js: support WeakReference

classlib/src/main/java/org/teavm/classlib/java/lang/ref/TWeakReference.java

@@ -19,7 +19,7 @@ public class TWeakReference<T> extends TReference<T> {
     private T value;
 
     public TWeakReference(T value) {
-        this.value = value;
+        this(value, null);
     }
 
     public TWeakReference(T value, @SuppressWarnings("unused") TReferenceQueue<T> queue) {

core/src/main/java/org/teavm/backend/javascript/JavaScriptTarget.java

@@ -21,6 +21,9 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
 import java.nio.charset.StandardCharsets;
 import java.text.DecimalFormat;
 import java.text.NumberFormat;
@@ -50,6 +53,11 @@ import org.teavm.backend.javascript.codegen.SourceWriter;
 import org.teavm.backend.javascript.codegen.SourceWriterBuilder;
 import org.teavm.backend.javascript.decompile.PreparedClass;
 import org.teavm.backend.javascript.decompile.PreparedMethod;
+import org.teavm.backend.javascript.intrinsics.ref.ReferenceQueueGenerator;
+import org.teavm.backend.javascript.intrinsics.ref.ReferenceQueueTransformer;
+import org.teavm.backend.javascript.intrinsics.ref.WeakReferenceDependencyListener;
+import org.teavm.backend.javascript.intrinsics.ref.WeakReferenceGenerator;
+import org.teavm.backend.javascript.intrinsics.ref.WeakReferenceTransformer;
 import org.teavm.backend.javascript.rendering.Renderer;
 import org.teavm.backend.javascript.rendering.RenderingContext;
 import org.teavm.backend.javascript.rendering.RenderingUtil;
@@ -143,7 +151,10 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
 
     @Override
     public List<ClassHolderTransformer> getTransformers() {
-        return Collections.emptyList();
+        return List.of(
+                new WeakReferenceTransformer(),
+                new ReferenceQueueTransformer()
+        );
     }
 
     @Override
@@ -154,6 +165,16 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
     @Override
     public void setController(TeaVMTargetController controller) {
         this.controller = controller;
+
+        var weakRefGenerator = new WeakReferenceGenerator();
+        methodGenerators.put(new MethodReference(WeakReference.class, "<init>", Object.class,
+                ReferenceQueue.class, void.class), weakRefGenerator);
+        methodGenerators.put(new MethodReference(WeakReference.class, "get", Object.class), weakRefGenerator);
+        methodGenerators.put(new MethodReference(WeakReference.class, "clear", void.class), weakRefGenerator);
+
+        var refQueueGenerator = new ReferenceQueueGenerator();
+        methodGenerators.put(new MethodReference(ReferenceQueue.class, "<init>", void.class), refQueueGenerator);
+        methodGenerators.put(new MethodReference(ReferenceQueue.class, "poll", Reference.class), refQueueGenerator);
     }
 
     @Override
@@ -321,6 +342,8 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
                 }
             }
         });
+
+        dependencyAnalyzer.addDependencyListener(new WeakReferenceDependencyListener());
     }
 
     public static void includeStackTraceMethods(DependencyAnalyzer dependencyAnalyzer) {

core/src/main/java/org/teavm/backend/javascript/intrinsics/ref/ReferenceQueueGenerator.java

