Rework jstack to use java.base only

In the target VM use only classes available in the java.base module.

Rework original implementation of jstack: "Implement jstack in 0.14" eclipse-openj9#5336

- Create the result string at the target instead of the attacher
- Delete unnecessary classes and packages
- Delete unit tests for deleted classes and other dead test code
- Minor stylistic cleanup while I have the files open

[ci skip]

Signed-off-by: Peter Bain <peter_bain@ca.ibm.com>

jcl/src/java.base/share/classes/com/ibm/tools/attach/target/Attachment.java

@@ -39,7 +39,6 @@
 import java.util.ServiceLoader;
 import openj9.tools.attach.diagnostics.base.DiagnosticProperties;
 import openj9.tools.attach.diagnostics.base.DiagnosticUtils;
-import openj9.tools.attach.diagnostics.spi.TargetDiagnosticsProvider;
 /*[IF Sidecar19-SE]*/
 import jdk.internal.vm.VMSupport;
 /*[ELSE] Sidecar19-SE
@@ -64,7 +63,6 @@ final class Attachment extends Thread implements Response {
 	private String attachError;
 	private final AttachHandler handler;
 	private final String key;
-	private TargetDiagnosticsProvider diagProvider;
 	private static final String START_REMOTE_MANAGEMENT_AGENT = "startRemoteManagementAgent"; //$NON-NLS-1$
 	private static final String START_LOCAL_MANAGEMENT_AGENT = "startLocalManagementAgent"; //$NON-NLS-1$
 
@@ -131,7 +129,6 @@ private static final class MethodRefsHolder {
 		portNumber = rc.getPortNumber();
 		this.key = rc.getKey();
 		this.handler = attachHandler;
-		diagProvider = null;
 		setDaemon(true);
 	}
 
@@ -224,12 +221,6 @@ boolean doCommand(InputStream cmdStream, OutputStream respStream) {
 					AttachmentConnection.streamSend(respStream, Response.ERROR
 							+ " " + attachError); //$NON-NLS-1$
 				}
-			} else if (cmd.startsWith(Command.GET_THREAD_GROUP_INFO)) {
-				try {
-					replyWithProperties(getDiagnosticsProvider().getThreadGroupInfo());
-				} catch (Exception e) {
-					replyWithProperties(DiagnosticProperties.makeExceptionProperties(e));
-				}
 			} else if (cmd.startsWith(Command.GET_SYSTEM_PROPERTIES)) {
 				Properties internalProperties = com.ibm.oti.vm.VM.getVMLangAccess().internalGetProperties();
 				String argumentString = String.join(" ", com.ibm.oti.vm.VM.getVMArgs()); //$NON-NLS-1$
@@ -306,18 +297,6 @@ private void replyWithProperties(Properties props) throws IOException {
 		IPC.sendProperties(props, responseStream);
 	}
 
-	private TargetDiagnosticsProvider getDiagnosticsProvider() {
-		if (diagProvider == null) {
-			for (TargetDiagnosticsProvider p: ServiceLoader.load(TargetDiagnosticsProvider.class)) {
-				if (null != p) {
-					diagProvider = p;
-					break;
-				}
-			}
-		}
-		return diagProvider;
-	}
-
 	/**
 	 * close socket and other cleanup
 	 */

jcl/src/java.base/share/classes/com/ibm/tools/attach/target/Command.java

@@ -54,7 +54,6 @@ public interface Command {
 	static final String GET_AGENT_PROPERTIES = "ATTACH_GETAGENTPROPERTIES"; //$NON-NLS-1$
 	static final String START_MANAGEMENT_AGENT = "ATTACH_START_MANAGEMENT_AGENT"; //$NON-NLS-1$
 	static final String START_LOCAL_MANAGEMENT_AGENT = "ATTACH_START_LOCAL_MANAGEMENT_AGENT"; //$NON-NLS-1$
-	static final String GET_THREAD_GROUP_INFO = "ATTACH_GET_THREAD_INFO"; //$NON-NLS-1$
 	static final String ATTACH_DIAGNOSTICS_PREFIX = "ATTACH_DIAGNOSTICS:"; //$NON-NLS-1$
 
 }

jcl/src/java.base/share/classes/com/ibm/tools/attach/target/IPC.java

@@ -1,6 +1,4 @@
 /*[INCLUDE-IF Sidecar16]*/
-package com.ibm.tools.attach.target;
-
 /*******************************************************************************
  * Copyright (c) 2009, 2019 IBM Corp. and others
  *
@@ -23,30 +21,32 @@
  * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
  *******************************************************************************/
 
