style

Author: roberttoyonaga

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

@@ -267,7 +267,7 @@ private void writeEmergencyDumpFile(GrowableWordArray sortedChunkFilenames) {
                 long bytesWritten = 0;
                 while (bytesRead < chunkFileSize) {
                     // Start at beginning
-                    getFileSupport().seek(chunkFd, 0); // seems unneeded. idk why???
+                    getFileSupport().seek(chunkFd, 0);
                     // Read from chunk file to copy block
                     long readResult = getFileSupport().read(chunkFd, copyBlock, WordFactory.unsigned(blockSize));
                     if (readResult < 0) { // -1 if read failed
@@ -341,7 +341,7 @@ private boolean filter(CCharPointer fn) {
             }
         }
 
-        // Verify if you can open it and receive a valid file descriptor
+        // Verify it can be opened and receive a valid file descriptor
         RawFileDescriptor chunkFd = getFileSupport().open(fullyQualified(fn), FileAccessMode.READ_WRITE);
         if (!getFileSupport().isValid(chunkFd)) {
             return false;
@@ -357,8 +357,7 @@ private boolean filter(CCharPointer fn) {
     }
 
     /**
-     * Given a chunk file name, it returns the fully qualified filename. See
-     * RepositoryIterator::fully_qualified
+     * Given a chunk file name, it returns the fully qualified filename.
      */
     @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-26+2/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp#L263-L273")
     private CCharPointer fullyQualified(CCharPointer fn) {

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

@@ -27,10 +27,6 @@
 import static com.oracle.svm.core.jfr.JfrThreadLocal.getJavaBufferList;
 import static com.oracle.svm.core.jfr.JfrThreadLocal.getNativeBufferList;
 
-import com.oracle.svm.core.jfr.oldobject.JfrOldObjectRepository;
-import com.oracle.svm.core.nmt.NmtCategory;
-import jdk.graal.compiler.word.Word;
-
 import org.graalvm.nativeimage.IsolateThread;
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.Platforms;
@@ -41,11 +37,13 @@
 import com.oracle.svm.core.Uninterruptible;
 import com.oracle.svm.core.heap.VMOperationInfos;
 import com.oracle.svm.core.jdk.UninterruptibleUtils;
+import com.oracle.svm.core.jfr.oldobject.JfrOldObjectRepository;
 import com.oracle.svm.core.jfr.sampler.JfrExecutionSampler;
 import com.oracle.svm.core.jfr.sampler.JfrRecurringCallbackExecutionSampler;
 import com.oracle.svm.core.jfr.traceid.JfrTraceIdEpoch;
 import com.oracle.svm.core.locks.VMMutex;
 import com.oracle.svm.core.memory.NullableNativeMemory;
+import com.oracle.svm.core.nmt.NmtCategory;
 import com.oracle.svm.core.os.RawFileOperationSupport;
 import com.oracle.svm.core.os.RawFileOperationSupport.FileAccessMode;
 import com.oracle.svm.core.os.RawFileOperationSupport.FileCreationMode;
@@ -59,6 +57,7 @@
 
 import jdk.graal.compiler.api.replacements.Fold;
 import jdk.graal.compiler.core.common.NumUtil;
+import jdk.graal.compiler.word.Word;
 
 /**
  * This class is used when writing the in-memory JFR data to a file. For all operations, except

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

@@ -47,6 +47,7 @@ public interface JfrChunkWriter extends JfrUnlockedChunkWriter {
     void markChunkFinal();
 
     void closeFile();
+
     void closeFileForEmergencyDump();
 
     void setMetadata(byte[] bytes);

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

@@ -34,7 +34,8 @@
 import org.graalvm.nativeimage.ImageSingletons;
 
 /**
- * The JFR emergency dump mechanism uses platform-specific implementations (see {@link JfrEmergencyDumpSupport}).
+ * The JFR emergency dump mechanism uses platform-specific implementations (see
+ * {@link JfrEmergencyDumpSupport}).
  */
 @AutomaticallyRegisteredFeature
 public class JfrEmergencyDumpFeature implements InternalFeature {

