[GR-66792] Switch all singletons with persist actions to SingletonTraits.

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/code/CodeInfoEncoder.java

@@ -28,7 +28,6 @@
 import static com.oracle.svm.core.util.VMError.shouldNotReachHereUnexpectedInput;
 
 import java.util.BitSet;
-import java.util.EnumSet;
 import java.util.Objects;
 import java.util.TreeMap;
 import java.util.function.Consumer;
@@ -70,12 +69,18 @@
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonLoader;
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
 import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
 import com.oracle.svm.core.meta.SharedField;
 import com.oracle.svm.core.meta.SharedMethod;
 import com.oracle.svm.core.meta.SharedType;
 import com.oracle.svm.core.nmt.NmtCategory;
 import com.oracle.svm.core.option.HostedOptionKey;
+import com.oracle.svm.core.traits.BuiltinTraits.BuildtimeAccessOnly;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacks;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacksSupplier;
+import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.Independent;
+import com.oracle.svm.core.traits.SingletonTrait;
+import com.oracle.svm.core.traits.SingletonTraitKind;
+import com.oracle.svm.core.traits.SingletonTraits;
 import com.oracle.svm.core.util.ByteArrayReader;
 import com.oracle.svm.core.util.Counter;
 import com.oracle.svm.core.util.VMError;
@@ -909,7 +914,8 @@ private static ValueInfo findActualValue(ValueInfo[] actualObject, UnsignedWord
 }
 
 @AutomaticallyRegisteredImageSingleton(onlyWith = BuildingImageLayerPredicate.class)
-class MethodTableFirstIDTracker implements LayeredImageSingleton {
+@SingletonTraits(access = BuildtimeAccessOnly.class, layeredCallbacks = MethodTableFirstIDTracker.LayeredCallbacks.class, layeredInstallationKind = Independent.class)
+class MethodTableFirstIDTracker {
     public final int startingID;
     public int nextStartingId = -1;
 
@@ -925,21 +931,31 @@ private MethodTableFirstIDTracker(int id) {
         startingID = id;
     }
 
-    @Override
-    public EnumSet<LayeredImageSingletonBuilderFlags> getImageBuilderFlags() {
-        return LayeredImageSingletonBuilderFlags.BUILDTIME_ACCESS_ONLY;
-    }
+    static class LayeredCallbacks extends SingletonLayeredCallbacksSupplier {
+        @Override
+        public SingletonTrait getLayeredCallbacksTrait() {
+            return new SingletonTrait(SingletonTraitKind.LAYERED_CALLBACKS, new SingletonLayeredCallbacks<MethodTableFirstIDTracker>() {
+                @Override
+                public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, MethodTableFirstIDTracker singleton) {
+                    int nextStartingId = singleton.nextStartingId;
+                    assert nextStartingId > 0 : nextStartingId;
+                    writer.writeInt("startingID", nextStartingId);
+                    return LayeredImageSingleton.PersistFlags.CREATE;
+                }
 
-    @Override
-    public PersistFlags preparePersist(ImageSingletonWriter writer) {
-        assert nextStartingId > 0 : nextStartingId;
-        writer.writeInt("startingID", nextStartingId);
-        return PersistFlags.CREATE;
+                @Override
+                public Class<? extends SingletonLayeredCallbacks.LayeredSingletonInstantiator<?>> getSingletonInstantiator() {
+                    return SingletonInstantiator.class;
+                }
+            });
+        }
     }
 
-    @SuppressWarnings("unused")
-    public static Object createFromLoader(ImageSingletonLoader loader) {
-        return new MethodTableFirstIDTracker(loader.readInt("startingID"));
+    static class SingletonInstantiator implements SingletonLayeredCallbacks.LayeredSingletonInstantiator<MethodTableFirstIDTracker> {
+        @Override
+        public MethodTableFirstIDTracker createFromLoader(ImageSingletonLoader loader) {
+            return new MethodTableFirstIDTracker(loader.readInt("startingID"));
+        }
     }
 }
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/meta/KnownOffsets.java

