oracle · graalvmbot · Jan 17, 2025 · Jan 6, 2025
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java
@@ -1012,7 +1012,7 @@ public Object[] getEnumConstantsShared() {
     @Substitute
     public InputStream getResourceAsStream(String resourceName) {
         String resolvedName = resolveName(resourceName);
-        return Resources.singleton().createInputStream(companion.module, resolvedName);
+        return Resources.createInputStream(companion.module, resolvedName);
     }
 
     @KeepOriginal

diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/Resources.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/Resources.java
@@ -34,10 +34,12 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
+import java.util.EnumSet;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
@@ -53,6 +55,7 @@
 import com.oracle.svm.core.ClassLoaderSupport.ConditionWithOrigin;
 import com.oracle.svm.core.MissingRegistrationUtils;
 import com.oracle.svm.core.SubstrateOptions;
+import com.oracle.svm.core.SubstrateUtil;
 import com.oracle.svm.core.configure.ConditionalRuntimeValue;
 import com.oracle.svm.core.configure.RuntimeConditionSet;
 import com.oracle.svm.core.feature.AutomaticallyRegisteredFeature;
@@ -67,6 +70,9 @@
 import com.oracle.svm.core.jdk.resources.CompressedGlobTrie.CompressedGlobTrie;
 import com.oracle.svm.core.jdk.resources.CompressedGlobTrie.GlobTrieNode;
 import com.oracle.svm.core.jdk.resources.CompressedGlobTrie.GlobUtils;
+import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
+import com.oracle.svm.core.layeredimagesingleton.MultiLayeredImageSingleton;
+import com.oracle.svm.core.layeredimagesingleton.UnsavedSingleton;
 import com.oracle.svm.core.util.ImageHeapMap;
 import com.oracle.svm.core.util.VMError;
 import com.oracle.svm.util.LogUtils;
@@ -78,15 +84,29 @@
  * Registered resources are then available from DynamicHub#getResource classes and
  * {@link Target_java_lang_ClassLoader class loaders}.
  */
-public final class Resources {
+public final class Resources implements MultiLayeredImageSingleton, UnsavedSingleton {
 
     private static final int INVALID_TIMESTAMP = -1;
     public static final char RESOURCES_INTERNAL_PATH_SEPARATOR = '/';
 
+    /**
+     * @return the singleton corresponding to this layer's resources in a layered build, the unique
+     *         singleton otherwise
+     */
+    @Platforms(Platform.HOSTED_ONLY.class)
     public static Resources singleton() {
         return ImageSingletons.lookup(Resources.class);
     }
 
+    /**
+     * @return an array of singletons corresponding to all layers in a layered build, or an array
+     *         with a single element otherwise
+     */
+    public static Resources[] layeredSingletons() {
+        assert !SubstrateUtil.HOSTED : "Accessing all layers resources at build time";
+        return MultiLayeredImageSingleton.getAllLayers(Resources.class);
+    }
+
     /**
      * The hosted map used to collect registered resources. Using a {@link ModuleResourceKey} of
      * (module, resourceName) provides implementations for {@code hashCode()} and {@code equals()}
@@ -139,20 +159,31 @@ public void setResourcesTrieRoot(GlobTrieNode<ConditionWithOrigin> resourcesTrie
         this.resourcesTrieRoot = resourcesTrieRoot;
     }
 
-    public EconomicMap<ModuleResourceKey, ConditionalRuntimeValue<ResourceStorageEntryBase>> getResourceStorage() {
-        return resources;
+    public void forEachResource(BiConsumer<ModuleResourceKey, ConditionalRuntimeValue<ResourceStorageEntryBase>> action) {
+        MapCursor<ModuleResourceKey, ConditionalRuntimeValue<ResourceStorageEntryBase>> entries = resources.getEntries();
+        while (entries.advance()) {
+            action.accept(entries.getKey(), entries.getValue());
+        }
+    }
+
+    @Platforms(Platform.HOSTED_ONLY.class)
+    public ConditionalRuntimeValue<ResourceStorageEntryBase> getResource(ModuleResourceKey storageKey) {
+        return resources.get(storageKey);
     }
 
