spark-gpu-master/unsafe/src/test/java/org/apache/spark/unsafe/PlatformUtilSuite.java
/*
 * 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;

import org.junit.Assert;
import org.junit.Test;

public class PlatformUtilSuite {

  @Test
  public void overlappingCopyMemory() {
    byte[] data = new byte[3 * 1024 * 1024];
    int size = 2 * 1024 * 1024;
    for (int i = 0; i < data.length; ++i) {
      data[i] = (byte)i;
    }

    Platform.copyMemory(data, Platform.BYTE_ARRAY_OFFSET, data, Platform.BYTE_ARRAY_OFFSET, size);
    for (int i = 0; i < data.length; ++i) {
      Assert.assertEquals((byte)i, data[i]);
    }

    Platform.copyMemory(
        data,
        Platform.BYTE_ARRAY_OFFSET + 1,
        data,
        Platform.BYTE_ARRAY_OFFSET,
        size);
    for (int i = 0; i < size; ++i) {
      Assert.assertEquals((byte)(i + 1), data[i]);
    }

    for (int i = 0; i < data.length; ++i) {
      data[i] = (byte)i;
    }
    Platform.copyMemory(
        data,
        Platform.BYTE_ARRAY_OFFSET,
        data,
        Platform.BYTE_ARRAY_OFFSET + 1,
        size);
    for (int i = 0; i < size; ++i) {
      Assert.assertEquals((byte)i, data[i + 1]);
    }
  }
}