@@ -26,7 +26,6 @@
 
 import java.lang.reflect.Field;
 import java.util.Arrays;
-import java.util.EnumSet;
 import java.util.function.Predicate;
 
 import org.graalvm.nativeimage.ImageSingletons;
@@ -40,7 +39,13 @@
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonLoader;
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
 import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
+import com.oracle.svm.core.traits.BuiltinTraits.BuildtimeAccessOnly;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacks;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacksSupplier;
+import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.Independent;
+import com.oracle.svm.core.traits.SingletonTrait;
+import com.oracle.svm.core.traits.SingletonTraitKind;
+import com.oracle.svm.core.traits.SingletonTraits;
 import com.oracle.svm.core.util.VMError;
 
 import jdk.graal.compiler.api.replacements.Fold;
@@ -157,28 +162,38 @@ public int getImageCodeInfoCodeStartOffset() {
         return imageCodeInfoCodeStartOffset;
     }
 
-    static class PriorKnownOffsets implements LayeredImageSingleton {
+    @SingletonTraits(access = BuildtimeAccessOnly.class, layeredCallbacks = PriorKnownOffsets.LayeredCallbacks.class, layeredInstallationKind = Independent.class)
+    static class PriorKnownOffsets {
         final int[] priorValues;
 
         PriorKnownOffsets(int[] priorValues) {
             this.priorValues = priorValues;
         }
 
-        @Override
-        public EnumSet<LayeredImageSingletonBuilderFlags> getImageBuilderFlags() {
-            return LayeredImageSingletonBuilderFlags.BUILDTIME_ACCESS_ONLY;
-        }
-
-        @Override
-        public PersistFlags preparePersist(ImageSingletonWriter writer) {
-            writer.writeIntList("priorValues", Arrays.stream(priorValues).boxed().toList());
-            return PersistFlags.CREATE;
+        static class LayeredCallbacks extends SingletonLayeredCallbacksSupplier {
+            @Override
+            public SingletonTrait getLayeredCallbacksTrait() {
+                return new SingletonTrait(SingletonTraitKind.LAYERED_CALLBACKS, new SingletonLayeredCallbacks<PriorKnownOffsets>() {
+                    @Override
+                    public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, PriorKnownOffsets singleton) {
+                        writer.writeIntList("priorValues", Arrays.stream(singleton.priorValues).boxed().toList());
+                        return LayeredImageSingleton.PersistFlags.CREATE;
+                    }
+
+                    @Override
+                    public Class<? extends SingletonLayeredCallbacks.LayeredSingletonInstantiator<?>> getSingletonInstantiator() {
+                        return SingletonInstantiator.class;
+                    }
+                });
+            }
         }
 
-        @SuppressWarnings("unused")
-        public static Object createFromLoader(ImageSingletonLoader loader) {
-            int[] priorValues = loader.readIntList("priorValues").stream().mapToInt(e -> e).toArray();
-            return new PriorKnownOffsets(priorValues);
+        static class SingletonInstantiator implements SingletonLayeredCallbacks.LayeredSingletonInstantiator<PriorKnownOffsets> {
+            @Override
+            public PriorKnownOffsets createFromLoader(ImageSingletonLoader loader) {
+                int[] priorValues = loader.readIntList("priorValues").stream().mapToInt(e -> e).toArray();
+                return new PriorKnownOffsets(priorValues);
+            }
         }
     }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/imagelayer/ImageLayerSection.java

@@ -29,7 +29,6 @@
 import org.graalvm.word.Pointer;
 
 import com.oracle.svm.core.c.CGlobalData;
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
 
 import jdk.graal.compiler.api.replacements.Fold;
 
@@ -38,7 +37,7 @@
  * contains the addresses of various important locations and information about values to patch at
  * runtime. See {@code ImageLayerSectionFeature} for details.
  */
-public abstract class ImageLayerSection implements LayeredImageSingleton {
+public abstract class ImageLayerSection {
 
     protected final CGlobalData<Pointer> initialSectionStart;
     protected final CGlobalData<WordPointer> cachedImageFDs;

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/LayeredModuleSingleton.java

@@ -34,15 +34,14 @@
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.Platforms;
 
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
 import com.oracle.svm.core.util.UserError;
 
 /**
  * This singleton keeps track of the {@code Module#openPackages} and {@code Module#exportedPackages}
  * from all image layers.
  */
 @Platforms(Platform.HOSTED_ONLY.class)
-public abstract class LayeredModuleSingleton implements LayeredImageSingleton {
+public abstract class LayeredModuleSingleton {
     public static final String ALL_UNNAMED_MODULE_NAME = "native-image-all-unnamed";
     public static final String EVERYONE_MODULE_NAME = "native-image-everyone";
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/StringInternSupport.java