+    @Platforms(Platform.HOSTED_ONLY.class)
     public Iterable<ConditionalRuntimeValue<ResourceStorageEntryBase>> resources() {
         return resources.getValues();
     }
 
+    @Platforms(Platform.HOSTED_ONLY.class)
     public int count() {
         return resources.size();
     }
 
-    public long getLastModifiedTime() {
-        return lastModifiedTime;
+    public static long getLastModifiedTime() {
+        var singletons = layeredSingletons();
+        return singletons[singletons.length - 1].lastModifiedTime;
     }
 
     public static String moduleName(Module module) {
@@ -169,6 +200,7 @@ public static ModuleResourceKey createStorageKey(Module module, String resourceN
         return new ModuleResourceKey(m, resourceName);
     }
 
+    @Platforms(Platform.HOSTED_ONLY.class)
     public static Set<String> getIncludedResourcesModules() {
         return StreamSupport.stream(singleton().resources.getKeys().spliterator(), false)
                         .map(ModuleResourceKey::module)
@@ -320,7 +352,7 @@ private static boolean wasAlreadyInCanonicalForm(String resourceName, String can
         return resourceName.equals(canonicalResourceName) || removeTrailingSlash(resourceName).equals(canonicalResourceName);
     }
 
-    public ResourceStorageEntryBase getAtRuntime(String name, boolean throwOnMissing) {
+    public static ResourceStorageEntryBase getAtRuntime(String name, boolean throwOnMissing) {
         return getAtRuntime(null, name, throwOnMissing);
     }
 
@@ -330,29 +362,31 @@ public ResourceStorageEntryBase getAtRuntime(String name, boolean throwOnMissing
      * {@link MissingResourceRegistrationError}. This is needed because different modules can be
      * tried on the same resource name, causing an unexpected exception if we throw directly.
      */
-    public ResourceStorageEntryBase getAtRuntime(Module module, String resourceName, boolean throwOnMissing) {
+    public static ResourceStorageEntryBase getAtRuntime(Module module, String resourceName, boolean throwOnMissing) {
         VMError.guarantee(ImageInfo.inImageRuntimeCode(), "This function should be used only at runtime.");
         String canonicalResourceName = toCanonicalForm(resourceName);
         String moduleName = moduleName(module);
-        ConditionalRuntimeValue<ResourceStorageEntryBase> entry = resources.get(createStorageKey(module, canonicalResourceName));
+        ConditionalRuntimeValue<ResourceStorageEntryBase> entry = getEntry(module, canonicalResourceName);
         if (entry == null) {
             if (MissingRegistrationUtils.throwMissingRegistrationErrors()) {
-                MapCursor<RequestedPattern, RuntimeConditionSet> cursor = requestedPatterns.getEntries();
-                while (cursor.advance()) {
-                    RequestedPattern moduleResourcePair = cursor.getKey();
-                    if (Objects.equals(moduleName, moduleResourcePair.module) &&
-                                    ((matchResource(moduleResourcePair.resource, resourceName) || matchResource(moduleResourcePair.resource, canonicalResourceName)) &&
-                                                    cursor.getValue().satisfied())) {
-                        return null;
+                for (var r : layeredSingletons()) {
+                    MapCursor<RequestedPattern, RuntimeConditionSet> cursor = r.requestedPatterns.getEntries();
+                    while (cursor.advance()) {
+                        RequestedPattern moduleResourcePair = cursor.getKey();
+                        if (Objects.equals(moduleName, moduleResourcePair.module) &&
+                                        ((matchResource(moduleResourcePair.resource, resourceName) || matchResource(moduleResourcePair.resource, canonicalResourceName)) &&
+                                                        cursor.getValue().satisfied())) {
+                            return null;
+                        }
                     }
-                }
 
