content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.kafka.controller;
  
  import org.apache.kafka.common.utils.MockTime;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  
  import java.util.ArrayList;
  import java.util.EnumSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.TreeMap;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.function.Supplier;
  
  import static java.util.concurrent.TimeUnit.MILLISECONDS;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  @Timeout(10)
  public class PeriodicTaskControlManagerTest {
      static class FakePeriodicTask {
          final AtomicInteger numCalls;
          final AtomicBoolean continuation = new AtomicBoolean(false);
          final PeriodicTask task;
          final AtomicBoolean shouldFail = new AtomicBoolean(false);
  
          FakePeriodicTask(
              String name,
              long periodNs
          ) {
              this.numCalls = new AtomicInteger();
              this.task = new PeriodicTask(name,
                  () -> {
                      numCalls.addAndGet(1);
                      if (shouldFail.getAndSet(false)) {
                          throw new NullPointerException("uh oh");
                      }
                      return ControllerResult.of(List.of(),
                          continuation.getAndSet(false));
                  },
                  periodNs,
                  EnumSet.noneOf(PeriodicTaskFlag.class));
          }
      }
  
      static class TrackedTask {
          final String tag;
          final long deadlineNs;
          final Supplier<ControllerResult<Void>> op;
  
          TrackedTask(
              String tag,
              long deadlineNs,
              Supplier<ControllerResult<Void>> op
          ) {
              this.tag = tag;
              this.deadlineNs = deadlineNs;
              this.op = op;
          }
      }
  
      static class PeriodicTaskControlManagerTestEnv implements PeriodicTaskControlManager.QueueAccessor {
          final MockTime time;
  
          final PeriodicTaskControlManager manager;
  
          final TreeMap<Long, List<TrackedTask>> tasks;
  
          int numCalls = 10_000;
  
          PeriodicTaskControlManagerTestEnv() {
              this.time = new MockTime(0, 0, 0);
              this.manager = new PeriodicTaskControlManager.Builder().
                  setTime(time).
                  setQueueAccessor(this).
                  build();
              this.tasks = new TreeMap<>();
          }
  
          @Override
          public void scheduleDeferred(
              String tag,
              long deadlineNs,
              Supplier<ControllerResult<Void>> op
          ) {
              if (numCalls <= 0) {
                  throw new RuntimeException("too many deferred calls.");
              }
              numCalls--;
              cancelDeferred(tag);
              TrackedTask task = new TrackedTask(tag, deadlineNs, op);
              tasks.computeIfAbsent(deadlineNs, __ -> new ArrayList<>()).add(task);
          }
  
          @Override
          public void cancelDeferred(String tag) {
              Iterator<Map.Entry<Long, List<TrackedTask>>> iter = tasks.entrySet().iterator();
              boolean foundTask = false;
              while (iter.hasNext() && (!foundTask)) {
                  Map.Entry<Long, List<TrackedTask>> entry = iter.next();
                  Iterator<TrackedTask> taskIter = entry.getValue().iterator();
                  while (taskIter.hasNext()) {
                      TrackedTask task = taskIter.next();
                      if (task.tag.equals(tag)) {
                          taskIter.remove();
                          foundTask = true;
                          break;
                      }
                  }
                  if (entry.getValue().isEmpty()) {
                      iter.remove();
                  }
              }
          }
  
          int numDeferred() {
              int count = 0;
              for (List<TrackedTask> taskList : tasks.values()) {
                  count += taskList.size();
              }
              return count;
          }
  
          void advanceTime(long ms) {
              time.sleep(ms);
              while (true) {
                  Iterator<Map.Entry<Long, List<TrackedTask>>> iter = tasks.entrySet().iterator();
                  if (!iter.hasNext()) {
                      return;
                  }
                  Map.Entry<Long, List<TrackedTask>> entry = iter.next();
                  if (time.nanoseconds() < entry.getKey()) {
                      return;
                  }
                  if (!entry.getValue().isEmpty()) {
                      Iterator<TrackedTask> taskIter = entry.getValue().iterator();
                      TrackedTask task = taskIter.next();
                      taskIter.remove();
                      try {
                          task.op.get();
                      } catch (Exception e) {
                          // discard exception
                      }
                      continue;
                  }
                  iter.remove();
              }
          }
      }
  