@@ -0,0 +1,58 @@
+/*
+ *  Copyright 2023 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.intrinsics.ref;
+
+import java.io.IOException;
+import java.lang.ref.ReferenceQueue;
+import org.teavm.backend.javascript.codegen.SourceWriter;
+import org.teavm.backend.javascript.spi.Generator;
+import org.teavm.backend.javascript.spi.GeneratorContext;
+import org.teavm.model.FieldReference;
+import org.teavm.model.MethodReference;
+
+public class ReferenceQueueGenerator implements Generator {
+    private static final FieldReference INNER_FIELD = new FieldReference(ReferenceQueue.class.getName(), "inner");
+    private static final FieldReference REGISTRY_FIELD = new FieldReference(ReferenceQueue.class.getName(),
+            "registry");
+
+    @Override
+    public void generate(GeneratorContext context, SourceWriter writer, MethodReference methodRef) throws IOException {
+        switch (methodRef.getName()) {
+            case "<init>":
+                generateInitMethod(context, writer);
+                break;
+            case "poll":
+                generatePollMethod(context, writer);
+                break;
+        }
+    }
+
+    private void generateInitMethod(GeneratorContext context, SourceWriter writer) throws IOException {
+        writer.append(context.getParameterName(0)).append(".").appendField(INNER_FIELD).ws().append("=")
+                .ws().append("[];").softNewLine();
+        writer.append(context.getParameterName(0)).append(".").appendField(REGISTRY_FIELD).ws().append("=")
+                .ws().append("new $rt_globals.FinalizationRegistry(x").ws().append("=>").ws()
+                .append(context.getParameterName(0)).appendField(INNER_FIELD)
+                .append(".push(x));").softNewLine();
+    }
+
+    private void generatePollMethod(GeneratorContext context, SourceWriter writer) throws IOException {
+        writer.append("var value").ws().append("=").ws().append(context.getParameterName(0))
+                .append(".").appendField(INNER_FIELD).append(".shift();").softNewLine();
+        writer.append("return typeof value").ws().append("!==").ws().append("'undefined'").ws()
+                .append("?").ws().append("value").ws().append(":").ws().append("null;").softNewLine();
+    }
+}

core/src/main/java/org/teavm/backend/javascript/intrinsics/ref/ReferenceQueueTransformer.java

@@ -0,0 +1,49 @@
+/*
+ *  Copyright 2023 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.intrinsics.ref;
+
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import org.teavm.model.ClassHolder;
+import org.teavm.model.ClassHolderTransformer;
+import org.teavm.model.ClassHolderTransformerContext;
+import org.teavm.model.ElementModifier;
+import org.teavm.model.FieldHolder;
+import org.teavm.model.MethodDescriptor;
+import org.teavm.model.ValueType;
+
+public class ReferenceQueueTransformer implements ClassHolderTransformer {
+    @Override
+    public void transformClass(ClassHolder cls, ClassHolderTransformerContext context) {
+        if (cls.getName().equals(ReferenceQueue.class.getName())) {
+            var field = new FieldHolder("inner");
+            field.setType(ValueType.parse(Object.class));
+            cls.addField(field);
+
+            field = new FieldHolder("registry");
+            field.setType(ValueType.parse(Object.class));
+            cls.addField(field);
+
+            var pollMethod = cls.getMethod(new MethodDescriptor("poll", Reference.class));
+            pollMethod.setProgram(null);
+            pollMethod.getModifiers().add(ElementModifier.NATIVE);
+
+            var constructor = cls.getMethod(new MethodDescriptor("<init>", void.class));
+            constructor.setProgram(null);
+            constructor.getModifiers().add(ElementModifier.NATIVE);
+        }
+    }
+}

core/src/main/java/org/teavm/backend/javascript/intrinsics/ref/WeakReferenceDependencyListener.java

@@ -0,0 +1,58 @@
+/*
+ *  Copyright 2023 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.intrinsics.ref;
+
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import org.teavm.dependency.AbstractDependencyListener;
+import org.teavm.dependency.DependencyAgent;
+import org.teavm.dependency.MethodDependency;
+import org.teavm.model.FieldReference;
+import org.teavm.model.MethodReference;
+
+public class WeakReferenceDependencyListener extends AbstractDependencyListener {
+    @Override
+    public void methodReached(DependencyAgent agent, MethodDependency method) {
+        if (method.getMethod().getOwnerName().equals(WeakReference.class.getName())) {
+            referenceMethodReached(agent, method);
+        } else if (method.getMethod().getOwnerName().equals(ReferenceQueue.class.getName())) {
+            agent.linkField(new FieldReference(ReferenceQueue.class.getName(), "inner"));
+            agent.linkField(new FieldReference(ReferenceQueue.class.getName(), "registry"));
+        }
+    }
+
+    private void referenceMethodReached(DependencyAgent agent, MethodDependency method) {
+        switch (method.getMethod().getName()) {
+            case "<init>": {
+                if (method.getParameterCount() == 2) {
+                    var field = agent.linkField(new FieldReference(method.getMethod().getOwnerName(), "value"));
+                    method.getVariable(1).connect(field.getValue());
+                    var pollResult = agent
+                            .linkMethod(new MethodReference(ReferenceQueue.class, "poll", Reference.class))
+                            .getResult();
+                    method.getVariable(0).connect(pollResult);
+                }
+                break;
+            }
+            case "get": {
+                var field = agent.linkField(new FieldReference(method.getMethod().getOwnerName(), "value"));
+                field.getValue().connect(method.getResult());
+                break;
+            }
+        }
+    }
+}

