/*
 * Copyright 2013 Ben Manes. All Rights Reserved.
 *
 * 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 com.github.benmanes.multiway;

import java.util.concurrent.Executors;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TransferQueue;

import com.google.common.base.Stopwatch;
import com.twitter.jsr166e.LongAdder;

/**
 * A simple bootstrap for inspecting with an attached profiler.
 *
 * @author Ben Manes ([email protected])
 */
public final class EliminationProfile {
  static final int DISPLAY_DELAY_SEC = 5;
  static final Integer ELEMENT = 1;

  final LongAdder calls;
  final Runnable runner;

  EliminationProfile() {
    calls = new LongAdder();

    // The task to profile
    runner = newEliminationStackRunner();
    //runner = newLinkedTransferQueueRunner();
  }

  void run() throws Exception {
    ConcurrentTestHarness.timeTasks(25, runner);
  }

  Runnable newEliminationStackRunner() {
    final EliminationStack<Integer> stack = new EliminationStack<>();
    return new Runnable() {
      @Override public void run() {
        final ThreadLocalRandom random = ThreadLocalRandom.current();
        for (;;) {
          if (random.nextBoolean()) {
            stack.push(ELEMENT);
          } else {
            stack.pop();
          }
          calls.increment();
        }
      }
    };
  }

  Runnable newLinkedTransferQueueRunner() {
    final TransferQueue<Integer> queue = new LinkedTransferQueue<>();
    return new Runnable() {
      @Override public void run() {
        final ThreadLocalRandom random = ThreadLocalRandom.current();
        for (;;) {
          if (random.nextBoolean()) {
            queue.offer(ELEMENT);
          } else {
            queue.poll();
          }
          calls.increment();
        }
      }
    };
  }

  void scheduleStatusTask() {
    Executors.newSingleThreadScheduledExecutor().scheduleWithFixedDelay(new Runnable() {
      final Stopwatch stopwatch = new Stopwatch().start();
      @Override public void run() {
        long count = calls.longValue();
        long rate = count / stopwatch.elapsed(TimeUnit.SECONDS);
        System.out.printf("%s - %,d [%,d / sec]\n", stopwatch, count, rate);
      }
    }, DISPLAY_DELAY_SEC, DISPLAY_DELAY_SEC, TimeUnit.SECONDS);
  }

  public static void main(String[] args) throws Exception {
    EliminationProfile profile = new EliminationProfile();
    profile.scheduleStatusTask();
    profile.run();
  }
}