Emit old object sample and jdk.DumpReason events. Fix testEmergencyDump purge in-flight data bug. checkstyle

gate fixes

cleanup

Author: roberttoyonaga

substratevm/src/com.oracle.svm.core.posix/src/com/oracle/svm/core/posix/jfr/PosixJfrEmergencyDumpSupport.java

@@ -70,7 +70,7 @@ public class PosixJfrEmergencyDumpSupport implements com.oracle.svm.core.jfr.Jfr
     @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-26+2/src/hotspot/os/posix/include/jvm_md.h#L57") //
     private static final int JVM_MAXPATHLEN = 4096;
     @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-26+2/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp#L47") //
-    private static int ISO8601_LEN = 19;
+    private static final int ISO_8601_LEN = 19;
     private static final byte FILE_SEPARATOR = "/".getBytes(StandardCharsets.UTF_8)[0];
     private static final byte DOT = ".".getBytes(StandardCharsets.UTF_8)[0];
     // It does not really matter what the name is.
@@ -88,37 +88,46 @@ public class PosixJfrEmergencyDumpSupport implements com.oracle.svm.core.jfr.Jfr
     public PosixJfrEmergencyDumpSupport() {
     }
 
+    @Override
     public void initialize() {
         pidBytes = String.valueOf(ProcessHandle.current().pid()).getBytes(StandardCharsets.UTF_8);
         pathBuffer = NativeMemory.calloc(JVM_MAXPATHLEN, NmtCategory.JFR);
         directory = WordFactory.nullPointer();
     }
 
+    @Override
     public void setRepositoryLocation(String dirText) {
         repositoryLocationBytes = dirText.getBytes(StandardCharsets.UTF_8);
     }
 
+    @Override
     public void setDumpPath(String dumpPathText) {
         dumpPathBytes = dumpPathText.getBytes(StandardCharsets.UTF_8);
     }
 
+    @Override
     public String getDumpPath() {
         if (dumpPathBytes != null) {
             return new String(dumpPathBytes, StandardCharsets.UTF_8);
         }
         return "";
     }
 
-    // Either use create and use the dumpfile itself, or create a new file in the repository
-    // location.
+    /*
+     * Either use create and use the dumpfile itself, or create a new file in the repository
+     * location.
+     */
+    @Override
     @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-26+3/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp#L433-L445")
     public RawFileDescriptor chunkPath() {
         if (repositoryLocationBytes == null) {
             if (!openEmergencyDumpFile()) {
                 return WordFactory.nullPointer();
             }
-            // We can directly use the emergency dump file name as the new chunk since there are no
-            // other chunk files.
+            /*
+             * We can directly use the emergency dump file name as the new chunk since there are no
+             * other chunk files.
+             */
             return emergencyFd;
         }
         Log.log().string("Creating a new emergency chunk file in the JFR disk repository").newline();
@@ -141,6 +150,7 @@ private RawFileDescriptor createEmergencyChunkPath() {
         return getFileSupport().create(getPathBuffer(), FileCreationMode.CREATE, FileAccessMode.READ_WRITE);
     }
 
+    @Override
     @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-26+2/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp#L409-L416")
     public void onVmError() {
         Log.log().string("Attempting JFR Emergency Dump").newline();
@@ -213,12 +223,6 @@ private GrowableWordArray iterateRepository(GrowableWordArray gwa) {
             if (count > 0) {
                 GrowableWordArrayAccess.qsort(gwa, 0, count - 1, PosixJfrEmergencyDumpSupport::compare);
             }
-// for (int i=0; i < count; i ++){ // todo remove
-// String name =
-// org.graalvm.nativeimage.c.type.CTypeConversion.toJavaString(GrowableWordArrayAccess.read(gwa,
-// i));
-// System.out.println("chunk file: "+ name);
-// }
         }
         return WordFactory.nullPointer();
     }
@@ -227,7 +231,7 @@ private GrowableWordArray iterateRepository(GrowableWordArray gwa) {
     static int compare(Word a, Word b) {
         CCharPointer filenameA = (CCharPointer) a;
         CCharPointer filenameB = (CCharPointer) b;
-        int cmp = LibC.strncmp(filenameA, filenameB, WordFactory.unsigned(ISO8601_LEN));
+        int cmp = LibC.strncmp(filenameA, filenameB, WordFactory.unsigned(ISO_8601_LEN));
         if (cmp == 0) {
             CCharPointer aDot = SubstrateUtil.strchr(filenameA, DOT);
             CCharPointer bDot = SubstrateUtil.strchr(filenameB, DOT);
@@ -306,8 +310,8 @@ private CCharPointer getRepositoryLocation() {
     }
 