core/src/main/java/org/teavm/backend/javascript/intrinsics/ref/WeakReferenceGenerator.java

@@ -0,0 +1,92 @@
+/*
+ *  Copyright 2023 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.intrinsics.ref;
+
+import java.io.IOException;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import org.teavm.backend.javascript.codegen.SourceWriter;
+import org.teavm.backend.javascript.spi.Generator;
+import org.teavm.backend.javascript.spi.GeneratorContext;
+import org.teavm.model.FieldReference;
+import org.teavm.model.MethodReference;
+
+public class WeakReferenceGenerator implements Generator {
+    @Override
+    public void generate(GeneratorContext context, SourceWriter writer, MethodReference methodRef) throws IOException {
+        switch (methodRef.getName()) {
+            case "<init>":
+                generateConstructor(context, writer);
+                break;
+            case "get":
+                generateGet(context, writer);
+                break;
+            case "clear":
+                generateClear(context, writer);
+                break;
+        }
+    }
+
+    private void generateConstructor(GeneratorContext context, SourceWriter writer) throws IOException {
+        writer.append("var supported").ws().append("=").ws();
+        isSupported(writer).append(";").softNewLine();
+        writer.append("var value").ws().append("=").ws().append("supported").ws()
+                .append("?").ws().append("new $rt_globals.WeakRef(")
+                .append(context.getParameterName(1)).append(")").ws();
+        writer.append(":").ws().append(context.getParameterName(0)).append(";").softNewLine();
+
+        writer.append(context.getParameterName(0)).append(".")
+                .appendField(new FieldReference(WeakReference.class.getName(), "value"))
+                .ws().append("=").ws().append("value;").softNewLine();
+
+        writer.appendIf().append(context.getParameterName(2)).ws().append("!==").ws().append("null")
+                .ws().append("&&").ws().append("supported)")
+                .appendBlockStart();
+        writer.append(context.getParameterName(2)).append(".")
+                .appendField(new FieldReference(ReferenceQueue.class.getName(), "registry"))
+                .append(".").append("register(").append(context.getParameterName(1))
+                .append(",").ws().append("value);").softNewLine();
+        writer.appendBlockEnd();
+    }
+
+    private void generateGet(GeneratorContext context, SourceWriter writer) throws IOException {
+        writer.append("var value").ws().append("=").ws().append(context.getParameterName(0)).append(".")
+                .appendField(new FieldReference(WeakReference.class.getName(), "value"))
+                .append(";").softNewLine();
+
+        writer.appendIf();
+        isSupported(writer).append(")").appendBlockStart();
+        writer.appendIf().append("value").ws().append("===").ws().append("null)")
+                .ws().append("return null;").softNewLine();
+        writer.append("var result").ws().append("=").ws().append("value.deref();").softNewLine();
+        writer.append("return typeof result").ws().append("!==").ws().append("'undefined'")
+                .ws().append("?").ws().append("result").ws().append(":").ws().append("null;").softNewLine();
+        writer.appendElse();
+        writer.append("return value;").softNewLine();
+        writer.appendBlockEnd();
+    }
+
+    private void generateClear(GeneratorContext context, SourceWriter writer) throws IOException {
+        writer.append(context.getParameterName(0)).append(".")
+                .appendField(new FieldReference(WeakReference.class.getName(), "value")).ws();
+        writer.append("=").ws().append("null;").softNewLine();
+    }
+
+    private SourceWriter isSupported(SourceWriter writer) throws IOException {
+        return writer.append("typeof ").append("$rt_globals.WeakRef").ws().append("!==").ws()
+                .append("'undefined'");
+    }
+}

core/src/main/java/org/teavm/backend/javascript/intrinsics/ref/WeakReferenceTransformer.java