      @Test
      public void testActivate() {
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          assertFalse(env.manager.active());
          env.manager.activate();
          assertTrue(env.manager.active());
          assertEquals(0, env.numDeferred());
      }
  
      @Test
      public void testDeactivate() {
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          assertFalse(env.manager.active());
          env.manager.activate();
          env.manager.deactivate();
          assertFalse(env.manager.active());
          assertEquals(0, env.numDeferred());
      }
  
      @Test
      public void testRegisterTaskWhenDeactivated() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.registerTask(foo.task);
          assertEquals(0, env.numDeferred());
      }
  
      @Test
      public void testRegisterTaskWhenActivated() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          assertEquals(1, env.numDeferred());
      }
  
      @Test
      public void testRegisterTaskWhenActivatedThenDeactivate() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          env.manager.deactivate();
          assertEquals(0, env.numDeferred());
      }
  
      @Test
      public void testRegisterTaskAndAdvanceTime() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          FakePeriodicTask bar = new FakePeriodicTask("bar", MILLISECONDS.toNanos(50));
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          env.manager.registerTask(bar.task);
          assertEquals(2, env.numDeferred());
          env.advanceTime(50);
          assertEquals(0, foo.numCalls.get());
          assertEquals(1, bar.numCalls.get());
          assertEquals(2, env.numDeferred());
          env.advanceTime(50);
          assertEquals(1, foo.numCalls.get());
          assertEquals(2, bar.numCalls.get());
          assertEquals(2, env.numDeferred());
          env.manager.deactivate();
      }
  
      @Test
      public void testContinuation() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          FakePeriodicTask bar = new FakePeriodicTask("bar", MILLISECONDS.toNanos(50));
          bar.continuation.set(true);
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          env.manager.registerTask(bar.task);
          assertEquals(2, env.numDeferred());
          env.advanceTime(50);
          assertEquals(0, foo.numCalls.get());
          assertEquals(1, bar.numCalls.get());
          assertEquals(2, env.numDeferred());
          env.advanceTime(10);
          assertEquals(2, bar.numCalls.get());
          env.advanceTime(40);
          assertEquals(1, foo.numCalls.get());
          assertEquals(2, bar.numCalls.get());
          assertEquals(2, env.numDeferred());
          env.advanceTime(10);
          assertEquals(3, bar.numCalls.get());
          env.manager.deactivate();
      }
  
      @Test
      public void testRegisterTaskAndUnregister() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          FakePeriodicTask bar = new FakePeriodicTask("bar", MILLISECONDS.toNanos(50));
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          env.manager.registerTask(bar.task);
          assertEquals(2, env.numDeferred());
          env.advanceTime(50);
          assertEquals(0, foo.numCalls.get());
          assertEquals(1, bar.numCalls.get());
          env.manager.unregisterTask(foo.task.name());
          assertEquals(1, env.numDeferred());
          env.manager.unregisterTask(bar.task.name());
          assertEquals(0, env.numDeferred());
          env.advanceTime(200);
          assertEquals(0, foo.numCalls.get());
          assertEquals(1, bar.numCalls.get());
          env.manager.deactivate();
      }
  
      @Test
      public void testReschedulingAfterFailure() {
          FakePeriodicTask foo = new FakePeriodicTask("foo", MILLISECONDS.toNanos(100));
          foo.shouldFail.set(true);
          PeriodicTaskControlManagerTestEnv env = new PeriodicTaskControlManagerTestEnv();
          env.manager.activate();
          env.manager.registerTask(foo.task);
          assertEquals(1, env.numDeferred());
          env.advanceTime(100);
          assertEquals(1, foo.numCalls.get());
          env.advanceTime(300000);
          assertEquals(2, foo.numCalls.get());
          env.manager.deactivate();
      }
  }
  