     /**
-     * See
-     * {@link com.oracle.svm.core.posix.jvmstat.PosixPerfMemoryProvider#restartableOpen(CCharPointer, int, int)}
+     * See com.oracle.svm.core.posix.jvmstat.PosixPerfMemoryProvider#restartableOpen(CCharPointer,
+     * int, int).
      */
     @Uninterruptible(reason = "LibC.errno() must not be overwritten accidentally.")
     private static int restartableOpen(CCharPointer directory, int flags, int mode) {
@@ -363,8 +367,6 @@ private CCharPointer fullyQualified(CCharPointer fn) {
 
         clearPathBuffer();
 
-        // TODO HS uses _path_buffer_file_name_offset to avoid building this part of th path each
-        // time.
         // Cached in RepositoryIterator::RepositoryIterator and used in fully_qualified
         idx = writeToPathBuffer(repositoryLocationBytes, idx);
 
@@ -386,7 +388,8 @@ private void clearPathBuffer() {
         LibC.memset(getPathBuffer(), Word.signed(0), Word.unsigned(JVM_MAXPATHLEN));
     }
 
-    private int writeToPathBuffer(byte[] bytes, int idx) {
+    private int writeToPathBuffer(byte[] bytes, int start) {
+        int idx = start;
         for (int i = 0; i < bytes.length; i++) {
             getPathBuffer().write(idx++, bytes[i]);
         }
@@ -412,6 +415,7 @@ private void closeDirectory() {
         }
     }
 
+    @Override
     public void teardown() {
         closeEmergencyDumpFile();
         closeDirectory();

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrChunkFileWriter.java

@@ -27,8 +27,6 @@
 import static com.oracle.svm.core.jfr.JfrThreadLocal.getJavaBufferList;
 import static com.oracle.svm.core.jfr.JfrThreadLocal.getNativeBufferList;
 
-import java.nio.charset.StandardCharsets;
-
 import com.oracle.svm.core.jfr.oldobject.JfrOldObjectRepository;
 import com.oracle.svm.core.nmt.NmtCategory;
 import jdk.graal.compiler.word.Word;
@@ -172,10 +170,10 @@ public void openFile(String outputFile) {
 
     // Used by JFR emergency dump
     @Override
-    public void openFile(RawFileDescriptor fd) {
+    public void openFile(RawFileDescriptor file) {
         assert lock.isOwner();
         filename = null;
-        this.fd = fd;
+        fd = file;
         openFile0();
     }
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrEmergencyDumpFeature.java

@@ -29,11 +29,20 @@
 import com.oracle.svm.core.feature.AutomaticallyRegisteredFeature;
 import com.oracle.svm.core.feature.InternalFeature;
 
+import jdk.graal.compiler.api.replacements.Fold;
+
+import org.graalvm.nativeimage.ImageSingletons;
+
 /**
  * The JFR emergency dump mechanism uses platform-specific implementations (see {@link JfrEmergencyDumpSupport}).
  */
 @AutomaticallyRegisteredFeature
 public class JfrEmergencyDumpFeature implements InternalFeature {
+    @Fold
+    static boolean isPresent() {
+        return ImageSingletons.contains(JfrEmergencyDumpSupport.class);
+    }
+
     @Override
     public boolean isInConfiguration(IsInConfigurationAccess access) {
         return VMInspectionOptions.hasJfrSupport();

