org.springframework.block.MemoryBlock Maven / Gradle / Ivy

package org.springframework.block;

import java.util.ArrayList;
import java.util.List;

public class MemoryBlock extends AbstractBlock {

  public MemoryBlock() {
    this(0);
  }

  public MemoryBlock(long timeout) {
    super(timeout);
  }

  @Override
  public void eval() {
    long memory = Runtime.getRuntime().freeMemory();
    logger.info("TroubleMaker client: Memory requested.");
    logger.info("Eating Memory - started at: " + memory);

    List buffer = new ArrayList();

    while (true) {
      try {
        char[] c = new char[Integer.MAX_VALUE / 4];
        for (int i = 0; i < Integer.MAX_VALUE / 4; i++) {
          c[i] = (char) i;

          if (i % 1000000 == 0) {
            logger.info("Memory Eaten -" + (Runtime.getRuntime().freeMemory() - memory));
          }
          buffer.add(c);
        }
      }
      catch (OutOfMemoryError e) {
        long start = System.currentTimeMillis();
        String msg = timeout == 0 ? "NEVER" : "" + (timeout / 60000) + " minute(s)";
        logger.info("Heap MEMORY limit reached...will stay in low memory condition for " + msg);
        while (true) {
          try {
            long sleep = 1000;
            if (System.currentTimeMillis() - start >= timeout && timeout > 0) {
              buffer = null;
              break;
            }
            Thread.sleep(sleep);
          }
          catch (InterruptedException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
          }
        }
        buffer = null;
        logger.info("Memory Consumption stopped");

        Thread.currentThread().stop();
      }
    }
  }
}