Zero-Garbage ContextInstances::forEach

independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/ContextInstancesGenerator.java

@@ -5,6 +5,7 @@
 import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
 import static org.objectweb.asm.Opcodes.ACC_VOLATILE;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -13,6 +14,7 @@
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 import org.jboss.jandex.DotName;
@@ -88,7 +90,7 @@ Collection<Resource> generate(DotName scope) {
         implementRemove(contextInstances, beans, idToField, lockField.getFieldDescriptor());
         implementClear(contextInstances, idToField, lockField.getFieldDescriptor());
         implementGetAllPresent(contextInstances, idToField, lockField.getFieldDescriptor());
-
+        implementForEach(contextInstances, idToField, lockField.getFieldDescriptor());
         contextInstances.close();
 
         return classOutput.getResources();
@@ -149,6 +151,31 @@ private void implementClear(ClassCreator applicationContextInstances, Map<String
         catchBlock.throwException(catchBlock.getCaughtException());
     }
 
+    private void implementForEach(ClassCreator contextInstances, Map<String, FieldDescriptor> idToField,
+            FieldDescriptor lockField) {
+        MethodCreator forEach = contextInstances.getMethodCreator("forEach", void.class, Consumer.class)
+                .setModifiers(ACC_PUBLIC);
+        // lock.lock();
+        // ContextInstanceHandle<?> copy = this.1;
+        // lock.unlock();
+        // if (copy != null) {
+        //    consumer.accept(copy);
+        // }
+        ResultHandle lock = forEach.readInstanceField(lockField, forEach.getThis());
+        forEach.invokeInterfaceMethod(MethodDescriptors.LOCK_LOCK, lock);
+        List<ResultHandle> results = new ArrayList<>(idToField.size());
+        for (FieldDescriptor field : idToField.values()) {
+            results.add(forEach.readInstanceField(field, forEach.getThis()));
+        }
+        forEach.invokeInterfaceMethod(MethodDescriptors.LOCK_UNLOCK, lock);
+        for (int i = 0; i < results.size(); i++) {
+            ResultHandle copy = results.get(i);
+            BytecodeCreator isNotNull = forEach.ifNotNull(copy).trueBranch();
+            isNotNull.invokeInterfaceMethod(MethodDescriptors.CONSUMER_ACCEPT, forEach.getMethodParam(0), copy);
+        }
+        forEach.returnVoid();
+    }
+
     private void implementRemove(ClassCreator contextInstances, List<BeanInfo> applicationScopedBeans,
             Map<String, FieldDescriptor> idToField, FieldDescriptor lockField) {
         MethodCreator remove = contextInstances

independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/MethodDescriptors.java

@@ -11,6 +11,7 @@
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.function.BiFunction;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -63,6 +64,9 @@ public final class MethodDescriptors {
 
     public static final MethodDescriptor SUPPLIER_GET = MethodDescriptor.ofMethod(Supplier.class, "get", Object.class);
 
+    public static final MethodDescriptor CONSUMER_ACCEPT = MethodDescriptor.ofMethod(Consumer.class, "accept",
+            void.class, Object.class);
+
     public static final MethodDescriptor CREATIONAL_CTX_CHILD = MethodDescriptor.ofMethod(CreationalContextImpl.class, "child",
             CreationalContextImpl.class,
             CreationalContext.class);

independent-projects/arc/runtime/src/main/java/io/quarkus/arc/impl/AbstractSharedContext.java

@@ -1,9 +1,6 @@
 package io.quarkus.arc.impl;
 
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
+import java.util.*;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -87,7 +84,11 @@ public void destroy(Contextual<?> contextual) {
 
     @Override
     public synchronized void destroy() {
-        Set<ContextInstanceHandle<?>> values = instances.getAllPresent();
+        List<ContextInstanceHandle<?>> values = new LinkedList<>();
+        instances.forEach(values::add);
+        if (values.isEmpty()) {
+            return;
+        }
         // Destroy the producers first
         for (Iterator<ContextInstanceHandle<?>> iterator = values.iterator(); iterator.hasNext();) {
             ContextInstanceHandle<?> instanceHandle = iterator.next();

independent-projects/arc/runtime/src/main/java/io/quarkus/arc/impl/ComputingCacheContextInstances.java

@@ -1,6 +1,7 @@
 package io.quarkus.arc.impl;
 
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 import io.quarkus.arc.ContextInstanceHandle;
@@ -38,4 +39,9 @@ public void clear() {
         instances.clear();
     }
 
+    @Override
+    public void forEach(Consumer<? super ContextInstanceHandle<?>> handleConsumer) {
+        instances.getPresentValues().forEach(handleConsumer);
+    }
+
 }

independent-projects/arc/runtime/src/main/java/io/quarkus/arc/impl/ContextInstances.java

@@ -1,6 +1,7 @@
 package io.quarkus.arc.impl;
 
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 import io.quarkus.arc.ContextInstanceHandle;
@@ -17,4 +18,6 @@ public interface ContextInstances {
 
     void clear();
 
+    void forEach(Consumer<? super ContextInstanceHandle<?>> handleConsumer);
+
 }

independent-projects/arc/runtime/src/main/java/io/quarkus/arc/impl/RequestContext.java

@@ -210,7 +210,7 @@ public void destroy(ContextState state) {
             if (reqState.invalidate()) {
                 // Fire an event with qualifier @BeforeDestroyed(RequestScoped.class) if there are any observers for it
                 fireIfNotEmpty(beforeDestroyedNotifier);
-                reqState.contextInstances.getAllPresent().forEach(this::destroyContextElement);
+                reqState.contextInstances.forEach(this::destroyContextElement);
                 reqState.contextInstances.clear();
                 // Fire an event with qualifier @Destroyed(RequestScoped.class) if there are any observers for it
                 fireIfNotEmpty(destroyedNotifier);