docs: Event-Based Asynchronous explanation + refactor (#2916)

* explation + refactor

* update logging

event-based-asynchronous/src/test/java/com/iluwatar/event/asynchronous/EventAsynchronousTest.java

@@ -0,0 +1,179 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.event.asynchronous;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Application test
+ */
+class EventAsynchronousTest {
+  private static final Logger LOGGER = LoggerFactory.getLogger(EventAsynchronousTest.class);
+
+  @Test
+  void testAsynchronousEvent() {
+    var eventManager = new EventManager();
+    try {
+      var aEventId = eventManager.createAsync(60);
+      eventManager.start(aEventId);
+      assertEquals(1, eventManager.getEventPool().size());
+      assertTrue(eventManager.getEventPool().size() < EventManager.MAX_RUNNING_EVENTS);
+      assertEquals(-1, eventManager.numOfCurrentlyRunningSyncEvent());
+      eventManager.cancel(aEventId);
+      assertTrue(eventManager.getEventPool().isEmpty());
+    } catch (MaxNumOfEventsAllowedException | LongRunningEventException | EventDoesNotExistException e) {
+      LOGGER.error(e.getMessage());
+    }
+  }
+
+  @Test
+  void testSynchronousEvent() {
+    var eventManager = new EventManager();
+    try {
+      var sEventId = eventManager.create(60);
+      eventManager.start(sEventId);
+      assertEquals(1, eventManager.getEventPool().size());
+      assertTrue(eventManager.getEventPool().size() < EventManager.MAX_RUNNING_EVENTS);
+      assertNotEquals(-1, eventManager.numOfCurrentlyRunningSyncEvent());
+      eventManager.cancel(sEventId);
+      assertTrue(eventManager.getEventPool().isEmpty());
+    } catch (MaxNumOfEventsAllowedException | LongRunningEventException | EventDoesNotExistException
+        | InvalidOperationException e) {
+      LOGGER.error(e.getMessage());
+    }
+  }
+
+  @Test
+  void testUnsuccessfulSynchronousEvent() {
+    assertThrows(InvalidOperationException.class, () -> {
+      var eventManager = new EventManager();
+      try {
+        var sEventId = eventManager.create(60);
+        eventManager.start(sEventId);
+        sEventId = eventManager.create(60);
+        eventManager.start(sEventId);
+      } catch (MaxNumOfEventsAllowedException | LongRunningEventException | EventDoesNotExistException e) {
+        LOGGER.error(e.getMessage());
+      }
+    });
+  }
+
+  @Test
+  void testFullSynchronousEvent() {
+    var eventManager = new EventManager();
+    try {
+      var eventTime = 1;
+
+      var sEventId = eventManager.create(eventTime);
+      assertEquals(1, eventManager.getEventPool().size());
+      eventManager.start(sEventId);
+
+      var currentTime = System.currentTimeMillis();
+      // +2 to give a bit of buffer time for event to complete properly.
+      var endTime = currentTime + (eventTime + 2 * 1000);
+
+      long sleepTime = endTime - System.currentTimeMillis();
+      if (sleepTime > 0) {
+        try {
+          Thread.sleep(sleepTime);
+        } catch (InterruptedException e) {
+          LOGGER.error("Thread interrupted: ", e);
+          Thread.currentThread().interrupt();
+        }
+      }
+
+      assertTrue(eventManager.getEventPool().isEmpty());
+
+    } catch (MaxNumOfEventsAllowedException | LongRunningEventException | EventDoesNotExistException
+        | InvalidOperationException e) {
+      LOGGER.error(e.getMessage());
+    }
+  }
+
+  @Test
+  void testFullAsynchronousEvent() {
+    var eventManager = new EventManager();
+    try {
+      var eventTime = 1;
+
+      var aEventId1 = eventManager.createAsync(eventTime);
+      var aEventId2 = eventManager.createAsync(eventTime);
+      var aEventId3 = eventManager.createAsync(eventTime);
+      assertEquals(3, eventManager.getEventPool().size());
+
+      eventManager.start(aEventId1);
+      eventManager.start(aEventId2);
+      eventManager.start(aEventId3);
+
+      var currentTime = System.currentTimeMillis();
+      // +2 to give a bit of buffer time for event to complete properly.
+      var endTime = currentTime + (eventTime + 2 * 1000);
+
+      long sleepTime = endTime - System.currentTimeMillis();
+      if (sleepTime > 0) {
+        try {
+          Thread.sleep(sleepTime);
+        } catch (InterruptedException e) {
+          LOGGER.error("Thread interrupted: ", e);
+          Thread.currentThread().interrupt();
+        }
+      }
+
+      assertTrue(eventManager.getEventPool().isEmpty());
+
+    } catch (MaxNumOfEventsAllowedException | LongRunningEventException | EventDoesNotExistException e) {
+      LOGGER.error(e.getMessage());
+    }
+  }
+
+  @Test
+  void testLongRunningEventException(){
+    assertThrows(LongRunningEventException.class, () -> {
+      var eventManager = new EventManager();
+      eventManager.createAsync(2000);
+    });
+  }
+
+
+  @Test
+  void testMaxNumOfEventsAllowedException(){
+    assertThrows(MaxNumOfEventsAllowedException.class, () -> {
+      final var eventManager = new EventManager();
+      for(int i=0;i<1100;i++){
+        eventManager.createAsync(i);
+      }
+    });
+  }
+
+
+
+}