@@ -27,7 +27,6 @@
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.EnumSet;
 import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Set;
@@ -46,20 +45,26 @@
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonLoader;
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
 import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
 import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonSupport;
 import com.oracle.svm.core.layeredimagesingleton.MultiLayeredImageSingleton;
 import com.oracle.svm.core.traits.BuiltinTraits.AllAccess;
+import com.oracle.svm.core.traits.BuiltinTraits.BuildtimeAccessOnly;
 import com.oracle.svm.core.traits.BuiltinTraits.NoLayeredCallbacks;
 import com.oracle.svm.core.traits.BuiltinTraits.RuntimeAccessOnly;
 import com.oracle.svm.core.traits.BuiltinTraits.SingleLayer;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacks;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacksSupplier;
+import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.Independent;
 import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.InitialLayerOnly;
 import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.MultiLayer;
+import com.oracle.svm.core.traits.SingletonTrait;
+import com.oracle.svm.core.traits.SingletonTraitKind;
 import com.oracle.svm.core.traits.SingletonTraits;
 import com.oracle.svm.util.ReflectionUtil;
 
 @AutomaticallyRegisteredImageSingleton
-public final class StringInternSupport implements LayeredImageSingleton {
+@SingletonTraits(access = BuildtimeAccessOnly.class, layeredCallbacks = StringInternSupport.LayeredCallbacks.class, layeredInstallationKind = Independent.class)
+public final class StringInternSupport {
 
     interface SetGenerator {
         Set<String> generateSet();
@@ -76,11 +81,7 @@ public static Field getInternedStringsField() {
 
     @Platforms(Platform.HOSTED_ONLY.class)
     public StringInternSupport() {
-        this(Set.of());
-    }
-
-    private StringInternSupport(Object obj) {
-        this.priorLayersInternedStrings = obj;
+        this.priorLayersInternedStrings = Set.of();
     }
 
     @Platforms(Platform.HOSTED_ONLY.class)
@@ -167,27 +168,27 @@ public static Object getImageInternedStrings() {
         return LayeredImageSingletonSupport.singleton().lookup(ImageInternedStrings.class, false, true);
     }
 
-    @Override
-    public EnumSet<LayeredImageSingletonBuilderFlags> getImageBuilderFlags() {
-        return LayeredImageSingletonBuilderFlags.BUILDTIME_ACCESS_ONLY;
-    }
+    static class LayeredCallbacks extends SingletonLayeredCallbacksSupplier {
+        @Override
+        public SingletonTrait getLayeredCallbacksTrait() {
+            return new SingletonTrait(SingletonTraitKind.LAYERED_CALLBACKS, new SingletonLayeredCallbacks<StringInternSupport>() {
+                @Override
+                public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, StringInternSupport singleton) {
+                    // This can be switched to use constant ids in the future
+                    List<String> newPriorInternedStrings = new ArrayList<>(singleton.internedStringsIdentityMap.size());
 
-    @Override
-    public PersistFlags preparePersist(ImageSingletonWriter writer) {
-        // This can be switched to use constant ids in the future
-        List<String> newPriorInternedStrings = new ArrayList<>(internedStringsIdentityMap.size());
+                    newPriorInternedStrings.addAll(singleton.internedStringsIdentityMap.keySet());
 
-        newPriorInternedStrings.addAll(internedStringsIdentityMap.keySet());
+                    writer.writeStringList("internedStrings", newPriorInternedStrings);
+                    return LayeredImageSingleton.PersistFlags.CALLBACK_ON_REGISTRATION;
+                }
 
-        writer.writeStringList("internedStrings", newPriorInternedStrings);
-        return PersistFlags.CREATE;
-    }
-
-    @SuppressWarnings("unused")
-    public static Object createFromLoader(ImageSingletonLoader loader) {
-        SetGenerator gen = (() -> Set.of(loader.readStringList("internedStrings").toArray(new String[0])));
-
-        return new StringInternSupport(gen);
+                @Override
+                public void onSingletonRegistration(ImageSingletonLoader loader, StringInternSupport singleton) {
+                    singleton.priorLayersInternedStrings = (SetGenerator) (() -> Set.of(loader.readStringList("internedStrings").toArray(new String[0])));
+                }
+            });
+        }
     }
 }
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/util/LayeredHostedImageHeapMapCollector.java

