Fix SimpleScheduler pause functionality.

Add return in SimpleScheduler::checkTriggers method if !running.

Unit test for SimpleScheduler::pause functionality
Pause and check isRunning returns false and scheduler doesn't trigger CountDownLatch::countDown

extensions/scheduler/deployment/src/test/java/io/quarkus/scheduler/test/PausedSchedulerTest.java

@@ -0,0 +1,48 @@
+package io.quarkus.scheduler.test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import javax.inject.Inject;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.scheduler.Scheduled;
+import io.quarkus.scheduler.Scheduler;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class PausedSchedulerTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest test = new QuarkusUnitTest()
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
+                    .addClasses(PausedSchedulerTest.Jobs.class)
+                    .addAsResource(new StringAsset("quarkus.scheduler.enabled=true"),
+                            "application.properties"));
+
+    @Inject
+    Scheduler scheduler;
+
+    @Test
+    public void testSchedulerPauseMethod() throws InterruptedException {
+        scheduler.pause();
+        assertFalse(scheduler.isRunning());
+        assertFalse(Jobs.LATCH.await(3, TimeUnit.SECONDS));
+    }
+
+    static class Jobs {
+        static final CountDownLatch LATCH = new CountDownLatch(2);
+
+        @Scheduled(every = "1s")
+        void countDownSecond() {
+            LATCH.countDown();
+        }
+    }
+
+}

extensions/scheduler/runtime/src/main/java/io/quarkus/scheduler/runtime/SimpleScheduler.java

@@ -122,6 +122,7 @@ void stop() {
     void checkTriggers() {
         if (!running) {
             LOGGER.trace("Skip all triggers - scheduler paused");
+            return;
         }
         ZonedDateTime now = ZonedDateTime.now();
         for (ScheduledTask task : scheduledTasks) {