001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.master.procedure;
019
020import org.apache.hadoop.hbase.TableName;
021import org.apache.hadoop.hbase.procedure2.LockStatus;
022import org.apache.hadoop.hbase.procedure2.Procedure;
023import org.apache.yetus.audience.InterfaceAudience;
024
025@InterfaceAudience.Private
026class TableQueue extends Queue<TableName> {
027  private final LockStatus namespaceLockStatus;
028
029  public TableQueue(TableName tableName, int priority, LockStatus tableLock,
030      LockStatus namespaceLockStatus) {
031    super(tableName, priority, tableLock);
032    this.namespaceLockStatus = namespaceLockStatus;
033  }
034
035  @Override
036  public boolean isAvailable() {
037    return !isEmpty() && !namespaceLockStatus.hasExclusiveLock();
038  }
039
040  @Override
041  public boolean requireExclusiveLock(Procedure<?> proc) {
042    return requireTableExclusiveLock((TableProcedureInterface) proc);
043  }
044
045  /**
046   * @param proc must not be null
047   */
048  private static boolean requireTableExclusiveLock(TableProcedureInterface proc) {
049    switch (proc.getTableOperationType()) {
050      case CREATE:
051      case DELETE:
052      case DISABLE:
053      case ENABLE:
054        return true;
055      case EDIT:
056        // we allow concurrent edit on the NS table
057        return !proc.getTableName().equals(TableName.NAMESPACE_TABLE_NAME);
058      case READ:
059        return false;
060      // region operations are using the shared-lock on the table
061      // and then they will grab an xlock on the region.
062      case REGION_SPLIT:
063      case REGION_MERGE:
064      case REGION_ASSIGN:
065      case REGION_UNASSIGN:
066      case REGION_EDIT:
067      case REGION_GC:
068      case MERGED_REGIONS_GC:
069        return false;
070      default:
071        break;
072    }
073    throw new UnsupportedOperationException("unexpected type " + proc.getTableOperationType());
074  }
075}