-                String glob = GlobUtils.transformToTriePath(resourceName, moduleName);
-                String canonicalGlob = GlobUtils.transformToTriePath(canonicalResourceName, moduleName);
-                GlobTrieNode<ConditionWithOrigin> globsTrie = getResourcesTrieRoot();
-                if (CompressedGlobTrie.match(globsTrie, glob) ||
-                                CompressedGlobTrie.match(globsTrie, canonicalGlob)) {
-                    return null;
+                    String glob = GlobUtils.transformToTriePath(resourceName, moduleName);
+                    String canonicalGlob = GlobUtils.transformToTriePath(canonicalResourceName, moduleName);
+                    GlobTrieNode<ConditionWithOrigin> globsTrie = r.getResourcesTrieRoot();
+                    if (CompressedGlobTrie.match(globsTrie, glob) ||
+                                    CompressedGlobTrie.match(globsTrie, canonicalGlob)) {
+                        return null;
+                    }
                 }
 
                 return missingMetadata(resourceName, throwOnMissing);
@@ -389,6 +423,16 @@ public ResourceStorageEntryBase getAtRuntime(Module module, String resourceName,
         return unconditionalEntry;
     }
 
+    private static ConditionalRuntimeValue<ResourceStorageEntryBase> getEntry(Module module, String canonicalResourceName) {
+        for (var r : layeredSingletons()) {
+            ConditionalRuntimeValue<ResourceStorageEntryBase> entry = r.resources.get(createStorageKey(module, canonicalResourceName));
+            if (entry != null) {
+                return entry;
+            }
+        }
+        return null;
+    }
+
     private static ResourceStorageEntryBase missingMetadata(String resourceName, boolean throwOnMissing) {
         if (throwOnMissing) {
             MissingResourceRegistrationUtils.missingResource(resourceName);
@@ -407,11 +451,11 @@ private static URL createURL(Module module, String resourceName, int index) {
         }
     }
 
-    public URL createURL(String resourceName) {
+    public static URL createURL(String resourceName) {
         return createURL(null, resourceName);
     }
 
-    public URL createURL(Module module, String resourceName) {
+    public static URL createURL(Module module, String resourceName) {
         if (resourceName == null) {
             return null;
         }
@@ -420,12 +464,12 @@ public URL createURL(Module module, String resourceName) {
         return urls.hasMoreElements() ? urls.nextElement() : null;
     }
 
-    public InputStream createInputStream(String resourceName) {
+    public static InputStream createInputStream(String resourceName) {
         return createInputStream(null, resourceName);
     }
 
     /* Avoid pulling in the URL class when only an InputStream is needed. */
-    public InputStream createInputStream(Module module, String resourceName) {
+    public static InputStream createInputStream(Module module, String resourceName) {
         if (resourceName == null) {
             return null;
         }
@@ -458,11 +502,11 @@ public InputStream createInputStream(Module module, String resourceName) {
         return data.isEmpty() ? null : new ByteArrayInputStream(data.get(0));
     }
 
-    public Enumeration<URL> createURLs(String resourceName) {
+    public static Enumeration<URL> createURLs(String resourceName) {
         return createURLs(null, resourceName);
     }
 
-    public Enumeration<URL> createURLs(Module module, String resourceName) {
+    public static Enumeration<URL> createURLs(Module module, String resourceName) {
         if (resourceName == null) {
             return null;
         }
@@ -541,6 +585,11 @@ private static boolean matchResource(String pattern, String resource) {
 
         return resource.startsWith(start) && resource.endsWith(end);
     }
+
+    @Override
+    public EnumSet<LayeredImageSingletonBuilderFlags> getImageBuilderFlags() {
+        return LayeredImageSingletonBuilderFlags.ALL_ACCESS;
+    }
 }
 
