:
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        subPids[ind] = secondVMPID;
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        subNames[ind] = "second VM";
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        ind++;
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        if (!isWindows() && thirdVMlsofPID != -1) {
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            // The third VM's lsof cmd should be the third non-windows sub-process to finish:
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            subPids[ind] = thirdVMlsofPID;
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            subNames[ind] = "third VM lsof";
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            ind++;
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        }
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        // The third VM should the last sub-process to finish:
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        subPids[ind] = thirdVMPID;
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        subNames[ind] = "third VM";
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        ind++;
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        if (isWindows()) {
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            // No lsof pids on windows so we use fewer array slots.
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            // Make sure they are marked as not used.
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            for (; ind < subPids.length; ind++) {
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                subPids[ind] = -1;
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            }
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        }
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        try {
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            for (ind = 0; ind < subPids.length; ind++) {
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                if (subPids[ind] == -1) {
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                    continue;
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                }
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                System.out.print("subs[" + ind + "]={pid=" + subPids[ind] + ", name=" + subNames[ind] + "}");
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                ProcessHandle.of(subPids[ind]).ifPresent(handle -> handle.onExit().orTimeout(subProcessTimeout, TimeUnit.SECONDS).join());
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                System.out.println(" finished.");
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            }
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        } catch (Exception e) {
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            // Terminate the "subs" line from above:
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            System.out.println(" Exception was thrown while trying to join() subPids: " + e.toString());
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            throw e;
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        } finally {
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            // Reread to get everything in the commFile:
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            out = new String(readAllBytes(commFile.toPath()));
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            System.out.println("<BEGIN commFile contents>");
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            System.out.println(out);
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            System.out.println("<END commFile contents>");
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        }
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        if (out.contains(RETAINS_FD)) {
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            return Result.FOUND_RETAINS_FD;
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        } else if (out.contains(LEAKS_FD)) {
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            return Result.FOUND_LEAKS_FD;
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        } else {
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            return Result.FOUND_NONE;
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        }
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    }
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    // first VM
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    public static void main(String[] args) throws Exception {
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        System.out.println("subProcessTimeout=" + subProcessTimeout + " seconds.");
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        System.out.println("First VM starts.");
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        String logPath = Utils.createTempFile("logging", LOG_SUFFIX).toFile().getName();
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        File commFile = Utils.createTempFile("communication", ".txt").toFile();
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        if (!isWindows() && !lsofCommand().isPresent()) {
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            throw new SkippedException("Could not find lsof like command");
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        }
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        ProcessBuilder pb = createLimitedTestJavaProcessBuilder(
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            "-Xlog:gc:\"" + logPath + "\"",
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            "-Dtest.jdk=" + getProperty("test.jdk"),
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            VMStartedWithLogging.class.getName(),
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            logPath);
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        pb.redirectOutput(commFile); // use temp file to communicate between processes
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        pb.start();
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        Result result = waitForSubPids(commFile);
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        if (result == Result.FOUND_RETAINS_FD) {
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            System.out.println("Log file was not inherited by third VM.");
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        } else if (result == Result.FOUND_LEAKS_FD) {
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            throw new RuntimeException("Log file was leaked to the third VM.");
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        } else {
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            throw new RuntimeException("Found neither message, test failed to run correctly");
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        }
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        System.out.println("First VM ends.");
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    }
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    static class VMStartedWithLogging {
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        // second VM
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        public static void main(String[] args) throws IOException, InterruptedException {
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            System.out.println(SECOND_VM_PID_PREFIX + ProcessHandle.current().pid());
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            ProcessBuilder pb = createLimitedTestJavaProcessBuilder(
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                "-Dtest.jdk=" + getProperty("test.jdk"),
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                VMShouldNotInheritFileDescriptors.class.getName(),
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                args[0],
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                "" + ProcessHandle.current().pid());
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            pb.inheritIO(); // in future, redirect information from third VM to first VM
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            pb.start();
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            if (!isWindows()) {
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                System.out.println("(Second VM) Open file descriptors:\n" + outputContainingFilenames("Second").stream().collect(joining("\n")));
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            }
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            if (false) {  // Enable to simulate a timeout in the second VM.
