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.ambari.server.logging;
  
  import java.util.Map;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.locks.ReadWriteLock;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  import com.google.common.base.Ticker;
  
  /**
   * Implements profiling for a ReentrantReadWriteLock.
   */
  final class ProfiledReentrantReadWriteLock implements ReadWriteLock {
  
    private final ProfiledReadLock readLock;
    private final ProfiledWriteLock writeLock;
  
    /**
     * @param delegate the lock to profile
     * @param ticker is the source of time information, replaceable for testing purpose
     * @param label is included in log messages for easier identification of locks (optional, may be empty or null)
     */
    ProfiledReentrantReadWriteLock(ReentrantReadWriteLock delegate, Ticker ticker, String label) {
      readLock = new ProfiledReadLock(delegate, ticker, label);
      writeLock = new ProfiledWriteLock(delegate, ticker, label);
    }
  
    @Override
    public ProfiledLock readLock() {
      return readLock;
    }
  
    @Override
    public ProfiledLock writeLock() {
      return writeLock;
    }
  
    private static class ProfiledReadLock extends ReentrantReadWriteLock.ReadLock implements ProfiledLock {
  
      private final LockProfileDelegate helper;
      private final ReentrantReadWriteLock delegate;
  
      ProfiledReadLock(ReentrantReadWriteLock delegate, Ticker ticker, String label) {
        super(delegate);
        this.delegate = delegate;
        helper = new LockProfileDelegate(ticker, label, this);
      }
  
      @Override
      public void lock() {
        boolean alreadyOwned = helper.logRequest();
        super.lock();
        helper.logRequestCompleted(alreadyOwned, true);
      }
  
      @Override
      public void lockInterruptibly() throws InterruptedException {
        boolean alreadyOwned = helper.logRequest();
        super.lockInterruptibly();
        helper.logRequestCompleted(alreadyOwned, true);
      }
  
      @Override
      public boolean tryLock() {
        boolean alreadyOwned = helper.logRequest();
        boolean result = super.tryLock();
        helper.logRequestCompleted(alreadyOwned, result);
        return result;
      }
  
      @Override
      public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
        boolean alreadyOwned = helper.logRequest();
        boolean result = super.tryLock(timeout, unit);
        helper.logRequestCompleted(alreadyOwned, result);
        return result;
      }
  
      @Override
      public void unlock() {
        super.unlock();
        helper.logUnlock();
      }
  
      /**
       * @return true if any thread holds this lock (note that the read lock may be shared between threads, hence the different semantics)
       */
      @Override
      public boolean isHeldByCurrentThread() {
        return delegate.getReadHoldCount() > 0;
      }
  
      @Override
      public Map<String, Long> getTimeSpentWaitingForLock() {
        return helper.getTimeSpentWaitingForLock();
      }
  
      @Override
      public Map<String, Long> getTimeSpentLocked() {
        return helper.getTimeSpentLocked();
      }
  
      @Override
      public Map<String, Integer> getLockCount() {
        return helper.getLockCount();
      }
  
      @Override
      public String toString() {
        return delegate.readLock().toString();
      }
  
      @Override
      public String getLabel() {
        return helper.getLabel();
      }
    }
  
    private static class ProfiledWriteLock extends ReentrantReadWriteLock.WriteLock implements ProfiledLock {
  
      private final LockProfileDelegate helper;
      private final ReentrantReadWriteLock delegate;
  
      ProfiledWriteLock(ReentrantReadWriteLock delegate, Ticker ticker, String label) {
        super(delegate);
        this.delegate = delegate;
        helper = new LockProfileDelegate(ticker, label, this);
      }
  
      @Override
      public void lock() {
        boolean alreadyOwned = helper.logRequest();
        super.lock();
        helper.logRequestCompleted(alreadyOwned, true);
      }
  
      @Override
      public void lockInterruptibly() throws InterruptedException {
        boolean alreadyOwned = helper.logRequest();
        super.lockInterruptibly();
        helper.logRequestCompleted(alreadyOwned, true);
      }
  
      @Override
      public boolean tryLock() {
        boolean alreadyOwned = helper.logRequest();
        boolean result = super.tryLock();
        helper.logRequestCompleted(alreadyOwned, result);
        return result;
      }
  
      @Override
      public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
        boolean alreadyOwned = helper.logRequest();
        boolean result = super.tryLock(timeout, unit);
        helper.logRequestCompleted(alreadyOwned, result);
        return result;
      }
  
      @Override
      public void unlock() {
        super.unlock();
        helper.logUnlock();
      }
  
      @Override
      public Map<String, Long> getTimeSpentWaitingForLock() {
        return helper.getTimeSpentWaitingForLock();
      }
  
      @Override
      public Map<String, Long> getTimeSpentLocked() {
        return helper.getTimeSpentLocked();
      }
  
      @Override
      public Map<String, Integer> getLockCount() {
        return helper.getLockCount();
      }
  
      @Override
      public String toString() {
        return delegate.writeLock().toString();
      }
  
      @Override
      public String getLabel() {
        return helper.getLabel();
      }
    }
  }
  