@@ -0,0 +1,46 @@
+/*
+ *  Copyright 2023 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.intrinsics.ref;
+
+import java.lang.ref.WeakReference;
+import org.teavm.model.ClassHolder;
+import org.teavm.model.ClassHolderTransformer;
+import org.teavm.model.ClassHolderTransformerContext;
+import org.teavm.model.ElementModifier;
+
+public class WeakReferenceTransformer implements ClassHolderTransformer {
+    @Override
+    public void transformClass(ClassHolder cls, ClassHolderTransformerContext context) {
+        if (!cls.getName().equals(WeakReference.class.getName())) {
+            return;
+        }
+        for (var method : cls.getMethods()) {
+            switch (method.getName()) {
+                case "<init>":
+                    if (method.parameterCount() == 2) {
+                        method.setProgram(null);
+                        method.getModifiers().add(ElementModifier.NATIVE);
+                    }
+                    break;
+                case "get":
+                case "clear":
+                    method.setProgram(null);
+                    method.getModifiers().add(ElementModifier.NATIVE);
+                    break;
+            }
+        }
+    }
+}

core/src/main/java/org/teavm/backend/javascript/runtime/ref/RuntimeWeakRef.java

@@ -0,0 +1,20 @@
+/*
+ *  Copyright 2023 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.javascript.runtime.ref;
+
+public final class RuntimeWeakRef {
+
+}

tests/src/test/java/org/teavm/classlib/java/lang/ref/WeakReferenceTest.java

@@ -0,0 +1,106 @@
+/*
+ *  Copyright 2023 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.lang.ref;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.teavm.junit.SkipJVM;
+import org.teavm.junit.TeaVMTestRunner;
+import org.teavm.junit.WholeClassCompilation;
+
+@RunWith(TeaVMTestRunner.class)
+@WholeClassCompilation
+@SkipJVM
+public class WeakReferenceTest {
+    private Node lastNode;
+
+    @Test
+    @Ignore
+    public void deref() {
+        var ref = createAndTestRef(null);
+
+        for (var i = 0; i < 100; ++i) {
+            lastNode = createNodes(18);
+            if (ref.get() == null) {
+                break;
+            }
+        }
+        assertNull(ref.get());
+    }
+
+    @Test
+    @Ignore
+    public void refQueue() {
+        var queue = new ReferenceQueue<>();
+        var ref = createAndTestRef(queue);
+        var hasValue = false;
+        for (var i = 0; i < 100; ++i) {
+            lastNode = createNodes(18);
+            var polledRef = queue.poll();
+            if (polledRef != null) {
+                hasValue = true;
+                assertNull(ref.get());
+                break;
+            } else {
+                assertNotNull(ref.get());
+            }
+        }
+        assertTrue(hasValue);
+    }
+
+    private WeakReference<Object> createAndTestRef(ReferenceQueue<Object> queue) {
+        var obj = new byte[4 * 1024 * 1024];
+        var ref = new WeakReference<Object>(obj, queue);
+        assertSame(obj, ref.get());
+        return ref;
+    }
+
+    @Test
+    public void clear() {
+        var obj = new Object();
+        var ref = new WeakReference<>(obj);
+        assertSame(obj, ref.get());
+
+        ref.clear();
+        assertNull(ref.get());
+    }
+
+    private Node createNodes(int depth) {
+        if (depth == 0) {
+            return null;
+        } else {
+            return new Node(createNodes(depth - 1), createNodes(depth - 1));
+        }
+    }
+
+    private class Node {
+        Node left;
+        Node right;
+        byte[] data = new byte[64];
+
+        Node(Node left, Node right) {
+            this.left = left;
+            this.right = right;
+        }
+    }
+}