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrEmergencyDumpSupport.java

@@ -1,4 +1,31 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, 2025, Red Hat Inc. 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 com.oracle.svm.core.jfr;
+
 import com.oracle.svm.core.os.RawFileOperationSupport;
 import org.graalvm.nativeimage.ImageSingletons;
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrEvent.java

@@ -74,6 +74,7 @@ public final class JfrEvent {
     public static final JfrEvent ObjectAllocationSample = create("jdk.ObjectAllocationSample", 5, JfrEventFlags.SupportsThrottling);
     public static final JfrEvent NativeMemoryUsage = create("jdk.NativeMemoryUsage");
     public static final JfrEvent NativeMemoryUsageTotal = create("jdk.NativeMemoryUsageTotal");
+    public static final JfrEvent DumpReason = create("jdk.DumpReason");
 
     private final long id;
     private final String name;

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrFeature.java

@@ -25,7 +25,6 @@
 package com.oracle.svm.core.jfr;
 
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 
 import org.graalvm.nativeimage.ImageSingletons;
@@ -155,7 +154,7 @@ private static HotSpotDiagnosticMXBean getDiagnosticBean() {
 
     @Override
     public List<Class<? extends Feature>> getRequiredFeatures() {
-        return  Arrays.asList(ThreadListenerSupportFeature.class, com.oracle.svm.core.jfr.JfrEmergencyDumpFeature.class);
+        return  Arrays.asList(ThreadListenerSupportFeature.class, JfrEmergencyDumpFeature.class);
     }
 
     @Override

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrRecorderThread.java

@@ -111,7 +111,6 @@ private void work() {
     }
 
     void endRecording() {
-//        com.oracle.svm.core.jfr.SubstrateJVM.get().vmErrorRotation();
         lock.lock();
         try {
             SubstrateJVM.JfrEndRecordingOperation vmOp = new SubstrateJVM.JfrEndRecordingOperation();

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrSymbolRepository.java

@@ -37,7 +37,6 @@
 import org.graalvm.word.WordFactory;
 
 import com.oracle.svm.core.Uninterruptible;
-import com.oracle.svm.core.c.struct.PinnedObjectField;
 import com.oracle.svm.core.collections.AbstractUninterruptibleHashtable;
 import com.oracle.svm.core.collections.UninterruptibleEntry;
 import com.oracle.svm.core.heap.Heap;
@@ -85,7 +84,6 @@ public long getSymbolId(String imageHeapString, boolean previousEpoch, boolean r
             return 0;
         }
 
-        assert Heap.getHeap().isInImageHeap("");
         assert Heap.getHeap().isInImageHeap(imageHeapString);
         int length = 0;
         length = UninterruptibleUtils.String.modifiedUTF8Length(imageHeapString, false);
@@ -102,7 +100,7 @@ public long getSymbolId(String imageHeapString, boolean previousEpoch, boolean r
     public long getSymbolId(PointerBase buffer, UnsignedWord length, int hash, boolean previousEpoch) {
         com.oracle.svm.core.util.VMError.guarantee(buffer.isNonNull());
         JfrSymbol symbol = StackValue.get(JfrSymbol.class);
-        symbol.setModifiedUTF8(buffer); // *** symbol in native memory
+        symbol.setModifiedUTF8(buffer); // symbol allocated in native memory
         symbol.setLength(length);
         symbol.setHash(hash);
 
@@ -134,7 +132,7 @@ public long getSymbolId(PointerBase buffer, UnsignedWord length, int hash, boole
             JfrNativeEventWriterDataAccess.initialize(data, epochData.buffer);
 
             JfrNativeEventWriter.putLong(data, newEntry.getId());
-            JfrNativeEventWriter.putString(data, (org.graalvm.word.Pointer) newEntry.getModifiedUTF8(), (int) newEntry.getLength().rawValue());
+            JfrNativeEventWriter.putString(data, (Pointer) newEntry.getModifiedUTF8(), (int) newEntry.getLength().rawValue());
             if (!JfrNativeEventWriter.commit(data)) {
                 return 0L;
             }