8230857: Avoid reflection in sun.tools.common.ProcessHelper
authorclanger
Mon, 23 Sep 2019 12:32:13 +0200
changeset 58265 577e17cab93f
parent 58264 4e96939a5746
child 58266 501df37ce76b
8230857: Avoid reflection in sun.tools.common.ProcessHelper Reviewed-by: sspitsyn, dholmes
src/jdk.jcmd/linux/classes/sun/tools/ProcessHelper.java
src/jdk.jcmd/linux/classes/sun/tools/common/ProcessHelper.java
src/jdk.jcmd/share/classes/sun/tools/common/ProcessArgumentMatcher.java
src/jdk.jcmd/share/classes/sun/tools/common/ProcessHelper.java
test/jdk/sun/tools/jcmd/TestProcessHelper.java
--- a/src/jdk.jcmd/linux/classes/sun/tools/ProcessHelper.java	Mon Sep 23 11:37:08 2019 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,149 +0,0 @@
-/*
- * 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;
-
-import java.io.IOException;
-import java.io.UncheckedIOException;
-import java.nio.file.Files;
-import java.nio.file.Paths;
-import java.util.jar.Attributes;
-import java.util.jar.JarFile;
-import java.util.stream.Stream;
-
-/**
- * A helper class that retrieves the main class name for
- * a running Java process using the proc filesystem (procfs)
- */
-public class ProcessHelper implements sun.tools.common.ProcessHelper {
-
-
-    private static final String CMD_PREFIX = "cmd:";
-    private static final ProcessHelper INSTANCE = new ProcessHelper();
-
-    public static ProcessHelper getInstance() {
-        return INSTANCE;
-    }
-
-    /**
-     * Gets the main class name for the given Java process by parsing the
-     * process command line. If the application was started with the <em>-jar</em>
-     * option this method returns the name of the jar file. If the application
-     * was started with <em>-m</em> or <em>--module</em> 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)
-     */
-
-    public 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<String> 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");
-    }
-
-}
-
-
--- /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 <em>-jar</em>
+     * option this method returns the name of the jar file. If the application
+     * was started with <em>-m</em> or <em>--module</em> 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<String> 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");
+    }
+}
--- a/src/jdk.jcmd/share/classes/sun/tools/common/ProcessArgumentMatcher.java	Mon Sep 23 11:37:08 2019 +0200
+++ b/src/jdk.jcmd/share/classes/sun/tools/common/ProcessArgumentMatcher.java	Mon Sep 23 12:32:13 2019 +0200
@@ -79,15 +79,10 @@
 
     private static boolean check(VirtualMachineDescriptor vmd, String excludeClass, String partialMatch) {
 
-        String mainClass = null;
+        // Try to get the main class name using (platform specific) ProcessHelper
+        String mainClass = ProcessHelper.getMainClass(vmd.id());
 
-        // Get the main class name using platform specific helper
-        ProcessHelper helper = ProcessHelper.platformProcessHelper();
-        if (helper != null) {
-            mainClass = helper.getMainClass(vmd.id());
-        }
-
-        // If the main class name is still unset then retrieve it with the attach mechanism
+        // If the main class name could not be retrieved by ProcessHelper, get it with the attach mechanism
         if (mainClass == null) {
             try {
                 VmIdentifier vmId = new VmIdentifier(vmd.id());
--- a/src/jdk.jcmd/share/classes/sun/tools/common/ProcessHelper.java	Mon Sep 23 11:37:08 2019 +0200
+++ b/src/jdk.jcmd/share/classes/sun/tools/common/ProcessHelper.java	Mon Sep 23 12:32:13 2019 +0200
@@ -25,33 +25,12 @@
 
 package sun.tools.common;
 
-import java.lang.reflect.Method;
-
 /**
  * A helper class to retrieve the main class name for a running
- * Java process.
+ * Java process. Default implementation returns null. Platform specific
+ * implementation currently available for Linux only.
  */
-
-public interface ProcessHelper {
-
-    /**
-     * Returns an instance of the ProcessHelper class.
-     *
-     * @return ProcessHelper object or null if not supported on this platform.
-     */
-    public static ProcessHelper platformProcessHelper() {
-        try {
-            Class<?> c = Class.forName("sun.tools.ProcessHelper");
-            @SuppressWarnings("unchecked")
-            Method m = c.getMethod("getInstance");
-            return (ProcessHelper) m.invoke(null);
-        } catch (ClassNotFoundException e) {
-            return null;
-        } catch (ReflectiveOperationException e) {
-            throw new InternalError(e);
-        }
-    }
-
+final class ProcessHelper {
 
