Wait for thread completion only if interrupted flag set

microprofile/fault-tolerance/src/main/java/io/helidon/microprofile/faulttolerance/FaultToleranceCommand.java

@@ -450,17 +450,17 @@ private void logCircuitBreakerState(String preamble) {
 
     /**
      * <p>After a timeout expires, Hystrix can report an {@link ExecutionException}
-     * while a thread is still running and cannot be interrupted (e.g. busy
-     * loop). Hystrix makes this possible by using another thread to monitor
+     * when a thread has been interrupted but it is still running (e.g. while in a
+     * busy loop). Hystrix makes this possible by using another thread to monitor
      * the command's thread.</p>
      *
      * <p>According to the FT spec, the thread may continue to run, so here
      * we give it a chance to do that before completing the execution of the
      * command. For more information see TCK test {@code
-     * TimeoutUninterruptableTest::timeoutTest}.</p>
+     * TimeoutUninterruptableTest::testTimeout}.</p>
      */
     private void waitForThreadToComplete() {
-        if (!introspector.isAsynchronous() && runThread != null) {
+        if (!introspector.isAsynchronous() && runThread != null && runThread.isInterrupted()) {
             try {
                 int waitTime = 250;
                 while (runThread.getState() == Thread.State.RUNNABLE && waitTime <= threadWaitingPeriod) {

microprofile/fault-tolerance/src/test/java/io/helidon/microprofile/faulttolerance/TimeoutNoRetryBean.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ *
+ * 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 io.helidon.microprofile.faulttolerance;
+
+import java.time.temporal.ChronoUnit;
+import javax.enterprise.context.Dependent;
+
+import org.eclipse.microprofile.faulttolerance.Timeout;
+import org.eclipse.microprofile.faulttolerance.exceptions.TimeoutException;
+
+/**
+ * Class TimeoutNoRetryBean.
+ */
+@Dependent
+public class TimeoutNoRetryBean {
+
+    @Timeout(value=1000, unit=ChronoUnit.MILLIS)
+    public String forceTimeoutSleep() throws InterruptedException, TimeoutException {
+        FaultToleranceTest.printStatus("TimeoutNoRetryBean::forceTimeout()", "failure");
+        Thread.sleep(2000);
+        return "failure";
+    }
+
+    @Timeout(value=1000, unit=ChronoUnit.MILLIS)
+    public String forceTimeoutLoop() throws TimeoutException {
+        FaultToleranceTest.printStatus("TimeoutNoRetryBean::forceTimeoutLoop()", "failure");
+        long start = System.currentTimeMillis();
+        while (System.currentTimeMillis() - start < 2000) {
+            // busy loop
+        }
+        return "success";
+    }
+}

microprofile/fault-tolerance/src/test/java/io/helidon/microprofile/faulttolerance/TimeoutTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2019 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2020 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,10 +17,13 @@
 package io.helidon.microprofile.faulttolerance;
 
 import org.eclipse.microprofile.faulttolerance.exceptions.TimeoutException;
+
 import org.junit.jupiter.api.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.lessThan;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 /**
@@ -29,11 +32,9 @@
 public class TimeoutTest extends FaultToleranceTest {
 
     @Test
-    public void testForceTimeout() throws Exception {
+    public void testForceTimeout() {
         TimeoutBean bean = newBean(TimeoutBean.class);
-        assertThrows(TimeoutException.class, () -> {
-            bean.forceTimeout();
-        });
+        assertThrows(TimeoutException.class, bean::forceTimeout);
     }
 
     @Test
@@ -59,4 +60,26 @@ public void testTimeoutWithRetriesAndFallback() throws Exception {
         TimeoutBean bean = newBean(TimeoutBean.class);
         assertThat(bean.timeoutWithRetriesAndFallback(), is("fallback"));
     }
+
+    @Test
+    public void testForceTimeoutSleep() {
+        TimeoutNoRetryBean bean = newBean(TimeoutNoRetryBean.class);
+        long start = System.currentTimeMillis();
+        try {
+            bean.forceTimeoutSleep();       // can interrupt
+        } catch (InterruptedException | TimeoutException e) {
+            assertThat(System.currentTimeMillis() - start, is(lessThan(2000L)));
+        }
+     }
+
+    @Test
+    public void testForceTimeoutLoop() {
+        TimeoutNoRetryBean bean = newBean(TimeoutNoRetryBean.class);
+        long start = System.currentTimeMillis();
+        try {
+            bean.forceTimeoutLoop();        // cannot interrupt
+        } catch (TimeoutException e) {
+            assertThat(System.currentTimeMillis() - start, is(greaterThan(2000L)));
+        }
+    }
 }