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                Thread.sleep(300 * 1000);
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            }
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            System.out.println("Second VM ends.");
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        }
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    }
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    static class VMShouldNotInheritFileDescriptors {
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        // third VM
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        public static void main(String[] args) throws InterruptedException {
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            System.out.println(THIRD_VM_PID_PREFIX + ProcessHandle.current().pid());
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            try {
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                File logFile = new File(args[0]);
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                long parentPid = parseLong(args[1]);
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                fakeLeakyJVM(false); // for debugging of test case
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                System.out.println(THIRD_VM_WAITING_PREFIX + parentPid);
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                ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().orTimeout(subProcessTimeout, TimeUnit.SECONDS).join());
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                if (isWindows()) {
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                    windows(logFile);
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                } else {
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                    Collection<String> output = outputContainingFilenames("Third");
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                    System.out.println("(Third VM) Open file descriptors:\n" + output.stream().collect(joining("\n")));
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                    System.out.println(findOpenLogFile(output) ? LEAKS_FD : RETAINS_FD);
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                }
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                if (false) {  // Enable to simulate a timeout in the third VM.
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                    Thread.sleep(300 * 1000);
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                }
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            } catch (CompletionException e) {
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                if (e.getCause() instanceof TimeoutException) {
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                    System.out.println("(Third VM) Timed out waiting for second VM: " + e.toString());
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                } else {
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                    System.out.println("(Third VM) Exception was thrown: " + e.toString());
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                }
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                throw e;
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            } catch (Exception e) {
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                System.out.println("(Third VM) Exception was thrown: " + e.toString());
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                throw e;
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            } finally {
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                System.out.println(EXIT);
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                System.out.println("Third VM ends.");
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            }
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        }
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    }
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    // for debugging of test case
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    @SuppressWarnings("resource")
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    static void fakeLeakyJVM(boolean fake) {
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        if (fake) {
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            try {
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                new FileOutputStream("fakeLeakyJVM" + LOG_SUFFIX, false);
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            } catch (FileNotFoundException e) {
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            }
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        }
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    }
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    static Stream<String> runLsof(String whichVM, String... args){
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        try {
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            Process lsof = new ProcessBuilder(args).start();
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            System.out.println(whichVM + LSOF_PID_PREFIX + lsof.pid());
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            return new BufferedReader(new InputStreamReader(lsof.getInputStream())).lines();
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        } catch (IOException e) {
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            throw new RuntimeException(e);
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        }
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    }
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    static Optional<String[]> lsofCommandCache = stream(new String[][]{
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            {"/usr/bin/lsof", "-p"},
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            {"/usr/sbin/lsof", "-p"},
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            {"/bin/lsof", "-p"},
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            {"/sbin/lsof", "-p"},
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            {"/usr/local/bin/lsof", "-p"}})
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        .filter(args -> new File(args[0]).exists())
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        .findFirst();
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    static Optional<String[]> lsofCommand() {
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        return lsofCommandCache;
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    }
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    static Collection<String> outputContainingFilenames(String whichVM) {
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        long pid = ProcessHandle.current().pid();
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        String[] command = lsofCommand().orElseThrow(() -> new RuntimeException("lsof like command not found"));
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        // Only search the directory in which the VM is running (user.dir property).
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        System.out.println("using command: " + command[0] + " -a +d " + USER_DIR + " " + command[1] + " " + pid);
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        return runLsof(whichVM, command[0], "-a", "+d", USER_DIR, command[1], "" + pid).collect(toList());
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    }
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    static boolean findOpenLogFile(Collection<String> fileNames) {
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        String pid = Long.toString(ProcessHandle.current().pid());
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        String[] command = lsofCommand().orElseThrow(() ->
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                new RuntimeException("lsof like command not found"));
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        String lsof = command[0];
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        boolean isBusybox = Platform.isBusybox(lsof);
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        return fileNames.stream()
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            // lsof from busybox does not support "-p" option
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            .filter(fileName -> !isBusybox || fileName.contains(pid))
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            .filter(fileName -> fileName.contains(LOG_SUFFIX))
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            .findAny()
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            .isPresent();
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    }
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    static void windows(File f) throws InterruptedException {
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        System.out.println("trying to rename file to the same name: " + f);
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        System.out.println(f.renameTo(f) ? RETAINS_FD : LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
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    }
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}
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