/**
    *
    * 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.hadoop.hbase.util;
  
  import java.io.InterruptedIOException;
  import java.io.IOException;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.CoordinatedStateManager;
  import org.apache.hadoop.hbase.master.HMaster;
  import org.apache.hadoop.hbase.regionserver.HRegionServer;
  
  /**
   * Utility used running a cluster all in the one JVM.
   */
  @InterfaceAudience.Private
  public class JVMClusterUtil {
    private static final Log LOG = LogFactory.getLog(JVMClusterUtil.class);
  
    /**
     * Datastructure to hold RegionServer Thread and RegionServer instance
     */
    public static class RegionServerThread extends Thread {
      private final HRegionServer regionServer;
  
      public RegionServerThread(final HRegionServer r, final int index) {
        super(r, "RS:" + index + ";" + r.getServerName().toShortString());
        this.regionServer = r;
      }
  
      /** @return the region server */
      public HRegionServer getRegionServer() {
        return this.regionServer;
      }
  
      /**
       * Block until the region server has come online, indicating it is ready
       * to be used.
       */
      public void waitForServerOnline() {
        // The server is marked online after the init method completes inside of
        // the HRS#run method.  HRS#init can fail for whatever region.  In those
        // cases, we'll jump out of the run without setting online flag.  Check
        // stopRequested so we don't wait here a flag that will never be flipped.
        regionServer.waitForServerOnline();
      }
    }
  
    /**
     * Creates a {@link RegionServerThread}.
     * Call 'start' on the returned thread to make it run.
     * @param c Configuration to use.
     * @param cp consensus provider to use
     * @param hrsc Class to create.
     * @param index Used distinguishing the object returned.
     * @throws IOException
     * @return Region server added.
     */
    public static JVMClusterUtil.RegionServerThread createRegionServerThread(
        final Configuration c, CoordinatedStateManager cp, final Class<? extends HRegionServer> hrsc,
        final int index)
    throws IOException {
      HRegionServer server;
      try {
  
        Constructor<? extends HRegionServer> ctor = hrsc.getConstructor(Configuration.class,
        CoordinatedStateManager.class);
        ctor.setAccessible(true);
        server = ctor.newInstance(c, cp);
      } catch (InvocationTargetException ite) {
        Throwable target = ite.getTargetException();
        throw new RuntimeException("Failed construction of RegionServer: " +
          hrsc.toString() + ((target.getCause() != null)?
            target.getCause().getMessage(): ""), target);
      } catch (Exception e) {
        IOException ioe = new IOException();
        ioe.initCause(e);
       throw ioe;
     }
     return new JVMClusterUtil.RegionServerThread(server, index);
   }
 
 
   /**
    * Datastructure to hold Master Thread and Master instance
    */
   public static class MasterThread extends Thread {
     private final HMaster master;
 
     public MasterThread(final HMaster m, final int index) {
       super(m, "M:" + index + ";" + m.getServerName().toShortString());
       this.master = m;
     }
 
     /** @return the master */
     public HMaster getMaster() {
       return this.master;
     }
   }
 
   /**
    * Creates a {@link MasterThread}.
    * Call 'start' on the returned thread to make it run.
    * @param c Configuration to use.
    * @param cp consensus provider to use
    * @param hmc Class to create.
    * @param index Used distinguishing the object returned.
    * @throws IOException
    * @return Master added.
    */
   public static JVMClusterUtil.MasterThread createMasterThread(
       final Configuration c, CoordinatedStateManager cp, final Class<? extends HMaster> hmc,
       final int index)
   throws IOException {
     HMaster server;
     try {
       server = hmc.getConstructor(Configuration.class, CoordinatedStateManager.class).
         newInstance(c, cp);
     } catch (InvocationTargetException ite) {
       Throwable target = ite.getTargetException();
       throw new RuntimeException("Failed construction of Master: " +
         hmc.toString() + ((target.getCause() != null)?
           target.getCause().getMessage(): ""), target);
     } catch (Exception e) {
       IOException ioe = new IOException();
       ioe.initCause(e);
       throw ioe;
     }
     return new JVMClusterUtil.MasterThread(server, index);
   }
 
   private static JVMClusterUtil.MasterThread findActiveMaster(
     List<JVMClusterUtil.MasterThread> masters) {
     for (JVMClusterUtil.MasterThread t : masters) {
       if (t.master.isActiveMaster()) {
         return t;
       }
     }
 
     return null;
   }
 
   /**
    * Start the cluster.  Waits until there is a primary master initialized
    * and returns its address.
    * @param masters
    * @param regionservers
    * @return Address to use contacting primary master.
    */
   public static String startup(final List<JVMClusterUtil.MasterThread> masters,
       final List<JVMClusterUtil.RegionServerThread> regionservers) throws IOException {
 
     if (masters == null || masters.isEmpty()) {
       return null;
     }
 
     for (JVMClusterUtil.MasterThread t : masters) {
       t.start();
     }
 
     // Wait for an active master
     //  having an active master before starting the region threads allows
     //  then to succeed on their connection to master
     long startTime = System.currentTimeMillis();
     while (findActiveMaster(masters) == null) {
       try {
         Thread.sleep(100);
       } catch (InterruptedException e) {
         throw (InterruptedIOException)new InterruptedIOException().initCause(e);
       }
       if (System.currentTimeMillis() > startTime + 30000) {
         throw new RuntimeException("Master not active after 30 seconds");
       }
     }
 
     if (regionservers != null) {
       for (JVMClusterUtil.RegionServerThread t: regionservers) {
         t.start();
       }
     }
 
