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 com.alibaba.metrics.instrument;
  
  import com.alibaba.metrics.Counter;
  import com.alibaba.metrics.Meter;
  import com.alibaba.metrics.MetricRegistry;
  import com.alibaba.metrics.Timer;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.concurrent.Callable;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Future;
  import java.util.concurrent.RejectedExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * An {@link ExecutorService} that monitors the number of tasks submitted, running,
   * completed and also keeps a {@link Timer} for the task duration.
   * <p/>
   * It will register the metrics using the given (or auto-generated) name as classifier, e.g:
   * "your-executor-service.submitted", "your-executor-service.running", etc.
   */
  public class InstrumentedExecutorService implements ExecutorService {
  
      private static final AtomicLong nameCounter = new AtomicLong();
  
      private final ExecutorService delegate;
      private final Meter submitted;
      private final Counter running;
      private final Meter completed;
      private final Timer duration;
      private final Meter rejected;
  
      /**
       * Wraps an {@link ExecutorService} uses an auto-generated default name.
       *
       * @param delegate {@link ExecutorService} to wrap.
       * @param registry {@link MetricRegistry} that will contain the metrics.
       */
      public InstrumentedExecutorService(ExecutorService delegate, MetricRegistry registry) {
          this(delegate, registry, "instrumented-delegate-" + nameCounter.incrementAndGet());
      }
  
      /**
       * Wraps an {@link ExecutorService} with an explicit name.
       *
       * @param delegate {@link ExecutorService} to wrap.
       * @param registry {@link MetricRegistry} that will contain the metrics.
       * @param name     name for this executor service.
       */
      public InstrumentedExecutorService(ExecutorService delegate, MetricRegistry registry, String name) {
          this.delegate = delegate;
          this.submitted = registry.meter(MetricRegistry.name(name, "submitted"));
          this.running = registry.counter(MetricRegistry.name(name, "running"));
          this.completed = registry.meter(MetricRegistry.name(name, "completed"));
          this.duration = registry.timer(MetricRegistry.name(name, "duration"));
          this.rejected = registry.meter(MetricRegistry.name(name, "rejected"));
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void execute(Runnable runnable) {
          submitted.mark();
          try {
              delegate.execute(new InstrumentedRunnable(runnable));
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public Future<?> submit(Runnable runnable) {
          submitted.mark();
          try {
              return delegate.submit(new InstrumentedRunnable(runnable));
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> Future<T> submit(Runnable runnable, T result) {
          submitted.mark();
          try {
              return delegate.submit(new InstrumentedRunnable(runnable), result);
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> Future<T> submit(Callable<T> task) {
          submitted.mark();
          try {
              return delegate.submit(new InstrumentedCallable<T>(task));
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) throws InterruptedException {
          submitted.mark(tasks.size());
          Collection<? extends Callable<T>> instrumented = instrument(tasks);
          try {
              return delegate.invokeAll(instrumented);
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException {
          submitted.mark(tasks.size());
          Collection<? extends Callable<T>> instrumented = instrument(tasks);
          try {
              return delegate.invokeAll(instrumented, timeout, unit);
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws ExecutionException, InterruptedException {
          submitted.mark(tasks.size());
          Collection<? extends Callable<T>> instrumented = instrument(tasks);
          try {
              return delegate.invokeAny(instrumented);
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws ExecutionException, InterruptedException, TimeoutException {
          submitted.mark(tasks.size());
          Collection<? extends Callable<T>> instrumented = instrument(tasks);
          try {
              return delegate.invokeAny(instrumented, timeout, unit);
          } catch (RejectedExecutionException e) {
              rejected.mark();
              throw e;
          }
      }
  
      private <T> Collection<? extends Callable<T>> instrument(Collection<? extends Callable<T>> tasks) {
          final List<InstrumentedCallable<T>> instrumented = new ArrayList<InstrumentedCallable<T>>(tasks.size());
          for (Callable<T> task : tasks) {
              instrumented.add(new InstrumentedCallable<T>(task));
          }
          return instrumented;
      }
  
      @Override
      public void shutdown() {
          delegate.shutdown();
      }
  
      @Override
      public List<Runnable> shutdownNow() {
          return delegate.shutdownNow();
      }
  
      @Override
      public boolean isShutdown() {
          return delegate.isShutdown();
      }
  
      @Override
      public boolean isTerminated() {
          return delegate.isTerminated();
      }
  
      @Override
      public boolean awaitTermination(long l, TimeUnit timeUnit) throws InterruptedException {
          return delegate.awaitTermination(l, timeUnit);
      }
  
      private class InstrumentedRunnable implements Runnable {
          private final Runnable task;
  
          InstrumentedRunnable(Runnable task) {
              this.task = task;
          }
  
          @Override
          public void run() {
              running.inc();
              final Timer.Context context = duration.time();
              try {
                  task.run();
              } finally {
                  context.stop();
                  running.dec();
                  completed.mark();
              }
          }
      }
  
      private class InstrumentedCallable<T> implements Callable<T> {
          private final Callable<T> callable;
  
          InstrumentedCallable(Callable<T> callable) {
              this.callable = callable;
          }
  
          @Override
          public T call() throws Exception {
              running.inc();
              final Timer.Context context = duration.time();
              try {
                  return callable.call();
              } finally {
                  context.stop();
                  running.dec();
                  completed.mark();
              }
          }
      }
  }
  