diff -r 4e96939a5746 -r 577e17cab93f src/jdk.jcmd/linux/classes/sun/tools/common/ProcessHelper.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jcmd/linux/classes/sun/tools/common/ProcessHelper.java Mon Sep 23 12:32:13 2019 +0200
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2019, 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 sun.tools.common;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.stream.Stream;
+
+/**
+ * A helper class that retrieves the main class name for
+ * a running Java process using the proc filesystem (procfs)
+ */
+final class ProcessHelper {
+
+ private static final String CMD_PREFIX = "cmd:";
+
+ /**
+ * Gets the main class name for the given Java process by parsing the
+ * process command line. If the application was started with the -jar
+ * option this method returns the name of the jar file. If the application
+ * was started with -m or --module option, the method returns
+ * the module name and the main class name.
+ * @param pid - process ID (pid)
+ * @return the main class name or null if the process no longer exists or
+ * was started with a native launcher (e.g. jcmd etc)
+ */
+ static String getMainClass(String pid) {
+ String cmdLine = getCommandLine(pid);
+ if (cmdLine == null) {
+ return null;
+ }
+ if (cmdLine.startsWith(CMD_PREFIX)) {
+ cmdLine = cmdLine.substring(CMD_PREFIX.length());
+ }
+ String[] parts = cmdLine.split("\0");
+ String mainClass = null;
+
+ if (parts.length == 0) {
+ return null;
+ }
+
+ // Check the executable
+ String[] executablePath = parts[0].split("/");
+ if (executablePath.length > 0) {
+ String binaryName = executablePath[executablePath.length - 1];
+ if (!"java".equals(binaryName)) {
+ // Skip the process if it is not started with java launcher
+ return null;
+ }
+ }
+
+ // To be consistent with the behavior on other platforms, if -jar, -m, or --module
+ // options are used then just return the value (the path to the jar file or module
+ // name with a main class). Otherwise, the main class name is the first part that
+ // is not a Java option (doesn't start with '-' and is not a classpath or a module
+ // whitespace option).
+
+ for (int i = 1; i < parts.length && mainClass == null; i++) {
+ if (i < parts.length - 1) {
+ if (parts[i].equals("-m") || parts[i].equals("--module") || parts[i].equals("-jar")) {
+ return parts[i + 1];
+ }
+ }
+
+ if (parts[i].startsWith("--module=")) {
+ return parts[i].substring("--module=".length());
+ }
+
+ // If this is a classpath or a module whitespace option then skip the next part
+ // (the classpath or the option value itself)
+ if (parts[i].equals("-cp") || parts[i].equals("-classpath") || parts[i].equals("--class-path") ||
+ isModuleWhiteSpaceOption(parts[i])) {
+ i++;
+ continue;
+ }
+ // Skip all other Java options
+ if (parts[i].startsWith("-")) {
+ continue;
+ }
+
+ // If it is a source-file mode then return null
+ if (parts[i].endsWith(".java")) {
+ return null;
+ }
+
+ mainClass = parts[i];
+ }
+ return mainClass;
+ }
+
+ private static String getCommandLine(String pid) {
+ try (Stream lines =
+ Files.lines(Paths.get("/proc/" + pid + "/cmdline"))) {
+ return lines.findFirst().orElse(null);
+ } catch (IOException | UncheckedIOException e) {
+ return null;
+ }
+ }
+
+ private static boolean isModuleWhiteSpaceOption(String option) {
+ return option.equals("-p") ||
+ option.equals("--module-path") ||
+ option.equals("--upgrade-module-path") ||
+ option.equals("--add-modules") ||
+ option.equals("--limit-modules") ||
+ option.equals("--add-exports") ||
+ option.equals("--add-opens") ||
+ option.equals("--add-reads") ||
+ option.equals("--patch-module");
+ }
+}