Implement uncaught exception handler for VT executor

mkouba · Oct 15, 2023 · d5ba035 · d5ba035
1 parent bd26805
commit d5ba035
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Showing 2 changed files with 19 additions and 26 deletions.
diff --git a/...tual-threads/runtime/src/main/java/io/quarkus/virtual/threads/VirtualThreadsRecorder.java b/...tual-threads/runtime/src/main/java/io/quarkus/virtual/threads/VirtualThreadsRecorder.java
@@ -4,7 +4,6 @@
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.Optional;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadFactory;
@@ -107,34 +106,27 @@ static ExecutorService newVirtualThreadPerTaskExecutorWithName(String prefix)
         Method ofVirtual = Thread.class.getMethod("ofVirtual");
         Object vtb = ofVirtual.invoke(VirtualThreadsRecorder.class);
         Class<?> vtbClass = Class.forName("java.lang.Thread$Builder$OfVirtual");
-        Method name = vtbClass.getMethod("name", String.class, long.class);
-        vtb = name.invoke(vtb, prefix, 0);
+        // .name()
+        if (prefix != null) {
+            Method name = vtbClass.getMethod("name", String.class, long.class);
+            vtb = name.invoke(vtb, prefix, 0);
+        }
+        // .uncaughtExceptionHandler()
+        Method uncaughtHandler = vtbClass.getMethod("uncaughtExceptionHandler", Thread.UncaughtExceptionHandler.class);
+        vtb = uncaughtHandler.invoke(vtb, new Thread.UncaughtExceptionHandler() {
+            @Override
+            public void uncaughtException(Thread t, Throwable e) {
+                logger.errorf(e, "Thread %s threw an uncaught exception:", t);
+            }
+        });
+        // .factory()
         Method factory = vtbClass.getMethod("factory");
         ThreadFactory tf = (ThreadFactory) factory.invoke(vtb);
 
         return (ExecutorService) Executors.class.getMethod("newThreadPerTaskExecutor", ThreadFactory.class)
                 .invoke(VirtualThreadsRecorder.class, tf);
     }
 
-    static ExecutorService newVirtualThreadPerTaskExecutor()
-            throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
-        return (ExecutorService) Executors.class.getMethod("newVirtualThreadPerTaskExecutor")
-                .invoke(VirtualThreadsRecorder.class);
-    }
-
-    static ExecutorService newVirtualThreadExecutor()
-            throws InvocationTargetException, NoSuchMethodException, IllegalAccessException {
-        try {
-            Optional<String> namePrefix = config.namePrefix;
-            return namePrefix.isPresent() ? newVirtualThreadPerTaskExecutorWithName(namePrefix.get())
-                    : newVirtualThreadPerTaskExecutor();
-        } catch (ClassNotFoundException e) {
-            logger.warn("Unable to invoke java.util.concurrent.Executors#newThreadPerTaskExecutor" +
-                    " with VirtualThreadFactory, falling back to unnamed virtual threads", e);
-            return newVirtualThreadPerTaskExecutor();
-        }
-    }
-
     /**
      * This method uses reflection in order to allow developers to quickly test quarkus-loom without needing to
      * change --release, --source, --target flags and to enable previews.
@@ -144,8 +136,9 @@ static ExecutorService newVirtualThreadExecutor()
     private static ExecutorService createExecutor() {
         if (config.enabled) {
             try {
-                return new ContextPreservingExecutorService(newVirtualThreadExecutor());
-            } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
+                String prefix = config.namePrefix.orElse(null);
+                return new ContextPreservingExecutorService(newVirtualThreadPerTaskExecutorWithName(prefix));
+            } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException | ClassNotFoundException e) {
                 logger.debug("Unable to invoke java.util.concurrent.Executors#newVirtualThreadPerTaskExecutor", e);
                 //quite ugly but works
                 logger.warn("You weren't able to create an executor that spawns virtual threads, the default" +

diff --git a/...s/runtime/src/test/java/io/quarkus/virtual/threads/VirtualThreadExecutorSupplierTest.java b/...s/runtime/src/test/java/io/quarkus/virtual/threads/VirtualThreadExecutorSupplierTest.java
@@ -33,8 +33,8 @@ void virtualThreadCustomScheduler()
 
     @Test
     @EnabledForJreRange(min = JRE.JAVA_20, disabledReason = "Virtual Threads are a preview feature starting from Java 20")
-    void execute() throws InvocationTargetException, NoSuchMethodException, IllegalAccessException {
-        Executor executor = VirtualThreadsRecorder.newVirtualThreadPerTaskExecutor();
+    void execute() throws ClassNotFoundException, InvocationTargetException, NoSuchMethodException, IllegalAccessException {
+        Executor executor = VirtualThreadsRecorder.newVirtualThreadPerTaskExecutorWithName(null);
         var assertSubscriber = Uni.createFrom().emitter(e -> {
             assertThat(Thread.currentThread().getName()).isEmpty();
             assertThatItRunsOnVirtualThread();