 @AutomaticallyRegisteredFeature

diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/ResourcesHelper.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/ResourcesHelper.java
@@ -32,18 +32,18 @@
 import java.util.Enumeration;
 import java.util.List;
 
-import com.oracle.svm.core.util.VMError;
-
 import org.graalvm.nativeimage.ImageInfo;
 
+import com.oracle.svm.core.util.VMError;
+
 public class ResourcesHelper {
 
     public static URL nameToResourceURL(String resourceName) {
-        return Resources.singleton().createURL(resourceName);
+        return Resources.createURL(resourceName);
     }
 
     public static URL nameToResourceURL(Module module, String resourceName) {
-        return Resources.singleton().createURL(module, resourceName);
+        return Resources.createURL(module, resourceName);
     }
 
     public static InputStream nameToResourceInputStream(String mn, String resourceName) throws IOException {
@@ -54,7 +54,7 @@ public static InputStream nameToResourceInputStream(String mn, String resourceNa
     }
 
     public static List<URL> nameToResourceListURLs(String resourcesName) {
-        Enumeration<URL> urls = Resources.singleton().createURLs(resourcesName);
+        Enumeration<URL> urls = Resources.createURLs(resourcesName);
         List<URL> resourceURLs = new ArrayList<>();
         while (urls.hasMoreElements()) {
             resourceURLs.add(urls.nextElement());

diff --git a/....oracle.svm.core/src/com/oracle/svm/core/jdk/resources/NativeImageResourceFileSystem.java b/....oracle.svm.core/src/com/oracle/svm/core/jdk/resources/NativeImageResourceFileSystem.java
@@ -84,10 +84,7 @@
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.regex.Pattern;
 
-import org.graalvm.collections.MapCursor;
-
 import com.oracle.svm.core.MissingRegistrationUtils;
-import com.oracle.svm.core.configure.ConditionalRuntimeValue;
 import com.oracle.svm.core.jdk.Resources;
 import com.oracle.svm.core.util.TimeUtils;
 
@@ -577,7 +574,7 @@ IndexNode getInode(byte[] path) {
         IndexNode indexNode = inodes.get(IndexNode.keyOf(path));
         if (indexNode == null && MissingRegistrationUtils.throwMissingRegistrationErrors()) {
             // Try to access the resource to see if the metadata is present
-            Resources.singleton().getAtRuntime(getString(path), true);
+            Resources.getAtRuntime(getString(path), true);
         }
         return indexNode;
     }
@@ -658,14 +655,15 @@ private void update(Entry e) {
     }
 
     private void readAllEntries() {
-        MapCursor<Resources.ModuleResourceKey, ConditionalRuntimeValue<ResourceStorageEntryBase>> entries = Resources.singleton().getResourceStorage().getEntries();
-        while (entries.advance()) {
-            byte[] name = getBytes(entries.getKey().resource());
-            ResourceStorageEntryBase entry = entries.getValue().getValue();
-            if (entry != null && entry.hasData()) {
-                IndexNode newIndexNode = new IndexNode(name, entry.isDirectory(), true);
-                inodes.put(newIndexNode, newIndexNode);
-            }
+        for (var resources : Resources.layeredSingletons()) {
+            resources.forEachResource((key, value) -> {
+                byte[] name = getBytes(key.resource());
+                ResourceStorageEntryBase entry = value.getValue();
+                if (entry != null && entry.hasData()) {
+                    IndexNode newIndexNode = new IndexNode(name, entry.isDirectory(), true);
+                    inodes.put(newIndexNode, newIndexNode);
+                }
+            });
         }
         buildNodeTree();
     }

diff --git a/...cle.svm.core/src/com/oracle/svm/core/jdk/resources/NativeImageResourceFileSystemUtil.java b/...cle.svm.core/src/com/oracle/svm/core/jdk/resources/NativeImageResourceFileSystemUtil.java
@@ -36,7 +36,7 @@ private NativeImageResourceFileSystemUtil() {
     }
 
