--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/8176717/TestInheritFD.java Thu May 03 15:17:27 2018 +0200
@@ -0,0 +1,148 @@
+import static java.io.File.createTempFile;
+import static java.lang.Long.parseLong;
+import static java.lang.System.getProperty;
+import static java.lang.management.ManagementFactory.getOperatingSystemMXBean;
+import static java.nio.file.Files.readAllBytes;
+import static jdk.test.lib.process.ProcessTools.createJavaProcessBuilder;
+
+import java.io.File;
+import java.io.IOException;
+
+import com.sun.management.UnixOperatingSystemMXBean;
+
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test TestInheritFD
+ * @bug 8176717 8176809
+ * @summary a new process should not inherit open file descriptors
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ * java.management
+ */
+
+/**
+ * Test that HotSpot does not leak logging file descriptors.
+ *
+ * This test is performed in three steps. The first VM starts a second VM with
+ * gc logging enabled. The second VM starts a third VM and redirects the third
+ * VMs output to the first VM, it then exits and hopefully closes its log file.
+ *
+ * The third VM waits for the second to exit and close its log file. After that,
+ * the third VM tries to rename the log file of the second VM. If it succeeds in
+ * doing so it means that the third VM did not inherit the open log file
+ * (windows can not rename opened files easily)
+ *
+ * The third VM communicates the success to rename the file by printing "CLOSED
+ * FD". The first VM checks that the string was printed by the third VM.
+ *
+ * On unix like systems, UnixOperatingSystemMXBean is used to check open file
+ * descriptors.
+ */
+
+public class TestInheritFD {
+
+ public static final String LEAKS_FD = "VM RESULT => LEAKS FD";
+ public static final String RETAINS_FD = "VM RESULT => RETAINS FD";
+ public static final String EXIT = "VM RESULT => VM EXIT";
+
+ // first VM
+ public static void main(String[] args) throws Exception {
+ String logPath = createTempFile("logging", ".log").getName();
+ File commFile = createTempFile("communication", ".txt");
+
+ ProcessBuilder pb = createJavaProcessBuilder(
+ "-Xlog:gc:\"" + logPath + "\"",
+ "-Dtest.jdk=" + getProperty("test.jdk"),
+ VMStartedWithLogging.class.getName(),
+ logPath);
+
+ pb.redirectOutput(commFile); // use temp file to communicate between processes
+ pb.start();
+
+ String out = "";
+ do {
+ out = new String(readAllBytes(commFile.toPath()));
+ Thread.sleep(100);
+ System.out.println("SLEEP 100 millis");
+ } while (!out.contains(EXIT));
+
+ System.out.println(out);
+ if (out.contains(RETAINS_FD)) {
+ System.out.println("Log file was not inherited by third VM");
+ } else {
+ throw new RuntimeException("could not match: " + RETAINS_FD);
+ }
+ }
+
+ static class VMStartedWithLogging {
+ // second VM
+ public static void main(String[] args) throws IOException, InterruptedException {
+ ProcessBuilder pb = createJavaProcessBuilder(
+ "-Dtest.jdk=" + getProperty("test.jdk"),
+ VMShouldNotInheritFileDescriptors.class.getName(),
+ args[0],
+ "" + ProcessHandle.current().pid(),
+ "" + (supportsUnixMXBean()?+unixNrFD():-1));
+ pb.inheritIO(); // in future, redirect information from third VM to first VM
+ pb.start();
+ }
+ }
+
+ static class VMShouldNotInheritFileDescriptors {
+ // third VM
+ public static void main(String[] args) throws InterruptedException {
+ File logFile = new File(args[0]);
+ long parentPid = parseLong(args[1]);
+ long parentFDCount = parseLong(args[2]);
+
+ if(supportsUnixMXBean()){
+ long thisFDCount = unixNrFD();
+ System.out.println("This VM FD-count (" + thisFDCount + ") should be strictly less than parent VM FD-count (" + parentFDCount + ") as log file should have been closed");
+ System.out.println(thisFDCount<parentFDCount?RETAINS_FD:LEAKS_FD);
+ } else if (getProperty("os.name").toLowerCase().contains("win")) {
+ windows(logFile, parentPid);
+ } else {
+ System.out.println(LEAKS_FD); // default fail on unknown configuration
+ }
+ System.out.println(EXIT);
+ }
+ }
+
+ static boolean supportsUnixMXBean() {
+ return getOperatingSystemMXBean() instanceof UnixOperatingSystemMXBean;
+ }
+
+ static long unixNrFD() {
+ UnixOperatingSystemMXBean osBean = (UnixOperatingSystemMXBean) getOperatingSystemMXBean();
+ return osBean.getOpenFileDescriptorCount();
+ }
+
+ static void windows(File f, long parentPid) throws InterruptedException {
+ System.out.println("waiting for pid: " + parentPid);
+ ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
+ System.out.println("trying to rename file to the same name: " + f);
+ System.out.println(f.renameTo(f)?RETAINS_FD:LEAKS_FD); // this parts communicates a closed file descriptor by printing "CLOSED FD"
+ }
+}
\ No newline at end of file