@@ -25,7 +25,6 @@
 package com.oracle.svm.core.util;
 
 import java.util.ArrayList;
-import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -38,7 +37,13 @@
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonLoader;
 import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
 import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
-import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
+import com.oracle.svm.core.traits.BuiltinTraits.BuildtimeAccessOnly;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacks;
+import com.oracle.svm.core.traits.SingletonLayeredCallbacksSupplier;
+import com.oracle.svm.core.traits.SingletonLayeredInstallationKind.Independent;
+import com.oracle.svm.core.traits.SingletonTrait;
+import com.oracle.svm.core.traits.SingletonTraitKind;
+import com.oracle.svm.core.traits.SingletonTraits;
 import com.oracle.svm.core.util.ImageHeapMap.HostedImageHeapMap;
 
 /**
@@ -50,7 +55,8 @@
  * {@code ImageHeapCollectionFeature#allMaps} to ensure it is always rescanned and reachable.
  */
 @Platforms(Platform.HOSTED_ONLY.class)
-public class LayeredHostedImageHeapMapCollector implements LayeredImageSingleton {
+@SingletonTraits(access = BuildtimeAccessOnly.class, layeredCallbacks = LayeredHostedImageHeapMapCollector.LayeredCallbacks.class, layeredInstallationKind = Independent.class)
+public class LayeredHostedImageHeapMapCollector {
     /**
      * Map keys of maps reachable in the current layer.
      */
@@ -92,24 +98,36 @@ public void registerPreviousLayerHostedImageHeapMap(HostedImageHeapMap<?, ?> hos
         return previousLayerReachableMaps;
     }
 
-    @Override
-    public EnumSet<LayeredImageSingletonBuilderFlags> getImageBuilderFlags() {
-        return LayeredImageSingletonBuilderFlags.BUILDTIME_ACCESS_ONLY;
-    }
+    static class LayeredCallbacks extends SingletonLayeredCallbacksSupplier {
+
+        @Override
+        public SingletonTrait getLayeredCallbacksTrait() {
+            return new SingletonTrait(SingletonTraitKind.LAYERED_CALLBACKS, new SingletonLayeredCallbacks<LayeredHostedImageHeapMapCollector>() {
+
+                @Override
+                public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, LayeredHostedImageHeapMapCollector singleton) {
+                    Set<String> reachableMapKeys = new HashSet<>(singleton.currentLayerReachableMapsKeys);
+                    if (singleton.previousLayerReachableMapKeys != null) {
+                        reachableMapKeys.addAll(singleton.previousLayerReachableMapKeys);
+                    }
+                    writer.writeStringList("reachableMapKeys", reachableMapKeys.stream().toList());
+                    return LayeredImageSingleton.PersistFlags.CREATE;
+                }
 
-    @Override
-    public PersistFlags preparePersist(ImageSingletonWriter writer) {
-        Set<String> reachableMapKeys = new HashSet<>(currentLayerReachableMapsKeys);
-        if (previousLayerReachableMapKeys != null) {
-            reachableMapKeys.addAll(previousLayerReachableMapKeys);
+                @Override
+                public Class<? extends LayeredSingletonInstantiator<?>> getSingletonInstantiator() {
+                    return SingletonInstantiator.class;
+                }
+            });
         }
-        writer.writeStringList("reachableMapKeys", reachableMapKeys.stream().toList());
-        return PersistFlags.CREATE;
     }
 
-    @SuppressWarnings("unused")
-    public static Object createFromLoader(ImageSingletonLoader loader) {
-        List<String> previousLayerReachableMapKeys = loader.readStringList("reachableMapKeys");
-        return new LayeredHostedImageHeapMapCollector(previousLayerReachableMapKeys);
+    static class SingletonInstantiator implements SingletonLayeredCallbacks.LayeredSingletonInstantiator<LayeredHostedImageHeapMapCollector> {
+
+        @Override
+        public LayeredHostedImageHeapMapCollector createFromLoader(ImageSingletonLoader loader) {
+            List<String> previousLayerReachableMapKeys = loader.readStringList("reachableMapKeys");
+            return new LayeredHostedImageHeapMapCollector(previousLayerReachableMapKeys);
+        }
     }
 }