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.spark.unsafe.memory;
  
  import org.apache.spark.unsafe.Platform;
  
  /**
   * A simple {@link MemoryAllocator} that uses {@code Unsafe} to allocate off-heap memory.
   */
  public class UnsafeMemoryAllocator implements MemoryAllocator {
  
    @Override
    public MemoryBlock allocate(long size) throws OutOfMemoryError {
      long address = Platform.allocateMemory(size);
      MemoryBlock memory = new MemoryBlock(null, address, size);
      if (MemoryAllocator.MEMORY_DEBUG_FILL_ENABLED) {
        memory.fill(MemoryAllocator.MEMORY_DEBUG_FILL_CLEAN_VALUE);
      }
      return memory;
    }
  
    @Override
    public void free(MemoryBlock memory) {
      assert (memory.obj == null) :
        "baseObject not null; are you trying to use the off-heap allocator to free on-heap memory?";
      if (MemoryAllocator.MEMORY_DEBUG_FILL_ENABLED) {
        memory.fill(MemoryAllocator.MEMORY_DEBUG_FILL_FREED_VALUE);
      }
      Platform.freeMemory(memory.offset);
    }
  }
  