org.openqa.selenium.server.BrowserResponseSequencer Maven / Gradle / Ivy

/*
Copyright 2012 Selenium committers
Copyright 2012 Software Freedom Conservancy

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 org.openqa.selenium.server;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import java.util.logging.Logger;

public class BrowserResponseSequencer {
  static Logger log = Logger.getLogger(BrowserResponseSequencer.class.getName());
  int num = 0;
  final Lock lock;
  final Condition numIncreased;
  final String uniqueId;

  public BrowserResponseSequencer(String uniqueId) {
    this.uniqueId = uniqueId;
    this.lock = new ReentrantLock();
    numIncreased = lock.newCondition();
  }

  public void increaseNum() {
    lock.lock();
    try {
      num++;
      numIncreased.signalAll();
    } finally {
      lock.unlock();
    }
  }

  public void waitUntilNumIsAtLeast(int expected) {
    lock.lock();
    try {
      while (true) {
        if (num >= expected) return;
        log.fine("Waiting " + uniqueId + ", expected sequence number " + expected + ", was " + num +
            ".");
        boolean timedOut = false;
        try {
          timedOut = !numIncreased.await(5, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
          log.log(Level.FINE, "interrupted", e);
        }
        if (timedOut) {
          log.warning(uniqueId + " expected sequence number " + expected + ", was " + num +
              ".  Continuing anyway");
          num++;
          numIncreased.signalAll();
        }
      }
    } finally {
      lock.unlock();
    }
  }

  @Override
  public String toString() {
    return uniqueId + ": " + num;
  }
}