     /**
      * Returns the main class name for the given Java process
@@ -59,6 +38,7 @@
      * @param pid - process ID (pid)
      * @return main class name or null if the main class could not be retrieved
      */
-
-    String getMainClass(String pid);
+    static String getMainClass(String pid) {
+        return null;
+    }
 }
--- a/test/jdk/sun/tools/jcmd/TestProcessHelper.java	Mon Sep 23 11:37:08 2019 +0200
+++ b/test/jdk/sun/tools/jcmd/TestProcessHelper.java	Mon Sep 23 12:32:13 2019 +0200
@@ -21,16 +21,13 @@
  * questions.
  */
 
-import jdk.internal.module.ModuleInfoWriter;
-import jdk.test.lib.JDKToolFinder;
-import jdk.test.lib.process.ProcessTools;
-import jdk.test.lib.util.JarUtils;
-import sun.tools.common.ProcessHelper;
-
 import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
 import java.lang.module.ModuleDescriptor;
+import java.lang.reflect.Method;
 import java.nio.file.FileSystems;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -44,6 +41,11 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import jdk.internal.module.ModuleInfoWriter;
+import jdk.test.lib.JDKToolFinder;
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.util.JarUtils;
+
 /*
  * @test
  * @bug 8205654
@@ -52,15 +54,13 @@
  *
  * @requires os.family == "linux"
  * @library /test/lib
- * @modules jdk.jcmd/sun.tools.common
+ * @modules jdk.jcmd/sun.tools.common:+open
  *          java.base/jdk.internal.module
  * @build test.TestProcess
  * @run main/othervm TestProcessHelper
  */
 public class TestProcessHelper {
 
-    private ProcessHelper PROCESS_HELPER = ProcessHelper.platformProcessHelper();
-
     private static final String TEST_PROCESS_MAIN_CLASS_NAME = "TestProcess";
     private static final String TEST_PROCESS_MAIN_CLASS_PACKAGE = "test";
     private static final String TEST_PROCESS_MAIN_CLASS = TEST_PROCESS_MAIN_CLASS_PACKAGE + "."
@@ -89,6 +89,29 @@
 
     private static final String[] PATCH_MODULE_OPTIONS = {"--patch-module", null};
 
+    private static final MethodHandle MH_GET_MAIN_CLASS = resolveMainClassMH();
+
+    private static MethodHandle resolveMainClassMH() {
+        try {
+            Method getMainClassMethod = Class
+                .forName("sun.tools.common.ProcessHelper")
+                .getDeclaredMethod("getMainClass", String.class);
+            getMainClassMethod.setAccessible(true);
+            return MethodHandles.lookup().unreflect(getMainClassMethod);
+        } catch (ClassNotFoundException | NoSuchMethodException | SecurityException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static String callGetMainClass(Process p) {
+        try {
+            return (String)MH_GET_MAIN_CLASS.invoke(Long.toString(p.pid()));
+        } catch (Throwable e) {
+            throw new RuntimeException(e);
+        }
+
+    }
+
     public static void main(String[] args) throws Exception {
         new TestProcessHelper().runTests();
     }
@@ -188,7 +211,7 @@
     }
 
     private void checkMainClass(Process p, String expectedMainClass) {
-        String mainClass = PROCESS_HELPER.getMainClass(Long.toString(p.pid()));
+        String mainClass = callGetMainClass(p);
         // getMainClass() may return null, e.g. due to timing issues.
         // Attempt some limited retries.
         if (mainClass == null) {
@@ -204,7 +227,7 @@
                 } catch (InterruptedException e) {
                     // ignore
                 }
-                mainClass = PROCESS_HELPER.getMainClass(Long.toString(p.pid()));
+                mainClass = callGetMainClass(p);
                 retrycount++;
                 sleepms *= 2;
             }