+package com.ibm.tools.attach.target;
+
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintStream;
-import java.security.SecureRandom;
-import java.io.File;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
 import java.nio.file.Paths;
 import java.nio.file.attribute.PosixFilePermission;
+import java.security.SecureRandom;
 import java.util.EnumSet;
-import java.util.Set;
 import java.util.Objects;
 import java.util.Properties;
 import java.util.Random;
+import java.util.Set;
 
 import static java.nio.file.attribute.PosixFilePermission.GROUP_READ;
 import static java.nio.file.attribute.PosixFilePermission.GROUP_WRITE;
 import static java.nio.file.attribute.PosixFilePermission.OTHERS_READ;
 import static java.nio.file.attribute.PosixFilePermission.OTHERS_WRITE;
-import static openj9.tools.attach.diagnostics.base.DiagnosticsInfo.OPENJ9_DIAGNOSTICS_PREFIX;
+import static openj9.tools.attach.diagnostics.base.DiagnosticProperties.OPENJ9_DIAGNOSTICS_PREFIX;
 
 /**
  * Utility class for operating system calls
@@ -153,7 +153,7 @@ public static void checkOwnerAccessOnly(String filePath) throws IOException {
 				actualPermissions.retainAll(NON_OWNER_READ_WRITE);
 				if (!actualPermissions.isEmpty()) {
 					final String permissionString = Files.getPosixFilePermissions(Paths.get(filePath), LinkOption.NOFOLLOW_LINKS).toString();
-					logMessage("Wrong permissions: " +permissionString + " for ", filePath); //$NON-NLS-1$ //$NON-NLS-2$
+					logMessage("Wrong permissions: " + permissionString + " for ", filePath); //$NON-NLS-1$ //$NON-NLS-2$
 					/*[MSG "K0805", "{0} has permissions {1}, should have owner access only"]*/
 					throw new IOException(com.ibm.oti.util.Msg.getString("K0805", filePath, permissionString));//$NON-NLS-1$
 				}
@@ -308,8 +308,8 @@ static private native int createFileWithPermissionsImpl(String path,
 	static String getTmpDir() {
 		String tmpDir = getTempDirImpl();
 		if (null == tmpDir) {
-			IPC.logMessage("Could not get system temporary directory. Trying "+JAVA_IO_TMPDIR); //$NON-NLS-1$
-			tmpDir = com.ibm.oti.vm.VM.getVMLangAccess().internalGetProperties().getProperty(JAVA_IO_TMPDIR); //$NON-NLS-1$
+			logMessage("Could not get system temporary directory. Trying " + JAVA_IO_TMPDIR); //$NON-NLS-1$
+			tmpDir = com.ibm.oti.vm.VM.getVMLangAccess().internalGetProperties().getProperty(JAVA_IO_TMPDIR);
 		}
 		return tmpDir;
 	}
@@ -524,9 +524,9 @@ public static void sendProperties(Properties props, OutputStream outStream)
 	public static Properties receiveProperties(InputStream inStream, boolean requireNull)
 			throws IOException {
 		byte msgBuff[] = AttachmentConnection.streamReceiveBytes(inStream, 0, requireNull);
-		if (IPC.isLoggingEnabled()) {
+		if (isLoggingEnabled()) {
 			String propsString = new String(msgBuff, StandardCharsets.UTF_8);
-			IPC.logMessage("Received properties file:", propsString); //$NON-NLS-1$
+			logMessage("Received properties file:", propsString); //$NON-NLS-1$
 		}
 		Properties props = new Properties();
 		props.load(new ByteArrayInputStream(msgBuff));

jcl/src/java.base/share/classes/module-info.java.extra

@@ -31,12 +31,10 @@ exports com.ibm.oti.vm to java.management, jdk.attach, jdk.management, openj9.jv
 exports com.ibm.oti.util to java.management, jdk.attach, jdk.jcmd, jdk.management, openj9.sharedclasses;
 exports com.ibm.tools.attach.target to jdk.attach, jdk.jcmd, jdk.management;
 exports openj9.management.internal to java.management;
-exports openj9.tools.attach.diagnostics.spi to jdk.attach, jdk.jcmd;
 exports openj9.tools.attach.diagnostics.base to jdk.attach, jdk.jcmd;
 exports jdk.internal.org.objectweb.asm to openj9.dtfj, openj9.dtfjview;
 // Following allows dtfj/dtfjview modules invoke module addReads & addExports programmatically via reflection APIs
 exports jdk.internal.module to openj9.dtfj, openj9.dtfjview;
 uses com.ibm.sharedclasses.spi.SharedClassProvider;
-uses openj9.tools.attach.diagnostics.spi.TargetDiagnosticsProvider;
 uses com.ibm.gpu.spi.GPUAssist.Provider;
 exports com.ibm.gpu.spi to openj9.gpu;

jcl/src/java.base/share/classes/openj9/tools/attach/diagnostics/base/DiagnosticProperties.java