     public static byte[] getBytes(String resourceName, boolean readOnly) {
-        Object entry = Resources.singleton().getAtRuntime(resourceName, true);
+        Object entry = Resources.getAtRuntime(resourceName, true);
         if (entry == null) {
             return new byte[0];
         }
@@ -49,7 +49,7 @@ public static byte[] getBytes(String resourceName, boolean readOnly) {
     }
 
     public static int getSize(String resourceName) {
-        Object entry = Resources.singleton().getAtRuntime(resourceName, true);
+        Object entry = Resources.getAtRuntime(resourceName, true);
         if (entry == null) {
             return 0;
         } else {

diff --git a/.../src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/resources/ResourceURLConnection.java b/.../src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/resources/ResourceURLConnection.java
@@ -74,7 +74,7 @@ public void connect() {
         String resourceName = urlPath.substring(1);
 
         Module module = hostNameOrNull != null ? ModuleLayer.boot().findModule(hostNameOrNull).orElse(null) : null;
-        Object entry = Resources.singleton().getAtRuntime(module, resourceName, true);
+        Object entry = Resources.getAtRuntime(module, resourceName, true);
         if (entry != null) {
             ResourceStorageEntry resourceStorageEntry = (ResourceStorageEntry) entry;
             List<byte[]> bytes = resourceStorageEntry.getData();
@@ -174,7 +174,7 @@ private void initializeHeaders() {
                     properties.add(CONTENT_LENGTH, String.valueOf(data.length));
                 }
 
-                long lastModified = Resources.singleton().getLastModifiedTime();
+                long lastModified = Resources.getLastModifiedTime();
                 Date date = new Date(lastModified);
                 SimpleDateFormat fo = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
                 fo.setTimeZone(TimeZone.getTimeZone("GMT"));

diff --git a/...tratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/EmbeddedResourceExporter.java b/...tratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/EmbeddedResourceExporter.java
@@ -33,11 +33,9 @@
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.graalvm.collections.EconomicMap;
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.Platforms;
 
-import com.oracle.svm.core.configure.ConditionalRuntimeValue;
 import com.oracle.svm.core.jdk.Resources;
 import com.oracle.svm.core.jdk.resources.ResourceStorageEntryBase;
 import com.oracle.svm.core.util.VMError;
@@ -101,12 +99,11 @@ private static List<ResourceReportEntry> getResourceReportEntryList(ConcurrentHa
         }
 
         List<ResourceReportEntry> resourceInfoList = new ArrayList<>();
-        EconomicMap<Resources.ModuleResourceKey, ConditionalRuntimeValue<ResourceStorageEntryBase>> resourceStorage = Resources.singleton().getResourceStorage();
-        resourceStorage.getKeys().forEach(key -> {
+        Resources.singleton().forEachResource((key, value) -> {
             Module module = key.module();
             String resourceName = key.resource();
 
-            ResourceStorageEntryBase storageEntry = resourceStorage.get(key).getValueUnconditionally();
+            ResourceStorageEntryBase storageEntry = value.getValueUnconditionally();
             List<SourceAndOrigin> registeredEntrySources = collection.get(key);
 
             if (registeredEntrySources == null && storageEntry != NEGATIVE_QUERY_MARKER) {

diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ResourcesFeature.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ResourcesFeature.java
@@ -199,7 +199,7 @@ public void addGlob(ConfigurationCondition condition, String module, String glob
 
         @Override
         public void addCondition(ConfigurationCondition condition, Module module, String resourcePath) {
-            var conditionalResource = Resources.singleton().getResourceStorage().get(createStorageKey(module, resourcePath));
+            var conditionalResource = Resources.singleton().getResource(createStorageKey(module, resourcePath));
             if (conditionalResource != null) {
                 classInitializationSupport.addForTypeReachedTracking(condition.getType());
                 conditionalResource.getConditions().addCondition(condition);