content: /*
      This file is part of the HeavenMS MapleStory Server
      Copyleft (L) 2016 - 2019 RonanLana
  
      This program is free software: you can redistribute it and/or modify
      it under the terms of the GNU Affero General Public License as
      published by the Free Software Foundation version 3 as published by
      the Free Software Foundation. You may not use, modify or distribute
      this program under any other version of the GNU Affero General Public
      License.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU Affero General Public License for more details.
  
      You should have received a copy of the GNU Affero General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
  package net.server.audit.locks.active;
  
  import config.YamlConfig;
  import java.text.DateFormat;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.TimeZone;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantLock;
  import java.util.concurrent.ScheduledFuture;
  import server.TimerManager;
  import net.server.audit.ThreadTracker;
  import net.server.audit.locks.MonitoredLockType;
  import net.server.audit.locks.MonitoredReentrantReadWriteLock;
  import net.server.audit.locks.MonitoredWriteLock;
  import net.server.audit.locks.empty.EmptyWriteLock;
  import tools.FilePrinter;
  
  /**
   *
   * @author RonanLana
   */
  public class TrackerWriteLock extends ReentrantReadWriteLock.WriteLock implements MonitoredWriteLock {
      private ScheduledFuture<?> timeoutSchedule = null;
      private StackTraceElement[] deadlockedState = null;
      private final MonitoredLockType id;
      private final int hashcode;
      private final Lock state = new ReentrantLock(true);
      private final AtomicInteger reentrantCount = new AtomicInteger(0);
  
      public TrackerWriteLock(MonitoredReentrantReadWriteLock lock) {
          super(lock);
          this.id = lock.id;
          hashcode = this.hashCode();
      }
      
      @Override
      public void lock() {
          if(YamlConfig.config.server.USE_THREAD_TRACKER) {
              if(deadlockedState != null) {
                  DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
                  dateFormat.setTimeZone(TimeZone.getDefault());
  
                  //FilePrinter.printError(FilePrinter.DEADLOCK_ERROR, "[CRITICAL] " + dateFormat.format(new Date()) + " Deadlock occurred when trying to use the '" + id.name() + "' lock resources:\r\n" + printStackTrace(deadlockedState));
                  ThreadTracker.getInstance().accessThreadTracker(true, true, id, hashcode);
                  deadlockedState = null;
              }
  
              registerLocking();
          }
          
          super.lock();
      }
      
      @Override
      public void unlock() {
          if(YamlConfig.config.server.USE_THREAD_TRACKER) {
              unregisterLocking();
          }
          
          super.unlock();
      }
      
      @Override
      public boolean tryLock() {
          if(super.tryLock()) {
              if(YamlConfig.config.server.USE_THREAD_TRACKER) {
                  if(deadlockedState != null) {
                      //FilePrinter.printError(FilePrinter.DEADLOCK_ERROR, "Deadlock occurred when trying to use the '" + id.name() + "' lock resources:\r\n" + printStackTrace(deadlockedState));
                      ThreadTracker.getInstance().accessThreadTracker(true, true, id, hashcode);
                      deadlockedState = null;
                  }
  
                  registerLocking();
              }
              return true;
          } else {
              return false;
          }
      }
      
      private void registerLocking() {
          state.lock();
          try {
              ThreadTracker.getInstance().accessThreadTracker(false, true, id, hashcode);
          
              if(reentrantCount.incrementAndGet() == 1) {
                  final Thread t = Thread.currentThread();
                  timeoutSchedule = TimerManager.getInstance().schedule(new Runnable() {
                      @Override
                      public void run() {
                          issueDeadlock(t);
                      }
                  }, YamlConfig.config.server.LOCK_MONITOR_TIME);
              }
          } finally {
              state.unlock();
          }
      }
      
      private void unregisterLocking() {
          state.lock();
          try {
              if(reentrantCount.decrementAndGet() == 0) {
                  if(timeoutSchedule != null) {
                      timeoutSchedule.cancel(false);
                      timeoutSchedule = null;
                  }
              }
              
              ThreadTracker.getInstance().accessThreadTracker(false, false, id, hashcode);
          } finally {
              state.unlock();
          }
      }
      
      private void issueDeadlock(Thread t) {
          deadlockedState = t.getStackTrace();
          //super.unlock();
      }
      
      private static String printStackTrace(StackTraceElement[] list) {
          String s = "";
          for(int i = 0; i < list.length; i++) {
              s += ("    " + list[i].toString() + "\r\n");
          }
          
          return s;
      }
      
      @Override
      public MonitoredWriteLock dispose() {
          state.lock();
          try {
              if(timeoutSchedule != null) {
                  timeoutSchedule.cancel(false);
                  timeoutSchedule = null;
              }
              
              reentrantCount.set(Integer.MAX_VALUE);
          } finally {
              state.unlock();
          }
          
          //unlock();
          return new EmptyWriteLock(id);
      }
  }
  