@@ -38,6 +38,15 @@
 public class DiagnosticProperties {
 	private final Properties baseProperties;
 
+	/**
+	 * Master prefix for property keys
+	 */
+	public static final String OPENJ9_DIAGNOSTICS_PREFIX = "openj9_diagnostics."; //$NON-NLS-1$
+	/**
+	 * Use for commands which return a single string
+	 */
+	public static final String DIAGNOSTICS_STRING_RESULT = OPENJ9_DIAGNOSTICS_PREFIX + "string_result"; //$NON-NLS-1$
+
 	private static final String JAVA_LANG_STRING = "java.lang.String"; //$NON-NLS-1$
 
 	/**
@@ -249,7 +258,7 @@ public static void dumpPropertiesIfDebug(String msg, DiagnosticProperties props)
 	 * @param props Properties object to dump
 	 */
 	public static void dumpPropertiesIfDebug(String msg, final Properties props) {
-		if (DiagnosticProperties.isDebug) {
+		if (isDebug) {
 			if (null != msg) {
 				System.err.println(msg);
 			}
@@ -294,7 +303,7 @@ public String printStringResult() {
 					buffWriter.println(msg);
 				}
 			} else {
-				buffWriter.println(getString(DiagnosticsInfo.DIAGNOSTICS_STRING_RESULT));
+				buffWriter.println(getString(DIAGNOSTICS_STRING_RESULT));
 			}
 		} catch (IOException e) {
 			buff = new StringWriter();
@@ -309,11 +318,11 @@ public String printStringResult() {
 	 * Create a properties file to hold a single string.
 	 * 
 	 * @param text text of the string
-	 * @return properties file containing the string, plus success indication
+	 * @return DiagnosticProperties object
 	 */
 	public static DiagnosticProperties makeStringResult(String text) {
 		DiagnosticProperties props = makeCommandSucceeded();
-		props.put(DiagnosticsInfo.DIAGNOSTICS_STRING_RESULT, text);
+		props.put(DIAGNOSTICS_STRING_RESULT, text);
 		return props;
 	}
 
@@ -327,12 +336,22 @@ public Properties toProperties() {
 	}
 
 	/**
-	 * @return Properties file indicating success
+	 * Report successful execution of a command
+	 * @return DiagnosticProperties object
 	 */
 	public static DiagnosticProperties makeCommandSucceeded() {
 		return makeStatusProperties(false, null); // $NON-NLS-1$
 	}
 
+	/**
+	 * Report an error in the command
+	 * @param message error message
+	 * @return DiagnosticProperties object
+	 */
+	public static DiagnosticProperties makeErrorProperties(String message) {
+		return makeStatusProperties(true, message); // $NON-NLS-1$
+	}
+
 	/**
 	 * Encode information about an exception into properties.
 	 * 
@@ -355,7 +374,7 @@ public static Properties makeExceptionProperties(Exception e) {
 	 * 
 	 * @param error true if the command failed
 	 * @param msg   status message
-	 * @return properties file encoding the status and message
+	 * @return DiagnosticProperties object
 	 */
 	public static DiagnosticProperties makeStatusProperties(boolean error, String msg) {
 		DiagnosticProperties props = new DiagnosticProperties();

jcl/src/java.base/share/classes/openj9/tools/attach/diagnostics/base/DiagnosticUtils.java

@@ -23,14 +23,20 @@
 
 package openj9.tools.attach.diagnostics.base;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Function;
 import java.util.function.Predicate;
+
 import com.ibm.oti.vm.VM;
 import com.ibm.tools.attach.target.IPC;
 
+import openj9.management.internal.LockInfoBase;
+import openj9.management.internal.ThreadInfoBase;
+
 /**
  * Common methods for the diagnostics tools
  *
@@ -41,6 +47,11 @@ public class DiagnosticUtils {
 	 * Command strings for executeDiagnosticCommand()
 	 */
 
+	/**
+	 * Run Get the stack traces and other thread information.
+	 */
+	public static final String DIAGNOSTICS_THREAD_PRINT = "Thread.print"; //$NON-NLS-1$
+
 	/**
 	 * Run System.gc();
 	 */
@@ -65,6 +76,7 @@ public class DiagnosticUtils {
 	 * Report only live heap objects.
 	 */
 	public static final String LIVE_OPTION = "live"; //$NON-NLS-1$
+	private static final String THREAD_LOCKED_SYNCHRONIZERS_OPTION = "-l"; //$NON-NLS-1$
 
 	private static final Map<String, Function<String, DiagnosticProperties>> commandTable;
 