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

@@ -30,6 +30,7 @@
 import org.graalvm.nativeimage.ImageSingletons;
 
 import jdk.graal.compiler.api.replacements.Fold;
+
 public interface JfrEmergencyDumpSupport {
     @Fold
     static boolean isPresent() {
@@ -42,10 +43,16 @@ static JfrEmergencyDumpSupport singleton() {
     }
 
     void initialize();
+
     void setRepositoryLocation(String dirText);
+
     void setDumpPath(String dumpPathText);
+
     String getDumpPath();
+
     RawFileOperationSupport.RawFileDescriptor chunkPath();
+
     void onVmError();
+
     void teardown();
 }

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

@@ -154,7 +154,7 @@ private static HotSpotDiagnosticMXBean getDiagnosticBean() {
 
     @Override
     public List<Class<? extends Feature>> getRequiredFeatures() {
-        return  Arrays.asList(ThreadListenerSupportFeature.class, JfrEmergencyDumpFeature.class);
+        return Arrays.asList(ThreadListenerSupportFeature.class, JfrEmergencyDumpFeature.class);
     }
 
     @Override

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

@@ -29,6 +29,7 @@
 
 public class JfrGCWhenSerializer implements JfrSerializer {
     private JfrGCWhen[] values;
+
     @Platforms(Platform.HOSTED_ONLY.class)
     public JfrGCWhenSerializer() {
         values = JfrGCWhen.values();

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

@@ -33,6 +33,7 @@
 
 public class JfrNmtCategorySerializer implements JfrSerializer {
     private NmtCategory[] nmtCategories;
+
     @Platforms(Platform.HOSTED_ONLY.class)
     public JfrNmtCategorySerializer() {
         nmtCategories = NmtCategory.values();

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

@@ -95,10 +95,9 @@ public long getSymbolId(String imageHeapString, boolean previousEpoch, boolean r
         return getSymbolId(buffer, WordFactory.unsigned(length), hash, previousEpoch);
     }
 
-
     @Uninterruptible(reason = "Locking without transition and result is only valid until epoch changes.", callerMustBe = true)
     public long getSymbolId(PointerBase buffer, UnsignedWord length, int hash, boolean previousEpoch) {
-        com.oracle.svm.core.util.VMError.guarantee(buffer.isNonNull());
+        assert buffer.isNonNull();
         JfrSymbol symbol = StackValue.get(JfrSymbol.class);
         symbol.setModifiedUTF8(buffer); // symbol allocated in native memory
         symbol.setLength(length);
@@ -181,10 +180,13 @@ private interface JfrSymbol extends UninterruptibleEntry {
 
         @RawField
         void setLength(UnsignedWord value);
+
         @RawField
         UnsignedWord getLength();
+
         @RawField
         void setModifiedUTF8(PointerBase value);
+
         @RawField
         PointerBase getModifiedUTF8();
     }

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

@@ -53,21 +53,32 @@
 import static com.oracle.svm.core.Uninterruptible.CALLED_FROM_UNINTERRUPTIBLE_CODE;
 
 /**
- * Repository that collects and writes used classes, packages, modules, and classloaders.
+ * Repository that collects and writes used classes, packages, modules, and classloaders. There are
+ * three kinds of tables used by this class: epochTypeData, flushed*, and typeInfo. The flushed*
+ * tables record which classes have already been flushed to disk. The epochTypeData tables hold
+ * classes that have yet to be flushed as well as classes that are already flushed (they are written
+ * by threads emitting events). The typeInfo table is derived at flushpoints by using the
+ * epochTypeData and flushed* tables to determine the set of classes that have yet to be flushed.
+ *
+ * Unlike other JFR repositories, there are no epoch data buffers that require lock protection.
+ * Similar to other constant repositories, writes/reads to the current epochData are allowed to race
+ * at flushpoints. There is no risk of separating events from constant data due to the write order
+ * (constants before events during emission, and events before constants during flush). The
+ * epochData tables are only cleared at rotation safepoints.
  */
 public class JfrTypeRepository implements JfrRepository {
     private static final String BOOTSTRAP_NAME = "bootstrap";
-    // The following tables are only used by the flushing/rotating thread
+    // The following tables are only used by the flushing/rotating thread.
     private final JfrClassInfoTable flushedClasses;
     private final JfrPackageInfoTable flushedPackages;
     private final JfrModuleInfoTable flushedModules;
     private final JfrClassLoaderInfoTable flushedClassLoaders;
     private final TypeInfo typeInfo;
 