     // Wait for an active master to be initialized (implies being master)
     //  with this, when we return the cluster is complete
     startTime = System.currentTimeMillis();
     final int maxwait = 200000;
     while (true) {
       JVMClusterUtil.MasterThread t = findActiveMaster(masters);
       if (t != null && t.master.isInitialized()) {
         return t.master.getServerName().toString();
       }
       // REMOVE
       if (System.currentTimeMillis() > startTime + 10000) {
         try {
           Thread.sleep(1000);
         } catch (InterruptedException e) {
           throw (InterruptedIOException)new InterruptedIOException().initCause(e);
         }
       }
       if (System.currentTimeMillis() > startTime + maxwait) {
         String msg = "Master not initialized after " + maxwait + "ms seconds";
         Threads.printThreadInfo(System.out,
           "Thread dump because: " + msg);
         throw new RuntimeException(msg);
       }
       try {
         Thread.sleep(100);
       } catch (InterruptedException e) {
         throw (InterruptedIOException)new InterruptedIOException().initCause(e);
       }
     }
   }
 
   /**
    * @param masters
    * @param regionservers
    */
   public static void shutdown(final List<MasterThread> masters,
       final List<RegionServerThread> regionservers) {
     LOG.debug("Shutting down HBase Cluster");
     if (masters != null) {
       // Do backups first.
       JVMClusterUtil.MasterThread activeMaster = null;
       for (JVMClusterUtil.MasterThread t : masters) {
         if (!t.master.isActiveMaster()) {
           try {
             t.master.stopMaster();
           } catch (IOException e) {
             LOG.error("Exception occurred while stopping master", e);
           }
         } else {
           activeMaster = t;
         }
       }
       // Do active after.
       if (activeMaster != null) {
         try {
           activeMaster.master.shutdown();
         } catch (IOException e) {
           LOG.error("Exception occurred in HMaster.shutdown()", e);
         }
       }
 
     }
     boolean wasInterrupted = false;
     final long maxTime = System.currentTimeMillis() + 30 * 1000;
     if (regionservers != null) {
       // first try nicely.
       for (RegionServerThread t : regionservers) {
         t.getRegionServer().stop("Shutdown requested");
       }
       for (RegionServerThread t : regionservers) {
         long now = System.currentTimeMillis();
         if (t.isAlive() && !wasInterrupted && now < maxTime) {
           try {
             t.join(maxTime - now);
           } catch (InterruptedException e) {
             LOG.info("Got InterruptedException on shutdown - " +
                 "not waiting anymore on region server ends", e);
             wasInterrupted = true; // someone wants us to speed up.
           }
         }
       }
 
       // Let's try to interrupt the remaining threads if any.
       for (int i = 0; i < 100; ++i) {
         boolean atLeastOneLiveServer = false;
         for (RegionServerThread t : regionservers) {
           if (t.isAlive()) {
             atLeastOneLiveServer = true;
             try {
               LOG.warn("RegionServerThreads remaining, give one more chance before interrupting");
               t.join(1000);
             } catch (InterruptedException e) {
               wasInterrupted = true;
             }
           }
         }
         if (!atLeastOneLiveServer) break;
         for (RegionServerThread t : regionservers) {
           if (t.isAlive()) {
             LOG.warn("RegionServerThreads taking too long to stop, interrupting");
             t.interrupt();
           }
         }
       }
     }
 
     if (masters != null) {
       for (JVMClusterUtil.MasterThread t : masters) {
         while (t.master.isAlive() && !wasInterrupted) {
           try {
             // The below has been replaced to debug sometime hangs on end of
             // tests.
             // this.master.join():
             Threads.threadDumpingIsAlive(t.master.getThread());
           } catch(InterruptedException e) {
             LOG.info("Got InterruptedException on shutdown - " +
                 "not waiting anymore on master ends", e);
             wasInterrupted = true;
           }
         }
       }
     }
     LOG.info("Shutdown of " +
       ((masters != null) ? masters.size() : "0") + " master(s) and " +
       ((regionservers != null) ? regionservers.size() : "0") +
       " regionserver(s) " + (wasInterrupted ? "interrupted" : "complete"));
 
     if (wasInterrupted){
       Thread.currentThread().interrupt();
     }
   }
 }