[GR-9632] Classloader methods on Thread and ClassLoader.

PullRequest: graal/1727

Author: vjovanov

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

@@ -49,6 +49,7 @@
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.locks.ReentrantLock;
 
+import org.graalvm.compiler.api.replacements.Fold;
 import org.graalvm.compiler.core.common.SuppressFBWarnings;
 import org.graalvm.compiler.word.ObjectAccess;
 import org.graalvm.compiler.word.Word;
@@ -737,9 +738,15 @@ static Package getPackage(Class<?> c) {
 /** Dummy class to have a class with the file's name. */
 public final class JavaLangSubstitutions {
 
-    @Platforms(Platform.HOSTED_ONLY.class)
     public static class ClassLoaderSupport {
-        public Map<ClassLoader, Target_java_lang_ClassLoader> classloaders = Collections.synchronizedMap(new IdentityHashMap<>());
+        public Target_java_lang_ClassLoader systemClassLoader;
+
+        @Platforms(Platform.HOSTED_ONLY.class) public Map<ClassLoader, Target_java_lang_ClassLoader> classLoaders = Collections.synchronizedMap(new IdentityHashMap<>());
+
+        @Fold
+        public static ClassLoaderSupport getInstance() {
+            return ImageSingletons.lookup(ClassLoaderSupport.class);
+        }
     }
 
     @Platforms(Platform.HOSTED_ONLY.class)//

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

@@ -35,6 +35,8 @@
 import com.oracle.svm.core.annotate.Substitute;
 import com.oracle.svm.core.annotate.TargetClass;
 import com.oracle.svm.core.hub.ClassForNameSupport;
+import com.oracle.svm.core.jdk.JavaLangSubstitutions.ClassLoaderSupport;
+import com.oracle.svm.core.snippets.KnownIntrinsics;
 
 @TargetClass(ClassLoader.class)
 @Substitute
@@ -106,12 +108,7 @@ private static Enumeration<URL> getSystemResources(String name) {
 
     @Substitute
     public static ClassLoader getSystemClassLoader() {
-        /*
-         * ClassLoader.getSystemClassLoader() is used as a parameter for Class.forName(String,
-         * boolean, ClassLoader) which is implemented as ClassForNameSupport.forName(name) and
-         * ignores the class loader.
-         */
-        return null;
+        return KnownIntrinsics.unsafeCast(ClassLoaderSupport.getInstance().systemClassLoader, ClassLoader.class);
     }
 
     @Substitute

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/thread/JavaThreads.java

@@ -566,7 +566,7 @@ final class Target_java_lang_Thread {
     @Inject @RecomputeFieldValue(kind = RecomputeFieldValue.Kind.NewInstance, declClass = AtomicReference.class)//
     AtomicReference<ParkEvent> sleepParkEvent;
 
-    @Delete //
+    @Alias//
     private ClassLoader contextClassLoader;
 
     @Alias//
@@ -614,15 +614,13 @@ final class Target_java_lang_Thread {
     native void setPriority(int newPriority);
 
     @Substitute
-    @SuppressWarnings("static-method")
     public ClassLoader getContextClassLoader() {
-        /* null indicates the system class loader */
-        return null;
+        return contextClassLoader;
     }
 
     @Substitute
     public void setContextClassLoader(ClassLoader cl) {
-        // noop
+        contextClassLoader = cl;
     }
 
     /** Replace "synchronized" modifier with delegation to an atomic increment. */
@@ -692,6 +690,7 @@ private void init(ThreadGroup g, Runnable target, String name, long stackSize) {
 
         this.group = g;
         this.daemon = parent.isDaemon();
+        contextClassLoader = parent.getContextClassLoader();
         this.priority = parent.getPriority();
         this.target = target;
         setPriority(priority);

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ClassLoaderFeature.java

@@ -41,7 +41,7 @@ public void afterRegistration(AfterRegistrationAccess access) {
     }
 
     private void createClassLoaders(ClassLoader classLoader) {
-        Map<ClassLoader, Target_java_lang_ClassLoader> classLoaders = ImageSingletons.lookup(ClassLoaderSupport.class).classloaders;
+        Map<ClassLoader, Target_java_lang_ClassLoader> classLoaders = ClassLoaderSupport.getInstance().classLoaders;
         if (!classLoaders.containsKey(classLoader)) {
             ClassLoader parent = classLoader.getParent();
             if (parent != null) {
@@ -53,12 +53,18 @@ private void createClassLoaders(ClassLoader classLoader) {
         }
     }
 
+    @Override
+    public void beforeAnalysis(BeforeAnalysisAccess access) {
+        createClassLoaders(ClassLoader.getSystemClassLoader());
+        ClassLoaderSupport.getInstance().systemClassLoader = ClassLoaderSupport.getInstance().classLoaders.get(ClassLoader.getSystemClassLoader());
+    }
+
     @Override
     public void duringSetup(DuringSetupAccess access) {
         access.registerObjectReplacer(object -> {
             if (object instanceof ClassLoader) {
                 createClassLoaders((ClassLoader) object);
-                return ImageSingletons.lookup(ClassLoaderSupport.class).classloaders.get(object);
+                return ClassLoaderSupport.getInstance().classLoaders.get(object);
             }
             return object;
         });