     /*
-     * epochTypeData tables are written to from threads emitting events and read from the
-     * flushing/rotating thread Their purpose is to lazily collect tagged JFR classes, which may
-     * later be serialized during flush/rotation.
+     * epochTypeData tables are written by threads emitting events and read from the
+     * flushing/rotating thread. Their purpose is to lazily collect tagged JFR classes, which are
+     * later serialized during flush/rotation.
      */
     private final JfrClassInfoTable epochTypeData0;
     private final JfrClassInfoTable epochTypeData1;
@@ -140,11 +151,7 @@ public int write(JfrChunkWriter writer, boolean flushpoint) {
      * referenced classes.
      *
      * This method does not need to be marked uninterruptible since the epoch cannot change while
-     * the chunkwriter lock is held. Unlike other JFR repositories, locking is not needed to protect
-     * a data buffer. Similar to other constant repositories, writes/reads to the current epochData
-     * are allowed to race at flushpoints. There is no risk of separating events from constant data
-     * due to the write order (constants before events during emission, and events before constants
-     * during flush). The epochData tables are only cleared at rotation safepoints.
+     * the chunkwriter lock is held.
      */
     private void collectTypeInfo(boolean flushpoint) {
         JfrClassInfoTable classInfoTable = getEpochData(!flushpoint);
@@ -255,8 +262,10 @@ private static long getSymbolId(JfrChunkWriter writer, String symbol, boolean fl
         return SubstrateJVM.getSymbolRepository().getSymbolId(symbol, !flushpoint, replaceDotWithSlash);
     }
 
-    // Copy to a new buffer so each table has its own copy of the data. This simplifies cleanup and
-    // mitigates double frees.
+    /*
+     * Copy to a new buffer so each table has its own copy of the data. This simplifies cleanup and
+     * mitigates double frees.
+     */
     @Uninterruptible(reason = "Needed for JfrSymbolRepository.getSymbolId().")
     private static long getSymbolId(JfrChunkWriter writer, PointerBase source, UnsignedWord length, int hash, boolean flushpoint) {
         Pointer destination = NullableNativeMemory.malloc(length, NmtCategory.JFR);
@@ -571,8 +580,10 @@ private void setPackageNameAndLength(Class<?> clazz, PackageInfoRaw packageInfoR
 
         assert buffer.add(dot).belowOrEqual(bufferEnd);
 
-        // Since we're serializing now, we must do replacements here, instead of the symbol
-        // repository.
+        /*
+         * Since we're serializing now, we must do replacements here, instead of the symbol
+         * repository.
+         */
         Pointer packageNameEnd = UninterruptibleUtils.String.toModifiedUTF8(str, dot, buffer, bufferEnd, false, dotWithSlash);
         packageInfoRaw.setModifiedUTF8Name(buffer);
 
@@ -702,7 +713,7 @@ private abstract class JfrTypeInfoTable extends AbstractUninterruptibleHashtable
         protected boolean isEqual(UninterruptibleEntry v0, UninterruptibleEntry v1) {
             JfrTypeInfo a = (JfrTypeInfo) v0;
             JfrTypeInfo b = (JfrTypeInfo) v1;
-            return a.getName() == b.getName();
+            return a.getName() != null ? a.getName().equals(b.getName()) : b.getName() == null;
         }
 
         @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)