@@ -82,6 +94,19 @@ public static String makeHeapHistoCommand(boolean liveObjects) {
 		return cmd;
 	}
 
+	/**
+	 * Create the command to run the Thread.print command
+	 * 
+	 * @param lockedSynchronizers print the locked ownable synchronizers
+	 * @return formatted string
+	 */
+	public static String makeThreadPrintCommand(boolean lockedSynchronizers) {
+		String cmd = lockedSynchronizers
+				? DIAGNOSTICS_THREAD_PRINT + DIAGNOSTICS_OPTION_SEPARATOR + THREAD_LOCKED_SYNCHRONIZERS_OPTION
+				: DIAGNOSTICS_THREAD_PRINT;
+		return cmd;
+	}
+
 	private static native String getHeapClassStatisticsImpl();
 
 	/**
@@ -120,6 +145,55 @@ private static DiagnosticProperties getHeapStatistics(String diagnosticCommand)
 		}
 		return DiagnosticProperties.makeStringResult(result);
 	}
+
+	private static DiagnosticProperties getThreadInfo(String diagnosticCommand) {
+		DiagnosticProperties result = null;
+		boolean okay = true;
+		boolean addSynchronizers = false;
+		String[] parts = diagnosticCommand.split(DIAGNOSTICS_OPTION_SEPARATOR);
+		/* only one option ("-l[=<BOOLEAN>]") is allowed, so the diagnosticCommand can comprise at most
+		 * the base command and one option, with an optional value */
+		if (parts.length > 2) {
+			okay = false;
+		} else if (parts.length == 2) {
+			String option = parts[1];
+			if (option.startsWith(THREAD_LOCKED_SYNCHRONIZERS_OPTION)) {
+				if ((THREAD_LOCKED_SYNCHRONIZERS_OPTION.length() == option.length()) /* exact match */
+						|| option.toLowerCase().equals(THREAD_LOCKED_SYNCHRONIZERS_OPTION + "=true")) { //$NON-NLS-1$
+					addSynchronizers = true;
+				}
+			} else {
+				okay = false;
+			}
+		}
+		if (!okay) {
+			result = DiagnosticProperties.makeErrorProperties("Command not recognized: " + diagnosticCommand); //$NON-NLS-1$
+		} else {
+			StringWriter buffer = new StringWriter(2000);
+			PrintWriter bufferPrinter = new PrintWriter(buffer);
+			bufferPrinter.println(System.getProperty("java.vm.info")); //$NON-NLS-1$
+			bufferPrinter.println();
+			ThreadInfoBase[] threadInfoBases = dumpAllThreadsImpl(true, addSynchronizers, Integer.MAX_VALUE);
+			for (ThreadInfoBase currentThreadInfoBase : threadInfoBases) {
+				bufferPrinter.print(currentThreadInfoBase.toString());
+				if (addSynchronizers) {
+					LockInfoBase[] lockedSynchronizers = currentThreadInfoBase.getLockedSynchronizers();
+					bufferPrinter.printf("%n\tLocked ownable synchronizers: %d%n", //$NON-NLS-1$
+							Integer.valueOf(lockedSynchronizers.length));
+					for (LockInfoBase currentLockedSynchronizer : lockedSynchronizers) {
+						bufferPrinter.printf("\t- %s%n", currentLockedSynchronizer.toString()); //$NON-NLS-1$
+					}
+				}
+				bufferPrinter.println();
+			}
+			bufferPrinter.flush();
+			result = DiagnosticProperties.makeStringResult(buffer.toString());
+		}
+		return result;
+	}
+
+	private static native ThreadInfoBase[] dumpAllThreadsImpl(boolean lockedMonitors,
+			boolean lockedSynchronizers, int maxDepth);
 
 	private static DiagnosticProperties runGC() {
 		VM.globalGC();
@@ -128,9 +202,9 @@ private static DiagnosticProperties runGC() {
 
 	static {
 		commandTable = new HashMap<>();
-		commandTable.put(openj9.tools.attach.diagnostics.base.DiagnosticUtils.DIAGNOSTICS_GC_CLASS_HISTOGRAM,
-				s -> getHeapStatistics(s));
-		commandTable.put(openj9.tools.attach.diagnostics.base.DiagnosticUtils.DIAGNOSTICS_GC_RUN, s -> runGC());
+		commandTable.put(DIAGNOSTICS_GC_CLASS_HISTOGRAM, DiagnosticUtils::getHeapStatistics);
+		commandTable.put(DIAGNOSTICS_GC_RUN, s -> runGC());
+		commandTable.put(DIAGNOSTICS_THREAD_PRINT, DiagnosticUtils::getThreadInfo);
 	}
 
 }